The cost of electricity storage per kilowatt-hour

Assuming N = 365 charging/discharging events, a 10-year useful life of the energy storage component, a 5% cost of capital, a 5% round-trip efficiency loss, and a battery storage capacity degradation rate of 1% annually, the corresponding levelized cost figures are LCOEC = $0.067 per kWh and LCOPC = $0.206 per kW for 2019.

The resulting price premium for energy that is self generated and stored of about 16 € cents per kWh generates a tangible profit margin in comparison to the optimized LCOES value of about 8.5 € cents per kWh.

Normalizing kp at 1 kW, the investor is entitled to a rebate of $400 for the first two kWh of energy storage, an additional rebate of $250 for the next two kWh, and a final rebate of $100 for the next two kWh, up to a duration of 6 h. Additional energy storage components corresponding to the initial 1 kW power rating do not receive any subsidy.

Part three compares energy density and capacity cost of several energy storage techniques. Capacity cost and required area are significant when considering storage densities in the TerraWatt-hour range. Thermal storage has the lowest cost. Part four compares the efficiency and energy leakage of the storage techniques of part 3.

Cost effective energy storage is arguably the main hurdle to overcoming the generation variability of renewables. Though energy storage can be achieved in a variety of ways, battery storage has the advantage that it can be deployed in a modular and distributed fashion 4.

For example: battery capacity cost per kWh = (cost of battery + installation cost + discounted maintainance costs and financing costs if a loan is used to purchase the battery) normalized to a capacity of 1 kWh. Levelized cost of storage (LCOS) quantifies the discounted cost per unit of released energy that was recovered from the storage device.