JPH1126799A - Solar lighting apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a solar lighting apparatus which avoids deteriorating the generating efficiency of a solar cell panel due to contamination or deposits and suppresses the reduction of the generation power in a time zone with low elevation angles of sun. SOLUTION: The apparatus comprises illumination prisms 20a, 20b, rotary drive for driving the prisms, a solar cell panel 32 to be a power feed source for this drive, controller for controlling the drive for an adequate rotation angle according to the location of the sun, an inner frame 12 for housing and supporting the prisms and drive, and a cover 49 for covering the prisms with the panel 32 mounted in the cover 49 such that panel 32 pref. locates near a north-east or north-west corner of the square frame 12 at a northern hemispherical area and near a south-east or south-west corner at a southern hemispherical area.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sunlight collecting device for guiding sunlight into a room, and more particularly to an improvement in a mounting position of a solar cell panel serving as a power supply source for a rotary driving device of a lighting prism.

[0002]

2. Description of the Related Art A sunlight collecting device is a device which can always collect sunlight at a suitable angle by controlling a rotation position of a lighting prism according to the altitude and azimuth of the sun. A conventional solar lighting device will be described with reference to FIG. In the figure, 1 is the roof of the building, 2a
Reference numerals 2d to 2d denote building walls. 3a and 3b are windows, and 4 is an electric light provided in a room of the building. Reference numeral 5 denotes a conventional sunlight lighting device, and reference numeral 6 denotes a duct that guides sunlight extracted by the sunlight lighting device 5 to a room. Further, reference numeral 20 denotes a daylighting prism which is a main component of a daylighting unit of the sunlight daylighting device 5. In the above-described configuration, sunlight is collected by the sunlight collecting device 5 and guided to the room through the duct 6.
Therefore, by using the sunlight collecting device 5, in a general residential house, sunlight can always be collected at a suitable angle in the daytime, so that lighting equipment is unnecessary or weak lighting is sufficient, which contributes to energy saving. On the other hand, since natural light can always be irradiated to a plant at a suitable angle, application to a plant plant has also been attempted, and certain results such as promotion of growth or improvement of taste have been obtained.

[0003] A daylighting prism 2 provided in a daylighting section.
0 is described in, for example, JP-A-61-18.
A configuration as described in Japanese Patent No. 0217 is known. As disclosed in the publication, as shown in FIGS. 4 (A) and 4 (B), a transparent plate having fine irregularities for performing a prism action on its surface, a so-called prism plate (Fresnel prism)
By rotating at least one of the prism plates P1 (or P2) in a state where two sheets of P1 and P2 are stacked,
It is configured to send direct rays of light from the sun in a fixed direction regardless of the position of the sun.

Further, FIG. 5 shows a specific configuration of a conventional solar lighting device, including a rotation driving device of the lighting prism and a solar cell panel serving as a power supply source of the rotation driving device.
This will be described with reference to (A) to (C). In FIG. 5, FIG. 5A is a plan view of a conventional solar lighting device 5, and FIG.
2 is a front view, and FIG. 1C is an enlarged side view of a main part near a solar cell panel. 14A and 14B, reference numeral 30 denotes a rotation driving device for the lighting prism, 31 denotes a holding device for the lighting prism, 25 denotes a light distribution plate, 12 denotes an inner frame (frame), 13 denotes an inner frame structure, and 14 denotes a light source. Denotes an outer frame, and 49 denotes a dome-shaped transparent cover.

[0005] The sunlight radiated to the two lighting prisms 20a and 20b arranged at a predetermined interval is guided into the building room through the light distribution plate 25 at a suitable angle by the lighting prisms 20a and 20b. Is done. Daylighting prism 2
Although not shown, the rotary drive device 30 of 0a and 20b includes a drive roller, an electric motor, a control device for controlling the electric motor,
And a setting device for giving a control command to the control device. First, a detection output from a sunlight condition detecting device (not shown) for detecting a condition such as altitude and direction of the sun is given to the setting device. . Next, in response to a drive command of the setting device, the drive roller is rotated via a motor by a control signal of the control device, and the rotational position of the light-receiving prisms 20a and 20b is always set to a position where sunlight can be collected at a suitable angle. It is adjusted to become. At this time, the power supply source for driving the electric motor is the solar cell panel 7.

