Solar panels

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Stu160
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Solar panels

Post by Stu160 » Tue Apr 12, 2022 12:14 pm

Hi All

Any solar panel experts on here ?
Looking for advice on a system and recommendations of companies to use .

Cheers

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scott_e
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Re: Solar panels

Post by scott_e » Tue Apr 12, 2022 4:04 pm

Interested in any knowledge in this area too. Keep hearing in the media the tech is cheaper than ever.

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Re: Solar panels

Post by campbell » Tue Apr 12, 2022 6:03 pm

Think Kenny (flyingscot) and Iain (timmsky) may have some insights.
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Re: Solar panels

Post by rawsco » Tue Apr 12, 2022 10:35 pm

+1

I got a quote recently and it was eye wateringly greedy, ROI was 28years, panel lifespan was expected to be 20years warranty 10.

Basically pointless, but that’s just price gouging. Suspect there would be a chunk of meat in there for negotiation but the guy didn’t even bother to price me for what I asked for.

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Re: Solar panels

Post by Stu160 » Tue Apr 12, 2022 11:02 pm

I have a couple of companies looking at it now , house , solar plus storage as we are out all day . Perhaps a 4kw with 13 kW storage.

Workshop as well, we ise about 140 kW a day so 20 is kW per hour ....Will see how it pans out and report back.

Liking the Tesla bank ....but £8k .....guess that's why the cars are expensive .....
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Re: Solar panels

Post by hendeg » Wed Apr 13, 2022 8:05 am

rawsco wrote:
Tue Apr 12, 2022 10:35 pm
I got a quote recently and it was eye wateringly greedy
Could just've been one of those 'I don't really want your business' quotes.

Like a lot of people, we thought about it at the time of the winter storms but never took it any further. It's only when you don't have any electricity that you realise how much you rely on it. We were lucky and were only out for a a few hours but I wouldn't have liked to have been one of those that were without for about a week. Our motivation would really be for energy security rather than financial benefit but it still has to be reasonable. It's not just storms that are the risk now. We don't use that much for the house but we have an electric car so a solar array with battery storage would be ideal. The technologies and suppliers are changing a lot just now and it just makes a bit of a minefield to navigate to find 'the best solution'.

I'll be watching this thread with interest but also keen to hear of other recent experiences.
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Re: Solar panels

Post by Mikie711 » Wed Apr 13, 2022 9:51 am

We already have a 4.6kw array on the roof but having the field means I have been looking at panels for a ground array. Planing aside the tricky bit is the support frame as they can be quite expensive. Other than that we have a south facing section with no over shadow and space for as many as we want to put in. Would need tied back to the house and possibly the grid but is pointless if we don't use battery storage and that is where the whole thing gets expensive.
Panels are easy, found some canadian solar 410w panels @ £180 ea. Our current array is made up of 305w panels (15) on a 42º roof with zero overshadow and generates approx 3600kw per year. That gives 240kW per panel per year, so 410w panels could produce 322kW per panel per year. For 20 panel ground array that would give a potential 6752kW of generation. If we scaled that to 40 panels our house, c/w GSHP, would be essentially off grid, if we also added sufficient battery storage. That however is where it falls apart, adding sufficient battery storage would add £20k to the price of the panels so the final bill would be £30k which even at current electricity prices is 10 year break even assuming no panel degradation and as expected performance.
If we used our old electricity price that goes out to over 15 years break even and again assumes to degradation in system performance. Over that period of time there would certainly be battery/inverter maintenance/replacement involved.
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Re: Solar panels

Post by flyingscot68 » Wed Apr 13, 2022 11:21 am

I did a bit of work for Zanussi Solar, that was before the Feed In Tariff ended which pretty much killed the industry at that time.

Panel quality was something they were always going on about, big differences in output/degradation and life span with the cheaper stuff.

The companies quoting should be able to provide a fairly accurate generation forecast based on your position and the aspect/angle of your roof, they'll also look at shadows etc.

Battery wise the Tesla one is very expensive, there's many other options out there. We used to sell the Duracell home storage battery linked to a system called Social Energy which is an energy trading platform. This works automatically buying and selling small amounts of energy using your battery. They use it for grid balancing and it makes you some money, a mate of mine uses it and is getting good results.

