WO2011076403A2

WO2011076403A2 - Energy conversion system

Info

Publication number: WO2011076403A2
Application number: PCT/EP2010/007865
Authority: WO
Inventors: S Koopmans
Original assignee: S Koopmans
Priority date: 2009-12-22
Filing date: 2010-12-22
Publication date: 2011-06-30
Also published as: WO2011076403A3

Abstract

The present invention is in the field of energy conversion. The present invention relates to an energy conversion system, comprising one or more of a system for energy transport, a transparent protection, a system for bundling radiation, an encasement system, an energy converter, an energy storage system, and a Source Tracking system. It further relates to a construction element comprising the energy conversion system, and to a method of energy conversion.

Description

ENERGY CONVERSION SYSTEM

TECHNICAL FIELD OF THE INVENTION

The present invention is in the field of energy conversion. The present invention relates to an energy conversion apparatus, comprising a system for bundling radiation, means for converting radiation into heat and into electricity, and wherein the apparatus optionally comprises one or more of a system for energy transport, a transparent protection, an encasement system, a Source Tracking system, an energy storage system, and a buffer system. It further relates to a construction element comprising the energy conversion apparatus, and to a method of energy conversion.

BACKGROUND OF THE INVENTION

In the field of energy conversion PV-systems are known. These systems generally use a PN-junction to convert solar energy to electricity.

A disadvantage of such a system is that the conversion is not very efficient, typically, for Si-solar cells, limited to 15%. Even using very advanced PV-cells, such as GaAs cells, the conversion is only about 25%. Inherently these systems are limited in their conversion.

Further these systems are expensive to manufacture. Typically production costs are nowadays in the order of 1.5i/Wpeak. As such, the return on investment takes in the order of 10-15 years, and only if governments subsidizes these kind of systems.

Also these kinds of systems are visually unattractive.

Further, solar boilers are known. Therein water is heated by solar radiation. The preheated water is then typically used for showering and possibly for central heating.

Also these systems are expensive to manufacture, not very efficient, and visually unattractive.

Further, parabolic trough power plants are known, using a curved trough which reflects the direct solar radiation onto a pipe containing a fluid (also called a receiver, absorber or collector) running over the length of the trough, above the reflectors. The trough is parabolic in one direction and straight in the other. For change of position of the sun perpendicular to the receiver, the trough tilts so that the direct radiation remains focused on the receiver. However, a change of position of the sun parallel to the trough does not require adjustment of the mirrors, since the light is simply concentrated elsewhere on the receiver. Thus the trough design does not require tracking on a second axis.

The receiver may be enclosed in a glass vacuum chamber. The vacuum significantly reduces convective heat loss.

A fluid (also called heat transfer fluid) passes through the receiver and becomes very hot. Common fluids are synthetic oil, molten salt and pressurized steam. The fluid containing the heat is transported to a heat engine where only a third (33%) of the heat is converted to electricity. The remainder is waste heat, and can not be used further. Further, these systems rely on very sunny environments, in order to provide the conversion efficiency. Also these systems can not be applied on e.g. roofs of houses, and they are relatively expensive.

Various documents recite an energy conversion system.

WO 2008015064 (A2) recites a floating solar platform comprising a bridge (10, 5,

21) connected to buoyancy elements (11), means (14, 23) for collecting received solar energy, said means being associated with said bridge and placed thereon, means (16, 24) for converting this energy, means (19) for storing the product of this conversion, and first propulsion means (12) for moving said platform to sites where it can benefit from optimum sunshine. The system is however not at all suited for being attached to a surface.

DE 202008 008747 recites a Photovoltaic device with flat Photovoltaic elements. Light is converted into electric energy and heat. US 2009229264 (A1)

US 2009229264 (A1 ) recites a multi-mode solar power generation system having a first energy conversion system that generates electricity from a working fluid heated by a portion of solar radiation focused by a plurality of heliostats. The unused radiation from the first energy conversion system can include radiation spillage or dumped radiation from a thermal receiver of the first energy conversion system.

EP 2048452 (A1) recites a roof based energy conversion system for a building with a roof having a roof frame structure and a plurality of solar energy converting tile assemblies. The system does not comprise means for bundling radiation.

US 5961739 (A) recites a hemispheric moving focus power plant with a hemispheric solar reflector for reflecting solar energy. The plant seems to be fixed. Further means for converting radiation into heat are absent.

US 4002031 (A) recites a solar energy converter uses gallium arsenide photovoltaic cells to convert light to direct current. Optical concentrators reduce the needed area of cells.

Many of the above systems are also complex, and therefore difficult to manufacture. As a consequence, many of these systems are also very expensive. The period for return on investment it therefore too long.

Many of the prior art systems can not be integrated, e.g. on a roof of a building.

Thus there still is a need for improved energy conversion system, which system overcomes one or more of the above disadvantages, while at the same time not jeopardizing other tavorable aspects of energy conversion.

SUMMARY OF THE INVENTION

The present invention relates to an apparatus for conversion of radiation, wherein the radiation is preferably radiation emitted by the sun or reflected by the moon, characterized in that the apparatus is fixed on a surface, wherein the apparatus it suited for receiving the radiation, wherein the apparatus comprises

a system for bundling the radiation,

means for converting radiation both into heat and into electricity, preferably comprising a mini turbine for converting sun radiation energy absorbed in the container into electricity, and

wherein the apparatus optionally comprises one or more of a system for energy transport (a), a transparent protection (b), an encasement system (c) preferably comprising one or more of a cleaning system, such as a lens cleaning system, a sealing for the encasement, fixing means for the encasement system, means for rotating the apparatus or part thereof around a longitudinal axis thereof substantially in the direction of the sun, at least one reflecting internal surface, and a support system, wherein the encasement preferably is substantially free of air in use, ja source tracking system (d) preferably comprising one or more of a servo drive, a positioning device, a computer, and software, an energy storage system (e) preferably selected from a storage system for heat and a storage system for electricity, an energy converter (f) selected from the group of a pressure to electricity converter, a heater, a process heater, and a central heating system, an energy management system (g), a PV layer (h) which layer is preferably applied to a surface of the container and/or which PV-layer is incorporated in a separate element, an absorber (i), a buffer system (j), and a rotator (k), as well as a construction element comprising the present apparatus.

The present apparatus as such is fixed on a surface and can rotate along a longitudinal axis thereof, i.e. rotate clockwise or anti-clockwise around said axis.

With the term fixed it is meant that the apparatus is in fact firmly attached in a permanent mode, of course allowing the apparatus to be installed and removed and/or repaired, if required.

The present apparatus converts radiation into both heat and electricity, which heat and electricity are in a form to be used further, i.e. reusable, such as for heating and for providing electricity to e.g. household appliances. The amount of waste heat generated is less than 50%, or put in other words, the efficiency of the total system is more than 50%. Waste heat refers to heat produced by machines, electrical equipment and industrial processes for which no useful application is found, and is regarded as a waste by-product. When produced by humans, or by human activities, it is a component of anthropogenic heat, which additionally includes unintentional heat leakage, such as from space heating. Thus the present invention is aimed at optimizing radiation conversion. In examples the efficiency of the total system is more than 75%, in some cases even more than 80%.

Various elements of the present apparatus as well as advantages will be discussed below in detail.

DETAILED DESCRIPTION OF THE INVENTION

In an example the present invention relates to an apparatus for conversion of radiation, wherein the radiation is preferably radiation emitted by the sun or reflected by the moon, characterized in that it comprises a system for energy transport, which system comprises

a. a container for liquid transport, preferably a tube-like container,

b. an insulation essentially surrounding the container having an inner surface, c. optionally a cavity in between the insulation and the container,

wherein the insulation comprises an opening to allow entrance of a bundle of radiation, preferably a non-parallel bundle of radiation, preferably an opening extending substantially over a length of the container, which opening is optionally covered by a material transparent for the radiation, and wherein the opening is smaller than 50% of the total area of the inner surface of the insulation, preferably smaller than 30% thereof, even more preferably smaller than 20% thereof, even more preferably smaller than 15% thereof, even more preferably smaller than 10% thereof, most preferably smaller than 5% thereof.