The holding device 31 for the daylighting prisms 20a and 20b includes a plurality of pressing rollers (not shown).
b is rotatably supported. In addition, as shown in FIG. 5A, in the conventional solar lighting device 5, the solar cell panel 7 is installed outside the transparent cover 49 so that power can be generated by the direct light of sunlight in consideration of power generation efficiency. Have been. Further, in order to prevent the daylighting prisms 20a and 20b from obstructing the daylighting, in the middle and high latitude regions of the Northern Hemisphere, as in Japan, sunlight shines from the south side all day long in the daytime, as shown in FIG. The solar cell panel 7 is attached to the southern part of the outer frame 14 for a skylight via a solar cell panel receiving base 15 at an appropriate angle so that sunlight can be received to the maximum. In this configuration, a method is adopted in which the amount of power generated by the solar cell panel 7 during the daytime is increased, the driving power of the daylighting prisms 20a and 20b is stored in a battery (not shown), and a decrease in power supply capacity in morning and evening when the solar altitude is low is adopted. ing.

[0007]

The above-mentioned solar lighting apparatus is usually installed outdoors such as on the roof of a building. Therefore, for example, the solar cell panel becomes dirty due to wind and rain or feces such as birds. In some cases, deposits such as leaves and fallen leaves may adhere. If the dirt and attached matter on the solar cell panel are left unattended, the sunlight will be blocked, and the power generation efficiency of the solar cell panel will be reduced, which may hinder the operation of the solar lighting device. In addition, in consideration of the adhesion of the dirt and deposits, if a large area of the solar cell panel is secured in advance so as to give a margin to the power generation capacity,
There is a problem that the manufacturing cost of the solar lighting device increases. In addition, as described above, since the solar lighting device is usually installed outdoors such as a building roof, it is difficult to perform maintenance work such as removing dirt and attached matter, and performing regular maintenance is difficult. If this is the case, there is a problem that the maintenance cost of the sunlight collecting device increases.

On the other hand, in the conventional solar lighting apparatus, when mounting the solar cell panel, an outer frame is installed on the skylight of the building, a mounting hole is opened in the outer frame, and the solar cell panel is mounted. However, there has been a demand for a solar lighting device that does not require such complicated installation work and has higher installation efficiency. Further, due to a demand for a reduction in the manufacturing cost of the solar lighting device, there is a demand for a solar lighting device in which the area of a solar cell panel used for power supply is reduced and a battery is unnecessary or a small-capacity battery is used. However, when the configuration is such that the battery is excluded or the capacity is reduced and the solar cell panel is reduced in this manner, the power generation capacity of the solar cell panel is reduced particularly in morning and evening when the solar altitude is low. That is, in the conventional solar lighting device, as described above, the solar cell panel is mounted at a certain angle inclined from the horizontal plane facing south, so that the amount of power generated during the day is increased, and the driving power of the lighting prism is supplied to the battery. Was used to compensate for the decrease in power supply capacity in the morning and evening. However, if the area of the solar panel was reduced as described above and the battery was not used or the capacity was reduced, the power generation capacity in the morning and evening was reduced. As a result, a problem arises in that the lighting prism cannot be driven. SUMMARY OF THE INVENTION The present invention provides a solar lighting device that prevents a decrease in power generation efficiency due to the adhesion of dirt and deposits on a solar cell panel, and also suppresses a decrease in power generation capacity in a time zone when the solar altitude is low.

[0009]

According to a first aspect of the present invention, there is provided a sunlight collecting apparatus, comprising: a light collecting prism disposed at a light collecting section; A plurality of lighting prisms arranged apart from each other, a rotary driving device for driving these lighting prisms, a solar cell panel serving as a power supply source of the rotary driving device, and an appropriate rotation of the lighting prism according to the position of the sun A control device for controlling the rotary driving device so as to form an angle, a frame body for housing and supporting the lighting prism and the driving device, and a solar lighting device including a cover for covering the lighting prism; It was configured to be installed inside.
By doing so, the solar cell panel is housed inside the cover, so that the incident efficiency of sunlight is slightly reduced. However, it is possible to prevent a decrease in power generation efficiency due to dirt and attached matter. Specifically, the power generation efficiency of the solar cell panel can be improved. Also, by mounting the solar cell panel inside the cover, the work of opening the mounting hole in the outer frame and mounting the solar cell panel, which was necessary when mounting the solar cell panel to the solar lighting device, is eliminated. The work efficiency of the installation work of the light collecting device is improved. Furthermore, since the work of attaching the solar cell panel to the outer frame is eliminated, and the outer frame manufactured in large quantities can be used as it is, it is possible to reduce the manufacturing cost of the solar lighting device.

