In modern power systems with high penetration of renewable energy generation, the energy storage is very important, not just for the load control for quite different time periods, but even in the frequency control. If it is missing, the anomalies occur, like the stagnant CO2 emission, export of the overproduction under unfavourable conditions, curtailments of wind-mills and/or negative market prices for electricity. The new technology is a high temperature thermal electric energy storage. It is based on the combination of three state-of-the-art technologies: pebble-heater, radial gas-turbine and electric resistive heating. Due to very high temperature (1100°C), low exergy losses during the heat transfer and water injection in the gas-turbine process, the round-trip efficiency is high even with nowadays available components. With some moderate improvements of the gas-turbine it could be increased towards 60%, even at 2MW low generator capacity. The discharge time is 10 h; due to the modular design, it may increase to 20 or even 30 h. The analysis of LCOES (levelized cost of electricity storage) shows that even today that system could be used in a viable way in countries with high insolation or on sites where an autarchic power supply may replace expensive market electricity.
Part of the book: Advancements in Energy Storage Technologies