We had solar panels installed a week ago. A few people have asked about them already, and I thought I might write up some of the things that I’ve learned in the process.
1. Watch out for salesmen. I made the mistake of asking a company for an online quote, not noticing that it was a quote service that gave my details to several solar companies. I was harrassed for weeks on the phone. Ask around locally, get some recommendations, and choose a handful of companies to contact directly. Be aware that, like the double glazing industry, they will want to send a salesperson round with presentations. One kept talking at me for two hours.
2. Time is short. I would have liked to have had solar installed years ago, and for a number of reasons we couldn’t do it until now. As it happens, shortly after I booked the job in, the government announced the closure of the feed-in tarriff in March next year. If you live in Britain and have been trying to decide if you should invest in solar, you might want to do it now. There will be fewer benefits to having solar next year. More on this another time, because the solar industry may be about to take a hit – again.
3. Install as many panels as you can. When I looked at a fully itemised quote (you may need to ask for this, as the big companies don’t bother) it was clear that the panels are not the big expense. By the time you’ve paid for scaffolding, labour and the inverter, whether you’re going to put 10 or 12 panels on the roof is not going to make a huge difference. The more you panels you can fit, the quicker the installation will will pay for itself. Our system will provide twice as much electricity as we use in a year, scaled in expectation of our next car being electric.
4. Domestic storage batteries don’t add up yet. I wanted a battery. I still do – solar produces the most electricity in the middle of the day, and we use it most at breakfast and dinner time. Unfortunately when I looked at how much electricity we actually use, what we pay for it and the cost of a battery unit, there’s currently no saving. The price of batteries is expected to fall considerably in the next couple of years. There may even be government support for storage coming. We’ll get one later.
5. Solar installation isn’t disruptive. We had one engineer on site, and he fitted the whole system on his own in a day and a half: one morning inside, running wires through the loft, and one day on the roof. There was no drama, very little noise or mess. As home improvements go, it’s one of the least disruptive of the many things we’ve done with the house over the years.
6. Get live energy monitoring. One advantage to modern solar systems is that you can get live energy monitoring on a phone app. Ours is through Solar Edge, which shows us what the system is generating, what we’re using ourselves and what’s being exported. It costs more to import from the grid than you get from selling back into it, so ideally you want to use your own power and do energy-intensive things when the sun is shining. Here’s a cloudless September day last week:
7. Solar power changes the way you use energy. In the graph above, you can see the waves of the fridge’s cooling cycles through the night, then a kettle boiling in the morning. My wife made some bread rolls to take to work, just a little bit too early to make it solar baking. In the afternoon I mowed the lawn, did a load of washing and cooked dinner before the power dipped in the evening. I am thinking a lot more about energy and when we use it. I’m much more aware of how much power things draw, and it would help if some of our appliances were lower wattage.
8. Smart appliances make total sense. I haven’t paid much attention to smart appliances. Sticking ‘smart’ in front of something is often a way of selling it to suckers. But seeing how the fridge draws energy at various points, or the peaks in demand that can occur if the kettle and oven are on at the same time, it really brings home what a balancing act the grid is performing. Smart appliances that draw energy when demand is low, EV batteries that discharge into the grid at peak times, and distributed storage are much less theoretical than they were to me last week.
9. Ask for bird proofing. Solar panels make lovely dry places for birds to nest, but they can cause a mess of twigs and bird poo that can clog and damage guttering. Over time, they can damage wiring too. It’s a whole lot cheaper to fit bird guards while the scaffolding is up, than have to pay for it to be retrofitted later.
For anyone in the Luton area, our installation was by the local company Gechnology, who I can recommend.
The Earthbound Report 
I’m in the U.S. and went solar about 4 years ago on a lease to own program.
We get credits for Kw put into the grid and use them at night or high demand times.
How do you monitor individual appliances? Would love to monitor mine.