[0010] In the solar lighting device according to the second aspect, one lighting prism disposed in the lighting portion or a plurality of lighting prisms arranged at a predetermined interval, and a rotation for driving these lighting prisms. A driving device, a solar cell panel serving as a power supply source of the rotation driving device, a control device for controlling the rotation driving device so that the lighting prism has an appropriate rotation angle according to the position of the sun, a lighting prism and a driving device And a dome-shaped cover that covers the daylighting prism, wherein the solar cell panel rotates the square frame inside the dome-shaped cover. It was configured to be mounted near the corner near the drive unit. In this way, by installing the solar cell panel inside the dome-shaped cover, it is possible to eliminate the influence when the lighting prism takes in sunlight, and the cover itself becomes dirty or adhered. In this case, the influence of the shadow created by these components on the solar cell panel can be minimized. Furthermore, by making the cover a dome shape, the distance between the attached matter and the solar cell panel can be increased as compared with the case where the cover is flat, and the shadow of the attached matter is less likely to hit the solar cell panel. The shadows are thinner and more effective. As a specific mounting position, when the solar cell panel is installed in the northern hemisphere area, as described in claim 3, the solar cell panel is mounted near the northeast or northwest corner of the rectangular frame inside the cover. In this case, the solar cell panel may be mounted near the southeast or southwest corner of the rectangular frame inside the cover.

According to a fifth aspect of the present invention, there is provided a daylighting apparatus, wherein one daylighting prism disposed in the daylighting section or a plurality of daylighting prisms arranged at a predetermined interval, and a rotation for driving these daylighting prisms. A driving device, a solar cell panel serving as a power supply source of the rotation driving device, a control device for controlling the rotation driving device so that the lighting prism has an appropriate rotation angle according to the position of the sun, a lighting prism and a driving device In a solar light collecting device provided with a frame for housing and supporting the light collecting prism and a cover for covering the light collecting prism, the solar cell panel is mounted inside the cover so as to be substantially horizontal. In this way, the power required to drive the lighting prism can be sufficiently generated even in a low solar altitude time period such as morning and evening, so that a battery is unnecessary or a small capacity can be obtained, and the solar cell panel itself can be formed. Can be reduced in size, and therefore, the manufacturing cost of the solar lighting device itself can be reduced.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of a solar lighting device according to the present invention will be described with reference to FIGS. 1 (A) and 1 (B) and FIGS. 2 (A) and 2 (B). FIG. 1 is a diagram showing a schematic configuration of a solar lighting device 40 of the present invention, wherein FIG. 1A is a plan view and FIG.
Is a longitudinal sectional front view. FIG. 2 is a diagram showing the effects of the shadows S1 and S2 on the solar cell panel 32 due to the deposit F.
FIG. 6A is a vertical sectional front view showing a case where the attached matter F adheres to the south side of the transparent cover 49, and FIG. FIG. 1 (A),
As shown in (B), the main configuration of the sunlight collecting device 40 of the present invention may be the same as the conventional sunlight lighting device 5 shown in FIG. The solar panel 7 attached to the outside of the transparent cover 4
9 is characterized by its configuration. Therefore, the same components as those of the conventional solar lighting device 5 are denoted by the same reference numerals, and description thereof will be omitted.

