Utility Week

Battery power has the potential to transform the electricity industry – but that doesn't mean energy storage is completely straightforward… Light on the charge brigade A s dawn broke on the first day of the 21st century, the fundamental issue the electricity industry had faced since its beginnings remained intact: despite some pioneering attempts to store hydro-electric generation there was no way of storing the bulk of the power that was generated. Fast forward to 2018 and there's a budding battery market that has the potential to help the country deliver on climate change commitments. Potential is the key word, as Western Power Distribution (WPD) Primary System Design Manager Tony Berndes points out: "The battery energy storage market is still in its infancy for electricity distribution where we are starting to see an increasing number of schemes connect to the network. The fact the market can mature rapidly is evidenced by National Grid's focus on fast frequency response. "It's now becoming clear to everyone involved in this technology that there are emerging markets in place. What's less clear is the way they are going to develop." Domestic In the Furzton area of Milton Keynes, WPD is currently running a trial as part of its LV Connect & Manage project. Volunteer householders are using batteries to store the power generated from their solar panels. At full capacity, the batteries are able to store enough energy to power a two-bedroom home for a day. That's important because, as the nation moves towards increased take-up of electric vehicles, the question of how they are to be charged is becoming critical. Over a year the power an electric vehicle requires is equivalent to the amount of electricity an average home uses. In March 2017 there were 37.5 million cars on the road and 27.2 million homes. Not all cars will be replaced by new electric vehicles but the projection that domestic customers will need to consume twice as much electricity as they currently do is not unreasonable. That throws up more questions. Firstly, how do you ensure the electricity to power both homes and cars is available? Traditionally, the industry would have looked at the potential peak demand of homes and cars and then built the infrastructure to ensure it could be delivered, even though for the majority of the year that peak would never be reached. The level of network investment required could easily run into billions of pounds, which would have a consequential impact on consumer bills. Network operators are working on other options. One possibility is to shift the time period when customers could charge their cars to favour overnight or other off-peak times. Another is to encourage publically available charging networks, enabling cars to charge through the day away from homes, thereby avoiding the peak period. Another question is where the power is to come from. It seems illogical to swap petrol and diesel cars for cleaner electric vehicles if they can't be supported by renewable generation. Early indications from the Furzton trial are that participants are impressed with the savings the solar panel and battery combination deliver. Long-term this type of technology could be instrumental in helping customers to keep bills static as their usage increases. Verdict: The current barrier to widespread take-up is the upfront cost of the equipment. Although prices are dropping, there is still some way to go before they are an affordable option for most households. For the moment better use of existing electrical infrastructure is a more economical option. Example of domestic solar battery "It's now becoming clear that there are emerging markets in place" 28 | 18TH - 24TH MAY 2018 | UTILITY WEEK

• Cover