The present apparatus is meant to convert radiation. In principle it may convert any type of radiation capable of heating a liquid, however its primary application is at present thought to be aimed at conversion of solar radiation or reflected solar radiation, such as from the moon. So typically radiation will comprise visible light, UV-light, IR-light etc. In an example the present apparatus is for converting direct or reflected solar radiation.

The radiation is converted, in first instance into heat. The converted radiation, or the energy content thereof, is typically obtained in a location where it is not used, or where it is in a form not required, such as in the form of heat where in this example electric energy is required. Typically also the converted radiation needs to be densified for transport, such as by converting it into electricity. Therefore the present apparatus comprises an energy transport system.

Such an energy transport system comprises a container for liquid transport. The container extends typically substantially over a length of the apparatus. The container typically has a length being (much) larger than a width or height thereof. The container may have any shape, such as cubic, or have a cross-section being essentially square like, elliptical, rectangular, multigonal, such as hexagonal, or circular. It is preferably a tube-like container, as such a tube-like container offers a relative small surface/volume ratio, and is further easy to manufacture. The container is made of a material that can withstand pressure to a certain extent, is relatively light, so that it can be handled easily and does not pose any unnecessary restrictions to a construction where the apparatus is placed. Further, the container is preferably of a dark color, such as black, in order to absorb as much radiation as possible. Typical materials for the container are polymers, metals, like alumina, etc. Further, the material should be durable over the life time of the apparatus.

With the term "liquid" any material is meant that at operating conditions, i.e. between -50 C and 500 C, is liquid, that is can flow, such as a gas, a liquid, a vapor etc. Important is that the liquid can flow and thereby transfer heat. Water, comprising additives to lower the melting point and increase the boiling point thereof, such as a salt, is a preferred liquid. The liquid may be brought under pressure.

In an example the energy transport system comprises an insulation essentially surrounding the container. This is an important feature, as it prevents leakage of secondary radiation, such as radiation emitted by a so-called black body. The prior art has neglected isolation of containers fully or to a large extent. Typically the insulation has an inner surface, directed towards the container, and an outer surface, directed to the environment. The insulation should be thick enough and of a material or construction to prevent leakage of radiation emitted by the container. It should also be durable, preferably be resistant to environmental conditions, such as UV-radiation, and operating conditions. In an example the insulation comprises an inner part and an outer part, wherein the inner part comprises a double walled pre-form, wherein the space in between the walls is filled with a medium with a low thermal conductivity (W/mK @ 293K), preferably lower or equal to the thermal conductivity of air, such as vacuum or a noble gas, and wherein the outer part comprises one or more insulating components preferably selected from glass wool, PUR-foam, cellular plastic, silica aero gel, and glass fibre applications.

The insulation comprises an opening. The opening allows for radiation to enter the insulation and transfer its energy to the container.

In an example the opening is located substantially over a length of the container. As such the amount of radiation that can enter the insulation and reach the container is increased.

In an example the opening is large enough to allow entrance of a bundle of radiation, preferably a non-parallel bundle of radiation. Preferably a substantial part of a bundle of radiation formed by the present apparatus reaches the container, more preferably almost all of the radiation reaches the container, such as more than 90%, preferably more than 95%, such as more than 99%. The radiation reaching the container heats up the liquid therein. Preferably the container allows for pressure built up within the container, such as up to pressures of at least a few times atmospheric pressure (i.e. up to 10000 kPa depending on the material). As such heat can be transferred or transported effectively and efficiently.

It is noted that in an example the heat is transported, e.g. by a tube system, to a turbine and to a heater, such as a central heating system in a home, in a building, in a green house, etc. As such, heat can also be stored, e.g. by pumping it into the earth, to be extracted at a later time when required.

The opening is optionally covered by a material transparent for the radiation. As such the container is protected from the environment. The covering may be formed of glass, a transparent plastic, such as polycarbonate, and is preferably durable and light.

In an example the opening is smaller than 50% of the total area of the inner surface of the insulation, preferably smaller than 30% thereof, even more preferably smaller than 20% thereof, even more preferably smaller than 15% thereof, even more preferably smaller than 10% thereof, most preferably smaller than 5% thereof. As such most of the radiation can enter and is kept inside the insulation.

In a further example the bundle of radiation is concentrated as much as possible. A way to achieve this goal is bundle the radiation entering the apparatus, thereby providing a very small concentrated bundle with a relatively small cross-sectional area, such that this cross-sectional area is smaller or equal to the opening of the insulation. An other way is to focus the bundle of radiation, such that a focal point thereof, or focus area thereof, is substantially inside the insulation. In the latter case also the cross-sectional area of the bundle close to the opening of the insulation is as small as possible. Also a combination of the two above ways of bundling is possible. Assuming a perfect focus system a cross-sectional area of a bundle may be a point, or in the present case typically a line. Thus the opening could in such a case be extremely small, such as much less than 1 % of the total area of the insulation. However, due to practical reasons, such as tolerances in mass-production of the present system, an opening of around 1 % is preferred. Further, due to a possible large concentration of radiation the opening may need to be a bit wider, in order to prevent burning thereof, such as 2%. It is noted that as the present apparatus relates to a system having a certain length and not to a substantially circular system, the system typically has a focal line or line along which the radiation is bundled. Therefore, if applicable, the term focus point throughout this application may also relate to a focal line. As such the amount of radiation of the container, being a hot body emitting radiation, exiting the insulation is minimal. Preferably most or all of the radiation of the container is kept inside the insulation. Preferably more than 50% of the radiation of the container is kept inside, more preferably 75%, even more preferably more than 90%, and most preferably more than 95%, such as more than 98%. As a consequence the opening in the insulation is preferably as small as possible. By having the opening as small as possible also convection losses are kept to a minimum level. In an example the inside of the insulation and/or the insulation may be of a material that reflects the radiation of the container to a large extent, such as being a metal, or a thin reflective coating. Also the outside of the insulation may comprise a reflective material, e.g. in order to prevent burning.

In an example the bundle of radiation is concentrated using a circular mirror, the mirror preferably being a longitudinal inside section of a cylinder. As such concentration is not optimal, but sufficient for the present invention. Further an absorber (element) may be provided. The absorber may collect radiation reflected by a mirror. In an example the absorber as one or more first surfaces having an absorbing surface, such as a black surface, and one or more second surfaces having a reflective surface, such as a metallic surface. In an example the metallic surface is adapted to reflect radiation onto the absorbing surface. An example thereof is a zigzag like element as detailed in the figures.

The energy transport system optionally comprises a cavity in between the insulation and the container. Such a cavity functions as a further insulation, and allows for radiation to enter the insulation and transfer its energy to the container. In an example the apparatus according to the invention comprises a container comprising an entrance substantially aligned with the opening of the insulation, wherein the container comprises two or three substantially concentric walls, wherein the container preferably is a pre-form, wherein a space in between the walls is filled with the liquid, which liquid preferably has a high specific heat capacity (kJ/kgK), and/or which liquid has a melting point below - 10 C, preferably below -50 C, and a boiling point above 50 C, preferably above 90 C.

The entrance of the container is substantially aligned with the opening of the insulation in order to maximize the amount of radiation entering the inner part of the container. Thereby the entrance, and the opening of the insulation, can be kept as small as possible, to comparable dimensions. The inner part of the container is formed by the double-walls or three walls of the container. These walls are substantially oriented concentric with respect to each other. The double walls, or three walls respectively, enclose a space, which space is filled with a liquid for energy transport towards the present energy converter.

