Thunder Energy sells the Bolt as one panel or two, with a Hoymiles inverter and a bracket in the box. It costs more than some rivals. It also gives a long warranty and a register reference that you can check.
What do you get in the box?
The Bolt has one 460 W panel. The Bolt 920 W has two. Both use a Hoymiles HMS-800-2WB inverter, which the maker says has an 800 VA maximum AC output. A Thunder Bolt bracket set is included, for ground or wall. A flat-roof set costs £34.99 extra. The cable is 5 m with a UK three-pin plug. We have not tested it. This is what the maker says.
How much does it cost?
The Bolt 460 W is £549.99 and the Bolt 920 W is £749.99. Price checked 12 October 2026. The price includes 20% VAT, because a kit you fit yourself is standard-rated. When we looked, the page header said in stock but the buy box said sold out. Check stock before you plan around it.
How much will it save a year?
The government says 800 W of panels saves about £70 to £110 a year. The Bolt 460 W is a single panel, so we scale it: 460 ÷ 800 × £70 to £110 comes to about £40 to £65 a year. The Bolt 920 W has two panels, but the inverter caps output at 800 VA, so it gets the full £70 to £110. These are our estimates, scaled from the government's 800 W figures.
How long does it take to pay for itself?
Divide the price by the saving. Bolt 460 W: £549.99 ÷ £65 = about 8.5 years, and £549.99 ÷ £40 = about 14 years. Bolt 920 W: £749.99 ÷ £110 = about 7 years, and £749.99 ÷ £70 = about 10.5 years. The two-panel Bolt is clearly the better buy. See is plug-in solar worth it? for more sums.
Is it on the ENA register?
Thunder Energy states the Bolt 460 W is "listed on the ENA Connect Direct register as a compliant Plug-in Solar device under reference THUNE/21203/V1". For the 920 W, the maker's reference is THUNE/21204/V1. These are the maker's claims. We have not confirmed them. Search for them on the ENA register yourself before you buy. The maker also says you must tell your network operator. See the DNO guide.
Where can you put it?
The bracket set suits a ground or wall spot. A flat roof needs the £34.99 flat-roof set. Face the panels south and tilted up for the best result. A shed, fence or flat roof can work. Our guide to those spots says what to check first.
Does the warranty outlast the payback?
Thunder Energy lists a 25-year panel product warranty and 30-year panel performance. The site also lists a 12-year inverter warranty. Payback is 7 to 14 years. The panel warranty beats it easily. The inverter warranty of 12 years is shorter than the slow end for the single panel, which is 14 years. That is a risk if you are in the slower case.
Is the Bolt Plus with a battery the same thing?
No. Thunder sells the Bolt Plus with a Vault battery for £1,549.99 (460 W) and £1,749.99 (920 W). That is a hard-wired route that needs an electrician. It is not plug-in solar. The plug-in rules cover panels only. Our battery guide has the sums, and they are not kind.
Who is it for, and who should skip it?
The Bolt 920 W suits someone who wants long warranties and a maker who gives a register reference. Skip the Bolt 460 W if price matters. At £549.99 it costs £100 more than some rivals with a similar panel, and pays back in 8.5 to 14 years. Skip the Plus-with-battery bundles unless you want a hard-wired system.
The quick version
- The Bolt 460 W is £549.99 and the Bolt 920 W is £749.99.
- We estimate payback at about 8.5 to 14 years and 7 to 10.5 years.
- Panels have 25 years, but the 12-year inverter warranty may end before a slow payback.