Implementations of the disclosed subject matter may provide a method of receiving utility account information of an energy utility for a customer that is also enrolled with a community solar energy generating system. The customer may have a first account and a first allocation of energy with the community solar energy generating system. The address information for the customer is scraped from the received utility account information. When it is determined that the address information of the utility account is different from the address information of the first account, the customer may be enrolled a second account with the community solar energy generating system using the scraped address information. A second allocation of energy for the second account may be provided that is the same as the first allocation of energy from the community solar energy generating system, and the first account may be subsequently closed.

The present disclosure provides systems and methods for an operation of an electric power plant comprising a renewable energy resource and an energy storage device. The method may comprise determining, at a first time, a forecast of predicted energy production by the electric power plant over a time period subsequent to the first time based on a forecast for the time period; detecting a current state of charge of the energy storage device; calculating a range of automatic generation controls the electric power plant is capable of satisfying for the time period based on the forecast of predicted energy production and the detected current state of charge of the energy storage device; and signaling, from the electric power plant to a central utility controlling a power grid, the range of automatic generation controls the electric power plant is capable of satisfying for the time period.

In large PV power plants, grounding of individual PV modules may lead to problems. The present invention overcomes such problems. The basis for the invention is a PV power plant comprising one or more PV generators, each comprising a PV string and an inverter with a DC input and an AC output. The PV string comprises at least one PV module and is electrically connected to the DC input of the inverter. The inverter comprises means for controlling the DC potential at the DC input depending on the DC potential at the AC output. The AC outputs of the inverters are coupled in parallel. The novel feature of the invention is that the PV power plant further comprises an offset voltage source, which controls the DC potential at the AC outputs. Thereby, the DC potential at the DC input will be indirectly controlled, and it is thus possible to ensure that the potentials with respect to ground at the terminals of the PV modules are all non-negative or all non-positive without grounding the PV modules. Ground loops can be avoided, and there is no need for the use of transformer-based inverters.

A method and associated apparatus for feeding electric power from a photovoltaic system via a grid connection point into an AC grid having a low short-circuit power is disclosed. The method includes connecting a DC voltage side of at least one first inverter of the photovoltaic system to a photovoltaic generator and an AC voltage side of the at least one first inverter to the grid connection point, wherein the at least one first inverter is operated as a current source, and connecting an AC voltage side of a second inverter of the photovoltaic system to the grid connection point, wherein the second inverter is operated as a voltage source based on measurement values of an AC voltage measured in the region of the photovoltaic system and a predefined characteristic curve. For a first total short-circuit power of all first inverters operated as a current source, and a second total short-circuit power of the AC grid and of the second inverter operated as a voltage source, a ratio of the second total short-circuit power to the first total short-circuit power is greater than or equal to 2.

A management system includes a first receiver receiving, at a predetermined time interval, a reference value of a reference power meter, a second receiver receiving, at an interval shorter than the time interval, a first measurement value of a first power meter closer to a power system than a merging point of a power line connected to a distributed power supply and a power line connected to a load device, a third receiver receiving, at an interval shorter than the time interval, a second measurement value of a second power meter for measuring power consumption of the load device, and a controller executing a first calibration process related to the first power meter based on a comparison between the reference value and the first measurement value and subsequently executing a second calibration process related to the second power meter based on the first measurement value and the second measurement value.

Aspects of the present invention relate to a method of controlling a hybrid power plant connected to a power network. The hybrid power plant comprises at least two types of renewable energy generator having an active power reserve for supplying additional active power. The method comprises, during a frequency event detected on the power network: determining an additional amount of active power to be provided to the power network to provide fast frequency response; calculating, based on a preset configuration and the active power reserve of the generators, a contribution from each of the at least two types of generator for supplying the additional amount of active power; and generating and dispatching active power requests to the generators for supplying the additional amount according to the calculated contributions.

A method, an apparatus, and a system for monitoring an islanding electricity generation unit are provided. The method includes determining an islanding electricity generation unit in a renewable energy station on the basis of collected electrical capacity at critical electrical nodes of the renewable energy station, and controlling a switch device corresponding to the determined islanding electricity generation unit to sever connection between the electricity generation unit and a collector line. The critical electrical nodes include nodes that have a collecting effect on grid-connected current of the electricity generation units of the renewable energy station, and each collector line being constructed to collect grid-connected current from at least one electricity generation unit and input same into a main transformer of the renewable energy station.

An energy storage system converts variable renewable electricity (VRE) to continuous heat at over 1000° C. Intermittent electrical energy heats a solid medium. Heat from the solid medium is delivered continuously on demand. An array of bricks incorporating internal radiation cavities is directly heated by thermal radiation. The cavities facilitate rapid, uniform heating via reradiation. Heat delivery via flowing gas establishes a thermocline which maintains high outlet temperature throughout discharge. Gas flows through structured pathways within the array, delivering heat which may be used for processes including calcination, hydrogen electrolysis, steam generation, and thermal power generation and cogeneration. Groups of thermal storage arrays may be controlled and operated at high temperatures without thermal runaway via deep-discharge sequencing. Forecast-based control enables continuous, year-round heat supply using current and advance information of weather and VRE availability. High-voltage DC power conversion and distribution circuitry improves the efficiency of VRE power transfer into the system.

A serial-parallel converter protection system includes a controller, a drive, a first switching transistor, and a second switching transistor. An input terminal of a converter is connected to an output terminal of the converter through the first switching transistor. The output terminal of the converter is connected in parallel with the second switching transistor. When an output voltage of the converter is greater than a first threshold, the controller controls the first switching transistor to be turned off and controls the second switching transistor to be turned on. In some embodiments, when the output voltage of the converter is greater than the first threshold, the controller controls the first switching transistor to be turned off and controls the second switching transistor to be turned on, so that the converter is bypassed, thereby preventing a voltage and a current from impacting a component inside the converter.

Various implementations power homes and businesses without needing to connect to electric utility company-provided power, i.e., they can operate off-grid. Generally the system includes solar panel racks (e.g., photovoltaic cells on sheets stabilized using ballasts, anchors, or mounting) that generate electrical power used to provide power to a building or that is stored on batteries. The system includes the solar panel racks and an enclosure to be installed at the premises and separate from the building. The enclosure includes the batteries and inverters that are electronically connected to the solar panel racks and batteries. The inverters are configured to convert direct current (DC) electricity from the solar power racks and batteries to alternating current (AC) electricity to provide power to the building via wires electrically connecting the inverters to the main panel of the building.