Thoughts on plug-in PV panels?

QrizB

Curious about your thoughts on these …

I'm all for it.

… it doesn't appear to me to be a practical solution.

That depends on what problem you're hoping to solve.

Take your entire property off-grid? No. Cover your base load for 8-9 months of the year? Yes.

For most, there would be too few panels to provide a useful output,

Most people have 100-200 watts of "stuff" that's using power 24h a day, 7 days a week. Broad band router, smart speaker, TV & digibox, phone chargers, that sort of thing. A 800-watt plugin system (the sort of thing @chris_n describes) will cover that usage from spring to autumn, for most of the day, on most days.

The payback period must be pretty high?

Let's imagine you pay £300 for an 800-watt system. That will generate 6-800 kWh a year. And then let's say that you can actually make use of 300 of those kWh each year (the rest is fed into the grid and lost in the noise).

300 kWh from the grid, at the Ofgem cap that will apply from April, would otherwise have cost you £74. That's your annual saving. Payback will therefore take about four years, which seems quite quick.

WIAWSNB

£200-300 for an 800W system is cheaper than I imagined.

What will It actually generate, given it's unlikely to be set up at the ideal orientation?

QrizB

https://forums.moneysavingexpert.com/discussion/comment/81938831#Comment_81938831

If you look at the thread linked by Lorian earlier, there's modelled examples for Swindon (central southern England) for an 800W system facing south with vertical panels, horizontal panels and an optimised panel angle.

Even the vertical panel makes ~600kWh/yr. Horizontal is almost 700kWh/yr and the optimal 39 degrees makes just over 800kWh/yr.

There's a link too to the PVGIS tool so you can check your own location.

Albermarle

https://forums.moneysavingexpert.com/discussion/comment/81938895#Comment_81938895

Presumably if you live North of the border, the wattage generated would be about half of that ?

WIAWSNB

I've looked at that other thread - hadn't realised it was there before starting this one.

Would a fair summary be, a couple of 400W panels would only cost around £250, which is pretty darned good, as they obviously have built-in inverters?

Installed vertically, they will likely output around 600W max, if south-facing, and in Summer.

This is a useful amount of power, but only if it is being used. If it isn't, it's 'wasted' (ie, the grid gets it!)

It should cover 'background' devices that draw little power, but are a constant drain - all the chargers, modems, laptops and stuff like that, but only during daylight hours.

If you don't 'use' the whole generated power - ie change your lifestyle and appliance use to suit sunshine levels - then you'll never get the full advantage of it.

It has the potential of saving, what? one to two pounds per day? But only if used under ideal circumstances as above. So, potentially a 2-3 year return.

Realistically, what will the average household get from this?

QrizB

Presumably if you live North of the border, the wattage generated would be about half of that ?

It depends on how far North …

• East Queensferry: 729 kWh/yr
• Thurso: 669 kWh/yr
• Lerwick: 611 kWh/yr
• Reykjavik, in Iceland: 567 kWh/yr

All figures from PVGIS for 800 watts of solar PV at the optimal angle.

Aussie_Tips

If you're considering this, please read my comment on the other Plug in solar thread

https://forums.moneysavingexpert.com/discussion/comment/81946414#Comment_81946414

Davesquire

https://forums.moneysavingexpert.com/discussion/comment/81938001#Comment_81938001

Looks very interesting. Good information. However…

I thought that I'd give the quote option a go, just to get an idea.

Details of your property, ok.

Area you live in, ok.

Address, hmmm, alright then.

Name, email, telephone number…wait a second!

In my experience, this ends up as either data harvesting or pressure selling repeat telephone calls.

The site is okay for basic details, but the rest is up to you.

QrizB

In my experience, this ends up as either data harvesting or pressure selling repeat telephone calls.

Yeah, Greenmatch exist as a lead-generation site for green energy sales.

Their "about" page says as much, although in different words:

https://www.greenmatch.co.uk/about-us