Hi all,
Sorry if this is elsewhere but I couldn't find it. I have had my system for just over a year and I am thinking of adding another battery. Annually I export 40% of my generation, then 30% to battery and 30% direct to home. From April to September I only drop to 0% charge on my battery occasionally. Is it worth spending the money on more capacity? Is it only worth it if I plan to use agile tariffs to charge the batteries from the grid in winter?
Thanks
Dave
Hey Dave,
Haven't you answered your own question? Your existing battery is big enough to store all of the energy you need each day for the six sunniest months of the year. And for the rest of the year, there's not much to store anyway. Without knowing further details, your existing battery is probably sufficient for a lot of the winter load too. And what's stopping you from moving to an agile tariff without the bigger battery and fully charging each Winter night? Consuming only 60% of generation, even with the battery is low: you could also look at other ways of usefully increasing your direct consumption, such as displacing other fuels for hot water heating, EV charging, etc before splashing out on a bigger battery.
Cheers
Steve
I’d personally stick with what you have same as above.
Bear in mind at some point batteries will start popping up 2nd hand down the line (I’ve seen 15+ Pylontech 1st Gens come and go on eBay last 2 months) so there may be opportunity to add storage relatively cheaper later.
I would look at adding a diverter if you have a hot water tank.
Divert some of that excess solar to hot water.
GE are releasing one later this year which I'm waiting to get my hands on too.
Replace my aging iBoost
TheDragon (GivEnergy) @L139110 Has the solar diverter become largely obsolete with the advent of battery storage? Won't the savings achieved with a diverter be about the same as with a simple time switch if a property has sufficient battery storage to iron out the peaks in demand, despite significantly higher installation costs for the diverter? Charge the battery in the morning, set the hot water timeswitch to coincide with peak generation and any extra will automatically come from the battery.
stevelewis yes, I kinda wondered -with batteries - why you'd want to spend £500 on a divertor device for your HW?
Batteries are a game changer for domestic solar!
stevelewis
Thank you
I hadn't look at it that way! I do export some in the winter months when I also import more. These were the months that I would be trying to make my money back on the investment.
The EV charging isn't an option as I don't need a car. I wanted the extra battery so I could get the savings associated with an EV but if I can't use the electricity as I don't need it it isn't a saving.
Most people I see on here seem to be with octopus for their agile tariffs. I was thinking of going for an economy 7 to simplify things. Any advice on this front.
Thank you,
I'm not sure what 15+ means? Storage, age? Sorry I'm not well read on this stuff.
I'm thinking of setting up a homemade solar system for my shed so this would be useful (as a fun project).
L139110 sorry it was just 15 different ones people had for sale over the past few months. (I bought 3 of them though)
L139110 The Octopus Agile tariff took a tumble as prices went up, I think most people have moved to Octopus Go, which is similar to Economy 7, but with a more competitive day rate and a 4 hour cheap rate window. Best to shop around and see what suits your needs.
I would agree with the octopus go as an option to support batteries as gives rate of 7.5p pet kWh from 0030 - 0430 (fixed for 12 months). Only recently had system installed - 12 panels plus 5.2kW battery storage, already going to increase storage capacity by a further 2.6kW to maximise low rate "purchase" in winter months and see how that pans out.
Taking a while to understand where the peaks and troughs are but, as with anything the devil is in the detail to plan consumption at peak times. But well happy!
stevelewis I think most people have moved to Octopus Go
I have recently moved from Octopus Go to Octopus Agile as I found last year that I was importing less than 1kWh per day on around 98% of the days between mid March and mid September but exporting a significant amount on most days. The benefit of Outgoing Agile variable rate more than offset the higher rate for the small amount of imported electric
As an example yesterday my import was 0.7kWh at a cost of 43p, but I exported 22kWh at a credit of £3.87. If I had been on Go, and all my import was at 7.5p per kWh my import would have only cost 38p less, but my import at 4.5p per kWh would have credited my account £2.88 less a net loss of £2.50.
Of course if your import/export balance is different the calculation would be different, but it is important to calculate the value of export as well as the cost of import. The standing charge on Go is also double the Agile standing charge.
Martyn thanks for an interesting take on Octopus Agile. Our PV was installed in 2013, so we benefit from a 50% deemed export. Moving to Agile, even during the summer, wouldn't work as well for us. Winter is a whole different story due to the ASHP consumption.
stevelewis Octopus Go doesn't give you the export tariff at the moment.
Octopus Agile is the only one that pays the £0.075 per kWh.
Billywizzer Octopus Go for consumption and a separate Feed In Tariff for the generation dating back to 2013 😁
Billywizzer Octopus Agile is the only one that pays the £0.075 per kWh
Octopus Outgoing Agile pays way more than the fixed agile. Has been over 15p per kWh for pretty much the whole of the last 4 weeks or more.
Not during off peak times it hasn't - there has been a big drop-off in export rates. Even at peak times for the last week it has rarely been above my normal supply tariff rate. Lots of wind and solar I guess.
Martyn Octopus Powerloop pays 15p per kwh exported between 4pm and 7pm. As an added bonus they charge 4.7p per kwh for any import between 23h30 and 05h30....
So we can almost cover our import bill by exporting 1/3 rd during the export hours.
Isn't Octopus Powerloop a trial thats only has 135 users and is currently closed to new entrants?