AU2016101578A4

AU2016101578A4 - Renewable energy trading mechanism for embedded networks

Info

Publication number: AU2016101578A4
Application number: AU2016101578A
Authority: AU
Inventors: Craig A. Burton
Original assignee: Individual
Current assignee: Individual
Priority date: 2016-09-07
Filing date: 2016-09-07
Publication date: 2016-10-13
Anticipated expiration: 2024-09-07

Abstract

Innovation patent for behind-meter sharing Craig Burton craiggenerationshared.com +61 44 999 7617 Title: renewable energy trading mechanism for embedded networks Abstract A system or method is described that facilitates the self-consumption of generated renewable energy within an embedded type electricity network. The invention is a trading mechanism consisting of embedded controllers for solar energy inverters and batteries as well as load control of other kinds. The novel claims concern the centralised (remote) coordination of generation and loads so that excess renewable energy generation is consumed by loads. In addition, excess demands are met by discharging stored renewable energy from any generator on the embedded network. Generators in this application include energy storage mechanisms which the scheme also envisages remotely controlling. Dwelling N Dwelling M Check meter Cloud Curtai i DRE is -------------------------- balanced Feeds in among Polls all batteries for low SoC Turns on charge oad(s) systems and ----------- no energy is Imports curtailed to 111"", \ Nets off the public Credits at retail ate utility S 1 Debits at retail rjte --------------------------------------------- A dwelling has Importing a load when Imports there 'is no -------- Zl-- II No local local power or Reads meter power has exceeded Debits at retail Mte local energy Pays use retailer 4

Description

The current invention is a technical solution to the problem of excessive renewable energy generation being exported to the greater public utility network (“fed in") rather than being used locally, where it is generated. At present, a solar cell array on a home or other site will generate electricity which should be used immediately, or if it is not used, it is curtailed to the utility network or lost as heat. There is considerable interest presently and some uptake of domestic scale solar energy storage batteries. These are very expensive and have short life spans. The battery is used to store the solar energy that is not used. After dark, the battery is discharged and the electricity is used on site, rather then being exported.

Because different households or work places consume electricity according to different uses, life patterns or other activities, two sites generating electricity will consume differently, perhaps one site exporting proportionally more than the other. If the sites have batteries, they are likely to make differing use of battery capacity. It should be noted that if a site does not use the charge in its battery one day then the next day, excess energy generation is not used to charge that battery (because it is fully charged) and this energy may again be exported.

Changes in regulations and laws can allow one adjacent generation site to electrically connect to another; whether houses, flats, businesses or other sites. This means that in the example above, if one site has unused battery charge at the end of a day, that instead of curtailing the next day’s excess electricity generation to the utility, it could use it to help charge the battery of the first site, which has capacity to be charged. In this way, the total amount of energy curtailed to the network or lost as heat is reduced and the two sites enjoy increased "self-consumption” of generated power. Increased self-consumption is more economic than claiming feed-in tariffs for curtailed power because the retail energy rate is a lot higher than the average wholesale rate used to determine the feed in tariff.

The current invention is a means to interconnect and coordinate sites that would otherwise remain isolated from each other - the interconnect is specifically for sharing locally generated electricity. The current invention is comprised of the wiring or easement which is installed to provide a secondary or supplementary power source between sites, along with systems at each site to allow the site to participate on the private network and may include Internet accessible services to control or read the private network, potentially from "the cloud".

In this way, there is centralised control of all electricity generation and centralised control of all energy storage. The invention lays the foundation also for centralised control of consumer devices using the private network electricity such that, for example, at peak solar generation time, an energy intensive device is switched on automatically. This kind of control, called Demand Management (DM), is already a thriving field and is not a claim of this application. Instead the use of DM with the current invention is a new co-location of technologies that would, for example, allow an energy intensive device at one site able to be powered by available battery charge or solar power generation at a local, privately connected but separate site in a coordinated manner unique to the current invention.

There are related but different technologies that should be mentioned as they are not claimed by this application. They are 1. Local Electricity Trading (or Virtual Net Metering), secondary feed-in credit markets and other methods of sharing energy locally that occur via the utility network “poles and wires”. This approach differs from the current application because it relies on the public utility network whereas the current invention uses a “private wire” that can be utilised in addition to and instead of the public network. 2. Batteries installed on the utility network that are charged and discharged locally. In this design, a battery is installed on a local utility network that is charged by fed-in electricity and then discharges this electricity when demand or congestion are high. Again, this is a utility side invention that relies solely on the public utility. 3. Site systems that interact with the utility grid to buy and sell electricity, to stabilise network frequency or perform some other arbitrage or service to the public utility network. Since the current invention is a private network, it does not provide these services. However, it should be noted that since the current invention is not necessarily “off-grid” energy managed by the invention could indeed by used for interaction with the public utility but that is not a claim made in the present application. 4. There are services and devices that manage renewable energy systems so that, for example, batteries are charged off the grid at low tariffs and discharged in high tariffs; services that balance charging across multiple batteries and the like but these are intended for single renewable energy installations and as such as not systems that coordinate multiple consumers as well as the public utility grid.

