How solar reduced Jo’s electricity bill to just £17

Friday, 17 September 20216 minute read

One month on from installation, home solar and battery storage trialist Jo is now up to 93% self-sufficient. Jo explains how, and why she can’t believe her luck.

Jo’s house covered in scaffolding and solar panels being installed

It's been a whole month since our solar and battery storage trial began, in partnership with Lightsource Labs. So we thought it was about time we caught up with one of the Pure Planet team members taking part in the trial to see how they’re finding things so far.

In this blog, Business Analyst Jo Bushnell explains what made her take part in the trial, what the installation was like and how she’s getting on with her new solar panels, battery storage and the accompanying Tribe app (spoiler alert: She loves it!).

What made you decide to get involved in the solar and battery storage trial?

My husband and I recently bought a house in Sedbury – a village in the Forest of Dean, just a stone throw from the Welsh border. Our house sits on a hill overlooking farmlands, with a backdrop of the handsome old Severn Bridge.

A view of the village of Sedbury showing Jo’s street with solar panels already installed on many of the houses

After moving here, we quickly noticed that the area is getting plenty of sunlight. It would also be difficult not to spot that almost every house on our street has solar panels on the roof. As we’ve always been huge fans of renewable home generation and reducing our carbon footprint, applying to take part in the trial was a no brainer and we went for it in a heartbeat!

How was the installation?

We were the fourth (out of five) house to have the kit installed so any teething problems that the installers may have had before were ironed out by the time they arrived in Sedbury on Thursday around 8.30 in the morning.

Jo’s house covered in scaffolding and awaiting the installation of the solar panels

The installation was quicker than we expected – it was all done and dusted by 3pm (I know that it took longer for my colleagues on the days prior). The installers were super friendly and knowledgeable and we did ask a lot of questions about each item of the kit that they installed. Overall, a really positive experience.

How have you found things so far?

We still can’t believe how lucky we were to be selected for the trial. It very quickly became clear that with our current usage patterns, we would be self-sufficient for most of the time during the day. But to find out that we can be up to 93% self-sufficient was a bit of a shock!

For a house with a really power-hungry electric cooker where we cook our meals every single evening, the cost of our electricity usage for the month of August was just over £9. Nine pounds! Add Membership Fee to it (£8) and you’ve got the lowest electricity bill ever.

We know that this will change in winter – because the sun is up for much less than in summer (so there’s less energy generated to store and supply our demand during the day) and because we’ll be switching the lights on much earlier in the mornings and evenings. But even so, if there’s enough sunlight to charge the battery, we’ll be saving loads on our monthly bills.

What do you think of the Tribe app?

It’s totally mind-blowing how much we’ve learned about our usage patterns and the efficiency (or, sometimes, lack of!) of the appliances at our place, thanks to Tribe.

Its two main features are a live view of the electricity flow between different parts of the installation (so the solar photovoltaic cells, or PV, battery, grid and the house) and a daily graph summarising what happened from midnight.

Screenshot of the Tribe app’s live view, which provides a snapshot of the current solar generation and battery status and screenshot of the power chart in the Tribe app, showing consumption and generation of electricity

You can learn how much energy the PV generated, how much of it was consumed by the appliances in the house, how long it took to charge the battery and, subsequently, how much of it was then discharged to meet the demand of the house. It also shows when electricity was pulled from the grid – this normally happens when there’s no or not enough solar generation or battery to sustain your self-sufficiency.

It took us one day to learn that the electric shower – an unassuming little box – is almost four (!) times more power consuming than the range cooker. We’ve found out that the dishwasher has two spikes in its energy usage (at the start and finish of the cycle) and that our fridge-freezer doesn’t consume much at all, despite it being rather large, and constantly on.

On a sunny day, we now try to use the on-demand appliances during the day, to maximise the output from the solar panels. On a cloudy day, when solar generation drops significantly, we allow the battery to fully charge to then let it support our demand in the evenings.

What would you say to anyone thinking about investing in solar and battery storage?

First, consider your location and the direction of the roof. At what times of the day is it getting sunlight? How will it differ season to season? This is the major consideration. If the roof isn’t getting much sunlight then solar may not be viable for your house.

Then think about your usage patterns at home. Is your consumption low during the day? Is it likely that you would generate a lot because there’s not much going on in the house when the sun shines? How much power and for how long do you need in the evenings? This will hint at the size of the battery storage you’re going to need when deciding on the kit for your home.

Finally, definitely go for battery storage. Unless your peak consumption is during the day and you don’t need any energy in the evenings, installing just solar PV wouldn’t really make a huge difference to your energy bills. In the future, there will also be more and more interesting export tariffs on the market, allowing you to discharge your battery at peak times at higher unit rates.

If all that sounds sensible then go for it. The long-term gains and your self-sufficiency are worth it.

Keep an eye on our website, blog and the Pure Planet Futures section of the Community, where we’ll be sharing updates on the progress of the trial, as well as information for Members who might like to get involved in the next stage of the trial themselves.

Business Analyst