Spring is the start of higher solar generation so it’s interesting to see how our 3.6kW system performed.
Our Monthly Solar Performance
March 2023
Generation this month of 266kWh was lower than expected when compared to the estimated generation of 312kWh for our solar system.
It was interesting to see our self consumption increasing to 37%. We’d started to increase our self consumption by checking the forecast and planning to run high power appliances (washing machine/dishwasher) on days where solar generation looked good. As we moved to Octopus Flux on 10th March we were now able to take advantage of the low cost flux period and run appliances on timers during this period.
The month started poorly and started to pick up towards the end of the month with some days over 15kWh. Our highest daily generation was 17.3kWh.
April 2023
What a difference a month can make! This month our generation of 458kWh was higher than the estimated generation of 403kWh. Our self consumption had also increased to a whooping 46%. This was helped by our move to an EV at the end of April. We were able to charge the EV off the 3 pin plug 2kW charger during the day and use some of the excess solar generation on a couple of days. That’s not something you can do with a petrol vehicle!
Every day except two were over 10kWh. We also saw six days over 20kWh. The highest being 24.4kWh on 4th April.
By the end of April since installation in December 2022 our solar system had already generated the equivalent of our annual electricity use. It took just over 4.5 months in winter and spring to produce the equivalent of our annual use. One of the reasons we installed solar was to generated our own green electricity and help the move towards a green energy future, theoretically we’d already become electricity neutral in the 5 worst months for solar generation.
May 2023
May started off quite poorly. By the mid May solar generation was only around 160kWh, which was quite low compared to May’s estimated generation. Thankfully great weather towards the end of the month meant generation increased and we ended by generating 487kWh, which was slightly higher than the estimated 443kWh expected.
We very nearly broke the 25kWh barrier on 20th May (24.9kWh). That barrier was broken the next day (21st May) with 26.5kWh, our highest ever daily generation.
Our self use consumption (29%) as a percentage of total consumption was lower than April. Whilst this sounds worst than April our total consumption had quadrupled due to getting an EV and charging at home. Actual self consumption had doubled as a kWh value due to being able to direct some excess solar to the EV instead of exporting it.
The EV means our daily electricity use can vary greatly. We also had a home battery installed at the end of May. Since it’s been installed our home has hardly imported any electricity.
Going forward the battery should be able to store solar power to meet the electricity demand of the home. Hopefully only the EV should need imported electricity to charge it.
Generation Performance
Generation performance has been very good in April and May. A period of poor weather in March meant that month was lower than expected. It’s good to see the actual generation closely meet the estimated expected generation for our 3.6kW system.
So far this year actual generation is slightly ahead of the estimated generation.
Savings
Due to initially starting on Octopus Outgoing then moving to Octopus Flux it’s made calculating actual monthly savings much harder. It didn’t help that our billing didn’t cover a calendar month. I’ve managed to create averages based upon billing from Octopus Energy. Thankfully that should be easier going forward as Octopus have altered our billing to calendar months so actual billing should align with data from the apps.
The savings really started to pick up in spring. The higher Octopus Flux SEG export rates have helped too. Spring brought total savings of £315.71. £238.58 was from SEG export payments as we exported a total of 986.1kWh this season. Self consumption of 224.9Kwh saved £76.43.
High SEG export revenue in the spring will hopefully continue throughout the summer months. The EV complicates matter tariff wise. The obvious tariff to have would be an EV tariff as we now have an EV, but SEG export rate would then drop to only 4.1p. I’m going to have to do some calculations and testing to see if staying on Octopus Flux is beneficial during the spring and summer months, even though the low cost period is slightly shorter and more expensive than the Octopus Go tariff. It is a shame that there doesn’t seem to be a tariff that designed for both solar and EV owners as the two often come together so well.
Summary
Key Statistics for spring:
* 1211kWh generated
* 986kWh exported
* 38% self sufficiency from solar
* £315.71 saved
* 26.5kWh (21st May 2023) - highest ever daily generation
Our spring results have started to show the benefits and potential savings that are possible with solar. Solar generation really started to pick up in spring. Hopefully it’s a sign that we can expect similar to the estimated generation through the summer months.
The installation of a home storage battery should mean we become less reliant on imports from the national grid for home use during the summer months. Hopefully we can also divert some of the excess solar energy to the EV instead of exporting it to the grid.
It will be interesting to see how the home battery and EV change the way we manage the solar generation. Up to now it’s been a case of try ing to use what we can by load shifting to good solar forecast periods, but generally don’t worry too much as SEG export rates have been great. The combination of home battery and EV does change things, especially when considering what our best tariff would be. Do we prioritise the EV or the SEG export? That’s something to think about over the coming months.