Solar panels and battery for house

[otherclive]

Seeing the success of a retrospective installation of panels and batteries in a Swansea social housing development of 600+ houses I have given some thought to a similar approach. Our house is positioned exactly north south with the line of the roof ridge. So although it could be unusual I thought about having six panels facing east and six facing west.

Has anyone had a domestic battery-panel system installed.

 

[Sam Vimes]

Yes, and quickly worked out that I'd never see the return on the initial outlay.

Check here to see if or when you'd get a return on your investment.

Solar Energy Calculator | Energy Saving Trust

 

[ProfJohnL]

Yes, and quickly worked out that I'd never see the return on the initial outlay.

Check here to see if or when you'd get a return on your investment.

Solar Energy Calculator | Energy Saving Trust

That rather depends on the cost electricity when purchased from the grid. If it continues to rise then pay back for a solar installation becomes more probable.

However as time goes by, the costs of installing PV and an on site storage solution is getting cheaper, and thus more viable. but cost isn't the only driver for some people, Some see a benefit in the security of supply when the grid has an outage, and of course others also like the reduction of emissions for the environment.

 

[JTQ]

Experience with using a portable panel suggests, facing other than towards the sun will "hurt" on those direct sun lit days, but not as significantly hurt with cloud covered days where power is coming from light off the clouds.
But the same experience shows that the days offering direct sunlight exposure, yield way more than cloudy days. Therefore, those are the ones to optimise the system for, rather than a system that happens to be not baddy hobbled on what will be poor yield days.
Your east and west facing panels IMO are thus a poor option.

 

[RogerL]

Experience with using a portable panel suggests, facing other than towards the sun will "hurt" on those direct sun lit days, but not as significantly hurt with cloud covered days where power is coming from light off the clouds.
But the same experience shows that the days offering direct sunlight exposure, yield way more than cloudy days. Therefore, those are the ones to optimise the system for, rather than a system that happens to be not baddy hobbled on what will be poor yield days.
Your east and west facing panels IMO are thus a poor option.

I have seen a contributor on a different forum was very happy with his north-south ridge installation - despite the panels working less efficiently than south facing, the increased area by using both east and west sides gave a higher total which was spead more widely during the day - the downside was the extra panel cost of doing both sides.

 

[otherclive]

Experience with using a portable panel suggests, facing other than towards the sun will "hurt" on those direct sun lit days, but not as significantly hurt with cloud covered days where power is coming from light off the clouds.
But the same experience shows that the days offering direct sunlight exposure, yield way more than cloudy days. Therefore, those are the ones to optimise the system for, rather than a system that happens to be not baddy hobbled on what will be poor yield days.
Your east and west facing panels IMO are thus a poor option.

The house actually receives quite a lot of light when the sun is traversing from east to west. But it’s an unfortunate fact that the apex line of the roof is north -south so south facing panels are an impossibility. I am looking to find information wrt panel efficiency at the respective direction of orientation to see tge variation.

 

[otherclive]

I have seen a contributor on a different forum was very happy with his north-south ridge installation - despite the panels working less efficiently than south facing, the increased area by using both east and west sides gave a higher total which was spead more widely during the day - the downside was the extra panel cost of doing both sides.

That was my thought process as going for two banks of six will compensate compared to the normal 8 panel fit in this area for those houses that face between SE and SW.

 

[ProfJohnL]

OC.

You might hope a panels output follows a half sine wave as the incidence of the sun light changes, but from graphs I have seen that is not the case, there is a marked sweet spot around 90 degrees as you would expect, but as the angle of deviation steadily increases the performance of the panel drops off far more quickly.

Each design of panel will have their own angular sensitivity characteristic. I guess the refractive index of the top layer plays a major part in this, so you would have to review the manufacturers specifications of the panels your considering.

Don't forget you also have to consider the angle of inclination of your roof in relation to the latitude of your property.

To maximise a penels yield, it needs to track the sun as its seen from the panels location but this degree of sophistication is very unlikely for domestic installations.

 

[Boff]

Our house lays on an east west axis. So the roof points almost due south so perfect for solar. However the house is in a conservation area so they won’t allow panels of roofs facing the road (ours) neighbours across the road can and have fitted panels to their properties.

 

[Beachball]

We also been thinking of solar battery panel system on our bungalow so i am watching this thread with interest .

