Our Renewable Energy Blogs

Microinverters usually cost £100 to £130 more per panel than a string inverter, and the best side-by-side test on an unshaded roof found they produced only about 0.5% more electricity. That test was run in 2011, so Spirit Energy and Gary Does Solar have built a new one on a real UK roof, with 24 LONGi panels split into three independently metered blocks. Over the coming years it will show whether microinverters earn their cost without shade, and whether bifacial panels generate anything extra from the back on an ordinary tiled roof.

The Warm Homes Loan Scheme, which opened on 27 October 2026, lets UK homeowners borrow up to £15,000 for solar panels and a further £15,000 for a home battery. The interest rate can be up to 5 percentage points lower than on a normal loan. It isn’t a grant, so you still repay every pound you borrow, but on the government’s own example of £10,000 over seven years the lower rate saves £1,993 in interest. The discount gets smaller the longer you borrow, and the loan does nothing to protect you from a poor installer, which is where most of the risk sits.

The add-ons on a UK solar quote fall into three groups. Bird mesh costs about £25 a panel and ArcBox connector enclosures about £25 each, and both are cheapest fitted during the main install, because adding them later usually means paying £600 to £800 for scaffolding again. Hot water diverters and optimisers only pay off in specific homes, and a mains voltage optimiser sold to solar owners is one to refuse.

Spirit Energy's 695 kWp installation at Philip Dennis Foodservice in Oxfordshire, split across a distribution warehouse and a cold store, is projected to save the business more than £85,000 a year on electricity with a five year payback and an IRR above 23%. Cold storage suits solar unusually well because refrigeration runs continuously, so almost every unit generated is consumed on site rather than exported at a lower rate. Self-consumption, not roof orientation or panel efficiency, is what drives commercial solar returns.

No UK hotel of ordinary density runs on solar power alone, and the reason is storeys rather than sunshine. Roof area per bedroom is the binding constraint: a two-storey country house hotel has twice the roof per bedroom of a four-storey city hotel, so it can cover roughly twice as much of its electricity. Realistic figures run from about a tenth of annual electricity on a tall urban building to about half on a low, sprawling site.

Across Spirit Energy's 23-site rollout for B&M Care Homes, internal rate of return ranges from 19 to 30 percent, and payback periods run from three to six years. That spread is not a sign of inconsistent work. It is what happens when the same design team and the same installation standard are applied to buildings that each have a different roof, a different daytime load, and a different grid connection.

For those who have their finger on the pulse of the solar energy market, it's becoming obvious that there is an increasing shift towards the manufacture and use of n-type solar from p-type panels in both commercial and domestic settings, to the point where the former now dominate. But why has this shift come about, and more fundamentally what is the difference between the two?

In the space of just a few years, the average panel we install on domestic projects has shot up from around 315W to at least 375W, with more and more residential modules breaking the 400W barrier.

This is down to a few factors, such as the widespread adoption of new, more efficient technologies, bigger cells and bigger modules:

When researching solar PV, you may have come across the phrase ‘tier 1 solar panels’. It’s used as a selling point by some manufacturers and installers to demonstrate the reliability of their products. But is that really the case?