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Re: Solar panels

Post by Dark » Wed Apr 13, 2022 11:45 am

hendeg wrote:
Wed Apr 13, 2022 8:05 am
Like a lot of people, we thought about it at the time of the winter storms but never took it any further.
My understanding (but might be wrong) that most home inverters & storage systems shut down automatically if mains power is interrupted so that your system isn't trying to send power back into the mains grid. You need to spend extra and get a system that supports "islanding" with an additional monitor & relay on the incoming mains supply.
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Re: Solar panels

Post by hendeg » Wed Apr 13, 2022 6:11 pm

I believe that's right. I've no idea how much it adds to the complexity or cost though.
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Re: Solar panels

Post by scott_e » Thu Apr 14, 2022 5:02 pm

No idea how valid this report is but maybe useful for the debate:

https://greenerenergygroup.co.uk/solar- ... land-cost/

Size --------------------Estimated Costs-----Panels--Roof-----Annual Saving---25 Years
3kW panel system £5,000 – £6,000 12 22 m² £160 £5,993
4kW panel system £6,000 – £8,000 16 29 m² £270 £9,240
5kW panel system £7,000 – £9,000 20 32 m² £320 £11,088
6kW panel system £8,000 – £10,000 24 43 m² £430 £14,533

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Re: Solar panels

Post by Stu160 » Thu Apr 14, 2022 8:47 pm

I have an appointment with then next week...
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Re: Solar panels

Post by j2 lot » Fri Apr 15, 2022 2:41 pm

We have had panels since 2012 and in FIT tariff terms still not recovered the purchase cost and we are on the highest FIT rate. We got some compensation for miss selling and If you factor in the reduction in our bills we are up on the deal bur that’s after 10 years. I have thought about battery install to try to reduce bills further but really not convinced we wouldn’t simply be throwing more money at it for no real benefit.
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Re: Solar panels

Post by robin » Sat May 07, 2022 2:58 pm

Remember to get your units right please, or Fat Bob Fisics will eat your babies!

A solar panel is rated in Watts - upper case W. If you've got enough panels, or a really big one, then you'll get more than a thousand Watts (on a sunny day) and that's kW (lower case k upper case W). This is a measure of power - power is energy over time.

If you run the panels for a day and want to work out how much energy you got out of them, you multiply power x time - and typically that'll be described in kWh (thousand Watt hours). This is a measure of energy.

As it happens the standard unit of electricity (according to your energy supplier) is the kWh.

So if your solar panels make one whole kWh then that's one unit on (or off) your bill.


So to use Mike's post as an example:

That gives 240kWh per panel per year, so 410W panels could produce 322kWh per panel per year. For 20 panel ground array that would give a potential 6752kWh of generation.

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Re: Solar panels

Post by Mikie711 » Sat May 14, 2022 11:23 am

One thing to bear in mind is that your DNO will have capped the export at 3.8kWh (capital W to keep Robin's blood pressure in check) so regardless of your generation rate your inverter (if grid tied) shouldn't produce more than 3.8kWh. That's assuming I have understood the blurb about export and grid tie conditions correctly.
j2 lot wrote:
Fri Apr 15, 2022 2:41 pm
We have had panels since 2012 and in FIT tariff terms still not recovered the purchase cost and we are on the highest FIT rate. We got some compensation for miss selling and If you factor in the reduction in our bills we are up on the deal bur that’s after 10 years. I have thought about battery install to try to reduce bills further but really not convinced we wouldn’t simply be throwing more money at it for no real benefit.

Does this take into account energy used that you have generated. We currently export about 60% of what we generate and am having a battery storage system installed to capture this as the export amount is assumed at 50% of generation and not metered. Therefore the more of the export electricity I can capture and use from the batteries the better.
For arguments sake, we generate approx 4000kWh per annum which means we are losing 2400kWh back to the grid. If we manage to capture and use all of the 2400 then that is an extra saving of £650 at current electricity prices plus we still get the export rate for approx 2000kWh, all be it at a 3p a unit. Our FIT rate works out at a lowly 7.2p for generation and export so based on the above annual generation rate it looks like:
Fit payment per year £290
Saved by batteries £650
Saved by current usage £432

The batteries are going to cost around £4k to install and if we manage to claw back the majority of the unused generation then we should save 4-500 a year which 8-10 year pay back just on the extra and that's before the next price hike in October.
Panels were always a long term prospect but look like they will be 10year break even, batteries will give us some protection from price hikes going forward and there is always room for expansion as prices come down.
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