 

[Ferrodo]

I have recently installed panels and batteries to my property and I am most impressed with the results. The initial cost is high but I believe that if you have the readies sitting in your bank then you may as well get it to work for you rather than attract just about zero interest in your bank. The installation will also put value onto the property especially as my house is totally electric with no gas. As far as I am aware of the grid goes down so does the solar system. You cannot use the “standard “ set up to power your home during a power outage. This is, I believe, to protect power workers from feed in from home solar systems. There is a way to over come this but not really worth it unless you need to power say medical equipment and the like.
Regards
T

 

[Paullus1959]

I have 12 PV solar panels fitted on the roof of my house which faces due South. I was fortunate to have them installed just before the government reneged on the agreement to halve the Feed In Tariff or F.I.T. in April 2012, by bringing the deadline forward by six months. This had a catastrophic effect on the booming Solar PV industry because this FIT reduction resulted in wholescale cancellation of orders leading to companies with hitherto full order books going out of business.
Fortunately, my installation was comissioned in mid-October 2011 and so I managed to qualify for the original higher FIT which stands now at around 52p per KWh my system generates. The current FIT is only around 3.79p per KWh. On average, I receive around £1200 per year from my solar panels and I recouped my initial outlay after six years. So, what I receive now is pure tax free profit.
It would obviously take significantly longer on the current FIT rate to recoup the initial installation cost. The government's reasoning behind reducing the FIT rate was so that people who installed PV systems early on in the scheme and paid premium prices were rewarded as early adopters. As the cost of installations dropped the FIT rate reduced accordingly.
I have looked into the cost of installing a battery storage system but I reason that it would again take several years to recoup the cost of the installation so, I'm currently content with my current system but I will reconsider if and when I have to replace the inverter which has a projected lifespan of 12-15 years.
One thing I would advise against is roof rental scheme where a PV system is installed on your roof for free. Yes you do benefit from reduced electricity useage but, you don't own the installation. The FIT however is actually paid to the the owner, which could cause complications with roof maintenance or the sale of the house as a third party is involved.
Oh, and as I write this an email has landed in my inbox asking for my FIT meter readings and it's been a very sunny three months. Happy days 🌞

 

[Tobes]

Like Paullus, I have a solar array installed back in 2012. Like OC, my ridge line is North-South, so my plant ( 3.1kW) is split 50:50 due East and Due West. All of my generation data is on line so you can have a poke to see how it stacks up. Tobes solar array. We also added a hot water controller in a couple of years in which diverted excess generation to the immersion heater.

This year we also added a 6kW / 16.4kWh battery system. Because we are east west, our peak output is relatively low, and we self consume much of our generated electricity, so the battery system was primarily to allow time shift from peak to off peak. As result, our average kWh price from the grid is about 8p. My initial calculations (in Jan '22) showed we should get a payback in about 10 years, but it may end up being sooner than that.

Happy to share more details if it helps!

 

[otherclive]

Like Paullus, I have a solar array installed back in 2012. Like OC, my ridge line is North-South, so my plant ( 3.1kW) is split 50:50 due East and Due West. All of my generation data is on line so you can have a poke to see how it stacks up. Tobes solar array. We also added a hot water controller in a couple of years in which diverted excess generation to the immersion heater.

This year we also added a 6kW / 16.4kWh battery system. Because we are east west, our peak output is relatively low, and we self consume much of our generated electricity, so the battery system was primarily to allow time shift from peak to off peak. As result, our average kWh price from the grid is about 8p. My initial calculations (in Jan '22) showed we should get a payback in about 10 years, but it may end up being sooner than that.

Happy to share more details if it helps!

Tobes
Many thanks that's an extraordinarily useful set of data, especially as your house's axis mirrors ours. Also I see that over 10 years there has been very little degradation of output from the panels. I had given thought to using electric to heat the hot water tank, as we currently use gas, and apart from the cooking the hot water is our sole use of gas (2 hrs per day max scheduled) and that is pretty well all year round, apart of course for when the CH is on. So cutting back on the gas in summer would also be useful. A "hot water" battery!!

 

[Tobes]

Tobes
Many thanks that's an extraordinarily useful set of data, especially as your house's axis mirrors ours. Also I see that over 10 years there has been very little degradation of output from the panels. I had given thought to using electric to heat the hot water tank, as we currently use gas, and apart from the cooking the hot water is our sole use of gas (2 hrs per day max scheduled) and that is pretty well all year round, apart of course for when the CH is on. So cutting back on the gas in summer would also be useful. A "hot water" battery!!

