Frequently asked questions

Solar energy means turning sunlight into usable power, like electricity for your home or heat for your water. The most common method is through photovoltaic panels, or PV panels, which use specialised semiconductors to turn sunlight directly into electricity. Traditionally, solar panels were mounted on rooftops or spread across open land. But Thunder takes it a step further by blending solar into the spaces we already live in.

Yes. They keep generating power even on cloudy days. If there's enough light to see, there's enough light for Storm or Bolt to get to work. Our panels use advanced TOPCon technology instead of the more common and less expensive PERC cells. While direct sunlight gives the best results, your system is still active even when it’s overcast.

Solar performance depends on angle and direction, and the further south you are in the UK, the better your results.

Our Storm kits are designed to deliver reliable output in typical UK conditions:

Storm 360W can produce up to 320 kilowatt-hours of electricity per year

Storm 710W can produce up to 640 kilowatt-hours per year

At an average electricity rate of around £0.25 per kilowatt-hour, that means:

Storm 360W could save you up to £80 per year

Storm 710W could save you up to £160 per year

As electricity prices rise, so will your savings grow over time.

Of course, solar output can shift with the seasons and even hour by hour. That's why we recommend using our Savings Calculator. Just pop in your address to get a more personalised view of what Thunder can do for your home.

We want you to feel good about your purchase, knowing it leads to real savings and a lighter impact on the planet.

Traditional solar setups in the UK usually take around 8 to 11 years to pay for themselves. That is because they often come with high costs for panels, installation, and planning permissions. With Thunder, it is a whole different story.

Based on the estimates above:

Storm 360W can pay for itself in around 6 years

Storm 710W brings returns in around 4 years

Even on a cloudy day, a Thunder plug-in kit puts you well ahead when it comes to value and payback time compared to traditional setups.

Each component comes with its own dedicated warranty. The microinverter is covered by a 10-year warranty. Solar panels are covered for 3 years, and accessories (cables, isolators, connectors, mounting hardware) for 2 years. All warranty periods start from the date of delivery. For full details, see our Warranty Policy.

Yes. You have 30 days from delivery to return your kit for any reason, as long as it is in resalable condition with all original parts and packaging. Return shipping is at your cost. Just email support@thunderenergy.co.uk with your order number and we will guide you through the process. Please do not send anything back before receiving return approval from us.

Thunder modules are built to last. With quality materials and durable design, they will keep producing clean energy for years to come. To keep them running at their best, just give them a quick wipe with a cloth every other month.

Everything you need, including the panels, cables, microinverter and mounting straps, is built for outdoor use. 

For balcony setups, just use the included straps to attach each panel securely to the railing. Make sure all straps are tightly fastened to keep the panels stable in all weather. Once mounted, connect each panel to the microinverter. The wiring is straightforward. Place the microinverter between the two panels so both sets of cables can reach it easily. 

For garden setups, you have total freedom. The key is to angle the panels toward the sun as much as possible. Some people mount them on fences like a piece of art; others place them on flat surfaces like patio roofs or garage tops. For maximum efficiency, ensure the surface is stable and gets sunlight. 

If you are using the Storm 360W kit, each of the two panels connects directly to the sides of the microinverter. If you have the Storm 710W kit, you will use the provided Y branch cable to pair two panels together, then plug the combined output into one side of the microinverter, and repeat the same for the other two panels on the opposite side. 

Finally, connect the included AC plug to the microinverter. From there, you can route the power to wherever it best fits into your home electrical system.

Before you get started, there are two key things to think about: where you will mount it and how it connects to your home’s electrical system.

Unlike traditional solar panels that can weigh 25 to 30 kilos and require heavy-duty supports, Thunder panels are lightweight, flexible and designed for everyday spaces. Whether it is a balcony railing, a garden fence, a patio roof or a terrace, as long as the surface is stable and receives good sunlight, you can make it work.

You can use our elastic fasteners or the built-in one-centimetre mounting holes to hang your panels securely and neatly.

On the electrical side, Thunder kits are built to comply with UK Wiring Regulations (BS 7671) and ENA G98. To keep everything safe and efficient, the power from your panels should feed into a dedicated radial circuit. That means no other devices share the same line, which ensures proper isolation, load protection and simple DNO notification.

A radial circuit is a single electrical line that runs directly from your consumer unit to one outlet or device, rather than looping through multiple sockets like a ring circuit. It is commonly used in gardens, garages or outdoor buildings in the UK, which makes it ideal for small solar connections.

