The UK's decision to legalise plug-in solar panels could bring solar power to renters and flat-dwellers for the first time, but the government's refusal to allow plug-in batteries has prompted questions over the value of the policy.
The change comes a day after government data revealed small-scale and rooftop systems accounted for all of July's growth in solar power capacity, pushing the UK's total solar capacity to 23GW.
Conventional rooftop solar has long been available to homeowners, but the new 800W plug-in units — enough to power everyday appliances such as laptops, fridges and televisions — can be bought off the shelf and installed without the cost and complexity of a full rooftop system.
The decision is a welcome move in the effort to democratise and decentralise power generation, allowing households to become part producers rather than simply consumers of electricity, Slovak battery maker InoBat vice-chair Andy Palmer says.
Germany installed more than 400,000 plug-in solar systems last year, while UK households had no legal route to use them, making the UK's decision "overdue", Palmer told Argus.
But the UK has stopped short at generation. Households can now plug a solar panel directly into their home, yet cannot easily pair it with a plug-in battery. This means excess electricity produced during the day cannot readily be stored for evening use. "Part of the benefit is lost," Palmer said.
UK looks to increase pairing of solar and batteries
The issue becomes more relevant as solar power accounts for a rising share of UK power supply.
Solar power provided a record-high 45pc of domestic generation during peak-load hours in April. And grid-scale batteries are increasingly being deployed to move some of that daytime renewable power output into higher-value evening hours, helping to limit the call on gas-fired generation.
Whether allowing plug-in battery storage becomes the next regulatory step remains unclear. The UK government estimates plug-in solar could save users up to £110/yr ($150/yr), based on the solar panels alone, with the technology's appeal resting largely on its low cost and simplicity.
But as more households generate electricity behind the meter, pressure may grow to let them store it too.
