Guest Blog: npower’s Wayne Mitchell on Energy Storage

How best to meet the energy storage shortfall Now the key polices of Electricity Market Reform are ready to roll, you could be forgiven for thinking we have – at […]

Register now!

By Geoff Curran

How best to meet the energy storage shortfall

Now the key polices of Electricity Market Reform are ready to roll, you could be forgiven for thinking we have – at last – got our energy needs sorted.

Certainly, in the key areas of promoting low-carbon generation and ensuring sufficient future capacity, we have some useful mechanisms in place. But there is still a gaping hole as far as energy storage is concerned.

As the UK generates more renewable power, the need for greater energy storage capacity will increase. Intermittent supply from the wind and sun means we have to ensure adequate back-up to meet demand on those still, cloudy days.

Lack of storage planning

Currently, the UK has just 2.8GW of grid-scale storage in the form of pumped hydro stations at four sites. Despite pledging to cut our greenhouse-gas emissions by 80% relative to a 1990 baseline by 2050 – an ambition unlikely to be achieved without a significant increase in renewable generation – planners didn’t factor in any more storage capacity. The most recent addition is more than 30 years old!

Other countries are taking storage requirements more seriously. Research by the Portuguese government, for example, suggests that a ratio of 3.5MW of installed wind capacity to 1MW of pumped hydro storage is appropriate for grid balancing purposes, and is investing accordingly.

Italy is also investing heavily in multiple energy storage projects via its National Grid equivalent, Terna. Meanwhile in Germany, incentives are made available to those installing solar PV to also include battery banks to facilitate continuous local supply.

A pan-European supergrid

The greater use of interconnectors to share electricity between European neighbours also offers a potential solution to balancing supply with demand. The UK already has 4GW of interconnector capacity to/from France, the Netherlands, Northern Ireland and Ireland, with plans to expand to Denmark and also Norway, which has plentiful hydro-power resources to provide additional power at times of need.

New technologies also offer storage potential – for example, compressed air, heated gravel and electrolyte and flow battery technologies. But these are slow to develop. Pumped hydro still remains the leading commercial storage option, despite decades of research into other sources.

So what’s the solution? As with most things energy-related, an integrated approach is likely to work best – more traditional pumped hydro, plus localised solutions (eg solar plus battery storage) and an expanded network of interconnectors, for example.

Whatever direction we take, one thing’s for certain – we need to do something and soon. For even if we dilute Portugal’s 1:3.5 storage to renewables ratio by half, the UK currently has a 1GW less energy storage than we currently need, which will increase to a 3GW deficit by 2020.

This is a sponsored article.