Author Topic: The cost-effectiveness of solar panels  (Read 8896 times)

hellymedic

  • Just do it!
Re: The cost-effectiveness of solar panels
« Reply #50 on: 03 March, 2017, 03:12:08 pm »
[Digressing] I am very fearful that parts of Watling Street nearby will become unwalkable/uncycleable when the sprouting tower blocks are completed.

ElyDave

  • Royal and Ancient Polar Bear Society member 263583
Re: The cost-effectiveness of solar panels
« Reply #51 on: 03 March, 2017, 04:03:08 pm »
Our roof is basically E-W. We got solar panels installed (8 on the slightly south facing side, 7 on the other) in October. The Generation tariff is 14.something and the export is 4.something. It cost just over 6 grand (our house is 3 storeys, so we needed extra scaffolding).
We have a website that we can see how much power we have generated today/last 30 days/forever. It's at a total of 299kWh, but it's been much better (106kWh) over the last 30 days - I think it's just longer days and some sunshine that's driven it up. We use an iBoost to divert electricity into our immersion heater, and since we've had the system we've rarely had to turn on the hot water at all - I hope that in the summer the gas boiler will stay off for weeks or even months at a time.
The total repayment time if you believe the salespeople is just over 7 years - I think it will be the other side of 8, but the FIT is for 20 years, and the panels have a 25 year guarantee (though the inverter guarantee is only 12 years they are only £600 or so), so a few months here or there makes little difference. It has also inspired me to seriously think about an electric car.

Battery storage systems to store electricity generated from PV systems are nowhere near economically viable right now though IMO.

I've had similar experience, with using an i-boost on the immersion heater.  We generate even with low light levels, but when it's sunny the water can end up too hot.  It's actually changed behaviours so that we now run the washing machine in the daytime when its sunny to use the "free electric".  So as well as the feed in and generation return, we've also seen a massive drop in consumption for both gas and electric.
“Procrastination is the thief of time, collar him.” –Charles Dickens

ElyDave

  • Royal and Ancient Polar Bear Society member 263583
Re: The cost-effectiveness of solar panels
« Reply #52 on: 03 March, 2017, 04:07:30 pm »
Apart from the tariff is linked to manufacturing price (as a barrier to buying), is there not the additional issue that if everyone fitted these things there would be far less need for a national generating capacity infrastructure, thus leaving us at the mercy of the Russians when the sun didn't shine?

There is the fact that the infrastructure can only cope with a certain amount of back-feed from PV installations, and in some areas permissions are being refused on that basis.

Yes, all to do with the voltage balancing to get the feed-in to flow in the right direction.  The thing is the networks are given gov't money to improve their networks to make it easier for thsi type of connection, so there really isn't any excuse for refusals.
“Procrastination is the thief of time, collar him.” –Charles Dickens

Kim

  • Timelord
Re: The cost-effectiveness of solar panels
« Reply #53 on: 03 March, 2017, 04:16:02 pm »
I've had similar experience, with using an i-boost on the immersion heater.  We generate even with low light levels, but when it's sunny the water can end up too hot.  It's actually changed behaviours so that we now run the washing machine in the daytime when its sunny to use the "free electric".  So as well as the feed in and generation return, we've also seen a massive drop in consumption for both gas and electric.

In the absence of much feed-in tariff, it seems that the main benefit to PV is if it provides electricity that you'd otherwise be paying the daytime rate for, particularly if that electricity is disproportionately expensive (eg. you have to burn diesel or LPG to get it, or going solar means you don't have to spend tens of thousands for the electricity board to run cables across some fields).  So you need to be using electricity in the middle of the day.  Which isn't all that good a match for electric cars (as that's typically when they're going to be Somewhere Else), and a washing machine only gets you so far.  Heating water may be a good way to cut your losses, but there are better ways of using solar power to heat water if that's your objective.

The big pay-off that doesn't generally apply to the UK is air-conditioning (which also tends to correlate with more sunlight, of course).  Maybe if you're working from home with a room full of computers?  Similarly, it may make more sense for businesses.

After that, I suppose it depends on how cheap the panels are going to get.  The cost of PVs is steadily improving, but it's always going to cost a fair bit for someone who knows what they're doing to spend a day on your roof.
Careful, Kim. Your sarcasm's showing...

LEE

  • "Shut Up Jens" - Legs.
Re: The cost-effectiveness of solar panels
« Reply #54 on: 03 March, 2017, 04:25:00 pm »
I've seen several videos of people heating swimming pools using DIY Solar heaters.

