Solar and Battery Storage are they viable ?

[scotview]

We are looking at installing solar and/or battery storage. I have tried to assess real payback.

Solar: 4kW array payback about 15 years.
Poor generation December through February here in NE Scotland when needed most.

Battery Storage : 16 kWh dual battery system payback about 10 years.
Assumes night time tariffs continue to be available and give a guaranteed, non-intermittent recharging source. Off-peak tariffs in NE Scotland might even fall drastically in the future.
Provides back-up power to run CH system during possible power cuts.

I can almost justify installing a battery system but am struggling with solar for our geographic location. I would very much appreciate your comments.
There is a lot of glossy sales pitch but very little real life examples out there for guidance.

Many thanks.

[DrFfybes]

There have been a couple of discussions on her about battery backup, and I think the outcome was financially it is an expensive way of having a power backup. I'd be interesting in your calcs and your overnight/day tariffs compared as 16kWh would suffice here for most of the year.

When we enquired a couple of years ago it was circa £1k per Kwh battery storage, and at the time our annual leccy bill was about £750/year (17p/kwHh) for the energy, plus standing charge, which you'd pay anyway. Best Economy7 style power rate was about 6p/unit overnight, so with a 10kWh battery we would save about £400/year, so we were looking about a 25 year payback ignoring price rises and inflation. 25 years was longer than the projected battery life, and performance would drop over time, extending the payback period.

We have a gas hob, gas fire, and wood burner, so electricity is only really needed for bath/shower, and our risk of long term power loss is low. In rural Scotland it might be higher risk, but a genny might be a cheaper alternative.

Paul

[BullDog]

I am not an expert here, not by any means. However, don't simply assume that because you have a battery storage that it will be available in a power cut. The installations I looked at specifically stated that in a power cut, the battery system wouldn't be available to power appliances. All to do with grid connectivity and synchronisation, apparently.

[fisher]

We are looking at installing solar and/or battery storage. I have tried to assess real payback.

I can almost justify installing a battery system but am struggling with solar for our geographic location. I would very much appreciate your comments.
There is a lot of glossy sales pitch but very little real life examples out there for guidance.

Many thanks.

What would you like to know? I have a 4kw solar array on a south facing roof in North Yorkshire which has been there for over 10 years. I have quarterly generation figures logged since installation.

I can dig these figures out and post them here if that helps.

Is your roof/installation site south facing?

[scrumpyjack]

Similarly I have a 4kw array in NE Herts put in over 10 years ago. The installers had to give a forecast by month of KW hours based on location and orientation etc. Our panels face SSEast and their annual estimate was 3,253 KW hrs. It is usually more and has averaged 3,500 per annum.

The financial payback in 2021 was £2,544 on my calculations. We got in in time for the higher levels of FIT in 2011, RPI linked. The installation then cost £10,600 (far more than now) but has long since paid back the cost.

[88V8]

We are looking at installing solar and/or battery storage. I have tried to assess real payback.

If one is looking at payback periods with a cold financial eye, one must deduct the income that one could have earned by investing the capital elsewhere.
I would say at the moment, 5% would be a yardstick.

V8

[BullDog]

We are looking at installing solar and/or battery storage. I have tried to assess real payback.

If one is looking at payback periods with a cold financial eye, one must deduct the income that one could have earned by investing the capital elsewhere.
I would say at the moment, 5% would be a yardstick.

V8

Absolutely agreed. Don't forget too that after 20 years you either have scrap PV system or in my case, SSE shares (because they're big in renewables) that I bought instead of a solar PV system.

So, all being well, my SSE shares pay regular dividends towards the energy bill and at the end of a PV systems life they may well have appreciated significantly. In fact, they already have, from around 1400p to 1700p.

[MaraMan]

We are looking at installing solar and/or battery storage. I have tried to assess real payback.

If one is looking at payback periods with a cold financial eye, one must deduct the income that one could have earned by investing the capital elsewhere.
I would say at the moment, 5% would be a yardstick.

V8

Absolutely agreed. Don't forget too that after 20 years you either have scrap PV system or in my case, SSE shares (because they're big in renewables) that I bought instead of a solar PV system.

So, all being well, my SSE shares pay regular dividends towards the energy bill and at the end of a PV systems life they may well have appreciated significantly. In fact, they already have, from around 1400p to 1700p.

Yes absolutely, I took the same view and invested in https://www.gsenergystoragefund.com/

[scrumpyjack]

We are looking at installing solar and/or battery storage. I have tried to assess real payback.

If one is looking at payback periods with a cold financial eye, one must deduct the income that one could have earned by investing the capital elsewhere.
I would say at the moment, 5% would be a yardstick.

V8

I would love to know where I can get 5% pa risk free, RPI indexed for 25 years! Marcus pay 0.7% gross, taxable, not indexed in any way.

[Hallucigenia]

Poor generation December through February here in NE Scotland when needed most.

And generally, you just have a lot less sun than southern England - about 2/3 as much, which pushes back payback times by 50%. Wind is a much better match to the load requirement up your way - and there's a good argument that these days it's a lot more efficient to buy in "professional" offshore wind than messing about with a domestic setup.

Off-peak tariffs in NE Scotland might even fall drastically in the future.

Quite - some kind of localised pricing feels like it's inevitable, although when it happens is another matter. Hopefully we'll get some clarity in the new energy security strategy which was due out this week but apparently has been held up by Carrie the PM wanting to make promises that Sunak doesn't want to pay for. And as and when it happens then that should kibosh the economics up your way of generating electricity yourself.

