Solar Panel 400W
£199.99
400W rigid solar panel with monocrystalline TOPCon cells, designed for gardens, sheds, outbuildings and suitable fixed installations. Compact, weather-resistant and supplied with pre-fitted MC4 connectors for easy integration with compatible solar equipment.
Free UK Delivery.
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Product Description
High-performance solar power in a compact rigid panel.
The Thunder Bolt 400W is a rigid monocrystalline TOPCon solar panel designed for fixed home solar installations where a robust framed panel is the right choice.
Rated at 400Wp, the panel measures just 1555 × 1134 mm and weighs 15 kg, making it well suited to gardens, sheds, outbuildings and suitable flat-roof mounting systems.
Pre-fitted 4 mm² DC leads with MC4 connectors make integration straightforward with compatible microinverters and other solar equipment. The panel is IP67 rated and tested to recognised IEC photovoltaic module safety and performance standards.
This listing is for the solar panel only. If you are looking for a complete system with microinverter, AC connection cable and mounting hardware, explore the Thunder Bolt plug-in solar kits.
Features
400W Solar Power
Generate up to 400Wp from a single compact rigid panel, ideal for adding meaningful solar capacity without requiring a large installation area.
TOPCon Solar Technology
Built with monocrystalline TOPCon cells for modern, high-performance solar generation in a durable rigid-panel format.
Compact Rigid Design
At 1555 × 1134 × 30 mm and 15 kg, Bolt 400W provides substantial solar capacity while remaining practical for smaller fixed installations.
Made for Fixed Outdoor Installations
Ideal for gardens, sheds, outbuildings, suitable flat roofs and other securely mounted locations where a conventional rigid solar panel is appropriate.
MC4 Ready
Supplied with 800 mm, 4 mm² DC cables and MC4 connectors, ready for connection to compatible solar equipment.
Tested for Solar Performance & Safety
Tested to IEC 61215 photovoltaic module performance standards and IEC 61730 photovoltaic module safety standards. TUV Certified.
Certification: TÜV Rheinland Certificate No. PV 50696798 0001
Standards: IEC 61215-1:2021, IEC 61215-1-1:2021, IEC 61215-2:2021, IEC 61730-1:2023 and IEC 61730-2:2023.
Technical Specifications
| Specification | Bolt 400W |
|---|---|
| Panel type | Rigid solar panel |
| Cell type | Monocrystalline TOPCon |
| Peak power (Pmax) | 400 Wp |
| Power tolerance | ±5% |
| Open circuit voltage (Voc) | 34.4 V |
| Maximum power voltage (Vmp) | 30.5 V |
| Short circuit current (Isc) | 13.7 A |
| Maximum power current (Imp) | 13.1 A |
| Bypass diodes | 3 |
| Maximum series fuse rating | 20 A |
| Maximum reverse current | 20 A |
| Maximum system voltage | 1500 V DC |
| Protection class | Class II |
| Fire rating | Class C |
| IP rating | IP67 |
| Operating temperature | -40°C to +85°C |
| Dimensions | 1555 × 1134 × 30 mm |
| Weight | 15 kg |
| DC cables | 800 mm, 4 mm² |
| Connectors | MC4 |
| Mounting holes | 4 × 9 × 11 mm |
FAQs
Is this a complete plug-in solar kit?
No. This product includes one Bolt 400W DC solar panel only. It does not connect directly to a UK socket. A compatible inverter or microinverter and the appropriate electrical connection equipment are required.
Where can I install the Bolt 400W panel?
The rigid panel is particularly suited to gardens, sheds, outbuildings, suitable flat roofs and other fixed locations using an appropriate solar mounting system.
Does the panel include a microinverter?
No. This listing is for the solar panel only. For a complete system including a microinverter, AC connection cable and mounting hardware, choose one of our Bolt plug-in solar kits.
Does it come with MC4 connectors?
Yes. The panel is supplied with pre-fitted 800 mm, 4 mm² DC cables with MC4 connectors.
How large is the Bolt 400W panel?
The panel measures 1555 × 1134 × 30 mm and weighs approximately 15 kg.
Is the Bolt 400W panel weather-resistant?
Yes. The panel has an IP67 rating and an operating temperature range of -40°C to +85°C.
Can I connect this panel to a microinverter?
Yes, provided the microinverter is electrically compatible with the panel's voltage and current characteristics. Always check the inverter's permitted DC input specifications before connection.
Can I add this panel to an existing solar system?
Potentially, but compatibility depends on the inverter, electrical configuration and existing panels. Do not add panels simply based on wattage alone. Voltage, current and inverter input limits must also be checked.
Know before you buy
Storm Panel Dimensions
80 cm