A few hundred metres of black hose-pipe, coiled into a rack, facing SW, and a small Solar panel driving a Pool Pump, to circulate the water out of the pool, through the hose and back to the pool.  Potentially very cheap to make and very effective.  If I had a pool.
Some people say I'm self-obsessed but that's enough about them.

Kim

  • Timelord
Re: The cost-effectiveness of solar panels
« Reply #55 on: 03 March, 2017, 04:30:42 pm »
I've seen several videos of people heating swimming pools using DIY Solar heaters.

A few hundred metres of black hose-pipe, coiled into a rack, facing SW, and a small Solar panel driving a Pool Pump, to circulate the water out of the pool, through the hose and back to the pool.  Potentially very cheap to make and very effective.

Quite.  That one's been cost-effective since forever, a swimming pool being an almost infinite hot-water sink.  I believe the typical bubblewrap outdoor pool cover is designed to achieve much the same effect.

Evacuated tubes are even more effective, and make sense if area is the limiting factor rather than cost.


Quote
If I had a pool.

Indeed.
Careful, Kim. Your sarcasm's showing...

Re: The cost-effectiveness of solar panels
« Reply #56 on: 03 March, 2017, 05:32:20 pm »
Large subterranean water tank plus heat-pump, perhaps?
Life is too important to be taken seriously.

ElyDave

  • Royal and Ancient Polar Bear Society member 263583
Re: The cost-effectiveness of solar panels
« Reply #57 on: 03 March, 2017, 06:24:07 pm »
I've had similar experience, with using an i-boost on the immersion heater.  We generate even with low light levels, but when it's sunny the water can end up too hot.  It's actually changed behaviours so that we now run the washing machine in the daytime when its sunny to use the "free electric".  So as well as the feed in and generation return, we've also seen a massive drop in consumption for both gas and electric.

In the absence of much feed-in tariff, it seems that the main benefit to PV is if it provides electricity that you'd otherwise be paying the daytime rate for, particularly if that electricity is disproportionately expensive (eg. you have to burn diesel or LPG to get it, or going solar means you don't have to spend tens of thousands for the electricity board to run cables across some fields).  So you need to be using electricity in the middle of the day.  Which isn't all that good a match for electric cars (as that's typically when they're going to be Somewhere Else), and a washing machine only gets you so far.  Heating water may be a good way to cut your losses, but there are better ways of using solar power to heat water if that's your objective.

The big pay-off that doesn't generally apply to the UK is air-conditioning (which also tends to correlate with more sunlight, of course).  Maybe if you're working from home with a room full of computers?  Similarly, it may make more sense for businesses.

After that, I suppose it depends on how cheap the panels are going to get.  The cost of PVs is steadily improving, but it's always going to cost a fair bit for someone who knows what they're doing to spend a day on your roof.

Wife works from home, when I'm not with clients I'm largely working from home, so it makes some sense, in that sense.

I think our payback will be in the order of 5 years or so
“Procrastination is the thief of time, collar him.” –Charles Dickens

Aunt Maud

  • Le Flâneur.
Re: The cost-effectiveness of solar panels
« Reply #58 on: 03 March, 2017, 06:48:00 pm »
If you really want to be a long hair, there's always the drain back solar option to pre heat your DHW.....Summer only in northern climes.

Re: The cost-effectiveness of solar panels
« Reply #59 on: 02 October, 2021, 10:22:44 pm »
A near neighbour is in the process of having panels installed which is laudable. They are however facing East. Would these not be better facing west? Are panels being misold or misleading advice being proferred?
Get a bicycle. You will never regret it, if you live- Mark Twain

Kim

  • Timelord
Re: The cost-effectiveness of solar panels
« Reply #60 on: 02 October, 2021, 11:13:24 pm »
Maybe they're Morning People?
Careful, Kim. Your sarcasm's showing...

Mr Larrington

  • A bit ov a lyv wyr by slof standirds
  • Custard Wallah
    • Mr Larrington's Automatic Diary
Re: The cost-effectiveness of solar panels
« Reply #61 on: 03 October, 2021, 12:06:37 am »
If you really want to be a long hair, there's always the drain back solar option to pre heat your DHW.....Summer only in northern climes.

Though that would require some sort of hot water tank which in my case I have not got.
External Transparent Wall Inspection Operative & Mayor of Mortagne-au-Perche
Satisfying the Bloodlust of the Masses in Peacetime

FifeingEejit

  • Not Small
Re: The cost-effectiveness of solar panels
« Reply #62 on: 03 October, 2021, 08:39:42 am »
Been pondering options, not that I currently have the dosh for it.
But when the boiler packs in, I've got a south-facing roof and garage door, the garage door is black.
On a sunny day in winter the door cannot be touched, and also all summer.