As described above, in the conventional solar lighting device 5 shown in FIG. 5, the solar cell panel 7 is provided outside the transparent cover 49 so that power can be generated by the direct light of sunlight in consideration of power generation efficiency. In addition, it is attached to the south side of the outer frame 14 at an appropriate angle from the horizontal plane. On the other hand,
1 (A) and 1 (B), a solar lighting device 40 of the present invention.
Then, the solar cell panel 32 is placed inside the transparent cover 49,
Moreover, in the middle and high latitude regions of the Northern Hemisphere as in Japan, the inner frame (frame body) 12 is mounted almost horizontally near the northeast or northwest corner (in the illustrated example, the northwest corner). When the solar cell panel 32 is configured to be mounted inside the transparent cover 49 in this manner, first, the transparent cover 49
Since the solar cell panel 32 is stored inside the solar cell panel, the solar cell panel 32 is not directly contaminated or adhered, so that it is possible to prevent a decrease in power generation efficiency caused directly by these. Next, even if the attached matter adheres to the transparent cover 49 and casts a shadow on the solar cell panel 32 with the movement of the sun on the solar cell panel 32, there is a gap between the attached matter and the solar cell panel 32. Since there is a distance, sunlight is less affected by the shadow of the deposit on the solar cell panel 32 due to the effect of diffusion and light diffraction by the scattering phenomenon of air molecules. In addition, since there is a certain distance between the transparent cover 49 and the solar cell panel 32, the probability that the shadow of the attached matter hits the solar cell panel 32 is reduced. By making the transparent cover 49 in a dome shape, the distance between the attached matter and the solar cell panel 32 can be increased as compared with the case where the transparent cover is formed in a flat shape,
The shadow of the attached matter hardly hits the solar cell panel 32, and the shadow becomes thinner, which is more effective.

Further, when the solar cell panel 32 is mounted near the northeast or northwest corner (the northwest corner in the illustrated example) of the inner frame (frame) 12 as described above, as shown in FIG. In the middle and high latitudes of the Northern Hemisphere (northern than the Tropic of the Tropics), sunlight L is radiated from the south side during the daytime throughout the day. Since the path of S1 and S2 becomes longer,
The effect of the diffusion and the light diffraction of the sunlight L is further increased, and the influence of the shadows S1 and S2 of the attached matter on the power generation efficiency of the solar cell panel 32 is further reduced. 2 (A) and 2 (B), S1 indicates a main shadow portion of the attached matter F, and S2 indicates a penumbra portion of the attached matter F. When the attached matter F adheres to the north side of the transparent cover 49, the distance from the attached matter F to the solar cell panel 32 is short, as shown in the vertical front view of the sunlight collecting device 40 in FIG. However, since the sunlight L is constantly radiated from the south side, the projected area on the solar cell panel 32 formed by the shadows S1 and S2 of the attached matter F is small.
The influence of the shadows S1 and S2 on the power generation efficiency of the solar cell panel 32 can be reduced. Therefore, when the solar cell panel 32 is mounted near the northeast or northwest corner of the inner frame (frame body) 12, the solar cell panel 32 due to the attachment F
This has the effect of further reducing the effect on

Further, the solar cell panel 32 is attached to the transparent cover 4.
By installing the solar cell panel 32 inside the building, the work of opening the mounting hole in the outer frame 14 and mounting the solar cell panel 32, which was necessary when mounting the solar cell panel 32, becomes unnecessary. The work efficiency of the mounting work on the solar cell panel is improved, and the solar cell panel 32 is disposed inside the transparent cover 49 having relatively high strength. It is hard to be damaged. Furthermore, since the work of attaching the solar cell panel 32 to the outer frame 14 is eliminated, the outer frame 14 mass-produced can be used as it is,
It is possible to reduce the manufacturing cost of the solar light collecting device 40.

On the other hand, as described above, in the conventional solar lighting device 5 shown in FIG. 5, the solar cell panel 7 is mounted at a certain angle inclined from the horizontal plane toward the south, thereby increasing the amount of power generated during the day. And the lighting prism 20
a, 20b of driving power is stored to compensate for a decrease in power supply capability in the morning and evening. On the other hand, in the solar lighting device 40 of the present invention shown in FIG. 1, the solar cell panel 32 is attached so as to be substantially horizontal. By doing so, it is possible to generate enough power to drive the daylighting prisms 20a and 20b for tracking the sun even in a time zone where the sun altitude is low, such as in the morning and evening, so that a battery is unnecessary or a small capacity is required. It is possible to reduce the size of the solar cell panel 32, and therefore, it is possible to reduce the manufacturing cost of the solar light collecting device 40.