Having solar does change how you use electricity. I try to do laundry during the day and turn off the lights at night.
I have a little meter that I can plug into a socket, plug the appliance into that, and it tells me how much power it’s drawing. I got it a few years ago to identify the things that were contributing to the underlying load on the house. I can get less precise readings by watching the live PV monitoring and seeing how the usage shifts as I switch things on. We cook on electric, and I’ve been noting how far I can turn up the heat and remain on solar.
Very useful article. Shame my semi doesn’t have a south-facing roof or I’d have done it ages ago. But I’m planning to move and solar is in my plans…
That’s one of several reasons why we didn’t install earlier – we’re not south facing either. Kind of west south west. When we moved in ten years ago the general wisdom was that our house wasn’t suitable for PV. By waiting a few years we’ve been able to install the next generation of panel, which is more efficient and also cheaper. We’ve also got power optimisers on each panel, and those are relatively new to the market. The economics have changed and our previously sub-optimal roof is now feasible.
Useful article! Do you use your solar to heat your home?
We have gas central heating, and reducing our heating bills with wall insulation is the next step towards my long term goal of a zero carbon home. But since we have excess solar power during the day at the moment, I am investigating low wattage trickle heaters. If all goes to plan we’ll be able to heat the house on solar during the day and then top it up in the evenings from the gas.
Well done Jeremy for joining the solar revolution. You are right about the scaffolding take the opportunity to do anything else up there while you are at it. My last installer said that he had installed some east facing roof systems and surprisingly it wasn’t that bad in terms of power output. In Edinburgh there is at least one system that must face almost due north also near Stirling on edge of M9. Like to know how they got that past the fit…
Interesting! I would like to have the option to measure our solar input and our electricity usage. Not sure if we could do that. At the moment I can only see whether we are running a surplus at that exact moment.
I do recognise myself in your description in the change in behaviour and awareness of power usage and when I run my appliances, and unfortunately also the relentless cold calling. (Iam confident my details were sold to a few different companies too. “Oh hello, it’s Mainframe ringing me again!”)
And yes affordable energy storage would be fantastic. Have you heard about this: https://www.wired.com/story/battery-built-from-concrete
It’s a fairly recent article, and it’s such an easy straightforward solution. To me (not an expert) it sounds amazing. Can’t believe we haven’t thought about this before.
GFY – what size array …. I’m guessing between 5 and 10 kw. My brother put in 27 kw of solar a few years back though he is n a small farm in sunny Saskatchewan. We have lived off grid for 4o years and have a 1 kw array which we plan to enlarge this winter to 3 kw. because we just installed an energy star full size freezer. We also have a 1 kw micro hydro turbine running 8 months of the year and we also use other solar applications like a solar oven, passive solar gain through windows, a true solar greenhouse with water energy storage, and a batch solar water heater that we bought in 1985 for $1200.00 and has served us trouble free ever since. It’s so wonderful for me to see solar finally being embraced more fully. It’s well past it’s due date. Great articles Jeremy … please keep up your inspiring research and writing… to borrow form Fritz Schumacher, good work!
Ours is 3.8, which is as much as we could stick on the roof. We’ve already done a lot of work on efficiency and our usage is under half the UK average, so that will provide what we need. Living off grid is another challenge altogether though, and it sounds like you have a lot of useful techniques. The water heater sounds like particularly good value! Solar PV is being rolled out widely, but passive solar is still underappreciated.
Jeremy, a bit of a practical point but is your Solar Edge monitoring integrated with a smart meter? Just wondering how it knows your own consumption. Look forward to hearing about wall insulation – internal or external? Nice work.
No, it’s an independent system with it’s own sensors for incoming and outgoing power. We’re having a smart meter installed next week, and I’m going to have to make sure they don’t wreck my monitoring in the process!
Insulation will be external. We’ve got some repairs to do on the front of the house that make the job rather complicated, so I suspect we won’t get the benefit of it this winter.