dstanners wrote: ↑Fri Jul 11, 2025 9:31 am
So, I've had two more offers.
Eon want just under 21k (so quite a bit more than their "non-binding indicative offer".
They have provided a detailed breakdown, which includes:
18 panels (450w) 1,3k Euros
7,7 battery 4k
Converter 1.3k
Cut off system (so that the PV generates and we can use electricity during power cuts) 1k
Wallbox 1.5k
Zaehlerschrank 1.8k
The rest (which actually is the vast majority) is all for various fittings, connections etc.
Vattenfall want 24k for the similar system.
Both are "going away to have a talk with the boss", to see if they can drop the price.
One interesting thing is that Eon have said that in their opinion at 7,7 kWh battery is possibly oversized, given a) our annual usage is so low (3000 pa), and b) I work from home during the day and can make most usage of electricity whilst it is being generated. Our electrician suggested 8kWh would be the right size.
Oh, and one annoying thing is that I can't for the life of me remember what Zaehlerschrank is in English at the moment...definitely not "counter cupboard". Bl00dy hell, has it really come to this?
More comments from me:
Your system is 66% of mine, and (without Akku) it costs 150% mine (mine bought 2019). I understand different location maybe play a role (does it? our installers were not local, they came from somewhere else and had to stay one night in a local hotel).
Fazit:
I think "PV prices have dropped soooo much in the last blabla years" is simply not true. Possibly just some fake news from the PV industry to make more profit.
Eric7 wrote: ↑Fri Jul 11, 2025 10:45 am
I work at home and have a lot of computers running at the same time so having power cuts isn't ideal. To that end I set up a 2kW battery to keep my main workstations & server going for a couple of hours in an emergency. The battery takes about 40ms to kick in, which isn't fast enough to stop the computers turning off, so I've got a UPS (I think 2 or 3ms switch time) in between the battery and the computers.
I'd love a big solar panel setup but we live right next to a forest, which puts the south side of the roof in shade for most of the year so I m pretty sure it wouldn't be worth it. Our electricity consumption is at least 11-12,000kW (it has been as high as 18,000kW), with a lot being consumed by the computers overnight so a big battery would definitely be useful for us.
very interesting, thanks for the info.
Well, of course in your situation (which is very different than most) Akku makes much more sense than most others.
12 kWh and 18 kWh are hugely different. We consume a total of 2.25 kWh/yr and my wife works from home (with a simple laptop)
Just curious: why don't you measure the exact amount of kWh used by the computers?
Eric7 wrote: ↑Fri Jul 11, 2025 10:45 am
I work at home and have a lot of computers running at the same time so having power cuts isn't ideal. To that end I set up a 2kW battery to keep my main workstations & server going for a couple of hours in an emergency. The battery takes about 40ms to kick in, which isn't fast enough to stop the computers turning off, so I've got a UPS (I think 2 or 3ms switch time) in between the battery and the computers.
I'd love a big solar panel setup but we live right next to a forest, which puts the south side of the roof in shade for most of the year so I m pretty sure it wouldn't be worth it. Our electricity consumption is at least 11-12,000kW (it has been as high as 18,000kW), with a lot being consumed by the computers overnight so a big battery would definitely be useful for us.
very interesting, thanks for the info.
Well, of course in your situation (which is very different than most) Akku makes much more sense than most others.
12 kWh and 18 kWh are hugely different. We consume a total of 2.25 kWh/yr and my wife works from home (with a simple laptop) Just curious: why don't you measure the exact amount of kWh used by the computers?
I suppose it's never really been that relevant. I need them running so I couldn't change the amount they used anyway.
I did replace 10 older HP workstations with 4 faster new ones which clearly saved a lot of kWs.
I think we'd use more than 2.25kW a year if we just sat in the dark with everything switched off!
When the seagulls follow the trawler, it's because they think sardines will be thrown into the sea.
Alberto wrote: ↑Fri Jul 11, 2025 10:47 am
I think "PV prices have dropped soooo much in the last blabla years" is simply not true. Possibly just some fake news from the PV industry to make more profit.
I think that comes from when the wholesale price dropped dramatically last year(ish?), as several new Chinese factories started production all at the same time and flooded the market for a while. Wholesale prices plummeted, then recovered a bit. Then went up and down again. Which got dubbed the "solarcoaster". But naturally that didn't get passed on to the consumer. I suspect there is more room to haggle these days though. It's worth a try.
Prices here are definitely 30% down on 2-3 years ago.
I think the larger battery doesn't make significant financial sense - particularly Alberto's table (if I have understood it correctly) would suggest a smaller battery would be more efficient. The slight difference (as I see it) is that a larger battery means I will be using less non-renewable energy as part of my overall energy consumption (even if it might be cheaper to use the grid more often).
Also, with an EV, my energy consumption would jump from 3100kwh to 5000kwh, based on the following rough calculation:
The EV Golf equivalent (id3) uses approximately 16kwh per 100km.
Using the car for say 12,000km per year, that would equate to total energy use of 1920kwh per year (12000 x 16 / 100).
As for emergency energy, that carries a fair bit of weight for me. When we had the floods here a few years back, we were without power for a couple of days (nearby villages went without power for a few weeks). Like Eric7, we also have (minor) power cuts most years due to lighting strikes.
