Energy storage system discharge coefficient

What is thermal storage efficiency?

The storage efficiency is the ratio between the energy gained by the heat transfer fluid, in a full discharge process, and the energy supplied to the thermal storage system, in a full charge process. The charge and discharge processes should be consecutive, so that heat losses over time are not included.

What is charge/discharge capacity cost & charge efficiency?

Charge/discharge capacity cost and charge efficiency play secondary roles. Energy capacity costs must be ≤US$20 kWh –1 to reduce electricity costs by ≥10%. With current electricity demand profiles, energy capacity costs must be ≤US$1 kWh –1 to fully displace all modelled firm low-carbon generation technologies.

What are the performance parameters of energy storage capacity?

Our findings show that energy storage capacity cost and discharge efficiency are the most important performance parameters. Charge/discharge capacity cost and charge efficiency play secondary roles. Energy capacity costs must be ≤US$20 kWh –1 to reduce electricity costs by ≥10%.

What is the time parameter for a charge & discharge cycle?

It is important to highlight that the time parameter is the same for both charge and discharge cycles and indicates the amount of time that a perfect charge (or discharge) would take, meaning when the system would be 100% charged (or discharged) at 100% energy retention (or delivery) efficiency (relative to the solid material storage availability).

What is discharging in thermal storage?

Discharging is the process during which energy is transferred or extracted from the thermal storage system. This definition can be qualified depending on acquired storage level: partial discharge: discharging ends when the storage level is above \ (0\%\).

What happens if a storage tank is continuously discharged?

With continuous discharge, the height of the hot section of the storage tank decreases continuously. Only a part of the thermal energy at high temperatures stored in the storage can be recovered as useful energy in the sense that it can be used for electrical power generation.