If your home already has a dedicated radial circuit, your electrician can connect directly to it. If not, installing one is straightforward for a qualified electrician, and we can help guide you through the process.

In short, the reason is safety and compliance.

Even though the UK standards for small-scale generation such as G98 and BS 7671 were written before balcony solar became common, they are still designed to ensure safe operation for everyone connected to the grid.

Thunder kits are engineered to meet these standards while keeping things simple for you. The setup described in the Installation Manual ensures:
 • Local double-pole isolation through a fused spur
 • Proper protection against reverse energy flow
 • Safe cable routing and clear labelling

All of these steps meet the intent of the IET Wiring Regulations (BS 7671:2018+A2:2022) and ENA G98 requirements for small-scale generation systems.

You do not need any kind of permission, but you must notify your local Distribution Network Operator (DNO) under ENA G98 regulations.

Thunder kits are already pre-certified for G98 compliance, so no pre-approval or MCS certification is required. However, the installer or you must send the G98 Form B to the DNO within 28 days after installation. This is a simple email process. The form is included in your box and already pre-filled with all product details, so it takes only a few minutes to complete.

In any event, Thunder kits include certified anti-islanding protection, which means they automatically shut down if the public grid goes offline. This protects both you and any engineers working on the network.

For balcony or visible outdoor installations, it is always a good idea to check local planning guidance. Most domestic solar panels are treated as permitted developments, but some councils may have visibility or listed-building rules, especially in conservation areas.

Either works. What really matters is making sure your panels get plenty of sunlight.

Since you are not making any permanent changes to the property, using a Thunder kit to generate your own clean energy is fine. Just make sure to return the socket to its original state when your tenancy ends. 

To keep things smooth and respectful, we recommend having a quick chat with your landlord. Let them know there is a safe and fully compliant way to produce your own power.

When in stock, your Thunder kit will be delivered within 1 to 3 working days. If it's not immediately available, just reach out to our customer support and we'll give you an accurate update. 

As for the cost, we keep it fair and transparent. Delivery fees are calculated at checkout based on your location and order size.

Yes, the kits are lightweight and designed for easy self-installation. That said, we recommend having someone around to lend a hand, which makes setup even smoother. 

When it comes to plugging the system into your home’s power supply, this step should be done by someone who is deemed electrically competent, in line with safety regulations. Better safe, fully charged, and stress-free.

Yes. We design and install integrated battery storage systems to maximise self-consumption and resilience.

Design and quotation can be delivered within days. Installation is typically completed within one week once approvals are in place.

Yes. We manage the full G98 or G99 submission process.

All panels and inverters include manufacturer warranties. Installation is carried out under MCS certified standards.

Yes. We regularly coordinate with architects and contractors on regulated developments.

Yes. We specialise in lightweight and compact PV systems where conventional panels may not be suitable.

Most projects receive a strategy within 3 to 5 working days after we review your SAP report and floor plans.

In most cases, no.

We focus on solar optimisation and system sizing, and avoid structural redesign wherever we can.

Yes. We can collaborate directly with your current SAP assessor or manage the compliance process through our trusted partners.

No problem. We can arrange a fresh SAP assessment and build a solar strategy from the ground up.

Full design, procurement and MCS-certified installation can be carried out by Thunder.

We typically need the project location, building type, and either roof/site plans or basic property details. If you don’t have drawings, we can still begin using satellite and survey data.

No. You can request a consultation first. Detailed drawings are helpful but not required to start feasibility or initial system sizing.

Our simulations use professional PV modelling tools that account for orientation, shading and system losses, so the production forecasts are realistic.

Most residential designs are completed within a few days, while larger commercial projects may take longer depending on complexity and data availability.

Yes. Our outputs are suitable for installers, developers, and consultants and can support planning, costing, and installation preparation.

A balcony solar system lets you generate renewable electricity from your balcony using plug-and-play solar panels and an inverter.

Yes, balcony solar panels are legal in the UK and ideal for apartments or homes without roof space.

Depending on the system size (300W to 1,000W), balcony panels can cover 20% to 30% of a small household's daily electricity use.

Yes, they still generate electricity in diffuse light conditions, though output will be reduced.

In most cases, no. Balcony solar kits are treated as portable appliances rather than structural installations.

Yes. They require no permanent fixtures and can be easily moved if you relocate.

Panels, microinverter, plug cable, mounting hardware, and optional battery storage.

Yes. Our balcony solar kits are modular and compatible with Thunder Energy battery systems.

Our systems are designed for DIY installation if you are a competent installer. Mount it, plug in and start generating.

All balcony solar systems come with a 3-year panel warranty.