In an example the container is formed of three walls, enclosing an inner and an outer space, each space in operation being filled with liquid. In operation in the inner space liquid flows in a first direction, whereas in the outer space liquid flows in a counter current direction. As such energy contained in the radiation entering the insulation is transferred efficiently from the liquid in the inner space towards the liquid in the outer space, and subsequently to the energy converter.

In an example the inner part of the container substantially encloses a cavity, wherein the radiation enters. As such radiation is captured inside the container to a large extent, preferably to more than 75%, such as more than 90%, preferably more than 95%, such as more than 98%.

In an example the inner wall of the container comprises of a radiation absorbing material, is formed of a radiation absorbing material, is colored, such as with pigment, such as being black, or a combination thereof. The radiation absorbing material is preferably capable of absorbing the radiation entering the apparatus as well as radiation emitted by the container.

The container is preferably a pre-form, for instance made my molding or extrusion. Pre-forms can be made very precise and at relatively low costs. The container can be made of a suitable material, such as plastic, a suited polymer, glass, or a combination thereof.

The specific heat capacity of the liquid is preferably high, in order to transport energy efficiently. Further, it is preferred that the liquid remains liquid or gas at operating conditions. In order to be operable at environmental conditions the liquid preferably does not freeze, i.e. has a freezing point lower than -50 C. Further, as the intensity of radiation can become very high, the boiling point of the liquid is preferably also high, i.e. larger than 90 C, such as larger than 110 C.

In an example the apparatus further comprises a buffer system. The buffer system can e.g. be filled if environmental temperatures are so low that the liquid runs a risk of solidifying in the container. Even further, the buffer system may be filled if pressure and/or temperature of the liquid in the container become too high. The buffer may be in the form of a secondary container, preferably being isolated. The buffer system and/or apparatus may comprise a pressure valve.

In an example the system for energy transport comprises a PV layer, which layer is preferably applied to a surface of the container and/or which layer is incorporated in a separate element.

By adding a PV-layer the person skilled in the art may further adjust the relative amount of radiation converted into electricity and into heat. The additional PV layer allows for extra conversion into electricity. Therefore the present apparatus, or construction element comprising said apparatus, may have smaller dimensions, and at the same time still be capable of supplying a required demand of specific energy, e.g. supplied to a household. Despite the fact that adding an additional PV-layer may be somewhat more expensive, a smaller system will consequently be less expensive, compared to a system without said layer.

A further advantage is that electricity is directly available to a consumer.

The PV-layer may be in the form of a layer deposited or applied to e.g. the surface of the container, preferably to the inner surface of the container, and/or may be a separate element comprising such a layer, positioned in the apparatus. The separate element may be positioned inside the container of the apparatus, for instance in a horizontal position, in a vertical position, or at a certain angle. Typically the element is in contact with the container. When the PV-layer is applied to the inner surface of the container, the container may at the same time function as a cooling element, which is a further advantage; such also holds for a case where the element is placed in full contact with the container, i.e. when a major surface of the element is in contact with the container. The separate element may also be positioned substantially outside the container, such as, in an example, at the entrance of the container.

In an example the PV-layer forms one or more solar cells. As such electrical energy can easily be transported. Typically also an electrical converter may be present.

In an example the PV-layer is selected from the group comprising a lll-V layer, a single junction, a multiple junction, such as a 3-junction and a 4 junction, a concentrator layer, a high efficiency layer, a doped Si-layer, and combinations thereof. In the present application the term "PV-layer" may therefore refer to a multiple layer system, and/or to a multiple junction system. Typically the PV-layer may be further optimized in terms of efficiency, temperature behavior, etc.

In an example the PV-layer comprises one or more of characteristics from the group consisting of a wide band gap, preferably a band-gap from 0.8-2 eV, at least one band gap widening element, and an alloy enhancer. Thus the PV-layer is further optimized in order to obtain the best possible performance, given the boundary limitations of a specific situation. In an example the inner wall of the container may comprise a reflective material, in order to reflect radiation towards an optionally present PV-layer.

In a second aspect the present invention relates to an apparatus for conversion of radiation according to the invention, comprising a transparent protection, which protection comprises a curved element having a certain refractive index, wherein an outer curve of the element is different from an inner curve of the element, such that a parallel bundle of radiation entering the protection at the outer curve thereof at a certain angle Θ exits the inner curve of the protection substantially parallel to the angle Θ.

The term "transparent" is used in the present invention to indicate that radiation in general, and solar radiation in particular, is substantially not hindered. That is substantially all of the radiation passes through a material, such as more than 90%. A transparent material or element therefore allows radiation to pass through, at least to a large extent.

Preferably the protection is made of a light material, such as a polymer material, such as polycarbonate and polymethylmethacrylate. Glass or a similar material is also suited. The material is further preferably durable for environmental influences, is preferably also strong enough to withstand hail, even large hail stones, preferably also durable for radiation, such as UV-radiation, and lasts preferably over the life time of the protection, or longer if the protection is recycled, such as twice the life time.

As the radiation emitting object, i.e. the sun or the moon, is relatively located far away, radiation will be received as a parallel bundle. In order to obtain optimal efficiency of conversion of radiation the bundle of radiation needs to be focused and/or densified or concentrated. Therefore in this embodiment the parallel bundle preferably enters the internal part of present apparatus in parallel. Thus the protection is formed such that an outer curve of an element thereof is different from an inner curve thereof, such that a parallel bundle of radiation entering the outer curve of the element exits the inner curve of the element substantially parallel. Thus, a parallel bundle entering the apparatus at a certain angle Θ remains parallel inside the protection under substantially the same angle Θ. Of course, relative to the outer curve of the element an angle of entrance (or incidence) varies over the outer curve. Similar, relative to the inner curve of the element an angle of refraction varies over the inner curve.

In this application the term "curved" is meant to refer to a substantially convex or concave surface, which surface taken as a hole is circular-like or elliptical-like. Thereon functional undulations may appear, as is further detailed. Undulations may appear on the outer curve, on the inner curve, or on both. An example comprises undulations on the inner curve in view of cleaning the outer curve.

In an example the outer curve of the element is being substantially circular and an inner curve is being elliptical-like, or vice versa. Also two elliptical like shapes, being different from each other are possible. Further, two elliptical shapes, or two circular shapes, having an off-set with respect to the or a center of said shapes, are possible.

As a consequence a thickness of the protection material varies, being thinner at the edges thereof relative to the center thereof.

An advantage of the present protection is that the efficiency of the present apparatus is increased by some 20%, or in other words, losses are reduces by some 20%.

A further advantage is that a curved protection offers more strength. It is expected that e.g. to climate change intensity of storms, frequency of hail and size of hail, increase. Therefore preferably a strong protection is provided, in order to minimize damage and extent life time of the present apparatus.

In an example the present invention relates to an apparatus for conversion of radiation according to the invention, comprising

a. a system for energy transport according to the present invention, comprising a container and an insulation,

b. a system for bundling radiation comprising one or more parabolic mirrors and/or one or more lens systems, and

c. wherein the liquid in the container absorbs energy from the system for bundling radiation.

As mentioned above the bundle of radiation may be bundled. In an example bundled radiation is directed towards the container, in order to absorb the energy thereof. Further the absorbed energy is transported by the present energy transport system. Preferably a focus point of the system for bundling radiation is located close to the container or in an example close to the center of the container, i.e. at a distance thereof of less than 0.5 times a diameter of the container, more preferably at less than 0.2 times, more preferably less than 0.1 times of a diameter. Preferably the focus point is located inside the insulation, more precisely inside a hollow space in the insulation.