Yes - the panel degradation has been so low as to be lost in the noise of weather each year. I should have mentioned, the original install was about £8.5K so it payed back inside its original prediction of 8 years. Since the energy crisis hit, we have started using our HW controller to run the immersion heater over night (7.5p / kWh as opposed to 10p / kWh for gas). We have a super insulated HW tank, so getting to a high temp over night is enough to provide showers for the whole house, and some washing up without running out.

Our E/W setup matches the performance of a due S set up in the height of summer. The real degradation comes in winter as the sun is so much lower in the sky. The steeper your roof, the more of an issue it becomes.

We are considering moving house in the next year or so, and one of the criteria I am looking for is a suitable south facing roof to add solar to. I would absolutely do it again, even without the FIT component, but would do it slightly differently. In 2012 we were (more or less) limmited to a max of 4kW of peak output from the panels. That constraint no longer applies, so I would be looking to put solar on ALL my available roof space (not just enough to cover my needs). The panel cost is much lower, so install is a significant portion. Inverters are also cheaper.

I would look to have enough generation (and battery storage) to produce my home needs for (at least) as much as 80% of the year. Feb to November inclusive. That should allow me to over produce for a good 50% of the year and to export that energy back to the grid for an income that would pay for my winter import.

 

[Ern]

Seeing the success of a retrospective installation of panels and batteries in a Swansea social housing development of 600+ houses I have given some thought to a similar approach. Our house is positioned exactly north south with the line of the roof ridge. So although it could be unusual I thought about having six panels facing east and six facing west.

Has anyone had a domestic battery-panel system installed.

Good interesting article. If those houses have reduced their demand from the Grid by 50% the benefits are worthwhile. However, the investment cost is crazy at over £10K per house. (These are small terraced houses).
There are proprietary energy storage units available from various suppliers such as Bosch - about the size of a standard domestic unit so would fit under a kitchen worktop. We need our smart meters to start getting smart so that we can benefit from low demand times. I am not sure what the energy suppliers are all waiting for because in theory they could provide the banded tariffs now.

 

[ProfJohnL]

A possible alternative to installing PV on your own house, and it is a bit of a curved ball, but there is a company who sell shares in wind turbines and you take a share of profit of the energy it generates. You can offset this against your energy bill.

There are some potentially important advantages to this,
1. Wind generator is already more efficient at power generation than PV.
2. You don't have to modify your house to install it.
3. Equipment maintenance is fully professionally managed.
4. If you move house you don't loose all the equipment you've installed and the cost benefit stays with you.

The downside is your still dependant on the grid for power.

If you would like to see more about it see

View: https://www.youtube.com/watch?v=65rlHr6ey4I

 

[Tobes]

A possible alternative to installing PV on your own house, and it is a bit of a curved ball, but there is a company who sell shares in wind turbines and you take a share of profit of the energy it generates. You can offset this against your energy bill.

There are some potentially important advantages to this,
1. Wind generator is already more efficient at power generation than PV.
2. You don't have to modify your house to install it.
3. Equipment maintenance is fully professionally managed.
4. If you move house you don't loose all the equipment you've installed and the cost benefit stays with you.

The downside is your still dependant on the grid for power.

If you would like to see more about it see

View: https://www.youtube.com/watch?v=65rlHr6ey4I

I am an investor in Kirk Hill, Ripple's second project. It's due to go live in about 12 months (end of 2023). Happy to share information about how that works too.

 

[Tobes]

Good interesting article. If those houses have reduced their demand from the Grid by 50% the benefits are worthwhile. However, the investment cost is crazy at over £10K per house. (These are small terraced houses).
There are proprietary energy storage units available from various suppliers such as Bosch - about the size of a standard domestic unit so would fit under a kitchen worktop. We need our smart meters to start getting smart so that we can benefit from low demand times. I am not sure what the energy suppliers are all waiting for because in theory they could provide the banded tariffs now.

Octopus Energy have a set of smart tariffs that give access to live pricing, or reduced pricing at cheap times. It's who I use for my low cost overnight rate. For customers with a smart meter, Octopus will be offering incentives to reduce stress on generation (probably during peak times) this winter. I participated in the the trial for that program early this year, and have signed up for this winter, though I am not expecting to benefit from the rebates as I don't use electricity at peak times anyway.

