Looking at the solar panel thread below got me thinking..
I’d love PV panels on our dormer (flat) roof as it’s south facing. But the install costs, and reading about the FIT dropping and dropping, make me think ‘is it worth it’?

I know it used to be seen as a worthwhile investment idea several years ago – is that still the case?

We’re not looking at moving any time soon….

Thoughts?

DrP

Will energy costs go up or down in the future? If your staying put look at things like the power wall and changing your thinking (washing machine and dishwasher on during the day etc.)

depends where you live. Kent I would say yes. lochaber I would say no

Solar thermal?

The FiTs have come down so much now that it’s going to take a long time to repay the installation costs (which have come down too but not by as much) through energy savings alone.

One of my colleagues who got in early makes £2,500 cash a year from his. All a bit unfair and counter-intuitive really.

According to the figures on the Scottish Homebuyers Report for my house I would have to live until I was 190 to see a return on investment for solar panels on the roof!

Move to the West of Scotland and fit hydro electric turbines in the rainwater downpipes of your house…you’ll never pay another leccy bill in your life.

A near neighbour of ours updated his 6 or 7 year old system last year. The doubling of the number of panels, upgrading wiring and control boxes etc would have cost him about half what the original install did (if you take all the grants out of the equation).
His original system had about 2/3rds paid for itself as far as he could work out. (It’s a bit tricky to work out as the tariffs have changed a couple of times, and there’s a completely new system now he’s upgraded his control box)

Me, i’ll get solar thermal, it’s cheaper and most (more than 50%) of my energy consumption is for heating/hot water anyway.

I don’t understand why wind hasn’t take off for homes?

Its plenty windy where we live.

Is it just that you need to big a turbine to get enough juice? B&Q did sell them for a while.

You need a big, tall turbine, big to get enough wind, tall to get away from roof lines, trees, turbulent flow, noise.

Best left to large scale installations.

Wind would probably be space. As for feed ins etc just remind me how much generation capacity is planned to replace all the stuff going offline. With a reduction in coal and gas, escalating and volatile gas pricing and lots of capacity at end of life I’d take the gamble that self generation will become more attractive. Again with storage coming online you don’t need to rely as much on fit as your using your own more not paying for other people’s.

Agree with using the sun to heat water. Very simple installation and would save lots on heating water.

They have been doing this lots in Portugal for years. Friend of the family has a business out there doing just this.

Scalded my arm once when I turned the tap on…. It was about 3am. Still hot!

I was looking to buy a place where the owner had installed a few impellers in the stream to charge some car batteries which provided lighting.

Solar is pretty marginal with the current regime. We were estimated about a 20 year payback, but the panels might hardly last that long. It works out better if you use a lot of daytime electricity in the summer, but who does that?

As for wind, the power you get is just too small to be significant. Plus noise and maintenance issues.

Think the next big thing will be domestic biomass.

Chap i work with is tinkering with a home biomass “system”, uses an old pellet burner thing to power a small steam turbine/generator and some other stuff, reclaims a lot of the waste heat as well. All self built and bodged up, uses half a dozen PLCs and an old PC to run it and link it into his home CH system.

Efficiency is pretty poor, but it works. Cost him virtually nothing, so despite the poor efficiency his only ongoing cost is pellets.

And his wife hates it.

Photovoltaic cells aren’t particularly expensive to make.
Weather-proofing (which usually means encasing in resin), installation and certification (needed for feed-in tariff) are the expensive bits.

If you can find a way to get the installation and certification parts cheaper, it may well work out.

Agree with others that heating water is a good use.

I have a box of tricks on my PV install that works out if I have spare capacity and dumps it to my immersion heater, was only a couple of hundred quid add on and means most of my summer water heating is done by solar, but without the added plumbing cost (and possibly needing a new tank) that “wet” solar water heating would entail.

Jeff

We have 2 panels on our roof for heating water. Its brilliant. We don’t have central heating so immersion heaters are our only other option. On very sunny days we’ve had water in the tank measuring over 85°C.
On less sunny days it heats it up to about 30° meaning the immersions have to do less.

And we are in Wales!

I’m in Scandinavia and solar is a viable option…….. most of the year.

You need a big, tall turbine, big to get enough wind, tall to get away from roof lines, trees, turbulent flow, noise.

Best left to large scale installations.

p’ah!

Solar thermal?

Out of the equation unfortunately – when we had our loft converted, we scrapped the boiler/tank for a modern combi (space was a premium) so solar thermal won’t work…

I forgot about the tesla batteries..that would be ideal – use NO ‘leccy from the grid..
I’ll look into that.

On a side note – when I get my lad’s play house built I’m going to get (from China) a little turbine and PV pack (about £150) to teach him about all this! It’ll be standard for our kids, I reckon!

DrP

Got one on the roof of the van, works great when wild camping.

http://www.soltechenergy.com/en/product/soltech-sigma

That’s one thing that pinged up on my searches for solar thermal. We’ll need a new roof at some point in the next 5-10 years. We’ll possibly do this, budget allowing. You’d probably only need the accumulator and some sort of control system to connect it to your existing radiator set up.

I reckon we’d need a bigger reservoir to connect to our system.

when I get my lad’s play house built I’m going to get (from China) a little turbine and PV pack (about £150)

Careful, only use it in a cake tin, you don’t want to burn his play house down 😉

had a look into this sort of stuff.

Basically you need to spend >20k to get any tangible benefit. The wind turbines were done by witch mag a while ago and wernt worth the outlay.

insulation was the best bang per buck.