The invention is a set of devices that operate at each energy consumer and each energy generator to balance these systems for • Optimal use of battery space • Optimal battery cycling • Best capture and use of disparate generators such as solar cells, windmills, water turbines or the like • Coordination of conventional assets such as inverters • Demand management across consumers and generators A simple instance of the invention could consist of 1. Two houses each with energy storage batteries and solar cell arrays 2. Each house is set up to use its own battery and solar array 3. Each house has an inverter 4. A private wire is run between the houses. This easement is connected to each house with an electricity controlling switching device 5. The switching device favours power from either the local PV array, the private network or the utility grid in that order of precedence. 6. If there is no solar energy being generated, the relay will direct power from the sharing network to the house. If no power is available from this sharing network then the relay favours the utility grid 7. The local house uses excess solar power to energise the shared network. 8. The control system of the current invention supplies the second house, or if there is excess generation, the batteries at either or both houses are charged. 9. This control may be achieved by example with Modbus controllers attached to the inverters of each house 10. The Modbus controller is a device that can be made with a microcontroller that can interface to the inverter via the Modbus language or similar control language. 11. The controller is itself remotely controlled via the Internet. 12. This remote control is the basis of having the Modbus controllers drive the inverters to perform charge, discharge so that the private energy sharing network is energised for sharing the energy 13. The Modbus controllers are under control via a centralised service (perhaps via the Internet] to enforce rules over the volume of shared energy. For example a rule may assert that each house has 24 hours to consume 50% of all renewable energy in all batteries as at 2pm. This rule will prevent a greedy household from taking more energy than is fairly shared. 14. Other rules can divide up generated power unevenly as the participants may favour. This might include a 60/40 balance, a fixed kWh allocation of generated power or the use of low-tariff grid energy to keep batteries at a minimum charge at all times. 15. The rules form the basis of benefits such as a. High levels of self-consumption of locally generated energy b. Participants incentivised to install more solar panels on their own roofs to benefit the network c. Cycling of batteries to extend their lifespan: batteries can be individually fully emptied before another battery on the network is fully emptied. Certain battery chemistries work better if batteries are fully cycled (such as Lithium] and others with 10% discharge (such as Lead]. d. Participants can purchase smaller batteries and enjoy the benefits comparable to larger or more expensive batteries not shared e. Potential reduction in the number of grid connections.

Participants that find they can rely 100% on their own renewable energy generation and that of the sharing network can disconnect from the utility grid. Other participants can be controlled to still keep all batteries at a minimum charge via the remaining utility grid connections f. The system can keep track of power generation and use and exeute a billing or credit mechanism solely among the participants or with the inclusion of the utility grid retailer so that grid costs are divided up correctly.

Claims

Claims

1. A method and/or system of technical control of renewable energy generators, storage devices, switching devices or other production systems (generators) and of one or more consumer loads - which can cause one or more generators to generate and one or more loads to consume simultaneously or otherwise closely coordinated.
2. The claim of 1 to include automated or manual controls, remote control via the Internet or other forms of remote control such as by software, services or hardware.
3. The claim of 1 such that the method of control can define that generators include energy storage devices that should charge or discharge. These storage devices may be batteries
4. The claims of 1 such that the method of control can define that the load is served by local energy generation; locally stored energy; energy from the public utility grid; or, energy from a private cable connected to another generator under control of the invention.
5. The claim of 4 defining a private cable or interconnection such that the control mechanism of 1 is installed at all consumers connected via this private cable and the private cable is used for the exchange of energy
6. The claim of 4 to include embedded networks or microgrids as a means of energy exchange - being conventional private networks that may be grid tied and typically involve electricity submeters within and a check meter at the connection to the utility.
7. The claim of 2 such that a service running on a remote computer server or servers accesses the controllers of claim 1 remotely (possibly via the Internet) and executes rules, algorithms or sequences to bring about control of the generators and loads
8. The claim of 7 such that rules, algorithms or sequences define one or more loads under the control of the system of claim 1 consume stored electricity from a separate but connected generator
9. The claim of 7 such that rules, algorithms or sequences define how two or more participants under control of the invention charge or discharge local batteries
10. The claim of 7 such that rules, algorithms or sequences define how one or more participants under control of the invention consume or curtail energy to or from one or more public utility grid connections
11. The claims of 7-10 such that rules, algorithms or sequences define how two or more participants under control of the invention shall take part in a trade wherein one a load is coordinated to consume the energy provided by a generator with a form of accounting of the energy exchanged in view to a billing or credit exchange arrangement.
12. The collective system of claims 8-11 such that if the utility grid fails to provide energy that the system can supply all consumers
13. The collective system of claims 8-11 such that locally generated or stored energy can be traded with the utility network retailer, the National Energy Market or another energy trading platform
14. The collective system of claims 8-11 such that locally generated or stored energy can be used for other network services such as frequency control, power conditioning, load, congestion reduction, removal of brown-outs, supply or any other services.