 

[RogerL]

For customers with a smart meter, Octopus will be offering incentives to reduce stress on generation (probably during peak times) this winter. I participated in the the trial for that program early this year, and have signed up for this winter, though I am not expecting to benefit from the rebates as I don't use electricity at peak times anyway.

As an Octopus customer, I was invited to take up these peak reduction rebates but for customers who have already minimised their energy consumption, as we have, it's just not possible to reduce peak consumption rates - it will though help the grid by getting less disciplined users to change their usage pattern.

 

[Paullus1959]

As an Octopus customer, I was invited to take up these peak reduction rebates but for customers who have already minimised their energy consumption, as we have, it's just not possible to reduce peak consumption rates - it will though help the grid by getting less disciplined users to change their usage pattern.

I'm with Octopus too and have just had gas and electric smart meters installed. I cannot reduce my consumption any further to be able to take advantage of the Octopus rebates either. All the appliances I own have high energy efficiency ratings and all of my lighting is now LED. I was more than happy when I checked my live energy consumption on my smart meter when I had no major appliances operating except, two fridges, a freezer, a PC and a TV on stanby, to see that I was only using 210w of electricity. Remarkable when you consider that a single old fashioned fillament type light bulb that gave reasonable lighting, could consume 200-300w.

Off topic I know but I have made a significant reduction in my gas consumption by simply turning the hot water and central heating temperature down on my combi-boiler. Hot water down from 68°C to 49°C and the CH down to 65°C. It seemed ridiculous that I was heating water up to 68°C and then having to add cold water to cool it enough to be bearable. 49°C is more than enough for a comfortable shower and doing the dishes etc.
You can't do this with a hot water tank though. Stored hot water has to be kept above 65°C to prevent the growth of the harmful Legionella bacteria.

 

[RogerL]

I'm with Octopus too and have just had gas and electric smart meters installed. I cannot reduce my consumption any further to be able to take advantage of the Octopus rebates either. All the appliances I own have high energy efficiency ratings and all of my lighting is now LED. I was more than happy when I checked my live energy consumption on my smart meter when I had no major appliances operating except, two fridges, a freezer, a PC and a TV on stanby, to see that I was only using 210w of electricity. Remarkable when you consider that a single old fashioned fillament type light bulb that gave reasonable lighting, could consume 200-300w.

Off topic I know but I have made a significant reduction in my gas consumption by simply turning the hot water and central heating temperature down on my combi-boiler. Hot water down from 68°C to 49°C and the CH down to 65°C. It seemed ridiculous that I was heating water up to 68°C and then having to add cold water to cool it enough to be bearable. 49°C is more than enough for a comfortable shower and doing the dishes etc.
You can't do this with a hot water tank though. Stored hot water has to be kept above 65°C to prevent the growth of the harmful Legionella bacteria.

Not quite - hot water should be stored at 60 degrees or higher according to HSE https://www.hse.gov.uk/healthservices/legionella.htm

 

[Sam Vimes]

Making the decision to have PV panels installed is not easy. Figures will vary but as one example a 4Kw system will be about £6k to install. The estimated savings each year where I live is about £500 so that's going to take 12 years before I would break even.

Now its a sad fact of life and not a pleasant thought but when you get to be over 70 years old your not sure how long you've got left. Average life expectancy for men is about 79 years and women 83. So just as your about to start seeing the benefit you might just shuffle off this mortal coil. (I'm hopeful I'll have longer because my father was just 7 days short of his 100th birthday)

Of course as fuel prices rise then the payback period would be shorter provided other things don't detract from that such as reductions in the Smart Export Guarantee, increased maintenance costs, replacement cost in case ,of failures

Currently you can easily get savings rates of 4.75% which on the £6k out lay you would have paid will yield £285 per year and you still have your capital to play with if you need it.

Maybe it would be better to use the money if you have it and your at that certain age to tick off the items on your bucket list.

 

[Bluetonic]

Maybe it would be better to use the money if you have it and your at that certain age to tick of the items on your bucket list

As someone that died this year and is only 54, I totally agree.
I'd love to invest in solar and battery store, but this won't be our last house and will be downsizing in 2 or three years when kids go to Uni or whatever, and I plan do do some fun stuff before I die for the last time

 

[otherclive]

Not quite - hot water should be stored at 60 degrees or higher according to HSE https://www.hse.gov.uk/healthservices/legionella.htm

I realise that the HSE guidance is for employers and landlords, but I wonder how many follow it to the letter, especially those with a Buy to Let property/properties.