The system for bundling radiation comprises one or more concave or convex parabolic mirrors and/or one or more lens systems. Preferably the number of mirrors and lenses is as small as possible, in order to reduce costs thereof and in order the reduce energy yield losses thereof. A system comprising one lens, or one concave and one convex parabolic mirror is preferred. The concave parabolic mirror is also referred to as a trough mirror. The system is preferably designed to bundle substantially all, or at least 90%, preferably 95%, most preferably 99% of the radiation entering the apparatus, and further to direct substantially all of the bundled radiation towards the container in order to absorb the energy thereof. As such the energy conversion yield, that is the ratio of energy converted and energy in the form of radiation entering, is as high as possible, i.e. higher than 80%, preferably higher than 90%.

In an example the present apparatus for conversion of radiation comprises a concave parabolic mirror which is substantially directed towards the sun or moon for bundling radiation, wherein a focus area of the bundled radiation is substantially inside the insulation.

As mentioned above, the present focus system comprises a focal line. The concave parabolic mirror has a central plane of symmetry, on which plane the focus line thereof is located, which central plane further comprises a vector perpendicular to the mirror, which vector is preferably oriented substantially parallel to azimuth angle of the bundle of radiation entering, that is having a deviation of less than 10 degrees, preferably less than 5 degrees, most preferably less than 1 degree, such as 0.1 degree. The present invention provides a system which allows for a deviation close to a tolerance of the manufacturer of the present system, i.e. virtually 0. The deviation is taken relative to an optimal orientation, i.e. perfectly aligned and the above vector parallel to the azimuth angle of the bundle of radiation. As the present apparatus is typically fixed to a surface, such as a roof, it can not correct for the altitude of radiation entering. The above also holds if the present system comprises a lens system, such as a convex (positive) lens.

As mentioned above, a focus area of the bundled radiation is substantially inside the insulation.

As a consequence the present system provides for yields of absorption of radiation entering of more than 80%, typically more than 90%, such as 95% or even 99%. Such is much better than prior art systems, typically having a yield of (much) less than 50%, such as the through system.

In a further example the system further comprises a convex parabolic mirror, wherein the convex mirror bundles radiation reflected from the concave mirror. The size of the second mirror is such that substantially all of the radiation bundled by the concave mirror is further bundled by the concave mirror. On the other hand, the convex mirror is as small as possible, as it hinders entrance of radiation.

Typically mirrors are molded and made of a light material. Further, in an example the first concave mirror forms an integral part of a housing or encasement of the present apparatus. By molding almost perfect concave mirrors, as well as lenses, can be made. The mirror may have a reflective coating, or may be made of a reflecting material, such as a metal. The material and/or the construction of the mirror must be durable to environmental influences, such as weathering, aging, UV-radiation etc.

In an example the present apparatus for conversion of radiation comprises a transparent protection such that the protection functions as a lens.

As such the protection has also a function of bundling radiation entering the system. By combining various functions the present apparatus is easier to manufacture, e.g. in less steps and comprising less elements, and therefore costs are reduced, and above all efficiency of conversion is increased. Preferably radiation is reflected as less as possible, in order to reduce yield losses.

In a further example the protection comprises two or more transparent elements, such that the protection functions as a lens. An outer element can e.g. be made of glass, an inner element can e.g. be made of polymer, whereas an optional intermediate element can be air, water, a polymer etc. In an example glass used for elements of the present apparatus exposed to environmental circumstances may be reinforced glass, being able to withstand impact of e.g. hail.

In a further example the protection comprises a curved element having a certain refractive index, wherein the protection has a thickness varying stepwise over the curve thereof such that a minimal thickness d_min of the protection is larger than 0.1 * a maximal thickness d_max, such that a parallel bundle of radiation entering the protection at an outer curve thereof exits an inner curve being focused. In a most example the minimal thickness d_min is almost equal to the maximal thickness d_max, that is from 0.90-0.99 * the maximal thickness d_max. As such the amount of material used for the protection is minimal, whereas the lens function thereof still is acceptable. It is noted that the thickness relates to a radial thickness of the protection.

In designing the above protection applicant has taken into account reflection coefficients, transmission coefficients, and refractive index (n) of the curved element and other material involved, such as air. Further, the form and thickness of the curved element have been optimized in terms of efficiency with respect to incidence angle of the radiation and refraction angle, taken relative to a normal (line) at a certain location (x,y,z) of the curved element. The curved element is designed such that radiation entering is focused to a focus point (or line). Even further, in view of production and functional tolerance and costs, the thickness of the material may on the one hand not vary to much, that is a minimal thickness is preferably not much smaller than a maximal thickness, and further the minimal thickness is large enough to provide protection, as indicated above.

In a certain aspect the above protection relates to a coaxial lens. In an example the protection relates to a lens which in certain aspects may be regarded as functioning as a curved Fresnel lens.

The efficiency, in terms of percentage of radiation entering being bundled, of the above lens is larger than 90%, typically larger than 92%, such as larger than 94%, mainly depending on the curvature thereof. It is noted that mainly losses at the edges of the present apparatus occur.

The minimal thickness d_min of the protection is preferably in the order of 3-10 mm, depending on e.g. the material used, optical properties thereof, and strength thereof. It is preferably larger than 0.1 * a maximal thickness d_max being preferably in the order of 3.1 -25 mm. The maximal thickness is preferably not too large in view of weight of the protection. The minimal thickness is preferably large enough to provide strength to the protection.

In an example the present invention relates to an apparatus for conversion of radiation according to the invention, comprises an encasement system for containing the apparatus and elements thereof, comprising one or more of a cleaning system, such as a lens cleaning system, a sealing for the encasement, fixing means for the encasement system, means for rotating the apparatus around a longitudinal axis thereof substantially in the direction of the sun, at least one reflecting internal surface, and a support system.

The encasement system fixes the present apparatus to a surface. The surface may be a roof, a wall, and the encasement system may be placed inside or outside. On the one hand the apparatus needs to be firmly attached to a surface if place outside, in order to withstand (strong) winds, storms etc. In a further aspect the apparatus preferably still is able to rotate around an axis thereof, in order to be oriented towards the azimuth angle of the sun or moon. Preferably the rotation can be established using a relatively small force, such as force provided by a means for rotating, such as a servo-drive. Preferably the encasement also comprises a cleaning system. Preferably such a cleaning system is located on one or both (longitudinal) sides of the containment. An example is a scraper, such as a metal scraper, which is firmly attached against the encasement. By rotating the encasement the encasement is cleaned at the same time. Preferably a cleaning system also cleans the lens and/or protection, if present. Thereby the clarity of the lens and/or protection is maintained during use.

If the encasement is used outside, preferably the encasement also comprises a sealing system, or is a sealing system, thereby keeping moisture, such as rain, outside.

Preferably the encasement comprises fixing means for the encasement system, thereby fixing the encasement firmly to a surface.

In order the rotate the apparatus towards the sun it preferably comprises means, such as a rotator, for rotating the apparatus around a longitudinal axis thereof substantially in the direction of the azimuth angle of the sun. Thereby the amount of radiation entering the apparatus is optimized, that is as the apparatus typically is fixed in a two-dimensional plane, which plane is per definition almost never located perpendicular with respect to radiation emitted by e.g. the sun, optimization is limited to orienting the apparatus around an axis within said plane towards the sun. Such means can be a servo-motor, being attached to a simple bar-system, which bar-system is on its turn attached to the apparatus. As an alternative the servo-motor is attached to a belt driving a wheel, the wheel being attached to the apparatus. One belt may be attached to a series of apparatuses. Preferably one servo-motor is attached to more than one apparatus, such as to two, five, or ten apparatuses, or to a complete construction element.

