@Edent we hit roughly the same - 90% of our electricity self-generated, and exported roughly a third of our output.

(annoyingly, at this time of year I could probably export 50% more if the grid would let me...)

@Edent Really keen to see real life numbers on this
Do you have an EV?
What power company are you using?

These aren't the final numbers - but are pretty indicative.

In the last 12 month, having 5kW of solar panels, and a 4.8kWh battery, has saved us a massive two-thirds of our electricity bill!

And that isn't even taking into account how much we sold back to our neighbours.

#Solar

ALT

@Edent I was collectingy numbers from last year so I could shop for a new energy provider, and I was more than a bit surprised that I only pay about €150-200 per year for my electric after the solar is netted in.

We leave a lot of electric devices on all the time, etc. The sun is working out pretty well.

@Edent cool isn’t it. Ours was a little higher at about 12% from the grid, but we also exported about 50% of everything we generated last month as well, and we didn’t discharge the battery to the grid either

@Edent welcome to the cult, sorry, club.

@Edent I’m sure you’ve posted this before, but how much did you pay for all of it, and how long does that make it take to break even?

@Edent Having 750 watts of solar panels and a 280 amp hour battery has saved me 100% of my electricity bill, since I don't have a grid connection so I don't have an electricity bill.

However, very sadly, I also haven't been able to pass anything on to my neighbours.

More maths!

Over the last 12 months, we purchased about 1.2MWh from the grid.

Across the same time, we sold 1.2MWh back to the grid!

I think that means our #solar panels and battery have got our domestic consumption down to #NetZero!

It also knocked about £750 off our electricity bills.

Now I just need to find a way to replace our gas boiler. Sadly can't have a heat pump.

@Edent that's awesome! my numbers (after adding in sell-back to grid, and also including the heat pump) say I've saved about 75%. It was a big outlay but absolutely worth it financially. (I didn't do it for the money but for the environment, but it's nice to hit both!)

@Edent what's your barrier to going heat punk?

@Edent I wonder how big of a battery one would need to use all of it yourself. I have an inkling that there's enough seasonal variation so that an EV wouldn't be enough.

@Edent if you do figure this out, I would be fascinated to hear how, because I also want shot of our gas boiler and also can't get a heat pump!

@Edent It is a shame you can’t have heat pump. We had ours installed last week.

@skylar @Edent old school immersion heaters and storage heaters still exist, and I think in cases like this could make a lot of sense. My flat has both, and the moment I’m done buying it from the landlord they’re going on smart switches hooked up to Octopus Agile pricing.

@skylar @Edent there’s also just plain old electric radiators. Not sure what the power usage looks like there and how viable it would be to run them off a home battery.

@jon @skylar
I'm experimenting with Infrared heating.
https://shkspr.mobi/blog/2022/03/experiments-with-far-infrared-heating/

Seems to work in small rooms, heats up quickly, relatively low electricity use.

Also have an electric tap for a basin. Again, fairly reasonable. But running a bath with it would be tricky.

@hirvox In January - the worst month - we purchased 192kWh of electricity.

A long range EV is about 70kWh.

I'm trying to do the maths on what size we'd need to save the summer excess.

@DamonHD physics, mostly.

https://shkspr.mobi/blog/2022/07/why-we-cant-have-an-air-source-heat-pump/

@Edent are you in a conservation area? If not then at least two of the restrictions you list may (no longer) apply, and the rules continue to be relaxed further. I am also in a terrace but I think that we are going to be able to make a heat pump work.

@Edent @DamonHD have you considered Air-to-air? I.e. air conditioners that can work in reverse? You can get minisplit systems bought and installed relatively cheaply. (Though it won't do your hot water obviously.)

@vksxypants @DamonHD yes, but the cost of retrofitting air conduits through the whole house is prohibitively expensive.

@Edent @vksxypants Are you aware of multi-head per-room mini-split units? Particularly given that you could heat some rooms with your IR units...

@DamonHD @vksxypants Interesting! Sadly, I think they still fall foul of my permitted woes. I'll do some more investigating.

@Edent @vksxypants The rules are continuing to unbend, though mini-splits may not benefit yet from grants or GDPOs. If you find out, please say.

(Given that I am doing a PhD on decarbonising UK home heating, I am unreasonably interested in the detail!)

@DamonHD @Edent Heat pumps are apparently a challenge to run off battery - my system is limited to about 4kW max discharge and the heat pump can pull a lot more than that. We'll see how this works out in practice.

@ryanc @DamonHD
Yeah and when it is sunny, we don't have any need for hot water.
We tried it with an iBoost and it was just a waste of energy.

@gsnedders @Edent I'm interested in this too.

It seems so idyllic but the set up costs are £££

@sarajw @gsnedders
I've written a bit about it before.
Payback depends on how expensive electricity is, and how much your install is.
When leccy prices spiked at the start if Russia's invasion, our payback went down to 5 years. Right now it's about 7ish.
Our install was expensive because we have a complicated roof & old wiring. Our battery manufacturer gave us a discount.

So prices anywhere from £3k to £15k depending on your local market & roof.

@Edent @gsnedders thank you, and yes makes sense! I think where we are, it made financial sense for a while because of subsidies, but said subsidies have subsided and now it feels like biding our time makes a little more sense.

There was/is also huge demand which made the costs and waiting lists for getting stuff installed spike very high.

Still mulling it over, as Germany's energy mix is still pretty dirty at times, with lignite being burned in places. I don't really want to be part of it.

@sheddi oh, I've been a member for a little while now!
https://shkspr.mobi/blog/tag/solar/?order=asc

@andrijson I publish all the generation data daily on GitLab - https://gitlab.com/edent/solar-data/

No EV any more. We're on Octopus dynamic tariff which changes price every 30 minutes.