Energy storage arrangement and installations

A method of controlling a heat pump in an installation in which the heat pump is coupled to a heat exchanger in an energy bank, the heat exchanger including phase-change material for the storage of energy, the energy bank including an optical source to launch light into the phase change material, wherein the optical source is controllable to produce light of different colors, one or more sensors to provide measurement data indicative of the amount of energy stored as latent heat in the phase change material, wherein the one or more sensors includes an optical sensing arrangement to detect light launched from the optical source after the light has passed through the phase change material, wherein the optical source and the optical sensing arrangement is configured to give a graduated measure of different energy storage states from empty to full, wherein the optical sensing arrangement is configured to detect at least some light of different colors;

• and
• a processor operatively connected to the one or more sensors, and which is configured to estimate an amount of energy stored in the phase change material based on information received from the optical sensing arrangement;
• the method comprising:
• the processor estimating the amount of energy stored in the phase change material based on information received from the optical sensing arrangement;
• and based on the estimation of the amount of energy stored in the phase change material, deciding whether to provide a start signal to the heat pump.

A method of controlling an energy bank including an in-building hot water supply system installation, wherein,

• the energy bank includes,
• a heat exchanger;
• an enclosure, and wherein the energy bank comprises within the enclosure:
• an input-side circuit of the heat exchanger comprises a connection to an energy source comprising a heat pump, and,
• an output-side circuit of the heat exchanger comprises a connection to an energy sink comprising in-building hot water system, and
• a phase-change material for the storage of energy;
• one or more sensors to provide measurement data indicative of the amount of energy stored as latent heat in the phase change material,
• an optical source to launch light into the phase change material, and
• a processor;
• the one or more sensors includes an optical sensing arrangement to detect light launched from the optical source after the light has passed through the phase change material;
• the optical source is controllable to produce light of different colours;
• the optical sensing arrangement is configured to give a graduated measure of different energy storage states from empty to full, wherein the optical sensing arrangement is configured to detect at least some of different colours;
• the processor is,
• operatively connected to the one or more sensors, and
• configured to estimate an amount of energy stored in the based on information from the optical sensing arrangement;
• the processor being configured to make a determination to trigger the starting of the heat pump based on measurement data from the optical sensing arrangement;
• and
• the method comprises,
• generating a determination of the amount of energy stored as latent heat in the phase change material;
• and
• based on that determination, deciding whether to provide a start signal to the heat pump.