The owners of the other part of the roof have 8 panels with space to spare.

I'm thinking that might allow for a decent set up of PV and water heating,

What resources are there out there to check this sort of thing out in advance without someone being sent to try to get you to buy NOW as my impulsiveness doesn't like that.
Cos like boilers always fail in winter so handing Mr Wooster-Bosch 3 grand for an install tomorrow is easy...

Sent from my BKL-L09 using Tapatalk


andytheflyer

  • Andytheex-flyer.....
Re: The cost-effectiveness of solar panels
« Reply #63 on: 03 October, 2021, 09:02:11 am »
I thought about this when there was an FIT.  My 30 yo house roof faces due south and there are no chimneys etc, so probably almost ideal.

I live in a small village conservation area.

Forget it.

Mrs Pingu

  • Who ate all the pies? Me
    • Twitter
Re: The cost-effectiveness of solar panels
« Reply #64 on: 03 October, 2021, 10:55:11 am »
FE, have you looked at https://www.homeenergyscotland.org/make-greener-choices-at-home-on-the-go ?
They have their own advisers so I would hope they'd be impartial and upfront.

(I was looking at solar panels when I first saw this site, but there are other things that need my money first. Also wasn't exactly sure what thrir cashback thing was all about).
Do not clench. It only makes it worse.

Wowbagger

  • Sylph
    • Musings of a Gentleman Cyclist
Re: The cost-effectiveness of solar panels
« Reply #65 on: 03 October, 2021, 11:00:14 am »
A near neighbour is in the process of having panels installed which is laudable. They are however facing East. Would these not be better facing west? Are panels being misold or misleading advice being proferred?

There are some north-facing solar panels in Southend... just here
Bach without a doubt.

Re: The cost-effectiveness of solar panels
« Reply #66 on: 03 October, 2021, 11:04:53 am »
The Energy Savings Trust has a useful feasibility calculator which includes orientation. It needs the postcode to highlight roof orientation, not to sell you something.

https://energysavingtrust.org.uk/tool/solar-energy-calculator/
Get a bicycle. You will never regret it, if you live- Mark Twain

Wowbagger

  • Sylph
    • Musings of a Gentleman Cyclist
Re: The cost-effectiveness of solar panels
« Reply #67 on: 03 October, 2021, 11:06:29 am »
I thought about this when there was an FIT.  My 30 yo house roof faces due south and there are no chimneys etc, so probably almost ideal.

I live in a small village conservation area.

Forget it.

There is a street in Leigh-on-Sea, Marine Parade, with some deliciously south-facing expansive roofs that could generate an awful lot of Teslas' worth of electrons. Not a panel in sight. I can only imagine that it's a "conservation" area therefore not into conserving the planet.

We got in touch with some IKEA associate some years ago who reckoned our roof orientation would indicate a payback period of 25 years on any outlay. I'd be over 90. I decided to carry on paying the hippies at Ecotricity.
Bach without a doubt.

SoreTween

  • Most of me survived the Pennine Bridleway.
Re: The cost-effectiveness of solar panels
« Reply #68 on: 03 October, 2021, 11:55:39 am »
As a data point / yard stick / discussion point my self installed ground mounted system is a year old on Oct-18.  It is 800w peak1 and has produced 551kWh so far.  It is of course south facing but not an ideal location, it is partially shaded in the middle of the day in high summer and from about 14:30 year round.  Ideally sited or if I got busy with a chainsaw I'd be over 650kWh/pa.

On paper my return on investment time should be 11 years but as an unregistered system I do not get paid for excess production exported so it is higher.  I could register it and get paid (pitifully, about a 1/4 of unit purchase cost) but if I did that I should probably double the system to 9m2, the max you can do ground mounted without planning permission.  I'm not going to do that, I'm fitting an east/west roof mounted system instead.

Cost was £1100.  If you can build a fence or small shed, fit a fused spur and deal with android and web apps you have the skills.  At that price it was cheap enough for me to consider it a hobby, a geek interest project.  Certainly far less than the hardtail 29er n+1 I had my eye on.
Cost for a ground mount 9m2 system would be about £1800 and produce, if unshaded, about 1.3MWh/pa.  Registering is free, it's just paperwork.  You can then estimate your ROI off your savings in power not purchased and power sold.  If it comes out over 10 years I'll be surprised.