Preferably the present apparatus comprises an encasement having at least one reflecting internal surface, preferably at least two reflecting internal surfaces. Thereby radiation not directly focused towards the present container is reflected towards said container. Typically this radiation is a consequence of the altitude of e.g. the sun with respect to the present apparatus, which altitude is larger or smaller than an angle of the surface, with respect to the horizontal plane of the earth, the present apparatus is attached to, such as the angle of a roof with respect to the surface of the earth. The at least one reflecting surface is therefore preferably located at one or both longitudinal ends of the present apparatus, which ends may be regarded as bottom and top part. The reflecting surface may be a metal (layer) or reflective coating.

Preferably the present apparatus comprises a support for attaching the apparatus to a surface, such as a wall or roof. Preferably the support comprises means for fixing it to the surface and to the apparatus, such as screws or clamps, respectively. The support may also be glued.

In an example the present invention relates to an apparatus for conversion of radiation according to the invention, comprising energy converters selected from the group of a pressure to electricity converter, and one or more of a heater and a central heating system, and an energy management system.

In an example the apparatus comprises a mini turbine for converting solar radiation energy absorbed in the container into electricity. Such a mini turbine is well known per se to the person skilled in the hard. The turbine converts pressurized liquid (liquid, vapor or gas) flow into electricity.

In an example the apparatus comprises a heater, preferably a heater for water. Heated water can be used for domestic and industrial applications, such as for showering, cleaning, central heating and process heating.

In an example the apparatus comprises a heat exchanger. Thereby heat can be upgraded in order to be used for domestic and industrial applications, such as for showering, cleaning, process heating and central heating. In a further example the apparatus comprises a central heating system.

Optional other energy converters are chemical energy converters, magnetic energy converters, etc.

In an example the apparatus comprises an energy management system. The energy management system optimizes the energy conversion in terms of amount of electricity and amount of heat generated through conversion, in terms of optimal temperature of the liquid in the container, in terms of storage of optional surplus of energy in which ever form, in terms of shutting down the system when optional overheating might occur, etc.

The software for solar tracking and energy management takes into account common information, general information for determining start parameters, household external costs and usage information, consumption of energy of a household, household market information for a specific country, such as the Netherlands (estimate 2009; underlying source: CBS), market information, System Cost information, System global layout information, system costs, purchase price, return on investment, WPeak costs, WPeak average absorbed and produced energy on a year basis, system absorption ratio, coverage, available average energy per segment, per day, and per season (e.g. geographic position data: Uithoorn - The Netherlands), loss factors, efficiency factors, available average energy per year, calculated and available forms of energy on yearly basis, geometric unit definition, geometric element definition, thermodynamic energy and design data relative to daily pattern, overview global element assembly, display system layout, and graphic overview results.

In an example the present invention relates to an apparatus for conversion of radiation according to the invention, comprising a Source Tracking system comprising one or more of a servo drive, a positioning device, a computer, and software.

The source tracking system is aimed at positioning the present apparatus towards the azimuth angle of the source of radiation, e.g. the sun or moon. As such it comprises a computer and software for calculating an optimal position, rotating the apparatus using e.g. a servo drive towards said optimal position through a positioning device as described above. A servo drive may of course also be replaced by means having a similar function and output. As input the computer needs to know the time of day, the day of the year, the year, the angle of the apparatus relative to the surface of the earth (horizontal projection thereof), and the angle of the surface, relative to e.g. north, south etc, or in other words the relative position of the apparatus with respect to the sun or to the moon. As output the computer positions the present apparatus optimally, e.g. in terms of azimuth angle, e.g. oriented towards the azimuth angle.

In an example the present invention relates to an apparatus for conversion of radiation according to the invention, comprising one or more energy storage systems selected from a storage system for heat, and a storage system for electricity.

As such surplus energy can be stored and used at a later time. Preferably an energy management system calculates optimal use and conversion rate and form of energy. A storage system can e.g. be a battery, an earth warmth system, an optionally pressured container, etc.

In an example the present invention relates to an apparatus for conversion of radiation according to the invention, in the form of one or more units wherein the one or more units can be removably attached to each other. When being mutually attached the one or more units form a closed surface, which is substantially no moisture can penetrate through. Preferably the units have a unit length of 15-500 cm, preferably 50-100 cm, the unit length being preferably equal to, or a multiple of, conventional units used for forming a substantially water-tight surface, such as a roof.

As such the present apparatus can easily be attached to a surface, such as a roof. By using standard elements having dimensions similar to or largely the same as conventionally used elements, such as roof tiles, the present invention can easily replace or be used as these conventional elements. Preferably the apparatus has dimensions similarto roof tiles, such as 30 cm by 25 cm, or multiple lengths thereof, such as 60 cm, 90 cm, 120 cm, 150 cm, etc.

In a further aspect the present invention relates to a construction element, such as a roofing, cladding, window, lighting, artistic application, comprising at least one apparatus, such as two or three, for conversion of radiation according to the invention.

Preferably the construction element is colored, such as in typical colors of a roof or cladding, in order to have an attractive appearance. Even more preferred the construction element is provided with visual elements providing e.g. a roof tile like structure. In the example horizontal visual elements would be provided.

The construction element can also be used as lighting, as artistic application etc. Further, it can be used as roofing in green houses, serving a purpose of heating and providing electricity, to the green house and optionally to neighboring houses or buildings.

In an example the present construction replaces a traditional roof, or tile thereon, fully or to a large extent. As such, the present construction can be applied to a full area of a suited roof, or at least to a large part thereof. Even further, by using standardized dimensions, comparable or equal to those used for construction purposes, also element typically present on a roof, such as windows, do not form an objection for use of the present construction, as the units can be mounted around these elements.

In an example the present construction comprises one ore more connectors selected from the group consisting of a two way connector, a three way connector and a four way connector. A such two, three or four elements may be connected. It is observed that a construction element may comprise more than one container. The connector may therefore comprise more than one entrance.

In a further aspect the present invention relates to a method of converting radiation into both electricity and heat, using an apparatus according to the invention. Advantages and details of such a method are described above.

The invention is further detailed by the accompanying figures, which are exemplary and explanatory of nature and are not limiting the scope of the invention.

DESCRIPTION OF THE DRAWINGS / FIGURES

The invention although described in detailed explanatory context may be best understood in conjunction with the accompanying figures and photographs.

Fig. 1 shows a perspective view of the present energy conversion system.

Fig. 2 shows a cross section of the present energy conversion system.

Fig. 3 shows a cross section of an example of the present energy conversion system.

Fig. 4 shows a cross section of an example of the present energy conversion system.

Fig. 5 shows a cross section of an example of the present energy conversion system.

Fig. 6a-h show cross sections of examples of the present energy conversion system and details thereof.

Fig. 7 shows a perspective view of an example of the present energy conversion system. Fig. 8 shows a perspective view of an example of the present energy conversion system.

Figure 9; Impression of a typical RTEC application and Impression of the TEEC system.

Figs.10 relates to specific details of the present apparatus/construction element. Figure 1 1 ; Absorber fixed, direct radiation pattern (input direction: 90, 60, 45, 30 degrees).

Figure 12; Absorber tracked, direct radiation pattern (input direction: 90, 60, 45, 30 degrees).

Figure 13; Absorber fixed, diffuse radiation pattern (input direction: 90, 60, 45, 30 deg -60 deg variance).

Figure 14; Absorber tracked, diffuse radiation pattern (input direction: 90, 60, 45, 30 deg -

60 deg variance).

Figs 15-26 show further examples.

Design of an example, the Solar Light Tube (SLT) system.

Overview and common components of the SLT system are shown in figures 1 and 2.