120 cm
BOLT: Plug-in solar made for UK homes




20-Year Financial Projection
Storm 710W Solar Kit With Battery
System Size
0.71 kWp
4 × Storm 178W
Year 1 Generation
525 kWh
London estimate
Year 1 Savings
£298
At 30p/kWh
Payback Period
~5 Years
April '26 prices

- YearElec rate (p/kWh)Generation (kWh)Self-use (kWh)Self-use savings (£)Battery arbitrage (£)Annual total (£)Cumulative (£)130.00525525£157£140£298£298230.90521521£161£144£305£603331.83517517£165£149£313£916432.78514514£168£153£322£1,238533.77510510£172£158£330£1,568634.78506506£176£163£339£1,907735.82503503£180£167£348£2,254836.90499499£184£172£357£2,611938.00496496£188£178£366£2,9771039.14492492£193£183£376£3,3531140.32489489£197£188£386£3,7381241.53486486£202£194£396£4,1341342.77482482£206£200£406£4,5401444.06479479£211£206£417£4,9571545.38475475£216£212£428£5,3851646.74472472£221£218£439£5,8241748.14469469£226£225£451£6,2751849.59465465£231£232£463£6,7371951.07462462£236£239£475£7,2122052.61459459£241£246£487£7,699
Annual consumption: 2,700 kWh (Ofgem typical medium household). Winter 60% / Summer 40%.
System: 4 x Storm 178W flexible solar panels (TopCon monocrystalline), total 0.71 kWp. Microinverter: Hoymiles HMS-800W-2T (800 VA, 2 MPPT, 96.7% peak efficiency).
Orientation: Modelled at 90-degree vertical mounting (typical for fence or balcony railing). This is a conservative estimate. Tilting panels to a more favourable angle will increase generation.
Year 1 generation: 525 kWh (estimated for London, based on typical balcony/fence mounting).
Panel degradation: 2% in year 1, 0.7%/year thereafter (conservative estimate for flexible ETFE panels).
Seasonal generation split: Winter 28% / Summer 72% (Thames region profile).
Self-consumption rate: 100% year-round. System output is well below household demand, so all generation is consumed on-site.
Electricity tariff: 30 p/kWh peak (average smart time-of-use daytime rate), 7 p/kWh off-peak (overnight rate), 3% annual inflation.
Battery: Hoymiles HiBattery 1920 AC (HB-1920-AC-SV), 1.92 kWh usable capacity, LiFePO4 cells, AC-coupled, 87% round-trip efficiency, IP66, 6,000+ cycle life, 10-year warranty.
Battery arbitrage: Off-peak grid charging at overnight rates, peak discharge during daytime. 365 days per year at full capacity (1.92 kWh). Solar generation is consumed directly by the household and does not charge the battery, leaving full battery capacity available for grid arbitrage year-round. Battery operates at 800W maximum output, sufficient to offset household base load during peak hours.
87% round-trip efficiency.
Battery arbitrage savings assume the customer is on a smart time-of-use tariff with off-peak overnight rates. Actual returns may be higher or lower than projected
depending on tariff availability and usage patterns. All figures are estimates based on the assumptions above and should not be considered as guaranteed
returns.
20-Year Financial Projection
Bolt 400W Solar Kit With Battery
System Size
0.40 kWp
1 x Bolt 400W
Year 1 Generation
445 kWh
London estimate
Year 1 Savings
£267
At 30p/kWh
Payback Period
~5 Years
July '26 prices

- YearElec rate (p/kWh)Generation (kWh)Self-use (kWh)Self-use savings (£)Battery arbitrage (£)Annual total (£)Cumulative (£)130.00445445


























