Solar panels and battery - any real world recommendations?

Ron-ski said:
Shortest distance is best due to voltage drop, the longer a cable the more the voltage drops, potentially meaning larger diameter cables are required. With PV you need to keep the voltage drop low on the DC cables and the AC cables.

Depending on what's under the paving slabs it could be easy, or a PIA if concrete. I'd take an exploratory look, just in case it's easy.
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Noted. I'll look at lifting the slabs and shorter route along the plant bed. Hoping our decorator will come this week to look at the shed. Regardless of solar, we were keen to spruce it up and fix the walls/floor anyway. Going to have a call with Skylar now.

Edit - now dealing with/waiting for quotes with Little Green Project, Skylar Solar, Heatable, Spirit Energy, Array Electrics and Project Green. Array Electrics are having a design meeting with me which has peaked my interest.
 
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Has anyone noticed the fixed octopus export tariff is no more!? Gone to variable. Lucky I extended my fix period when I did.

Looks like the 15pkw could be on thin ice making pay back period longer.
 
Nathan said:
Has anyone noticed the fixed octopus export tariff is no more!? Gone to variable. Lucky I extended my fix period when I did.

Looks like the 15pkw could be on thin ice making pay back period longer.
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Are there any regulations that stipulate that providers have to pay you for your excess generation? Or can they all just decide to remove payments at the drop of the hat?
 
They have to pay SEG which is 3/4p per kWh or something safe like that.

Don’t forget Eon pays 16p if octopus drop their rates, they’ll shed customers like no tomorrow given they also have zero exit fees.
 
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Quotes and calls up the wazoo at the moment. Wasn't aware of the Sigenergy outputting half it's capacity, don't think it's a deal breaker though. And just learned about minimum voltage - Heatable said 4 panels on our shed is cutting it close to minimum for a normal string array. They are doing a quote using the Alpha battery storage system.
 
What do you mean "Sigenergy outputting half it's capacity"?

You could have one panel on the shed, and still get a suitable inverter, but potentially an issue if they wanted to use the same inverter for the house panels. I really don't think four panels in series will be a problem, that's easily over 120v. My four panel string is currently at 133v. They just need to chose a suitable inverter, although I'm surprised they are not pushing you towards micro inverters.
 
He means the output of the batteries are half their rating, so the 5kWh battery outputs at 2.5kW and the 8kWh at 4kW. They parallel up though, so with every battery you increase your charge/discharge rate.
 
Yeah, what reef says. None of them have suggested micro inverters, just had a design call with one company (the most detailed so far) who suggested boosters* (I think that was the term) for the shed panels to improve efficiency. Also seems one company have suggested 4 >600w panels for the shed and judging by the specs, would not fit on the roof. Going to do a comparison table of the quotes.

Edit - thanks @b0rn2sk8 - yes optimisers.
 
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4 panels on an MPPT are fine if the startup voltage of the inverter is low enough and the voltage of the panels themselves high enough. 3 panels would always be a struggle though.

The Trina Vertex S+ panels are over 40v per panel so would work well.
 
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doodah said:
boosters
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Optimisers?

Either way, you can get small inverters for the shed if needed like individual micro inverters or something like a 1.5kw or 2kw string inverter. They’ll have start up voltages low enough because they are designed for small numbers or single panels.

It’s only an issue if you try to use a small number of panels on a string into a large inverter with multiple strings.
 
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reef said:
He means the output of the batteries are half their rating,
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So you need to match quantity/size of batteries to suit the inverter, not an issue but could push cost higher.

My startup voltage is battery voltage+ 5v, so around 53v to 62v
 
Ron-ski said:
So you need to match quantity/size of batteries to suit the inverter, not an issue but could push cost higher.

My startup voltage is battery voltage+ 5v, so around 53v to 62v
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Ive gone for two of the 10.0 batteries (9.02kWh in reality) on my garage install as it'll give me a 9.4kW charge/discharge rate. Enough to cover the 8kW electric shower and heat pump ticking along together which is probably the most we'll ever draw. The inverter is 12kW, so if Northern power are stingy on the G99 then I could get a third for full 12kW charge/discharge and have space for clipping.
 
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Torn about battery size. Still waiting on 2 more quotes but on the low end we have £12k for 4 kW of generation/10 kWh Sig battery/8 kWh Sig inverter - Project Green. And on the high end; ~6,000 kW of generation/10 kWh Alpha or Sig battery/5 kWh inverter (Alpha) or 10 kWh inverter (Sig) - this is with Heatable for £16k.

Other quotes falling around £14k mark.
 
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b0rn2sk8 said:
Bin off heatable - it’s never a £16k install, not even in the Covid/energy price shock peak.
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Oh don't worry, we won't be going with them and knew they'd be the most expensive from what I've read in this thread.

Wondering if I should tweak Project Green's quote to add optimisers/inverters for the shed roof. And looking forward to Array Electrics quote, their design meeting was far more extensive than the others.
 
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Ron-ski said:
Do you have shading issues on the shed?

Have you tried www.degeesolar.co.uk they're near Dartford and will fit Fogstar batteries.
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A wee bit from a big pylon near our house and a small tree next to the shed. Thank you, haven't come across Fogstar batteries. I'm just looking into Fox which is in one of our quotes, far less cycle life/modularity isn't as convenient/no gateway compared to the Sig. And this quote only has the 8 kWh Sig battery in stock, ideally wanted the 10.

Edit - turns out it was over 6,000 kWh production for the Project Green quote (£12k). Decent. Companies House says they've been around a decade and whilst they review well on Trust Pilot, it's only 14 review and in the last few months.
 
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Finally got my DNO approval letter at the end of last week, but as I was in Germany for work I could’t sort out the paperwork for the export with Octopus.

Did that finally today and hopefully have it sorted soon so I can be paid for the extra I generate.
 
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