Generally, the SLT is designed for outdoor applications, for bundling incoming radiation energy, absorbing this energy and transmitting this for further processing. It consist of the following four functional system parts as shown in figures 1 and 2:

1. An encasement including an upper lens (100), a lower bottom (110), a radiation insulation system (120), an absorption system (130) and an end cap and/or an absorption system support device (140). Various design options for the encasement system exist of which 4 possible embodiments are explained further down

2. A mechanical support and location system for the encasement including support brackets (200) and clamping strips (210). Generally, the brackets are mechanically fastened (e.g. bolted) or chemically fastened (e.g. glued) onto a base or may be part of that base. The clamping strips are mechanically clamped onto the brackets and permanently locates the encasement whilst at the same time allowing the encasement to rotate. An additional function of the clamping strip is to provide a weather seal between the encasement and clamping strip so that rain, moisture and wind is prevented from passing through. A further function of the clamping strip is to provide a lens cleaning action by wiping along the encasement, scraping off any dirt, when it rotates along its longitudinal axis, while tracking the light source (sun or moon).

3. A fixed position energy medium transportation system (300) including a closed circuit piping system for transporting the converted radiation energy to a different location. The piping system is connected to the encasement rigidly or by means of a rotating coupling. The transportation system is designed to hold a high pressure and high temperature medium. Parts of it may be flexible in order to allow it to follow the rotational movement forth and back of the encasement to which is it connected 4.A Radiation Source Tracking System (RSTS) including a drive system (400) for rotating the encasement and pointing the upper lens system towards the light source. The tracking system may consist of a computer based servo-drive system or comparable drive system suitable for this purpose which, in turn, may drive a timing belt or other actuation mechanism which, in turn, rotate the encasement. More SLT's will rotate synchronic when connected to the drive system in line. Longitudinally, SLT's may be located in a stacked order whilst still be connected to the drive system. Other actuation systems, such as pneumatically or hydraulically bases systems, may also be applicable. In case the position of the light source adheres to a known and cyclic pattern, such as the daily position of the sun relative to the position of the system location, the information necessary to control and actuate the tracking system can be calculated from the time-position information of the light source.

Design options for the encasement system:

a. Solar Light Tube with single concave parabolic mirror (see figure 3);

Here, radiation is entering the curved upper half of the encasement system (100) to hit a concave parabolic shaped mirror (160) of which purpose it is to reflect parallel incoming radiation into a focus-line at a certain distance above the mirror. The focus-line is entering an internal black coated absorption shape, preferable a tube. A purpose of the internal shape is to minimize blackbody radiation losses by re-deflecting the emission of blackbody radiation onto itself as much as possible. Heat is transferred through the inner wall and absorbed by a heat transfer medium, like a fluid or similar (130). To further minimize energy radiation- and convection losses the surface area of this shape is encased by insulation (120).

Material thickness compensation for circular shaped curves:

Depending on component geometry and material refraction properties the transmission of radiation is deflected at each change-over location of two transparent or partially transparent materials. For flat plate geometry of uniform thickness where geometry angles on either side of the material is equal, the direction of radiation at the point of exit will be equal to the direction of radiation at the point of entrance. However, for components with a curved geometry of equal thickness this will not be the case because the material angle at the radiation exit location will be different from that of the radiation entrance location. Thus, for a circular curve of uniform thickness, parallel incoming radiation on the outer entrance side will leave the curve on the inner exit side in a diverge manner. Therefore, in order to obtain a parallel exit direction over the entire exit surface area compensation is preferred in material thickness. For circular shaped curves this may be achieved by introducing an offset of the center point of the inner curve relative to that of the outer curve whereby the material becomes thinner as it approaches both ends of a parabolic mirror.

b. Solar Light Tube with primary concave and secondary parabolic convex mirror

(see figure 4);

Similar to a. above, the absorption element can be replaced by a secondary parabolic convex mirror (150) which purpose it is to reflect and further bundle the radiation into a focus-line through the bottom center of the primary parabolic mirror (160). Here the radiation bundle can be absorbed by an absorption element similar to that described in a. above or, alternatively, hit externally a fully closed tubular element which is partially encased by insulation (130). Space may exist between the absorption element and the insulation (120). The material of the insulation encasing is such that the emission of blackbody radiation from the absorption element is partially being re-deflected onto itself by the insulation encasing (125).

c. Solar Light Tube with Curved Internal Focus (CIF) coax lens (see figure 5); The application of reflection mirrors as in design option a. en b. above limit the radiation catch-area, because secondary components are located in the field of radiation (see figure 3 and 4) therefore limiting radiation absorption efficiency. To improve on this, any system of bundling and absorbing radiation energy is preferably located in-line instead of reflected and bundled by mirrors. To keep the in-line radiation focus-line within the envelope of the required geometry of the encasing, the employment of a single homogenous transparent material lens would require a lot of bulk. This would make it both expensive and heavy to employ. The CIF coax lens design in this option offers a bundling of radiation energy by employing a system of stacked in-line lenses. Here, radiation passes a first stage curved transparent element (100), a second stage cheap en lightweight material, fluid or gel with a refraction index well above 1 (170), and a third stage which may again be of similar material as stage one (180). An example may be the application of water in the second stage which also may include anti-freeze agents to prevent freezing of the fluid. After passing through the CIF coax lens system the focal-line enters an absorption element system as described in a. above (120) (130).

d. Solar Light Tube with CIF Fresnel lens (see figure 6);

To further improve on weight- and cost reduction the coax lens system as described in c. above can be replaced by a homogeneous transparent material CIF Fresnel type lens (100). Here, bulk material of the curved design that would otherwise be required to obtain a smooth lens design is removed in radial direction at polar intervals. This staged or staggered design (Fresnel) causes a staged deflection of an incoming parallel radiation bundle towards the focal-line. To obtain a combined focal-line result of all staged radiation bundles, the inner or exit curve of each stage need to be computer optimized with respect to the component geometry, the material refraction properties and the desired radiation flow pattern. After passing through the CIF Fresnel lens system, the radiation focal-line enters an absorption element system as described in a. above (120) (130).

Generally, the geometry of the CIF Fresnel lens system is characterized by the incorporation of three convex curvatures as follows:

" a smooth outer curve which may be parabolic, elliptical, circular, or of any other suitable type of curvature " an intermediate curve which is similar to the outer curvature and which provides a minimal thickness of base material and identifies the start of the "Fresnel" shape

an inner curve which marks the end of the "Fresnel" shape.

The above geometry may also be inverted whereby the convex curvature is replaced by a concave curvature. Here, the outer curve identifies the start of the "Fresnel area", the intermediate curve the end thereof and the inner curve the provides the parabolic, elliptical, circular, or any other suitable type of smooth curvature.

To fulfill material requirement, weight, material costs and build up, and keep radiation losses caused by material impurities as low as possible the curvatures should be located as close as practicable, i.e. the lens should be as thin as possible. Furthermore, the flatter the curvature the less radiation reflection losses will be the result. Figure 6b shows an example of a slightly curved normal lens without the "Fresnel" design. This full material lens is bulky, heavy, expensive to manufacture and requires a high level of material purity. Figures 6c to 6h show CIF Fresnel lenses with increasing curvature where radiation losses increase from around 8% to respectively 10%

Thus figures 6a-6h show various curved lenses. Efficiencies of these lenses vary. Some fields of application;

Arrays of SLT's may be applied as roofing or cladding elements. Figure 7 shows an array of SLT's with a non-transparent lower encasement. Here, for esthetic reasons the lower half can have any desired color. Figure 8 shows an array of SLT's with a fully transparent encasing. This design layout will transmit part of the radiation which is not absorbed by the system and may be applied anywhere where reduced transmission of light is needed (e.g. transparent roofing and cladding).

