EcoFlow vs Thunder Energy: Which Plug-In Solar System Is Right for UK Homes?

Plug-in solar is about to become a reality in UK homes. The government has confirmed it. The regulations are being updated. And the question everyone is now asking is: which system should I buy?

Two names keep coming up: EcoFlow, the global portable power brand, and Thunder Energy, a UK-based company that has been installing compact solar systems on balconies, fences and garden walls before plug-in was even on the table.

These are genuinely different products built with different approaches. This post puts them side by side so you can decide which one fits your home.

The two systems

EcoFlow STREAM is part of EcoFlow's wider portable energy ecosystem. The UK balcony solar kit typically includes two 400W rigid glass solar panels and the STREAM microinverter, giving you up to 800W of capacity. EcoFlow is a global brand headquartered in Shenzhen, China, known for portable power stations and battery products. Their balcony solar range is designed primarily for European markets and has been adapted for the UK.

Thunder Storm is available in two sizes: the Storm 360W (two flexible panels) and the Storm 710W (four flexible panels), both paired with a Hoymiles HMS-800W microinverter. Thunder Energy is a UK-based company headquartered in London, focused specifically on compact solar for homes where traditional rooftop solar is not viable. Thunder has completed real installation projects across London, including a multi-flat balcony solar project in North London.

Panel weight: the biggest practical difference

This is where the two systems diverge most significantly, and it matters more than you might think.

EcoFlow uses rigid glass panels. Each 400W panel weighs 21.8 kg. A two-panel system means 43.6 kg of panels that need to be mounted on your balcony railing, wall or outdoor surface. That is a serious amount of weight, particularly for older balconies, timber fences or lightweight garden structures common across UK housing stock.

Thunder uses lightweight flexible panels. Each panel weighs 3.5 kg. The Storm 710W with four panels totals 14 kg. The Storm 360W with two panels totals 7 kg.

To put that in perspective: a full EcoFlow panel setup weighs more than three times a Thunder Storm 710W. If you are mounting on a garden fence, shed wall or balcony railing, this difference determines whether the installation is physically possible.

Price

EcoFlow STREAM kits start from £499 (member price) for a lattice balcony system with two 400W rigid panels and the STREAM microinverter. The non-member price is £579. Kits for concrete and glass balconies start from £649 to £749 depending on the configuration. These prices are for the kit only with no installation included. Mounting brackets are sold separately.

Thunder Storm 360W starts from £499. The Storm 710W starts from £649. Both kits include flexible panels, the Hoymiles HMS-800W microinverter and mounting hardware.

Where Thunder pulls ahead on value is the installation option. Professional installation across Greater London is available for £399 on top of any kit. That covers a qualified electrician, fused spur wiring on a dedicated radial circuit, and G98 DNO notification. With EcoFlow, you buy the kit and then need to find and pay for an electrician separately, as UK regulations currently require professional installation for all plug-in solar systems.

Installation and UK support

Both systems require professional electrical installation in the UK right now. EcoFlow is upfront about this on their UK website, stating that the STREAM microinverter must be connected to the distribution board by a qualified electrician.

The difference is what happens after you buy.

With Thunder, you can book professional installation directly. Thunder handles the full process: site assessment, panel mounting, electrical connection, and G98 DNO notification. If something goes wrong, Thunder is based in London and provides direct UK after-sales support. Thunder also sells kits for DIY customers across the UK and provides free guidance on finding a local electrician and completing the DNO notification process.

With EcoFlow, installation is your responsibility. You purchase the kit, source your own electrician, and handle the DNO process yourself. EcoFlow's customer support is available in the UK, but the company is a global manufacturer and does not offer installation services.

This is not a criticism of EcoFlow. They are a hardware company selling a product. Thunder is a hardware company that also provides installation and ongoing support in the UK. Different models, different strengths.

What happens when plug-in solar regulations arrive?

Both systems are designed for plug-in operation. When the new UK standards (BS 7671 Amendment 4 and the BSI product standard) come into effect, both EcoFlow and Thunder systems should be able to transition to a simple socket connection.

The key difference is that Thunder customers who have already installed via hardwired connection will need only a minor change to switch to plug-in. The panels and microinverter stay exactly the same.

Where each system works best

EcoFlow is a strong choice if you want a system with a large battery ecosystem and plan to expand with multiple STREAM units over time. EcoFlow's smart home integration features are great, too. If you are comfortable sourcing your own electrician and managing the installation process, EcoFlow offers a polished product with a global brand behind it.

Thunder is a better fit if you need lightweight panels for surfaces that cannot support heavy rigid glass (fences, older balconies, sheds), you want professional installation handled for you in London, you value UK-based after-sales support, or you are a property developer looking for SAP/EPC compliance support. Thunder's flexible panels open up mounting options that are simply not available with rigid panels.

Frequently asked questions

Is EcoFlow STREAM available in the UK?

Yes. EcoFlow sells the STREAM range through their UK website with kits starting from £499 for members. However, as with all plug-in solar in the UK, the system currently requires professional electrical installation. It cannot simply be plugged into a socket until the new regulations take effect.

Can I install EcoFlow without an electrician in the UK?

Not currently. EcoFlow's own UK documentation states that the STREAM microinverter must be wired into the distribution board by a qualified electrician. This applies to all plug-in solar systems in the UK until the new wiring standards come into effect.

Which is cheaper, EcoFlow or Thunder?

At kit level, they are similar. Both start from £499. However, Thunder offers professional installation across Greater London for £399 on top of any kit, covering electrician, wiring and DNO notification. With EcoFlow, you need to source and pay for your own electrician separately.

Can EcoFlow panels go on a garden fence?

This would be difficult. Each EcoFlow 400W rigid panel weighs 21.8 kg. Most UK garden fences are not designed to support that kind of load. Thunder's flexible panels weigh 3.5 kg each, making fence mounting practical and safe.

Does Thunder offer installation outside London?

Thunder currently offers professional installation across Greater London. For customers outside London, Thunder sells kits for DIY installation and provides guidance on finding a qualified local electrician and completing the G98 DNO notification.

Which system is better for renters?

Both systems are portable in principle. However, Thunder's lightweight flexible panels (3.5 kg each) are significantly easier to remove and take with you when you move compared to EcoFlow's 21.8 kg rigid panels. For renters who want minimal disruption when moving, Thunder's weight advantage is meaningful.