Energy storage

Bill Butler (Letters, 28 November) seems to believe mass storage of renewable energy is imminent. There are four problems with energy storage and, when combined, they demonstrate that such a system is unachievable for the foreseeable future.

Cost. We already pay extra to generate renewable energy. We would need to pay additional subsidies for storage. The laws of supply and demand show that if this idea goes global the price of resources for its development would soar. Nobody can truly state the cost, but energy costs per head doubling is a conservative estimate.

Energy losses. Wind generates around 18 times more energy compared to the energy used to deploy it. Conversion of this electricity to, for example, methane, has a conversion efficiency of about a third. Therefore that 18-fold advantage of wind is reduced to six. Yet more energy is lost in the transmission system construction and operation.

Construction. A colossal amount of new infrastructure would be required. This would include energy converters, storage facilities, transmission lines and new devices to utilise the energy, including electric vehicles. There is a growing shortage of engineers and certain raw materials, so the supply chain could never deliver.

Recharging. At the start of a low-wind period the storage units would need to be full, and at the end they would need to be recharged. Presumably, most of the wind fleet would be required to power the UK when the wind returns, so where does the energy come from for mass recharging? After the three-week low wind event in September, the data from Elexon suggest significant net recharging wouldn’t have restarted until mid-October and may not have completed; then in early November it entered a discharge-charge cycle; from mid-November net discharge again.

G Moore

Braeface Park

Alness