Solar Panel experiences

Following our Solar Panels Evening here is some information and some experiences from those with Solar Panels (some contributors wish not to be named.)

Dr. Ellie Standen

Eco Whittlesford member Ellie is Senior Associate of the Cambridge Institute for Sustainability Leadership. She delivered a very interesting and useful talk. Her notes can be seen here.

John Rawle

EW member John's account of his solar experience is here - he is happy to talk to anyone who has any questions etc.

Sally Thomas

You can read the account from Sally Thomas here.

Laura Sims - My Solar Panels Experience

Installation & costs: We applied for Solar panels under the South Cambridgeshire Solar Together scheme early 2022 and paid a small deposit in April 2022. The panels were finally fitted 20th April 2023 by a company called Greenscape energy who won the bid. In retrospect, I wish I had got a couple of other quotes because Greenscape weren’t really offering any options and I would have liked to know what else was possible.

For instance, they surveyed my roof and said they could only fit 6 panels. I pointed out other areas of the roof but they said the panels had to be all together otherwise you would need a separate inverter for each separate panel. I’d like to have known what that option cost, but they weren’t really offering it. Also they said they weren’t providing panels for flat roofs at the moment. A supply issue I think. Again, I’d have liked that as an option to consider, though we would have needed planning permission, I believe.

When I looked at the layout they proposed I was able to point out they could fit in another panel, so we had 7 fitted in the end. We also had pigeon netting fitted to stop pigeons nesting underneath the panels, which we’d heard can be a problem.

We wanted batteries for storage & were advised that we did not need more than 4.8kw storage

The inverter (that controls panels and sends power to the house, batteries or grid) & batteries take up an area roughly 50 x 23 x 220 cm, and should be reasonably close to your existing fuseboard. They ran a cable from panels on the roof down the wall of our house and into the utility room. They didn’t need to do much or create any damage on the installation, but it helps that we have a new extension with lots of cavity walls & ceilings. Installation took a day, and there was scaffolding round the house for nearly 3 weeks (just in case anything went wrong with the panels). The inverter wasn’t working properly a few days after install, something to do with a firmware update, and Greenscape were slow to sort this out with the manufacturer. I would say they were slow throughout the process.

They were probably cheaper than other suppliers due to the Solar Together scheme. The whole thing cost £7,872

Using solar panels

Our roof is south west & has no shadowing. The average daily power generated has been 11.7kw hours, about £3.78 in current electricity prices. The best day was 19kw hours. I hadn’t realised that the panels will still generate a bit of power even if it isn’t sunny, as long as it is still daylight.

I think it is essential to have battery storage. You can sell back to the grid, but they buy at a very low price so it is best to try & use the energy yourself. During the day in summer our house uses about 0.3 kw per hour, so nowhere near what we generate. We mostly don’t cook during the day and the washing machine & dishwasher don’t use a lot of power. I would say we could do with a couple more batteries in order to make the most of what we generate.

I do have an electric car, so try to add charge to that during the day. However if the power being generated is below about 1.3kwh, it wont add charge to the car (I have Myenergi Zappi charger). Of course, sometimes I’m using my car during the day.

The company predicted we would break even on the cost of installing vs. money saved after 9 years. However my motivation for doing this was to help the planet rather than save money.

Anon - Our Solar Installation

I live in West End - and we have recently installed solar power using the Solar Together initiative by South Cambs. Our installation includes 18 solar panels - 2 rows - top row with 10 panels - bottom row has 8. Rated at 6.7 kWh at full capacity. Our roof with the solar panels is basically west facing. These feed an inverter and currently 6 x 2.4kWH batteries - I think I will add another 2 batteries soon.

The installation was done by Greenscape (Ipswich) who won the contract to install.

The installation of solar panels and the electrics including the inverter eventually happened in October - but unfortunately they "ran out of batteries the week before”. It took just one day for the whole installation. The batteries (4) were installed 5 weeks later in November. Rather frustrating to be producing electricity to the grid for no reward!

We have learnt a lot since the installation - including how long it took for the installation to be recognised by the Power Network and then Octopus (12 - 14 weeks altogether) during which time there was no payment for the excess electricity produced. I am getting 15p/kWh for the exported electricity now.

There is an app provided by the Inverter manufacturer (Solis) which gives quite a lot of information in realtime (well nearly realtime):-

how much is being generated by the solar panels and the daily production sum
how much is being consumed and the daily consumption sum
how much electricity is coming from the grid and the daily import sum
how much is being exported to the grid and the daily sum at the time you are looking at the app.

Watching all of this is rather compulsive - and as we are new to this even more so. There is also a website where you can look at the daily, monthly and yearly data for the above.

Last October and for most of the winter we had very dull weather (all that rain) and so I became rather despondent about the amount of electricity being produced - but as spring was much sunnier, and the sun moved more northerly in the sky, the amount of electricity produced increased to much higher levels - and to over 30kWh per day in recent times (mid May onwards). It is cloudy and overcast as I write this at 12 noon and the panels are still producing around 2kWh - but in bright skies we have had 5kWh and above. So it is very variable, and therefore predicting what the “earnings” are going to be is nigh impossible. However given the phenomenal increases in fuel prices (the majority of which occurred after I signed up to the project) I have little doubt, even with the lower prices projected for the future that it will have been a good investment as it was bought outright. I would not want to be borrowing the money for the investment.

Two other points:

We had hoped to use the stored battery electricity during power cuts (for stairlift, and powered beds and chairs) but currently that doesn’t work - as soon as there is a power cut everything is off. In discussion with Greenscape there is a work around - but only from one power socket installed near the inverter (in the roof). So no good to us!
The other unexpected factor was that the inverter will only deplete the battery storage to around 20% of their capacity - so a fifth of the battery storage capacity is not available. (I believe some batteries are built to allow greater depletion now - down to around 10%.)

There will be several FAQ lists on the internet - here is the link to Greenscape: https://greenscapeenergy.co.uk/solar-panels/solar-faqs