Figure 9 shows a roofing of a house comprising various units according to the invention. The surface area of this construction element is about 35 m². The construction element is more than sufficient to supply the energy requirement of an average family in the Netherlands.

Purpose, working principle and design features of the invention: The invention relates to a Concentrated Solar Power (CSP) system which purpose it is to convert solar energy, or any other radiation based energy source, into electricity and thermal energy . It consists of a Radiation to Thermal Energy Converter (RTEC) system, a build in Photovoltaic (PV) conversion system and a Thermal to Electric Energy Converter (TEEC) system. These two systems are connected and work together to provide a means for the decentralized generation of electrical, thermal and cooling power from solar energy. Figure 10 provides an indication how this can be achieved. Here, an ammonia-water based absorption cooling and heat- pump cycle to provide cooling energy or pull in more thermal-energy from outside is integrated and driven by left-over heat from the primary thermo-dynamic electrical generating cycle.

The RTEC receives radiation energy from its external source which is concentrated via a static positioned concave circular mirror onto a radially positioned absorber with an effective receiving height equal to the radius of the concave circular mirror. As the purpose of CSP systems is to elevate energy concentration by focusing radiation onto a specific point- or line, any diffuse radiation patterns, such as occurs in cloudy weather conditions, will interfere with this process. In the northern en southern hemisphere diffuse weather conditions are dominant and count for between 60% to 70% of daytime. Therefore, conventional CSP systems which output and conversion efficiencies are dependent on a continuous and direct solar-energy supply, are not very will suited to apply in these regions. This invention as described here, includes means to overcome this handicap by combining a larger absorber receiving area with low radiation losses. Figure 11 and 12 below show a computer analysis of a circular mirror layout with a fixed and a with a tracking absorber layout in direct sunlight. Figure 13 and 14 show the same in diffuse sunlight. Because of 2- dimensional symmetry, circular mirrors do not need to be incorporated in tracking and may remain static. Also parabolic or other shaped mirrors may be integrated for this purpose. Optionally, a tracking system may be incorporated to follow any movement of the radiation source. However, non 2-dimensional symmetrical mirrors, such as parabolic type mirrors, do have to be incorporated in tracking to be efficient.

From the figures above it can be seen that in order for the RTEC to function efficiently in diffuse weather conditions the absorber must be approximately twice the size of that needed for direct radiation conditions.

The absorber contains a fluid, typically as water or any other suitable liquid for this purpose, to convert the concentrated radiation energy into high pressure steam or any other vaporous or gaseous medium. Typically, pressures and temperatures may reach 20 bar and 200 Celsius. This medium is transported to the TEEC system for further processing. In order to minimize heat loss the absorber and transportation system operates in vacuum and is connected to the outside world via low heat-conductive structural materials. The vacuum is contained by a glass plate at the radiation entrance side.

For initial and direct conversion of radiation into electricity, a Photovoltaic (PV) film is integrated onto the inner side of the glass plate. For the PV film material to function more efficiently it has to remain at a temperature well below 80-90 degrees Celsius. To achieve this, the film material is, firstly, positioned in vacuum at the bottom side where no exchange of convective heat can take place, secondly, it is adhered to cold glass at the top side because glass absorbs minimal radiation which is cooled by the external environment and thirdly, radiation that passes through is absorbed inside the vacuum environment by the absorber and well away from the PV film material. Additionally, some radiation losses from the hot absorber may be reabsorbed by the PV film material which has an increasing effect on system conversion efficiency.

The TEEC incorporates Micro Turbine Technology (MTT) and may receive any mix of high pressure and high temperature fluid, vapor or gas. The vapor and gas component is separated and thermo-dynamically expanded via a high speed turbine with integrated electrical generator and converted into electricity and left-over low thermal energy. The latter may be used for additional heating purposes such as for the production of warm water and industrial process heat. Alternatively, it may function as a heat source to drive an integrated ammonia-water based absorption cycle to produce cooling power or, in reverse, pull in additional thermal-energy into the cycle. In case heat demand out-way supply, the TEEC can be connected to existing and conventional carbon fuel based heating systems as a in-line pre-heat station.

In line with the above and according to to-days technology, it is estimated that on - average, the combination of PV and MTT can convert 16% and 20% of input, respectively, whereby the remainder will consist of useful thermal-energy, thereby bringing the total potential efficiency of such a system to around 70%.

The RTEC is designed for manufacture as a structural building component according to the click and fit principle. It is weather tight and can be applied as a roofing, cladding or pavement material and can be laid in any configuration. It consists of two main elements: a vacuum insulated glass covered aluminum extruded beam with endcovers, incorporating the CSP system, and a vacuum insulated connector device for passing the absorbed energy between the elements. Figure 9 shows a typical application.

Uniqueness

The uniqueness of the this invention manifest itself in the design of a new click and fit modular building system incorporating integrated Concentrated Solar Power combining . Photovoltaic- and Micro Turbine Technology to convert radiation, such as that from the sun, into electricity and usable thermal-energy. It is designed for manufacture, can be mass-produced and installed on surfaces such as roofs, walls and walkways without the need for specialized training. Based on current fossil energy prices, it is calculated that the ROI (Return Of Investment) equates to around 5 years, or less. This is achieved by combining designing for low cost manufacture, wide scale of application and the achievement of high efficiencies in mixed weather conditions.

Design features of the SunTwig®

The "SunTwig" is a modular click and fit weather tight building system designed with a build in Concentrated Solar Power (CSP) system to operate in vacuum. It contains a high pressure and temperature fluid, vaporous or gaseous medium, such as water, to absorb the radiation energy and transport this away. It consists of the following three components:

1. a vacuum receiver element (VRE) for receiving radiation energy such as that from the sun.

2. a vacuum connector element (VCE) to connect the receiver elements together and to allow the exchange of high pressure and temperature medium.

3. a energy conversion unit (ECU) to convert thermal-energy into electricity and left over thermal- energy.

It is designed for roofing, cladding and paving purposes and can be installed by anyone without the need for specialized training. The following figures illustrate the main design features.

Figure 15 below shows an example of a SunTwig® layout that may be build around a square window opening and its details. Combining various lengths of the receiving elements with appropriate connectors provide the necessary configuration. Connectors, which are shown below the drawn in transparent cover plates, click and fit together to insure the pressure tight transport and exchange of the fluid medium between the elements.

Figure 15: Layout example.

Figure 16; variable length VRE

Figure 17; connector detail VRE with transparent cover for illustration purposes only

Figure 18; detail VRE; wherein Pos. nr. - Description:

13 - Absorber tube; 14 - Plate cover; 15 - adaptor; 16 - internal circlip; 17 - spring washer; 18 - Viton O-ring; 19 - Viton O-ring; 20 - EPDM rubber weather strip; 21 - EPDM rubber sealing chord; 22 - end cover VRE; 23 - extruded channel; 24 - high clarity low iron glass cover; 25 - absorber fin design.

Figure 19; Detail VRE; wherein Pos. nr. - Description:

20 - EPDM rubber weather strip; 21 - EPDM rubber sealing chord; 22 - end cover VRE; 24 - high clarity low iron glass cover; 25 - absorber fin design; 26 - mirror finish plate

The absorber fin design (pos. 25) is integrated with the absorber tube (pos. 13) which purpose it is to receive and convert radiation into thermal-energy and pass this on the fluid medium that flow inside the absorber tube. The shape of the fin design is specifically chosen to minimize radiation loss. Only the downward facing surface of the fin is blackened to receive the bulk of reflected radiation from the mirror component such that outgoing "blackbody" radiation is transmitted onto itself and recycled. Dependent on the direction of installation of the VRE, the absorber can also be pre-positioned or rotated to optimize its position towards the source of radiation whereby the design of the centre of rotation may be altered to suit.

