Advice on improving self use for solar energy generated?

Solar Thermal & Power Diverters

Last Post by IanMK13 1 year ago

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energy-optimiser

(@energy-optimiser)

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Joined: 1 year ago

Posts: 5

Topic starter 15/08/2024 5:33 pm

Hello there, I've been thinking about exploring solar panels, day/night tariffs and maximsing self use. Any tips on how one can improve self use of solar energy, especially for appliances and EV charging -- rather than importing from the grid. Any one here that has done this well? Happy to connect offline if easier.

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Anonymous 5011

(@Anonymous 5011)

Joined: 3 years ago

Posts: 563

15/08/2024 6:55 pm

Really depends if you get paid for export and how much you get paid per kWh.

We don't get paid. So will talk about my case.

Without a battery anything more than 3.2kW you end up exporting quite a bit in summer. Unless you dump to immersion and hot water. Even in NE Scotland and quite a bit of shade we didn't really pay for hot water in summer.

We then added another 3.6kW PV and 13.5kW battery, ASHP and moved to E7.

According to our weekly reports our summer average cost per kWh used is about 4p and Jan Dec was 20p kWh driving a heat pump (we had 2 weeks at -9 also).

Battery is best way to self consume. We still use immersion diverter. Last cylinder heat was yesterday at 4am, next one will be tomorrow morning (so 48hrs). Which is good as we have had a poor solar day today, so didn't use the battery to heat DHW. We still import, mainly due to a pretty poor summer, on average 4 to 5kWh. But that includes running ASHP on cooling mode, MVHR, sewage treatment plant fan our base load is around 17kWh.

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IanMK13

(@ianmk13)

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Joined: 3 years ago

Posts: 194

15/08/2024 7:47 pm

I've been on Octopus Agile ToU tariff for 10 months now. I have an EV but don't use it a lot, so this is the best tariff for me (No ASHP. Gas DHW & CH). Annual consumption ~5MWh.

I had solar panels (5kWp) and battery (13.5kWh) installed on 1st July and have paid only standing charges since then, saving approximately £80 in 6 weeks. I've exported 380kWh to the grid so far but not been paid for it (waiting for the DNO to get their finger out!), nominally worth £57.

Come winter, I'll be playing tunes on the battery, charging at cheaper overnight rates, so improving on what I achieved last winter without a battery.

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