There is herein described energy storage systems. More particularly, there is herein described thermal energy storage systems and use of energy storable material such as phase change material in the provision of heating and/or cooling systems in, for example, domestic dwellings.

A system and methods for heating and cooling are provided. The system may include an energy collector and an adaptive panel connected to the energy collector. The adaptive panel may a radiative cooling layer configured to dissipate heat from the energy collector. The radiative cooling layer may further include a thermo-responsive polymer configured to adjust transparency depending on temperature. The system may include a solar heating layer configured to absorb solar irradiation that passes through the radiative cooling layer and transfer heat to the energy collector.

A pivot window includes a laminated body. The laminated body includes two sheets of a plate material; a peripheral end member provided at a peripheral end parts of the two sheets of the plate material; and a cell array plate material which is interposed between the two sheets of the plate material and which has a plurality of cells respectively having a gas phase and encapsulating a latent heat storage material having a melting point and a freezing point in a specific temperature range. The pivot window further includes a rotation mechanism for causing the laminated body to perform at least half rotation in a vertical direction.

A novel portable solar energy system includes a solar concentrator, a thermal storage device, an azimuth adjustment system, an elevation system, and a heat exchanger, all mounted on a rotatable support frame. In a particular embodiment, the thermal storage device remains at a fixed vertical height and fixed tilt orientation when adjustments are made to the azimuth adjustment system and/or the elevation adjustment system.

A novel portable solar energy system includes a solar concentrator, a thermal storage device, an azimuth adjustment system, an elevation system, and a heat exchanger, all mounted on a rotatable support frame. In a particular embodiment, the thermal storage device remains at a fixed vertical height and fixed tilt orientation when adjustments are made to the azimuth adjustment system and/or the elevation adjustment system.

A method of operating a solar energy plant and a solar plant are disclosed. Thermal energy produced in the plant is used to heat a first volume of water and charge a hot store in the plant. Electricity produced in the plant operates a heat engine or other device, such as a refrigeration unit, to extract heat and consequently cool a second volume of water and charge a cold store. As desired, energy is transferred from the hot store to a heat engine and energy is transferred from the heat engine to the cold store to operate the heat engine to produce power in the plant.

The present disclosure provides pumped thermal energy storage systems that can be used to store electrical energy. A pumped thermal energy storage system of the present disclosure can store energy by operating as a heat pump or refrigerator, whereby net work input can be used to transfer heat from the cold side to the hot side. A working fluid of the system is capable of efficient heat exchange with heat storage fluids on a hot side of the system and on a cold side of the system. The system can extract energy by operating as a heat engine transferring heat from the hot side to the cold side, which can result in net work output. Systems of the present disclosure can employ solar heating for improved storage efficiency.

The present disclosure provides pumped thermal energy storage systems that can be used to store electrical energy. A pumped thermal energy storage system of the present disclosure can store energy by operating as a heat pump or refrigerator, whereby net work input can be used to transfer heat from the cold side to the hot side. A working fluid of the system is capable of efficient heat exchange with heat storage fluids on a hot side of the system and on a cold side of the system. The system can extract energy by operating as a heat engine transferring heat from the hot side to the cold side, which can result in net work output. Systems of the present disclosure can employ solar heating for improved storage efficiency.

A heat transfer or storage medium containing a nitrate salt composition including at least one alkali metal nitrate and optionally alkaline earth metal nitrate; and, at least one alkali metal nitrite and optionally alkaline earth metal nitrite in an amount of 1.1 to 15.0 mol %. The molar amount of the alkali metal nitrite and optionally alkaline earth metal nitrite for a desired temperature is calculated by $x_{\mathrm{nitrite}}=\frac{K_6\left(T\right)}{K_6\left(T\right)+\sqrt{P_{O2}}}$
X.sub.nitrite is the mole fraction of nitrite,
K.sub.6(T) is the temperature-dependent equilibrium constant of the reaction nitrate ⇄nitrite+½ oxygen (NO.sub.3.sup.−⇄ NO.sub.2.sup.−+½ O.sub.2),
pO.sub.2 is the oxygen partial pressure and T is the temperature of the nitrate salt composition.

A heat transfer or storage medium containing a nitrate salt composition including at least one alkali metal nitrate and optionally alkaline earth metal nitrate; and, at least one alkali metal nitrite and optionally alkaline earth metal nitrite in an amount of 1.1 to 15.0 mol %. The molar amount of the alkali metal nitrite and optionally alkaline earth metal nitrite for a desired temperature is calculated by $x_{\mathrm{nitrite}}=\frac{K_6\left(T\right)}{K_6\left(T\right)+\sqrt{P_{O2}}}$
X.sub.nitrite is the mole fraction of nitrite,
K.sub.6(T) is the temperature-dependent equilibrium constant of the reaction nitrate ⇄nitrite+½ oxygen (NO.sub.3.sup.−⇄ NO.sub.2.sup.−+½ O.sub.2),
pO.sub.2 is the oxygen partial pressure and T is the temperature of the nitrate salt composition.