The following figures 20 - 22 show more details of the VCE.

The purpose of the VCE is to provide a means of linking the pressure systems, namely the high pressure energy transportation system and the insulating vacuum system, and keeping them separate from each other.

The VCE is a connector which can be composed from a pool of 9 structural sub- elements to any configuration that is needed to connect the VRE to any layout. These sub-elements are, wherein each may have 2 or more exits/entrances at any side:

1. 2way inner tube; to transport the high pressure and temperature fluid medium

2. 3way inner tube; the same is before;

3. absorber connection tube; to connect absorbers from VRE's and allow rotational movement.

4. 2way outer tube; to position and contain the inner tube in a vacuum 5. 4way outer tube; same as before

6. male adaptor; to connect to the female adaptor and link VCE's lengthwise

7. female adaptor; to connect to the male adaptor and link VCE's lengthwise

8. end adaptor; to provide a pressure tight end cap for the VCE

9. connection tube; to connect the inner VCE tubes together through the inside of the male-female adaptors

Figure 20; dynamic 6way male-female connector (outer and inner tube are left transparent for illustration purposes)

Figure 21 ; static 4way male-female connector (outer and inner tube are left transparent for illustration purposes)

Figure 22; Detail VCE; wherein Pos. nr. - Description:

1 - absorber connection tube; 3 - inner tube; 6 - Viton O-ring; 7 - open metal spacer; 8 - outer tube; 9 - Viton O-ring; 10 - female adaptor; 1 1 - male adaptor; 12 - connection tube

Figure 23; Detail VCE; wherein Pos. nr. - Description:

1 - absorber connection tube; 2 - Viton O-ring; 3 - inner tube; 4 - Viton O-ring; 5 - external circlip; 8 - outer tube; 13 - absorber tube

Figure 24 shows an apparatus having a PV-layer on the inner surface of the insulation. The PV-layer has a thickness in the order of a few micrometer or less, depending of the specific layer. An advantage is that the PV-layer can be directly applied on the surface of the insulation, which may be a glass layer.

Figure 25 shows an apparatus having a PV-layer on a carrier, such as a silicon substrate, forming a separate element. An advantage of this configuration is that readily available solar-cell systems can be used.

Figure26 shows an apparatus having a PV-layer on an outside wall of the container, possibly on a carrier, such as a silicon substrate, forming a separate element. The PV-layer covers a substantial part of surface area available, which surface area is located inside the opening of the insulation. An advantage of this configuration is that readily available solar-cell systems can be used, and the cells can be manufactured relatively easy and at relative low costs.

Claims

1. Apparatus for conversion of radiation, wherein the radiation is preferably radiation emitted by the sun or reflected by the moon, characterized in that the apparatus is fixed on a surface, wherein the apparatus it suited for receiving the radiation, wherein the apparatus comprises a system for bundling the radiation,

wherein the apparatus optionally comprises one or more of a system for energy transport (a), a transparent protection (b), an encasement system (c) preferably comprising one or more of a cleaning system, such as a lens cleaning system, a sealing for the encasement, fixing means for the encasement system, means for rotating the apparatus or part thereof around a longitudinal axis thereof substantially in the direction of the sun, at least one reflecting internal surface, and a support system, wherein the encasement preferably is substantially free of air in use, a source tracking system (d) preferably comprising one or more of a servo drive, a positioning device, a computer, and software, an energy storage system (e) preferably selected from a storage system for heat and a storage system for electricity, an energy converter (f) selected from the group of a pressure to electricity converter, a heater, a process heater, and a central heating system, an energy management system (g), a PV layer (h) which layer is preferably applied to a surface of the container and/or which PV-layer is incorporated in a separate element, an absorber (i), a buffer — system (j), and a rotator (k).

2. Apparatus for conversion of radiation according to claim 1 , comprising a system for energy transport, which system comprises

a. a container for liquid transport, preferably a tube-like container,

wherein the insulation comprises an opening to allow entrance of a bundle of radiation, preferably a non-parallel bundle of radiation, preferably an opening extending substantially over a length of the container,

which opening is optionally covered by a material transparent for the radiation, and wherein the opening is smaller than 50% of the total area of the inner surface of the insulation, preferably smaller than 30% thereof, even more preferably smaller than 20% thereof, even more preferably smaller than 15% thereof, even more preferably smaller than 10% thereof, most preferably smaller than 5% thereof.

3. Apparatus according to claim 2, wherein the container comprises an entrance substantially aligned with the opening of the insulation, wherein the container comprises two or three substantially concentric walls, wherein the container preferably is a pre-form, wherein a space in between the walls is filled with the liquid, which liquid preferably has a high specific heat capacity (kJ/kgK), and/or which liquid has a melting point below - 10 C, preferably below -50 C, and a boiling point above 50 C, preferably above 90 C.

4. Apparatus for conversion of radiation according to claim 1 , comprising a transparent protection, which protection comprises a curved element having a certain refractive index, wherein an outer curve of the element is different from an inner curve of the element, such that a parallel bundle of radiation entering the protection at the outer curve thereof at a certain angle Θ exits the inner curve of the protection substantially parallel to the angle Θ.

5. Apparatus for conversion of radiation according to claim 4, comprising a transparent protection, having an outer curve of the element being substantially circular and an inner curve being elliptical-like, or vice versa.

6. Apparatus for conversion of radiation according claim 1 , comprising

a. a system for energy transport according to claim 2 or claim 3, comprising a container and an insulation,

b. a system for bundling radiation comprising one or more mirrors such as parabolic mirrors and/or one or more lens systems, and

7. Apparatus for conversion of radiation according to claim 6, wherein a concave parabolic mirror is substantially directed towards the sun or moon for bundling radiation, wherein a focus area of the bundled radiation is substantially inside the insulation,

optionally further comprising a convex parabolic mirror, wherein the convex mirror bundles radiation reflected from the concave mirror, and

optionally comprising a transparent protection comprising two or more transparent

_, elements, such that the protection functions as a lens.

8. Apparatus for conversion of radiation according to any of the preceding claims, comprising a transparent protection, which protection comprises a curved element having a certain refractive index, wherein the protection has a thickness varying stepwise over the curve thereof such that preferably a minimal thickness d_min of the protection is larger than 0.1 ^* a maximal thickness dmax, such that a parallel bundle of radiation entering the protection at an outer curve thereof exits an inner curve being focused.

9. Apparatus for conversion of radiation according to claim 1 , wherein the PV-layer forms one or more solar cells.

10. Apparatus according to claim 9, wherein the PV-layer is selected from the group comprising a lll-V layer, a single junction, a multiple junction, such as a 3-junction and a 4-junction, a concentrator layer, a high efficiency layer, a doped Si-layer, and combinations thereof.

1 1 . Apparatus according to any of claims 9-10, wherein the PV-layer comprises one or more of characteristics from the group consisting of a wide band gap, preferably a band-gap from 0.8-2 eV, at least one band gap widening element, and an alloy enhancer.

12. Apparatus for conversion of radiation according to claim 1 , in the form of one or more units, preferably with a unit length of 15-500 cm, more preferably 50-100 cm, wherein the one or more units can be removably attached to each other.

13 Construction element, such as a roofing, cladding, window, lighting, artistic application, comprising at least one apparatus, such as two or three, for conversion of radiation according to any of the previous claims.

14. Construction element according to claim 13, comprising one ore more connectors for connecting the apparatus of any of claims 1 -12 selected from the group consisting of a two way connector, a three way connector and a four way connector.

15. Click and fit modular building system comprising at least one apparatus according to any of claims 1 -12 and/or one or more construction elements according to any of claims 13-14 and/or one or more connectors for connecting the at least one apparatus and/or construction element.