Solar install, batteries, exporting and ev tariffs

[Nickj]

So found out on another thread you can have solar, batteries, export to grid and have an ev tariff so my interest has been resparked.

Interested to know if anyone has this set up and how it’s performing, and any regrets?

Are you all using Octopus intelligent and their outgoing 15p export tariff?

Does my quote look around what you’d expect. It’s a local company, really like them as not pushy. 18 panel system, 12kw batteries for £13k, £1200 extra to have the system flush fitted ‘in roof’ and an extra £700 to change my old pod point to a zappi that would integrate.

 

[Nickj]

The house set by the way is all electric, air source heat pump with under floor heating throughout down stairs. Charging a taycan and missis has an Evoque hybrid that has a 13kw battery and currently uses battery ev only mode most days as it’s a small battery but just about covers her daily miles of 30 or so. Hopefully get a few more miles out of it in warmer weather! Also thinking of getting air con installed ahead of summer!

 

[Dabz]

I have a similar setup to you, but no heat pump (currently quotes are showing a 132 year payback?!). I use OVO and Charge Anytime, so car charging is 7p kWh, and I tend to use grid-only for the car and save all the solar and battery for the house

 

[Nickj]

I have a similar setup to you, but no heat pump (currently quotes are showing a 132 year payback?!). I use OVO and Charge Anytime, so car charging is 7p kWh, and I tend to use grid-only for the car and save all the solar and battery for the house

As in you’ve got solar and batteries already installed? How can payback be 132 years?!
I have OVO currently and it’s great but now moving back to octopus OI as I want to charge the wife’s hybrid over night at same time. I also have one eye on the solar install with this decision so I can charge batteries also on cheap rate, so it’s all ready to go and combine with an octopus export tariff also.

 

[kempez]

The quote looks about right to me. We got our 16 panel setup, with 10 kw (3kw inverter) of batteries and Pidgeon wire for about £11.5k, plus a few hundred more I paid for a Solar iBoost to maintain my tanks hot water when we have spare solar. That was June 2022. We're on Octopus EV and at some point, when the app actually works, I will switch to Octopus IO

 

[Dabz]

As in you’ve got solar and batteries already installed? How can payback be 132 years?!
I have OVO currently and it’s great but now moving back to octopus OI as I want to charge the wife’s hybrid over night at same time. I also have one eye on the solar install with this decision so I can charge batteries also on cheap rate, so it’s all ready to go and combine with an octopus export tariff also.

Yeh we already have 7.4kw solar with 7.6kw of batteries. I got a heat pump quote recently and it was £9297 AFTER the government grant, and estimated savings of £70 per year, making it over 100 years before we make our money back! I was shocked, queried with with the company (heat Geek) and they said sadly, yes, that's the price. Really disappointed as I was very ready to jump on the ASHP thing and get our gas disconnected.

With the solar on OVO I do things like charge the batteries during the day so we use nothing during peak hours, to get our £15/month power move credit. For 8 months of the year our electricity spend is practically nothing other than charging the EV at 7p/kwh.

 

[Nickj]

Yeh we already have 7.4kw solar with 7.6kw of batteries. I got a heat pump quote recently and it was £9297 AFTER the government grant, and estimated savings of £70 per year, making it over 100 years before we make our money back! I was shocked, queried with with the company (heat Geek) and they said sadly, yes, that's the price. Really disappointed as I was very ready to jump on the ASHP thing and get our gas disconnected.

With the solar on OVO I do things like charge the batteries during the day so we use nothing during peak hours, to get our £15/month power move credit. For 8 months of the year our electricity spend is practically nothing other than charging the EV at 7p/kwh.

Ah ok got you, 132 years to pay back the air source pump. Ours was fitted as new build, but to be honest don’t find it very efficient hence your payback period!

Does your system charge the batteries up daily during winter days?

I do like the OVO power move events and was being credited £50 a month for 2 months on the bounce, which was a bonus. I do think octopus may be better for me, charge batteries, taycan, hot water, hybrid evoque all at low rate then sell back to grid solar generated is the plan.

 

[Dabz]

Ah ok got you, 132 years to pay back the air source pump. Ours was fitted as new build, but to be honest don’t find it very efficient hence your payback period!

Does your system charge the batteries up daily during winter days?

I do like the OVO power move events and was being credited £50 a month for 2 months on the bounce, which was a bonus. I do think octopus may be better for me, charge batteries, taycan, hot water, hybrid evoque all at low rate then sell back to grid solar generated is the plan.

During the winter we get barely anything - ours is south facing with no shading but on many days there’s no generation at all. The shorter days in Dec/Jan are a write off. It’s only this week that we’ve started filling the batteries again each day, but it should now be like that until October with any luck.

I love our solar though, I recommend it to everyone and find it fascinating to see electricity being generated

 

[Nickj]

During the winter we get barely anything - ours is south facing with no shading but on many days there’s no generation at all. The shorter days in Dec/Jan are a write off. It’s only this week that we’ve started filling the batteries again each day, but it should now be like that until October with any luck.

