The disclosed technology includes an on-demand water heater which uses an electric heat source to heat the water. The on-demand water heater can have a low fluid capacity heating chamber which has an inlet and an outlet, an electric heat source for heating the water, and a controller to control the electric heat source and maintain the temperature of the water at a predetermined temperature setting. The on-demand water heater can be powered by a direct current power source. The on-demand water heater can also utilize a solar thermal system to provide additional heat to the water.

The invention relates to a system for extracting thermal energy, a method for operating such a system and a thermal module for such a system. More particularly, the system is for extracting thermal energy from sunlight or other thermic energy sources.

A boiler unit (100) housed in an enclosure, the boiler unit (100) configured to receive a solid state combined heat and power generating device (130). The boiler unit (100) comprises a heating device (110) to produce heat; and a control unit (120) to independently control each of the heating device (110) and the solid state combined heat and power generating device (130). The boiler unit (100) is operable without the solid state combined heat and power generating device (130) being present.

An evaporator with integrated heat recovery incorporates a vapor tube in a combustion chamber surrounded by a water jacket. The water jacket is in fluid communication with an exhaust gas heat exchanger. Coolant circulates in series or parallel first and second coolant flows through the exhaust gas heat exchanger to recover heat from exhaust gasses leaving the combustion chamber and through the water jacket surrounding the combustion chamber to recover heat not delivered to the operating fluid. The evaporator may incorporate a condenser within the housing and in fluid communication with the exhaust gas heat exchanger and/or water jacket. The evaporator may be divided to flow in parallel through the condenser the exhaust gas heat exchanger. The water jacket may be fluidly connected with one or the other of the condenser or the exhaust gas heat exchanger.

The disclosed technology includes an on-demand water heater which uses an electric heat source to heat the water. The on-demand water heater can have a low fluid capacity heating chamber which has an inlet and an outlet, an electric heat source for heating the water, and a controller to control the electric heat source and maintain the temperature of the water at a predetermined temperature setting. The on-demand water heater can be powered by a direct current power source. The on-demand water heater can also utilize a solar thermal system to provide additional heat to the water.

Various disclosed embodiments include combined heating and power modules and combined heat and power devices. In an illustrative embodiment, a combined heat and power device includes a heating system including: at least one burner; at least one igniter configured to ignite the at least one burner; a fluid motivator assembly including an electrically powered prime mover; and a heat exchanger fluidly couplable to the fluid motivator assembly. At least one thermophotovoltaic converter has a photon emitter and at least one photovoltaic cell, the photon emitter being thermally couplable to the at least one burner, the at least one photovoltaic cell being thermally couplable to the heat exchanger.

The disclosed technology includes an on-demand water heater which uses an electric heat source to heat the water. The on-demand water heater can have a low fluid capacity heating chamber which has an inlet and an outlet, an electric heat source for heating the water, and a controller to control the electric heat source and maintain the temperature of the water at a predetermined temperature setting. The on-demand water heater can be powered by a direct current power source. The on-demand water heater can also utilize a solar thermal system to provide additional heat to the water.

A system, an arrangement and method for heating and cooling of several building spaces-or buildings includes two or more building spaces or buildings, and a secondary thermal network including a supply line and a return line. The arrangement further comprises two or more building connections arranged parallel to each other and between the supply line and provided in connection with the two or more building spaces or buildings, a ground hole and a geothermal heat exchanger provided to the ground hole and arranged in connection with the secondary thermal network.

An energy generating system for generating thermal energy and electrical energy for a premises. The system includes an engine that drives an AC power generator to supply supplemental or standby power to the premises. The thermal energy given off by the engine is also coupled to the premises to provide heat thereto. A processor controls the various parameters of both the energy generating system and the premises to coordinate the proper heating and cooling thereof.

An evaporator with integrated heat recovery incorporates a vapor tube in a combustion chamber surrounded by a water jacket. The water jacket is in fluid communication with an exhaust gas heat exchanger. Coolant circulates in series or parallel first and second coolant flows through the exhaust gas heat exchanger to recover heat from exhaust gasses leaving the combustion chamber and through the water jacket surrounding the combustion chamber to recover heat not delivered to the operating fluid. The evaporator may incorporate a condenser within the housing and in fluid communication with the exhaust gas heat exchanger and/or water jacket. The evaporator may be divided to flow in parallel through the condenser the exhaust gas heat exchanger. The water jacket may be fluidly connected with one or the other of the condenser or the exhaust gas heat exchanger.