Why I can't see solar panels being worth it, any body else written them off once and for all?

Blooo

Having looked at several posts of 'real world' users generating tiny amounts in winter from their solar panel arrays, I can't really ever see them being viable for me. Like most we hardly use any electric in the summer, and solar would seemingly give us virtually free generation during the peak summer months. So based on this year we'd save perhaps £350-£600. However in winter, with heat pump central heating and hot water the array and battery storage we'd need to make it in any way worth it would be impossibly expensive. We'd be almost entirely reliant on the grid.

We could use 40-60KW per day in the depth of winter. So unless I've got I an enormous level of battery storage too store lots of electricity from maybe September sun, it's a laughable and an expensive eco fantasy that this will ever be financially viable. With solar panels and what, 500KW, 1000KW, 2000KW batteries? An enormous amount of battery storage costs, the space lost with the batteries, and the heat, all that comes with ownership - then add to that tens of thousands of pounds investment. It'll take generations to get the money back, but by then the system will have needed replacing multiple times.

If you're 'electric only'. I just can't see it being of significant benefit unless you have a super insulated eco house, which typically is for the elite!

ecraig

You’re missing the key bit regarding offsetting.

in the summer you will sell your excess energy to the grid and the money will be added as credit to your energy balance. You’ll then use that credit to cover your bills in the winter when you’ll inevitably buy energy from the grid.

if you get a pv quote from an installer they will give you guidance on how much you’ll likely export in the summer, and how much that is likely to be worth.

QrizB

Obvious trolling?

Or just a complete misunderstanding of how it works?

I can't decide.

EricMears

QrizB said:

Obvious trolling?

Or just a complete misunderstanding of how it works?

I can't decide.

If a troll then a very patient one as  'Blooo' has been an MSE member for 4 years.

I'd go with "complete misunderstanding".  And indeed a misunderstanding of the difference between kW & kWh.

QrizB

True, but in those four years they've started ten threads but have only posted one comment. That's a bit fire-and-forget.

Ectophile

You're mixing up financially viable, and generating enough energy to go off-grid.

In the winter, solar is a bit of a washout in the UK.  On those rare sunny days, they will generate useful amounts of power.  The rest of the time, they may just cover your base load.

But that all changes come the spring when the days are longer and sunnier.  With my rather old panels and modest battery, I can generate almost everything I need from spring through to autumn.  And that includes night-time usage.

When it's sunny, l can generate more electricity that I know what to do with.  And don't forget that you can sell your excess back to the grid.

QrizB

OK, I'm going to assume the OP isn't a troll and is just misguided.

Blooo said:

Like most we hardly use any electric in the summer, and solar would seemingly give us virtually free generation during the peak summer months. So based on this year we'd save perhaps £350-£600.

If you spend £4000 to put 4kWp on the roof you might expect to generate 4000kWh/yr.

That's currently worth £600 if you export it all at 15p/kWh, and pay for itself in 6-7 years.

Or, if you use 1000kWh to replace mains electricity at 25p/kWh and export the rest, it's worth £700, and pay for itself in 5-6 years.

Blooo said:

However in winter, with heat pump central heating and hot water the array and battery storage we'd need to make it in any way worth it would be impossibly expensive. We'd be almost entirely reliant on the grid.

Whatever you do, unless you're into off-grid living you're going to be reliant on the grid. You need somewhere to sell your summer suplus (the grid) and somewhere to buy power in winter (the grid).

Blooo said:

We could use 40-60KW per day in the depth of winter. So unless I've got I an enormous level of battery storage too store lots of electricity from maybe September sun, it's a laughable and an expensive eco fantasy that this will ever be financially viable.

You don't need a battery at all. That's what the grid is for.

Let's assume that your household consumes 3000kWh/yr for general living, 1000kWh/yr for hot water and 4000kWh/yr for space heating. That's 8000kWh/yr. At 25p/kWh it will cost you £2000 to buy it from the grid.

If you have space on your roof / in your garden for 12kWp of solar PV, costing maybe £10k to install and generating 12000kWh/yr, you might use 2000kWh of it yourself (reducing your grid consumption to 6000kWh) and export the remaining 10000kWh for 15p/kWh, earning £1500.

Buying 6000kWh from the grid at 25p/kWh will cost £1500. You're now cost-neutral.

Again, no battery required.

What's laughable and a fantasy is the idea that you need to be a rugged individualist with a well, smallholding and composting toilet to benefit from solar power.

Blooo said:

If you're 'electric only'. I just can't see it being of significant benefit unless you have a super insulated eco house, which typically is for the elite!

Insulation is always a help to reduce your space heating demand, but it's hardly "for the elite". You can buy enough to insulate the average loft for £300 from B&Q.

UncleK

We have a well insulated fairly large house, ground source heat pumps, wet under floor heating, 11 kW of solar panels and 18 kWh of batteries. We had to do something when we moved in four years ago as the house needed much work but certainly we could have done less.

Our electricity bill (Octopus) for 2023 to date is:

High rate: £779

Night rate: £952

Standing charge: £175

Refund for selling back electricity: £776

And I reckon we saved £1443 by not buying electricity in the first place (i.e. using the solar generated electricity directly)

The batteries are a boon in two ways - in the obvious way of saving the electricity generated during the day so you can use it at night, but also charging up at night rate during the winter so you can use electricity stored during the day.

I reckon payback time for the solar/battery kit is about six or seven years. But yes, it doesn't take you off the grid!

silverwhistle

Well, I am elite as I have an ex-council terrace which is well insulated and has 4kWp of solar. I've now saved up to refurbish the bathroom and will be removing the wet radiator which gets in the way and will be installing an electric towel rail to run on cheap overnight electricity.

Next steps are an air to air heat pump which is a lot cheaper than a wet system and the very old double glazing from the mid 80s could do with replacing at which stage the larger windows will be replaced by triple glazing.

My energy bills are not something I worry about although it's taken a few steps and a bit of effort to get there. Can I suggest to the OP not to be so dismissive of "eco" changes and actually do something to improve their own situation. All our situations are different so suggesting one solution and saying it isn't suitable may be true, so you need to find something that improves things for you..