Hugh Massam, principal consultant at E=, believes a key trend in 2013 is batteries finally starting to feature in decentralised energy.
My garden is inhabited by squirrels. This time of year they are getting fatter, eating like crazy, busily harvesting everything they can lay their claws on and secreting it somewhere.
They might just be rats with better PR and some people don’t like them – I thought the chart on my neighbour’s shed wall tracked how many squirrels he’d spotted, until he told me it was a body count – but like good rats they’ve learned: Energy to keep you warm now is good. Energy stored locally, and released when you need it, is better, and can maybe even save your life when the chips are down.
For a highly evolved species that has been distributing energy for nearly 2,000 years (the Jin dynasty apparently sent gas down bamboo pipes in around 280 AD), it seems to me we’re behind the squirrels – our means of seriously bulk-storing any type of energy you can’t stack in a shed or carry in a bucket are over a century old – flywheels, for example. We have barely moved beyond low-pressure tanks or hydro reservoirs, which are really just overgrown buckets most of the time.
Why does this matter? Because of course, power demand is rising, central generation is very inefficient, and the UK’s evening peaks are still with us – even schoolkids in Britain have learned the phrase ‘TV pickup’ recently, and apparently our tea-drinking habit makes it worse in the UK than anywhere thanks to all those kettles switching on, especially in ad-breaks. The fact is, despite improvements in insulation, catchup TV, more efficient appliances and some local generation, the evening peaks are still a reality, and will be until most of us live in highly efficient housing and stop boiling kettles – i.e. for the foreseeable future.
Bursts from hydro plants are a good answer but we all know that generally, large power plants operating intermittently – whatever they run on, but historically high-carbon – are a rubbish solution, any central generation is inefficient and today’s most prevalent renewable energies are inconveniently inconsistent.
So to my mind the business case for more batteries is blinding and it’s a mystery why more people aren’t finding economic ways to peak-shave by storing cheap power generated at 3am from the grid or a windmill, or at noon from a solar panel. Especially if power can be stored safely close to where it’s needed – in your house, or on your street.
Nothing new about the concept, and lithium-ion and half a dozen battery technologies are being tested, as well as compressed air and other novelties. So, in the second century of electricity distribution, it was a relief to finally see domestic battery storage as a reality. At recent trade shows the first domestic batteries for UK PV were suddenly in evidence, in either Li-ion or lead-gel versions. You still need a large cupboard space – and a large bank balance, the payback is up to 18 years – but you can now store loads of the electricity your solar panels generated in the daytime, to use to cook at night. They claim self-sufficiency of over 70% for solar households.
Others have made the medium-scale version work: A group of Scottish and Southern’s ‘carbon zero homes’ use PV tiles to charge one shared Li-ion battery – cheaper and more efficient.
In the US, Japan and now Canada they already use large, usually sodium-sulphur batteries as part of traditional grid supply, to peak-shave or to avoid dropouts for a few hundred houses in remote locations. The Shetland Islands will soon commission a 1MW battery. Besides avoiding brownouts and extending life by reducing stress on ageing cables and transformers, bonuses can include emergency cover for power cuts, and reduced emissions from fossil-fuel backup generators.
So why are there not more?
Capital cost is one issue, the rare earths and chemicals needed by most batteries is another, and a fire in an NGK sodium-sulphur battery hasn’t helped. Retrofit costs and where to put shared batteries on my street are other issues – but new-build estates and using existing substation plots would be a start. As with many technologies, the most efficient and long-lasting solutions seem pricey: but to me this seems like it should be more than a £/kWh calculation – batteries deserve extra consideration because it’s scaleable up and down, and it can easily be right where it’s needed – almost any size, and anywhere.
Specialist contractors S&C told me 5 to 8%of their business globally is now building and managing battery storage. So far it’s mostly in the US. We have around 300,000 substations in the UK, so as the nation that drove the global tea industry and created the ‘TV pickup’, why are we not leading in building more battery storage?
E equals is a specialist energy communications consultancy based in Cambridge, UK.