My results after a couple of years running

So my system went live in March 2022. Since then I've been gathering monthly data. At the end of 2023 I had a full calender years worth of data and thought I'd summarise it to give an idea of how the systems performed.

Excluding EV Charging (see note at the end) and standing charge, my household electricity cost for the last 12 months has been £442. Without solar & battery that would have been £1134, so I've saved around £700 this year. If I also include SEG export payments (Octopus Outgoing Lite) of £108 - thats a total saving of over £800.

Overall I can say I'm pleased with my setup, how its performing and the benefits its returning.

One note - the majority of my peak grid use is a morning electric shower. If I switch to a shower from my how water cylinder, my grid peak usage will be almost zero

For reference my system is 5.2kwp of solar (JA Solar) & 7.2kwh of battery (Pylontech). The system is a Moixa Smart Battery, so needs no management from me. I don't have a PV Diverter or Solar EV charger - Hot Water heating and EV charging is done off-peak. I'm on Octopus Go and have chosen it over Flux as my Off-Peak EV charging would exceed any benefits of bigger flux export rates

A note on my EV Charging stats - the observant amongst you will see that theres a marked increase in household consumption between August and December - this is due to having to do quite a bit of daytime EV charging and I've had to consider it household consumption as I have no easy way to split off the EV daytime charge data from normal household consumption

Tracking your own savings

If you'd like to track your own savings, there's a very simple approach.

Each month take the following readings - all are in kWh

1. Export reading from your smart meter 
2. Solar consumed by your house from your systems App 
3. Off-peak charging to your battery from your App
4. Battery to house (might be "Discharge from your battery") from your App

With these numbers there are two calculations needed. One for what the cost would have been without your system and one for with the system

Without your system = (Solar consumed by house + Battery to house) x (normal peak rate tariff)

With your system = (Off-peak to battery x off-peak tariff) - (Export x Export tariff) 

The difference between the two is your saving, and if you track that saving over time against what you spent on your system you'll track your Payback/ROI

Caveat - this won't be 100% accurate as there are losses from what goes into Vs what comes out of the battery, but it should be pretty good for most.

Next Step: Further Reading 

One final note

If this blog has helped and you go on to installing a solar or battery solution, please let me know by leaving a comment and sharing this page as I really like to know I've been able to help. 

If you're considering a move to Octopus to charge your batteries in the darker months, please consider using my referral link below (click on the Octopus) as it will give each of us £50 off our Octopus bill.