I love our solar though, I recommend it to everyone and find it fascinating to see electricity being generated

Ah ok, not good on the winter generation. The quote suggests 6kw per day ? We are SW Facing with no shade on the solar side. This doesn’t sound realistic then?

I do think I would love the solar and would get into it though like you so this is good to know.

 

[Dabz]

Here’s Dec and Jan this winter - it works out a little below 4kwh a day. It does vary - the graph below is mid-Dec to mid-Jan and some days are nothing, others not too bad

On the other hand, in the summer it generates more than we can deal with so we end up dumping a load in to the grid. This year we’ll have 2 EVs so if we’re home we’ll plug in and used the excess for those. During a week away in July last year we were exporting over 110kw to the grid on top of what the house was using to idle

 

[bn8959]

I have:

6kWp panels (15x REC 400w)
SolarEdge 3.6kW inverter (DNO wouldn’t allow me a 5kW one annoyingly)
Tesla Powerwall (13.5kWh)
Zappi EVSE
Eddi hot water diverter

only have the Taycan and Zappi since October though.

im on Octopus Intelligent. 7.5p import cheap rate and 15p export.

here is my monthly generation:

During summer there is enough generation to fully charge the Powerwall and fully heat my hot water, and see us through the night on battery - so zero grid use from around May to September. Note - no EV to charge last summer.

Although last summer I only got 4p/kwh export and gas was expensive, now it’s the other way round I’ve disabled the Eddi, as it’s better to export the excess solar.

during winter the Powerwall comes in to its own. It’s VERY clever, learning use and solar output and looking at weather forecast, it will charge just enough over night and allow maximum export of what’s left. They are expensive, but my mate has as more panels and a bigger inverter than me, but a 10kwh battery without the intelligence - his frequently runs out.
The Powerwall can also isolate the house from the grid completely (via a big relay in the gateway box), so you can run happily in powercuts.

I love the whole thing and I’m looking forward to be able to charge the Taycan from 100% solar this summer! Although with the current rates it would still be better to charge from grid overnight and export excess solar during the day.

having the EV to get the OI tariff to be able to charge the Powerwall overnight is the biggest winner though!

 

[bn8959]

Oh, my roof layout is far from optimal too. Half my panels facing NW! However the pitch of my roof is only 20 degrees, so they still work surprising well!

I do love the SolarEdge inverter for its data!

 

[Nickj]

Here’s Dec and Jan this winter - it works out a little below 4kwh a day. It does vary - the graph below is mid-Dec to mid-Jan and some days are nothing, others not too bad

On the other hand, in the summer it generates more than we can deal with so we end up dumping a load in to the grid. This year we’ll have 2 EVs so if we’re home we’ll plug in and used the excess for those. During a week away in July last year we were exporting over 110kw to the grid on top of what the house was using to idle

That’s really useful. So in essence during the winter 4 months I may see 4-5kw generated to use in the house, but could charge the batteries and 2 cars, heat the water over night all on the cheap OI window, so winter bill would be much better but still a chunk, maybe half now. Our heating on air source heat pump cains kws! But summer would have plenty and should be able to export so should get a credit maybe the rest of the year?

 

[Nickj]

I have:

6kWp panels (15x REC 400w)
SolarEdge 3.6kW inverter (DNO wouldn’t allow me a 5kW one annoyingly)
Tesla Powerwall (13.5kWh)
Zappi EVSE
Eddi hot water diverter

only have the Taycan and Zappi since October though.

im on Octopus Intelligent. 7.5p import cheap rate and 15p export.

here is my monthly generation:

During summer there is enough generation to fully charge the Powerwall and fully heat my hot water, and see us through the night on battery - so zero grid use from around May to September. Note - no EV to charge last summer.

Although last summer I only got 4p/kwh export and gas was expensive, now it’s the other way round I’ve disabled the Eddi, as it’s better to export the excess solar.

during winter the Powerwall comes in to its own. It’s VERY clever, learning use and solar output and looking at weather forecast, it will charge just enough over night and allow maximum export of what’s left. They are expensive, but my mate has as more panels and a bigger inverter than me, but a 10kwh battery without the intelligence - his frequently runs out.
The Powerwall can also isolate the house from the grid completely (via a big relay in the gateway box), so you can run happily in powercuts.

I love the whole thing and I’m looking forward to be able to charge the Taycan from 100% solar this summer! Although with the current rates it would still be better to charge from grid overnight and export excess solar during the day.

having the EV to get the OI tariff to be able to charge the Powerwall overnight is the biggest winner though!

Again, brilliant info, much appreciated. I’ve had the DNO applied for. Why did they limit the inverter, and what does the smaller inverter mean to your system?

 

[Nickj]

Also, your below comment,

“I’m on Octopus Intelligent. 7.5p import cheap rate and 15p export”

I shouldn’t have any problem getting this set up should I? Previously I was told they wouldn’t let you have this as basically your charging cheaper and exporting higher? Do they manage/ check/ validate this?

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