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A few thoughts about the state of the UK installation market for solar and battery storage.

I keep seeing adverts with crazy low prices for installation of solar and storage. I know from experience that the companies offering these prices will not do a good job. They work on a virtually non-existent margin, and rely on volume to create enough revenue. It’s not just small companies – there are plenty of bigger companies that employ this model too. My advice: steer well clear!

A good install starts with understanding the clients needs. Both current and potential future consumption need to be understood to correctly size a system within the physical restraints of the property. A one-size-fits-all approach fails at this first hurdle.

Then there is the quality of the equipment: it’s not just the panels and inverters that matter (and they very much do!), but all the other seemingly insignificant components, from the MC4 connectors to the cable, breakers, consumer units etc. Skimping on any one of these things will not only cause recurring problems that can be difficult to identify and fix, they can also represent a very real fire hazard.

Then we come to the work itself. The installers working for these cut price companies will undoubtedly be under pressure to get the job done in a fixed amount of time. Well trained and experienced installers can work fast and well, but you are unlikely to find any on these jobs. They are likely to be poorly trained with little experience or understanding of the equipment they are working with. They will be poorly motivated, and likely to cut corners. This means that, for example, they will probably not take time and care to terminate cables well, and use calibrated tools to achieve correct torque. Again this leads to potential problems and fire hazards. The lack of understanding also means they probably will not know how to commission the equipment properly, or even check that they have the CT clamp the right way round. So you may be left with a barely functioning system that has not been set up correctly.

Commissioning and proper handover of a system is a crucial step that is usually skipped by the cowboys. Manufacturers have tried to make they process as simple as possible, but the installer must have at least a basic knowledge of how a system works to be able to do it properly. They also need to understand the consumer app, and how to set it up properly for the customer, and show the customer how to use it. This means being able to go through the different work modes, how to set schedules, and explaining how to get the most from the system. This rarely happens, I’m sad to say.

Finally, there is the admin side of things. Before the install can happen, an application must be made on your behalf to the DNO, and permission received to install the specified equipment. Once installed, the DNO must again be notified, and commissioning documents sent in to them. MCS also sets out requirements for handover documents: you must be given an SLD, instructions for basic operation of your system, warranties etc.

In conclusion: if you want an unsafe system that barely functions, will more than likely require costly repairs, with no explanation of how to operate it, then by all means go with the cheapest quote!

If you want a quality, well thought out installation that will work for years to come without regular repairs, and a thorough explanation of how it can work best for you, then take your time to find an installer that cares about what they are doing. It may cost you more at first, but it will save you in the long run, and give you peace of mind that it has been done properly.

Seasonal storage combined with current battery technology is the future.

The problem we have in the UK is that our solar generation is very much seasonal, and of course the majority of it happens when we need it the least. This will become even more pronounced a problem as we transition away from using gas to heat our homes. Heat pumps are way more efficient, but the cost of installing and running them outweighs the benefits for a large number of homeowners, myself included.

For six months of the year, the solar panels on my house are going to generate more electricity than I can use or store, and that excess is exported to the grid, generally at times of least demand. At the moment it makes financial sense to export that energy, but that is not going to continue. Export prices have recently dropped by 25%, and that downward trajectory is only going to continue.

I have 10kWh of battery storage, which allows me to run almost entirely from off peak electricity through the winter, but between that and the gas I use to heat my home, my bills are still not where I want them to be in winter. Were I to switch to electric heating, that 10kWh of storage would not be anywhere near adequate. I would probably need closer to 50kWh, and that starts to become expensive. There are ways to see return – I could for example switch to agile export and use the extra storage to export during peaks to maximise revenue, or register with a VPP aggregator such as Axle and have them utilise the extra capacity.

Ideally, what is needed for homes like mine is to move towards greater self sufficiency and away from importing energy. This is the ultimate protection against price shocks and any kind of energy instability. The way to achieve this is through seasonal storage: capturing and storing that excess generation in the summer and using it through winter. This is a very hard thing to achieve, particularly on such a small scale. Long term storage using current technologies tends to be very inefficient, and only works well at scale. I have looked at a couple of ideas being developed, and although interesting I don’t think they are quite there yet.

The first is sand batteries: basically a big insulated box of sand is buried in your garden, and is heated with excess energy. That heat is then used when required to heat either water or air in your home in winter. I don’t know what the round trip efficiency is, but I don’t expect it to be great. Its not really a practical solution for many, but it could work for some homes More info here: https://www.batsand.com/heating-battery

The second is Hydrogen fuel cells: excess energy is converted to hydrogen through electrolysis, which is then converted back to electricity via fuel cells. There are systems available, but they are very expensive, large and unwieldy. Hopefully this will change as the technology gradually improves, and becomes more affordable. There are companies offering systems at the moment such as: https://creouk.com/hydrogen-systems/

Season storage is not yet affordable or practical for those without large homes and deep pockets, but the technology is evolving, and I hope will soon mature to a point where it does start to make sense in both practical and financial terms. Seasonal storage combined with short term battery and solar technology that we already have will eventually lead to energy independence for many homes and businesses, reducing reliance on the grid, and also reducing the need for the massive infrastructure required to transmit energy over long distances. Localised generation and storage is surely the way forward.

I have successfully connected my WHES single phase Agave system to Home Assistant, which means I can now use automations to avoid draining the house battery when charging the car.

I prefer this to making the system ‘blind’ to the charger as many installers are doing currently. Although it does get round the problem caused by using Octopus Intelligent Go and similar tariffs, it means that you don’t get a complete picture of your usage through the monitoring app, and also poses a risk, albeit small, of blowing the DNO fuse.

With the help of Claude AI in generating the YAML code for HA, an ESP32 board and RS485 to TTL converter, the system is now running smoothly after a few teething problems. The code generated by Claude had a few mistakes that needed editing out, plus a few tweaks to make it work the way I have everything wired here needed a bit of experimentation to get right. I also discovered the Wifi antenna on the ESP32 board I bought was very poor, so had to relocate it next to the router to avoid dropouts. However, ti all seems to be running smoothly now, and I just need to perfect my automations in HA.

I designed the first UK installation of the WHES Powerpod S2 on behalf of Volta Eco Systems Ltd, with installation due to be completed this month by Spartek ECS Ltd.

The WHES Powerpod S2 is an all in one hybrid inverter and storage system with a range of inverter power from 3.6kW to 10kW on single phase. Storage comes in stackable 4.99kWh modules, with up to 4 in one stack, and multiple stacks are possible on a single inverter with the addition of extra HV boxes.

This is a versatile, compact, easy to install system.

This first system is a large one for single phase: 2 x 8kW inverters, each with 15kWh of storage, running in parallel, with 22kWp of panels on the roof. The homeowner is installing ASHP and air to air conditioning on a fairly large house, so will be using a comparatively large amount of electricity. This system will not only generate a lot over the summer months, but will allow him to maximise use of off peak electricity in the winter.

I will be attending to assist with commissioning, and look forward to seeing this system in action