Methods and arrangements for controlling the reactive power of a power generator from an initial reactive power state to a desired reactive power state are disclosed. The power generator belongs to a power farm coupled to an electrical grid. During a transition state, changes in voltage and reactive power demand are detected and control of reactive power is passed from the power farm to the power generator controller, then to a transition controller and finally back to the power farm. The power generator may be a wind turbine and the power farm a wind farm.

According to an embodiment, energy management system includes client and server. Server includes acquisition unit, estimation unit, calculator and controller. Acquisition unit acquires data concerning electrical equipment in a building including a storage battery from client. Estimation unit estimates energy demand and energy generation amount in building based on the data. Calculator calculates, based on the energy demand and the energy generation amount, operation schedule of the electrical equipment to optimize energy balance in building under a constraint that minimizes dump power to be discarded after storage battery is fully charged. Controller creates control information to control electrical equipment based on operation schedule.

An apparatus operation plan creation device according to an embodiment includes a power generation quantity predictor, a power demand predictor, a hot water demand predictor, an estimator, a decider, a calculator, and a plan creator. The power generation quantity predictor predicts a quantity of power generation. The power demand predictor predicts a quantity of power demand. The hot water demand predictor predicts a quantity of hot water demand. The estimator estimates a quantity of power generation by a fuel cell based on a predicted value of a quantity of hot water demand. The decider decides a quantity of power storage of a storage battery. The calculator calculates a power storage loss and a power purchase loss based on a predicted value of a quantity of power generation, a predicted value of a quantity of power demand, and a quantity of power storage of a storage battery, and calculates a deduction amount that is obtained by subtracting the sum of the power storage loss and the power purchase loss from a power sales profit that is based on the quantity of power generation. The plan creator creates a threshold value for defining a charging or discharge operation of the storage battery and a plan for an operation or stop operation of the fuel cell such that the deduction amount is increased.

A control system for a solar power plant includes: plural power conditioning systems performing grid connection control of transmission of electrical power generated by a solar power generator to a power grid; and a supervisory controller which issues a target output command to each power conditioning system so that interconnection point electrical power, electrical power fed to the power grid, becomes equal to or smaller than an upper limit output value. The supervisory controller: receives an urgent request including information related to a time of day at which the upper limit output value is scheduled to be changed and the scheduled upper limit output value; and calculates a target value of the interconnection point electrical power for each time of day so that the interconnection point electrical power conforms to the scheduled upper limit output value by the scheduled time of day.

A power generation amount prediction apparatus includes a first detector, acquisition unit, database, and controller. The first detector detects a measured value of the power generation amount of a photovoltaic power generation device. The acquisition unit acquires a predicted value of the power generation amount by the photovoltaic power generation device at specific times. The database stores the measured value and the predicted value for each of the specific times for a plurality of days. The controller calculates a corrected predicted value for each of the specific times based on a maximum measured value, a maximum predicted value, and a predicted value newly received by the acquisition unit. The maximum measured value and the maximum predicted value are respectively the maximum value, for each of the specific times, of the measured value and of the predicted value for a predetermined number of days.

Systems and methods are provided for intelligent energy source monitoring and selection control to enable power delivery in a multi-modal energy system. A multi-modal energy system includes a control system, power supply systems, and an electrical distribution system. The power supply systems are coupled to the control system. The power supply systems include a mains utility power system and at least one renewable power system. The electrical power distribution system is coupled to the control system. The control system is configured to monitor each power supply system to determine a power availability of each power supply system, determine an amount of power usage by the electrical power distribution system, and selectively connect and disconnect one or more of the power supply systems to the electrical power distribution system based on the determined power availability of the power supply systems and the determined power usage of the electrical power distribution system.

An energy storage system (ESS) includes a battery pack, a power converter, a battery management system (BMS) configured to control and monitor, in real time, the battery pack, a load power controller coupled to the battery pack and an external power source, connected to loads, and an integrated controller configured to control an operation of each component, determine an exclusive supply initiation time based on energy management schedule information including the exclusive supply initiation time, an exclusive supply termination time, and power supply timing information, control power to be supplied to the loads exclusively using power of the battery pack at the exclusive supply initiation time, and, when a current residual charge amount of the battery pack is at least one residual charge amount in the power supply timing information, control power supply to one of the loads set to correspond to the residual charge amount to be cut.

A photovoltaic system with an inverter, at least one solar panel for providing electrical power, and electrical wiring for coupling electrical power from the at least one solar panel to the inverter. Also included is a transmitter for transmitting a messaging protocol along the electrical wiring, where the protocol includes a multibit wireline signal. Also included is circuitry for selectively connecting the electrical power from the at least one solar panel along the electrical wiring to the inverter in response to the messaging protocol.

A method and a device to heat water in an electrical boiler are disclosed. The method include the steps of storing user's requests of hot water in association with corresponding times of requests, heating water in advance to a next user's request, wherein the next user's request is estimated on the stored user's requests. The device is the hardware implementing the method.

Systems and methods are provided for intelligent energy source monitoring and selection control to enable power delivery in a multi-modal energy system. A multi-modal energy system includes a control system, power supply systems, and an electrical distribution system. The power supply systems are coupled to the control system. The power supply systems include a mains utility power system and at least one renewable power system. The electrical power distribution system is coupled to the control system. The control system is configured to monitor each power supply system to determine a power availability of each power supply system, determine an amount of power usage by the electrical power distribution system, and selectively connect and disconnect one or more of the power supply systems to the electrical power distribution system based on the determined power availability of the power supply systems and the determined power usage of the electrical power distribution system.