One of the things we wanted solar to do was to reduce our energy bill monthly outgoings as I saw investing in solar as pay our energy bills upfront.
To look at if installing solar has affected our energy bills I need to understand our energy use over a year. Thankfully due to the amount of data gathering by our Solar Inverter, Octopus Energy and Myenergi app's I know where we used energy in our home in 2023.
Our Home energy use
In 2023 we used a total of 1604kWh of electricity (home use only - this doesn't include the EV) and 4832kWh of gas for heating and hot water.
If we were compare this against the average gas and electricity use in the UK provided by Ofgem we are in the low energy use category. I'm not surprised our home electricity use is in the low category as there is only my wife and I, but I'm surprised our gas use is as low as it is because we have a 3 bedroom semi. In a way it's not surprising as our gas boiler thermostat monitors the temperature in our open plan lounge/diner/kitchen, which is where we spend the majority of time. The rest of the house is colder in the winter months but that's not too much of an issue as we don't spend as much time in those parts of our home.
Energy use without Solar
Like many others our energy use has varied over the year. Our gas use was higher in winter than in summer due to the need to heat our home in the winter. Our electricity use has differed too. This is mainly due to like many others we started to minimise our electricity use as much as possible over the winter of 22-23 because energy prices were so high. As we got used to having solar and a home battery we started to drop back into old habits of increased energy use because our energy bills had dropped because of solar.
Energy Use with Solar
Once we consider our solar panels our energy demand is either met by imported electricity from the national grid or from electricity generated by our solar panels. This is why there is a difference between the amount of electricity kWh's between the two tables with and without solar.
There isn't any difference in our gas use as electricity generated by our solar panels cannot be used for central heating or to provide hot water as we have a gas combo boiler.
Having solar panels has directly reduced our energy bills as it provides some of the electricity used by our home. In 2023 solar reduced the cost of importing electricity from £1220.27 to £879.70, a reduction of £340.57.
Solar Export Revenue
Any excess solar generation isn't lost as it is exported to the national grid. We weren't paid for our exported generation until the end of February. We were also able to be paid for exporting electricity from our home battery during the winter saving Sessions.
When we look at the effect solar has had on our monthly energy bills it has reduced our energy bills for our home down from £101.69 a month to just £25.79. That's only 25% of the original monthly cost.
Cost savings by swapping to an EV
We are very lucky that we were able to swap our previous company car to an electric vehicle in April 2023. There is very little difference in the monthly cost of ownership of having an EV over the previous ICE car as it's a company car. This is due to the very favourable BiK rates currently pushed by the UK government.
When I compare the cost of having the Ioniq 5 EV to a comparable ICE vehicle (petrol Hyundai Tuscon is a similar size) at present the difference in running costs is huge.
Since we got it at the end of April 2023 we've done 23k miles in only 11 months (average of 2090 miles per moth). If I compare the cost of petrol for a similar sized petrol ICE vehicle it would cost circa £250 a month in petrol. Charging the EV at home costs around £50 a month. That's a saving of around £200 a month.
Granted if we use public charging whilst away from home on longer journeys it would cost much more as rapid charging can cost up 85p per kWh. Since getting the EV we have only used public charging on probably 10 occasions. Even then we minimise the amount of charge by only putting in enough to get us home.
The cost to run an EV is unlikely to stay as low as less than 3p per mile forever. At some point the government will need to replace the loss of tax income from petrol/diesel sales. It's quite likely this will be in the form of a cost per mile tax at some point in the near future. The change to charge EV's VED from April 2025 shows an intent to start taxing EV's by the UK government.
Overall savings
If we add the EV savings to the solar savings its quite a saving as shown in the table below.
If we compare the combined savings against the total installation costs of the solar panels, home battery and EV charger the overall pay back would be less than 4.5 years.
It's great to know the combined savings, especially with the current EV savings (which won't stay low forever), will help pay off the cost of installing all of this technology quite quickly. Hopefully this will be before additional tax is applied to running an EV. That would leave us with a fully paid off solar and home battery system that will provide us with cheap green power for many years to come.