Energy storage could slash cost of UK decarbonisation by £3.5bn

The UK can cut the cost of decarbonising its electricity supply by more than £3.5bn if it can create a grid-scale electricity storage system to balance the variable output of renewables.

That’s according to a report from QBC, a company looking to build such a system. The group’s technology of choice is pump storage – pumping water uphill into large reservoirs when power is abundant and then letting it flow down again to generate power when needed.

QBC is currently developing a grid-scale pumped hydro site in North Wales, and claims it has identified locations throughout Britain with low planning risk that could deliver 10GW of such storage.

It claims this amount of storage would come at an overall cost to the UK at least two times lower than the current strategy of renewables supported by stand-by fossil fuelled generation. It would also cut 5m tonnes of CO2 emissions.

A reliable energy storage system would also mean the UK needs to build less renewable capacity, as each new GW of storage would displace at least one GW of future offshore wind – at less than half the cost, said the report.

Imperial College estimates that by 2020 Britain will effectively be throwing away up to 27% of wind electricity. Storage could reportedly enable Britain to cut that waste to just 7%.

Playing catch-up

The report authors wrote: “Other countries have coupled the building of new storage to renewables so that surplus energy can be captured and used later when the wind fails to blow or the sun does not shine. More than 99% of electricity storage around the world uses pumped hydro technology due to its low cost and proven reliability.

“But successive UK governments have ignored the potential of pumped hydro storage, choosing instead to use CO2-producing diesel generators and gas power stations as backup.

“As a result, electricity consumers pay three times over – pay to build renewables, pay operators to curtail or throw away potential generation when there is too much electricity, and pay to keep fossil-fuelled generation in reserve.”

QBC chairman Peter Taylor added: “Putting the UK back on a par with other nations will take time. A single new pumped hydro storage facility might take anything up to seven years from initial proposal to actually beginning operation. With 30GW of renewables planned for 2020 Britain does not have the luxury of being able to continue kicking the storage can down the road.

“Our survey shows that Britain could achieve as much as 50GWh of storage using innovative pumped hydro alone. We don’t claim pumped hydro is the sole answer to the UK’s storage needs.

“Certainly it is the tried and tested option, but we see a future where the UK incorporates different storage technologies at different layers in the system.”

Energy train

Tesla recently supplied part of this puzzle with its innovative Powerwall system, which acts like a giant battery on the wall of homes and businesses, absorbing and distributing renewable power.

The Netherlands is also investigating its own groundbreaking new magnetic-train system which could store up to 10% of the country’s daily energy needs in the form of kinetic energy.

The so-called energy train would be powered up by renewable energy, travelling up to 2,000kmph around circular track inside a vacuum.

Once started, the friction is so low inside the vacuum tunnel, that the train loses barely energy to keep moving. Then when power is needed, the kinetic energy is converted back int electricity.

Brad Allen

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