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3 strings on my 8kW inverter (Growatt MIN 8000 TL-X2 1ph) works well.
Solar panels and battery - any real world reccomendations?
- Thread starter GinG
- Start date
Man of Honour
I'd say so.
Also don't worry about the ROI too much either as we just don't know what the export tariffs or import tariffs are likely to be. Do it for the fact that for 70% of the year with a system of that size you can almost be self sufficient. In summer NW panels do help a lot.
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Soldato
Right, £2340 to add on an additional 11 panels (150*, 40* incline) and increase the inverter size. That brings the cost down to £1325/kWp...
They predict an increase in production of ~2350kWh annually which seems conservative vs the numbers Ron-ski is expecting from his 12, but that's OK. They have raised the likelihood that my DNO will want to cap my export, which may add slightly to the cost (they have a recent install of the same size with an additional DNO cost of several hundred quid for witnessing etc) but while irritating it isn't the end of the world...
I think this extra is a no-brainer, glad I asked here - thanks!
They predict an increase in production of ~2350kWh annually which seems conservative vs the numbers Ron-ski is expecting from his 12, but that's OK. They have raised the likelihood that my DNO will want to cap my export, which may add slightly to the cost (they have a recent install of the same size with an additional DNO cost of several hundred quid for witnessing etc) but while irritating it isn't the end of the world...
I think this extra is a no-brainer, glad I asked here - thanks!
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Soldato
Mine are at 120 degrees, so less north than yours.
No idea where you are in the country, but for roughly around Derby PVGIS reckons around 2850 kWh.
JRC Photovoltaic Geographical Information System (PVGIS) - European Commission
Photovoltaic Geographical Information System (PVGIS)
those numbers are cray cray for NW panels, my SSE panels 10x440w is only estimated at 3680kwh/yr
Associate
My 4.62kW of NW facing panels (137 degrees and 35 degree tilt) have beat the PVGIS prediction in every month since I got them installed in January aswell. Since installation from 10th January to the end of May, they should have produced 976kWh but have actually managed 1135kWh. That's on an annual prediction of 2794kWh and the weather has not been great either.
You're doing the right thing getting them put in at the same time. I didn't do this as I was told by pretty much everyone it wouldn't be worth it so ended up paying more when I finally got it done.
You're doing the right thing getting them put in at the same time. I didn't do this as I was told by pretty much everyone it wouldn't be worth it so ended up paying more when I finally got it done.
Soldato
Mine are at 120 degrees, so less north than yours.
No idea where you are in the country, but for roughly around Derby PVGIS reckons around 2850 kWh.
JRC Photovoltaic Geographical Information System (PVGIS) - European Commission
Photovoltaic Geographical Information System (PVGIS)re.jrc.ec.europa.eu
Wirral, between Chester and Liverpool basically, at the top of a tall hill.
This was my experience with literally every single installer I contacted. They all suggest it just is not worth it, you'll never get the return on it etc etc but yet the numbers suggest I will definitely benefit from these 11 panels. I wonder why? It can't be just an attitude of "South-facing good, North-facing bad" can it? Perhaps there's a perception that if they do size systems like this people just get upset at the outright cost when compared with someone else doing South-only quotes and they just keep it simple to compete?
Ah well, I'll take my newly-sized 12.76kW 8872kWh/yr SE/NW system and see if it does work out the way the thread suggests!
Just waiting on DNO approval now, hopefully get it installed while there's still some summer left!
It’s definitely a perception thing and working off old rule of thumbs which don’t account for better panel technology. Installers are still peddling cookie cutter 4kw systems they can fit without approval rather than considering current and future demand (EVs and heat pumps) on what is a 25+ year investment.
It wasn’t that many years ago when sub 300w panels were still a thing and NW panels wouldn’t have been worth it. Newer panels are so much better with low light.
It wasn’t that many years ago when sub 300w panels were still a thing and NW panels wouldn’t have been worth it. Newer panels are so much better with low light.
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Next question buddy - how does one lock down the charger? I've seen you can set a pin on that hardware unit which must be entered at the start of each charging session... How does that work with octopus intelligent go?
Soldato
Don't forget to keep us updated, and if you can join the PV Output team - link below. Warning, it gets addictive
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Soldato
Don't forget to keep us updated, and if you can join the PV Output team - link below. Warning, it gets addictive
Haha will do - spotted some people with very similar postcodes to me on there already... small world!
Soldato
I think this extra is a no-brainer, glad I asked here - thanks!
Sadly too few people ask for advice from a group of people with many decades of combined data and experience. The key thing is we aren't after your money, or making an effort to profit from you, mostly the opposite, so the advice may be counter to the 'professionals' but they will be following guidance from MCS etc. and recommendations that are no longer optimal given how cheap solar PV now is.
Soldato
Something I will need to tackle in time is to work out how to dump excess solar power into my hot water tank once the batteries are full. I have a vented cylinder at present, the contents of which are gas-heated by a system boiler which has some automated valves to switch between the hot water and the central heating as required. As far as I can see, there is no provision to heat this water using electricity. I'm not sure I can stand the thought of replacing things right now if its not a really simple fix, nor is it at all appealing to run a supply to where the tank is from the CU due to an absolutely moronic lack of future planning by both the previous owners and the electricians who re-wired the place in the mid-2000s.
Soldato
Depending on the export rate, it may be better (certainly easier) to simply export it.
Soldato
Yeah as ron says thats what I now do even though I have a diverter.
I do however use the new controls for powerups and super cheap agile times to heat the hot water
@DRZ do you have an immersion as thats what they use
Mine is the iboost https://www.marlec.co.uk/product/solar-iboost/
I do however use the new controls for powerups and super cheap agile times to heat the hot water
@DRZ do you have an immersion as thats what they use
Mine is the iboost https://www.marlec.co.uk/product/solar-iboost/
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I had an iBoost and i've now an Eddi. However, as has been said above, I now fully charge my car, batteries and water overnight @ 7.5p to maximise the amount of solar I can export @ 15p.
Soldato
Other thing I forgot to add earlier is that its constantly evolving, price of gas (or oil etc) vs elec, and the price of export.
Also at individual level if you are export capped.
Also at individual level if you are export capped.
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Yeah, make hay while the sun shines....it might all change tomorrow. Hopefully octopus will match or increase the export rate at my 12 month renewal.
Soldato
I wouldn’t bother with heating the tank on solar. The initial cost vs gas use/export at present shows it’s certainly not worth it. Perhaps in the future if export changes which I doubt.
I bought an expensive EV charger in order to divert my solar, pointless however when it’s 50% the cost overnight when exporting in the day.
I bought an expensive EV charger in order to divert my solar, pointless however when it’s 50% the cost overnight when exporting in the day.
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