If your staying put look at things like the power wall

Have you seen what they cost?

Doubt you’d make your money back in years….

It works out better if you use a lot of daytime electricity in the summer, but who does that?

We average about 75p/day on leccy…..

solar PV can still be worth doing but you wont be getting ‘rich’ off it. if you use a lot of leccy during the day then you’ll benefit most.

You shouldn’t be paying much more than £4-5K for a 4kW system installed on a standard roof.

until we get smart meters that can measure(and allow you to be paid for) your export then sticking excess into a hot water tank is a good thing. sort of.
—————————————————————————-
as for domestic solar thermal – depends what fuel you’d be replacing, and how much hot water you use. There are loads of ways to maximise the benefits of solar year round but they all need reasonably bespoke heating systems (think underfloor heating, a mix of heat sources and a very well insulated house) but for a standard solar panel/hot water tank setup, the numbers are something like the following:

a 210 litre cylinder needs 13.5kW hours to heat to 60degC. a properly sized solar thermal system (approx 4msq of flat plate collector) will do this, on average, half the year. that’s 13.5 x 180 kWh = 2430 kWh of energy per year.

if you are on gas, you’ll be paying about 3.5p per kwh – that’s a saving of £85 a year.

oil at 5p/kwh saves you £120, LPG approx £145

ubnless you DIY, you aren’t going to get a decent system installed, with cylinder change, for less than £3K. you can do the sums.

you will cut your carbon footprint, you will feel slightly better for doing that, you wont save money.

What is the best sort of setup if you want to combine a solar thermal rooftop system with your household hot water system?
I’m about to replace my boiler and I’m wondering if I should be looking at this option…

There are a tiny number of new build estates with solar panels built into the roof, rather than mounted on top. I think this is the way to go, minimising the expensive installation as all the scaffolding and whatnot is up already and there’s work going on anyway. It’s disappointing that the government scrapped the tighter regulations on home efficiency as this would be much more common otherwise.

I’d quite like some for our house, but I’m under no illusion that it would give any financial return; our leccy bill is pretty tiny anyway, so it would just be because I’m a hippy who would like to help stop getting our energy by pumping it out of the ground.

you will cut your carbon footprint, you will feel slightly better for doing that, you wont save money.

But if you include the CAPEX CO2 cost of the extra HW etc, then you’ll have to wait a few years before you start cutting your total carbon footprint through lower OPEX CO2.

Hmm..maybe i’m just trying to fuel (chuckle) the ‘feel good’ part of my concious..
When we had the loft done there’s tonnes of insulation as per new BRs, and LED lights throughout.

Maybe this is a non starter unless there’s bigger incentives…

Time to chuck another manatee on the log burner…

DrP

Time to chuck another manatee on the log burner…

You Monster!

Do you know how much CO2 is released into the environment when you burn a manatee??

Environmentally sustainable dugong would be a better option.

Manatee’s are rubbish – you need an Elephant Seal to get a decent calorific output.

I don’t understand why wind hasn’t take off for homes?

Its plenty windy where we live.

It’s because although it is comparatively windy, the amount of energy you can extract from the wind is still lower than what you can get from solar panels (yes, even somewhere like Britain)

Wind turbines (even decent sized ones) in built up areas don’t generate enough energy to offset the carbon dioxide generated building and installing them, so are completely pointless.*

*This was the case a couple of years ago anyway, I would imagine one day we’ll be good enough at making them that this is no longer the case.

Now they’ve stuck the offshore wind farms up off the coast of Worthing, I might install a wind turbine actually.
Not sure why they needed more wind farms – it’s windy enough here already without farming more….

DrP

Not sure why they needed more wind farms – it’s windy enough here already without farming more…

EU quotas, although now we’re leaving they might just let all the wind die…..

Think of the baby robins footflaps!
How will they die smashing into the ground fly away safely?

re opex capex and the savings numbers quoted and ruthlessly barging past he OP with total disregard.

It kind of depends where you are in terms of your current system.

If Project Divorce and Bankruptcy goes ahead we’ll be buying an old farm house currently heated by LPG with approx 0 inches of insulation and several pitches of roof that currently give direct ventilation and hydration access. From this starting point a complete refit with thermal stores running from solar theraml, wood burner and a small oil fired reserve makes economic sense producing both hot water AND space heating. But this is at the far end of the spectrum.

As can be seen from my other post on the subject solar hasn’t had its day just yet, storage battery technology is giving it a 2nd lease of life at least down here in sunny Kent.

for a standard solar panel/hot water tank setup, the numbers are something like the following:

a 210 litre cylinder needs 13.5kW hours to heat to 60degC. a properly sized solar thermal system (approx 4msq of flat plate collector) will do this, on average, half the year. that’s 13.5 x 180 kWh = 2430 kWh of energy per year.

if you are on gas, you’ll be paying about 3.5p per kwh – that’s a saving of £85 a year.

oil at 5p/kwh saves you £120, LPG approx £145

ubnless you DIY, you aren’t going to get a decent system installed, with cylinder change, for less than £3K. you can do the sums.

you will cut your carbon footprint, you will feel slightly better for doing that, you wont save money.

THis is exactly what I reckon my DIY system is saving us, I put 20 vacuum tube collectors on the roof facing SW and in high June we get 160 litres of water at 60c, which pre-heats the water entering the main house cylinder. It was a simple system to install and cost me about…. £850! So, ten years.