Currently, when the wind wont blow and the sun wont shine – and we’ve not been able to store any of that carbon free energy – we have a massive problem. It is for this reason that the House of Lords Science and Technology committee, on which I am honoured to serve, has just launched our latest inquiry into this very subject. The aim of our inquiry is to understand the contribution long duration energy storage can make to a net zero grid.

The Government has set a target for a fully decarbonised electricity system by 2035 and Net Zero across the whole of the UK by 2050. This will require a large increase in variable renewable electricity generation from wind and solar and a substantial increase in electricity demand as the heat and transport sectors are electrified to remove dependence on fossil fuels.

In order to balance supply and demand in this future energy system across different timescales, different types of energy storage technology will be needed. Short-duration energy storage to balance the grid, such as that provided by batteries, is important, but this inquiry will focus on longer-duration storage – in excess of 4 hours.

It is clear that the UK is likely to need substantial investment in infrastructure that can store energy across days, weeks, months, and years. Medium-duration energy storage could be defined as between 4 and 200 hours, while long-duration energy storage would store energy for over 200 hours.

Recent events have only served to underline the critical importance of energy security, economically and societally. There are an array of technologies worthy of investigation, such as hydrogen, compressed air, redox flow batteries, molten salts, pumped hydro or synthetic fuels.

That’s the tech, what of the business case, at best uncertain right now.  The enquiry must thus establish what market interventions may need to be introduced in this space and which policy objectives may be required to support.

Our committee’s inquiry will take evidence on these issues and seek to establish whether the Government has sufficient policies in place to support medium- and long-duration energy storage and whether it is on track to deliver this potentially significant component of a net zero energy system.

In our call for evidence, which we have just launched, we are seeking answers to issues such as:

• How much medium and long duration storage we may need to hit our net zero targets;
• How the storage will interact with the grid and in what circumstances it may be called upon;
• What is the range of estimates for likely electricity demand in 2035;
• What role could greater grid interconnectivity between Great Britain, Northern Ireland and other nations play in addressing the imbalance between supply and demand; and,
• What role could demand-side management of electricity play in reducing the dependence on storage.

At the heart of the inquiry will be the very straightforward question – albeit one that is more straightforward to ask than to answer perhaps – which technologies can scale up to play a major role in storage?

As with any and all new technologies we will also need to discover the level of ‘readiness’ to understand the time scale for each potential solution to positively impact. The Committee will scrutinize Government action so far in this area and current plans to address this potential piece of our Net Zero target.

We will also be seeking and considering international comparators and examples of successful programmes in this space.  Alongside this the Committee wants to understand how much of an export market the UK may be able to build in long duration storage technologies.  Not least, what research base we may currently have in any of the potential technology solutions. As is often the case, not least in the UK context, we must more than consider the scale-up question.  Do we have the finance, the skills, the training schemes, the workforce?

Our call for evidence, which, in effect, kicks off our inquiry will close at one minute to midnight on September 11.

Parliament’s Select Committee work can only be fully effective with as full and diverse a range of external informed contributions as possible.  If you feel you have a perspective to bring to bear on this enquiry, please do submit a written response.

You can find the call for evidence at https://committees.parliament.uk/call-for-evidence/3209

You can submit written evidence to the Committee at https://committees.parliament.uk/submission/#/evidence/3209/preamble

We will hear oral evidence throughout the Autumn and conclude the enquiry with the publication of the  Committee’s report with our recommendations for Government.