Homeowner Blog

Ofgem granted Tesla Energy Ventures an electricity supply licence on 11 March 2026, making Tesla the only home battery manufacturer in Great Britain that can also sell a household its electricity (Octopus is releasing a home battery soon too!). The hardware has moved with it, and a three-phase Powerwall went on sale in Germany on 23 April. A Powerwall is the way into all of it.

Every solar and battery system comes down to three parts: the panels, the battery and the inverter. Everything else is cabling and optional extras. A typical UK home system with a battery costs somewhere between £9,000 and £14,000 at today's prices and usually pays for itself in around seven years, after which it carries on generating for decades, as the systems Spirit Energy installed in 2010 are still doing.

These nine mistakes account for most of the money lost on a UK solar and battery installation, and nearly all of them are made at the quotation stage rather than on the roof. The most expensive is fitting fewer panels to bring the price of a quote down, because the panels themselves are only around 5 to 10% of the total cost of the job. Spirit Energy has designed and installed these systems since 2010, and the same errors still turn up in the quotes homeowners bring in for a second opinion.

Britain will see its deepest solar eclipse in decades this evening, with as much as 96% of the sun blocked by the moon in parts of the country, the closest the UK has come to totality since the total eclipse over Cornwall in 1999. The dip lasts around two hours and will barely register on a typical home solar system's annual output, since the effect behaves much like a passing bank of thick cloud. It matters far more to the national grid than to your roof, which is why Octopus Energy is running a UK wide power down session between 6pm and 8pm tonight.

The battery is usually the single most expensive part of a solar and battery installation, and the right size depends on one thing: your average daytime electricity usage once overnight and EV charging are stripped out. As a rule, undersize if you're unsure how your usage will change, since storage can be added later but never removed. Oversize only for a genuine power cut reserve or a confirmed future load like a heat pump. 

The installed price gap between the Tesla Powerwall 3, Sigenenergy SigenStor, and Fox Evo is under 4% when measured on cost per usable kilowatt-hour of storage. Spirit Energy has installed all three, including the first Powerwall 3 commissioned in the UK, and the honest conclusion is that price alone should not drive this decision.

China's Ministry of Finance announced on 9 January 2026 that the country would scrap export VAT rebates across a long list of products from 1 April. Solar panels lost the rebate entirely. Battery products had theirs cut from 9% to 6%, with the rest scheduled to disappear on 1 January 2027.

TL;DR GivEnergy was, for a long time, one of the most recognisable names in UK home battery storage. So when news broke in early April 2026 that the company had filed a Notice of Intention to Appoint Administrators, it sent a shockwave through the industry.

“I can’t buy solar, I won’t be in this building long enough to see the returns.”  

TL;DR

Winter is when a home battery should deliver the biggest savings because electricity is often priciest and solar generation is lowest. But cold temperatures can limit charging and power if a battery cannot manage its own temperature. Look for strong thermal management, outdoor-ready weatherproofing with a suitable IP rating, and an installer who sets your system up to reliably off-peak charge.