1The panels are 800W peak but the system isn't.  The IQ7A microinverters max out at ~ 710W but to count as a paperwork free system it's peak panel power you must use.  Why did I fit 800W panels if I can't use it all? The panels will degrade over time, the microinverters will not.  At about their mid life point, 13 years, the panels will have degraded to match the microinverters.
2020 targets: None
There is only one infinite resource in this universe; human stupidity.

Re: The cost-effectiveness of solar panels
« Reply #69 on: 03 October, 2021, 12:15:49 pm »
The Energy Savings Trust has a useful feasibility calculator which includes orientation. It needs the postcode to highlight roof orientation, not to sell you something.

https://energysavingtrust.org.uk/tool/solar-energy-calculator/
Interesting.  Putting in an unshaded flat roof that can point due south to get max sun ... I stand to lose £2k over the lifetime of the panels.  Not sure how to get the calculator to turn a profit.
Strange things are afoot at the circle K.

Re: The cost-effectiveness of solar panels
« Reply #70 on: 03 October, 2021, 12:37:20 pm »
The Energy Savings Trust has a useful feasibility calculator which includes orientation. It needs the postcode to highlight roof orientation, not to sell you something.

https://energysavingtrust.org.uk/tool/solar-energy-calculator/
Interesting.  Putting in an unshaded flat roof that can point due south to get max sun ... I stand to lose £2k over the lifetime of the panels.  Not sure how to get the calculator to turn a profit.

We would break even on cost but importantly the CO2 savings are important. 

No loss, why not?

SoreTween

  • Most of me survived the Pennine Bridleway.
Re: The cost-effectiveness of solar panels
« Reply #71 on: 03 October, 2021, 12:57:58 pm »
It does seem challenging to get positive fiscal benefit. The CO2 benefit is plenty positive, production CO2 return is only a couple of years on a typical solar installation.  Based on my limited experience the energy generation is about right, I thought maybe they'd be low as this stuff is improving constantly.  It's the installation cost that kills it.  If you GAMI it only seems fiscally beneficial if you need roof work anyway.
2020 targets: None
There is only one infinite resource in this universe; human stupidity.

Wowbagger

  • Sylph
    • Musings of a Gentleman Cyclist
Re: The cost-effectiveness of solar panels
« Reply #72 on: 03 October, 2021, 10:20:18 pm »
If you really want to be a long hair, there's always the drain back solar option to pre heat your DHW.....Summer only in northern climes.

We've had a solar panel for hot water for 16 years. We find that on a sunny day between mid-February and mid-October it heats the water sufficiently for a hot shower (40°C). IN teh warmer 6 months of the year, the weather has to be very dull all day for the water not to get pretty warm. Ours is an idiosyncratic beast and between November and early Feb next door's chimney casts a shadow on the PV panel (about 1' square) which provides the electricity to drive the pump. I think we would have better winter results if it didn't do this.

If it's sunny all day between early April and Late September, the water becomes scaldingly hot. We have two thermometers embedded in the tank's insulation. Occasionally they read in excess of 70°C.

Yesterday, a cold, wet, dull day, I turned on the electric immersion element to give us some hot water. That's the first time since last winter.
Bach without a doubt.

FifeingEejit

  • Not Small
Re: The cost-effectiveness of solar panels
« Reply #73 on: 03 October, 2021, 10:49:51 pm »
FE, have you looked at https://www.homeenergyscotland.org/make-greener-choices-at-home-on-the-go ?
They have their own advisers so I would hope they'd be impartial and upfront.

(I was looking at solar panels when I first saw this site, but there are other things that need my money first. Also wasn't exactly sure what thrir cashback thing was all about).

ta,


Seems the battery is the make or break for PV, but doubles the cost. but then also doubles the saving.



FifeingEejit

  • Not Small
Re: The cost-effectiveness of solar panels
« Reply #74 on: 03 October, 2021, 11:04:07 pm »
The Energy Savings Trust has a useful feasibility calculator which includes orientation. It needs the postcode to highlight roof orientation, not to sell you something.

https://energysavingtrust.org.uk/tool/solar-energy-calculator/
Interesting.  Putting in an unshaded flat roof that can point due south to get max sun ... I stand to lose £2k over the lifetime of the panels.  Not sure how to get the calculator to turn a profit.

We would break even on cost but importantly the CO2 savings are important. 

No loss, why not?

Most people think in terms of money, anything else is too abstract to care about.

If the estimates from the people Mrs Pingu linked to are right, I'd be about a grand more to install solar heating over a replacement boiler, but if that's with minimal plumbing then it would be a fair bit more in reality.