The solar lighting device of the present invention is not limited to the above embodiment. For example, in the above-described embodiment, the configuration in which one solar cell panel is attached to the inside of the transparent cover of the solar light collecting device has been described. However, depending on the required area of the solar cell panel, the solar cell panel is divided into two or more sheets. Of course, the present invention also includes a solar lighting device configured to be mounted near corners (specifically, for example, northeast and northwest corners) of two or more inner frames. Also, the case has been described in which the lighting prism is indirectly driven by the rotary driving device via the rotating ring, but the lighting prism may be directly driven by the rotary driving device.

Furthermore, in the above-described embodiment, the case where the solar lighting device of the present invention is used in the middle and high latitude regions of the Northern Hemisphere has been described. A lighting device is applied. For example, in the mid- and high-latitude regions of the Southern Hemisphere (south of the Tropics), sunlight is radiated from the north side during the day, and so in such regions (eg, most of Australia, New Zealand, Argentina, South Africa, etc.). In the case where the light collecting device is installed, the solar cell panel may be attached near the southeast or southwest corner of the inner frame (frame). On the other hand, in low-latitude regions (for example, Southeast Asia, parts of Central and South America, and central Africa) sandwiched between the tropic and tropic lines, sunlight shines vertically from the north, south, or from the top depending on the season. The same effect as described above can be obtained by attaching to any corner of the inner frame (frame) in consideration of other seasonal factors such as the dry season and the rainy season.

[0019]

The solar lighting device of the present invention has the following excellent effects because it is constructed as described above. (1) By adopting a configuration in which the solar cell panel is attached to the inside of the transparent cover, the solar cell panel is housed inside the transparent cover, so that there is no direct contamination or adhesion of attached matter. Therefore, it is possible to prevent a decrease in power generation efficiency due to the above. (2) By mounting the solar cell panel inside the transparent cover, a hole for mounting the solar cell panel is formed in an outer frame, which is necessary when the solar cell panel is mounted on the solar lighting device, and the solar cell panel is mounted. The work is eliminated, and the work efficiency of the installation work of the solar lighting device is improved. (3) Further, since the work of attaching the solar cell panel to the outer frame is eliminated, and the outer frame manufactured in large quantities can be used as it is, it is possible to reduce the manufacturing cost of the solar lighting device. (4) By installing the solar cell panel near the corner of the inner frame (frame) as in the solar lighting device according to claim 2, the solar cell panel is installed inside the transparent cover. In addition to eliminating the effect of the lighting prism when collecting sunlight, if the transparent cover itself becomes dirty or adheres, the effect of these shadows on the solar cell panel on the power generation efficiency is minimized. Can be reduced. (5) Also, by making the transparent cover into a dome shape,
The distance between the attached matter and the solar cell panel can be increased as compared with the case where the transparent cover has a flat shape, and the shadow of the attached matter hardly hits the solar cell panel, and the shadow becomes thinner, which is more effective. (6) As a specific mounting position, when the solar cell panel is installed in the northern hemisphere area, as described in claim 3, the solar cell panel is installed near the northeast or northwest corner of the rectangular frame, and installed in the southern hemisphere area. In this case, as described in claim 4, when the solar cell panel is mounted near the southeast or southwest corner of the frame, the above (1) is achieved.
The effects described in (4) to (4) can also be obtained in the northern hemisphere area and the southern hemisphere area. (7) When the solar battery panel is mounted so as to be substantially horizontal as in the solar lighting device according to the fifth aspect, it is necessary to drive the lighting prism even in a time zone where the sun altitude is low such as morning and evening. Since sufficient power can be generated, a battery is unnecessary or small in capacity, and the size of the solar cell panel itself can be reduced, so that the manufacturing cost of the solar lighting device itself can be reduced. Become. (8) Further, as in the prior art, when the solar cell panel is mounted at a predetermined inclination angle, a high-precision mounting position and the inclination angle of the solar cell panel plate are required for installation of the solar lighting device. However, when the solar cell panels are mounted so as to be substantially horizontal as described in claim 5, the mounting work does not have to be as high as in the past, and the mounting work becomes easier.

[Brief description of the drawings]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a view showing an embodiment of a solar lighting device according to the present invention, wherein FIG. 1 (A) is a plan view and FIG. 1 (B) is a longitudinal sectional front view.

FIGS. 2A and 2B are diagrams showing the influence of a shadow on a solar cell panel due to a deposit. FIG. 2A shows a case where the deposit adheres to the south side of the transparent cover, and FIG. It is a vertical front view which shows the case where it did.

FIG. 3 is a schematic vertical sectional front view showing one application example of a conventional solar lighting device.

4A and 4B are diagrams showing a basic configuration of a conventional daylighting prism, wherein FIG. 4A is a perspective view and FIG. 4B is a longitudinal sectional front view.

5 (A) is a plan view, FIG. 5 (B) is a front view, and FIG. 5 (C) is a photovoltaic cell showing a configuration of a conventional solar lighting device provided with a solar cell panel plate. It is a principal part enlarged side view near a panel.

[Explanation of symbols]

 12: Inner frame (frame) 20a, 20b: Daylighting prism 30: Rotary drive device 32: Solar cell panel 40: Sunlight daylighting device of the present invention 49: Transparent cover

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Tetsuo Miyamoto 2-5-5 Keihanhondori, Moriguchi-shi, Osaka Sanyo Electric Co., Ltd. (72) Inventor Masanobu Numa 2-5-2 Keihanhondori, Moriguchi-shi, Osaka No. 5 Sanyo Electric Co., Ltd.

Claims (5)

[Claims] 1. A single daylighting prism or a plurality of daylighting prisms arranged at a predetermined interval in a daylighting unit, a rotation driving device for driving these daylighting prisms, and power supply of the rotation driving device A solar cell panel serving as a source, a control device for controlling the rotation driving device so that the lighting prism has an appropriate rotation angle according to the position of the sun, a frame housing and supporting the lighting prism and the driving device, and the lighting A solar lighting device comprising a cover for covering a prism, wherein the solar cell panel is mounted inside the cover. 2. A single daylighting prism or a plurality of daylighting prisms arranged at a predetermined interval in a daylighting unit, a rotation driving device for driving these daylighting prisms, and power supply of the rotation driving device A solar cell panel serving as a source, a control device that controls the rotation driving device so that the lighting prism has an appropriate rotation angle according to the position of the sun, a rectangular frame that stores and supports the lighting prism and the driving device, And a solar lighting device provided with a dome-shaped cover that covers the lighting prism, wherein the solar cell panel is mounted near a corner near the rotary drive device of the rectangular frame inside the dome-shaped cover. A solar lighting device characterized by the above-mentioned. 3. A single daylighting prism or a plurality of daylighting prisms arranged at a predetermined interval in a daylighting unit, a rotation driving device for driving these daylighting prisms, and power supply of the rotation driving device A solar cell panel serving as a source, a control device that controls the rotation driving device so that the lighting prism has an appropriate rotation angle according to the position of the sun, a rectangular frame that stores and supports the lighting prism and the driving device, And, in a solar lighting device provided with a cover that covers the lighting prism, when the installation location of the solar lighting device is in the northern hemisphere region, the solar cell panel is located in the northeast of the rectangular frame inside the cover or A solar lighting device installed near the northwest corner. 4. A single lighting prism or a plurality of lighting prisms arranged at predetermined intervals in a lighting unit, a rotation driving device for driving these lighting prisms, and power supply of the rotation driving device A solar cell panel serving as a source, a control device that controls the rotation driving device so that the lighting prism has an appropriate rotation angle according to the position of the sun, a rectangular frame that stores and supports the lighting prism and the driving device, And in a solar lighting device provided with a cover that covers the lighting prism, when the installation location of the solar lighting device is in the southern hemisphere region, the solar battery panel is located southeast of the rectangular frame inside the cover or A solar lighting device installed near the southwest corner. 5. A single lighting prism or a plurality of lighting prisms arranged at predetermined intervals in a lighting unit, a rotation driving device for driving these lighting prisms, and power supply of the rotation driving device A solar cell panel serving as a source, a control device for controlling the rotation driving device so that the lighting prism has an appropriate rotation angle according to the position of the sun, a frame housing and supporting the lighting prism and the driving device, and the lighting A solar lighting device comprising a cover for covering a prism, wherein the solar cell panel is mounted inside the cover so as to be substantially horizontal.