In the meantime, it's always worth concentrating on the less sexy stuff like insulation. Something else to consider might be wood-pellet heating, it needs a fair bit more space and a local source of pellets, but a friend on a farm has one and is very happy with it once the original design of pellet feeder was replaced.

[ReformedCharacter]

Something else to consider might be wood-pellet heating, it needs a fair bit more space and a local source of pellets, but a friend on a farm has one and is very happy with it once the original design of pellet feeder was replaced.

I have read that a lot of the wood pellets come from Russia and they're in short supply right now. So not just gas and oil...

I bought too many logs last year, at least too many to stack in the garden to dry without clogging up the space. I don't feel too bad about that now

RC

[scotview]

Quite - some kind of localised pricing feels like it's inevitable

In the meantime, it's always worth concentrating on the less sexy stuff like insulation. Something else to consider might be wood-pellet heating,

Thanks for the reply H.

I think batteries are a good compromise for up here, especially if off peak rates drop. Also, the idea of running the gas CH system during a week long January power cut is very appealing.

We've done the insulation bit, draught proofing and zone heating installation (my wife even shuts doors now !)

One of my golfing buddies has a wood-pellet system but we don't have the room for a hopper.

PS How do you get several quotes on a reply post, I've even seen quotes from different folkies on a reply post.

[scotview]

I am not an expert here, not by any means. However, don't simply assume that because you have a battery storage that it will be available in a power cut. The installations I looked at specifically stated that in a power cut, the battery system wouldn't be available to power appliances. All to do with grid connectivity and synchronisation, apparently.

The particular inverter I'm looking at will automatically cut off the house supply from the grid and transfer over to essential supplies, like central heating boiler/pump (100 watts). You do need an earth rod installed to guarantee a secure earth. When the inverter sees that the grid is back it disconnects the essential supplies and puts the whole house back onto grid supply. It also has solar feed continuity, if that is installed.

[DrFfybes]

I think batteries are a good compromise for up here, especially if off peak rates drop. Also, the idea of running the gas CH system during a week long January power cut is very appealing.

You might need a larger battery for that, solar top up would be minimal in winter, so unless all you ran was the CH pump you would struggle.

PS How do you get several quotes on a reply post, I've even seen quotes from different folkies on a reply post.

Place your cursor in your reply post at the point you want the quote to be inserted.
Scroll down the earlier posts and highlight the bit you want to insert.
Hit the quote marks at the top tight of that particualr post and it happens by magic (or clever software, there's little difference).

Paul

[fisher]

Here are my quarterly and yearly total figures for the Kwh generated by my 4kW solar array. These are for a South Facing Roof in North Yorkshire. Please note that my quarters initially ended on the 5th of the month (e.g. Q1 2012 was actually 06/12/2011 to 05/03/2012) but from 2017 onwards I moved them nearer to the end of the month (e.g. Q1 2018 was 01/01/2018 to 31/03/2018).

[scotview]

Here are my quarterly and yearly total figures for the Kwh generated by my 4kW solar array.

Thank you very much fisher for taking the time to prepare that information. That's exactly the type of real user data I was looking for.

The Q1 production figure is significantly reduced, as one would expect. Your overall overall average production of about 3700 kWh is impressive.

Our home is orientated South East at the front and we probably have poorer daylight conditions up here. I would imagine my figures would be significantly lower.

Just one question. Presumably you are still receiving the original FIT. If you were starting out from scratch like me, would you still think that solar, with the significantly poorer FIT, would still be viable for you.

Again, many thanks for taking the time to post these figures, very useful info.

[Hallucigenia]

I have read that a lot of the wood pellets come from Russia and they're in short supply right now. So not just gas and oil...

Drax get most of their pellets from North American sawmill waste. Being in a rural area, my understanding is that my friend gets them locally, my unreliable memory is that at a domestic scale as of a few years ago, the economics didn't work out unless they were being transported less than 30 miles or something like that, they're a lot of bulk to transport so they're only a local solution. But one thing the Highlands have is trees, and the lower population density means the houses are more likely to have the necessary space for storage. Which is why I mentioned it in this thread, it's not really an option for more urban areas.

PS How do you get several quotes on a reply post, I've even seen quotes from different folkies on a reply post.

You just need multiple

(quote="scotview"] [/quote]

blocks like you get one of when you hit the Reply button (replace the round bracket with a square bracket, and the name with the person you're quoting) - either copy and paste or use the Quote button.

[PhaseThree]

Here are my quarterly and yearly total figures for the Kwh generated by my 4kW solar array.

Thank you very much fisher for taking the time to prepare that information. That's exactly the type of real user data I was looking for.

The Q1 production figure is significantly reduced, as one would expect. Your overall overall average production of about 3700 kWh is impressive.

Our home is orientated South East at the front and we probably have poorer daylight conditions up here. I would imagine my figures would be significantly lower.

Just one question. Presumably you are still receiving the original FIT. If you were starting out from scratch like me, would you still think that solar, with the significantly poorer FIT, would still be viable for you.

Again, many thanks for taking the time to post these figures, very useful info.

You might find it useful to look at the online PVGIS system. Select your location, intended array size and orientation and it shows you the expected output on a monthly basis. It is usually seen as being pretty accurate in the absence of shading etc.

https://re.jrc.ec.europa.eu/pvg_tools/en/

[vrdiver]

PS How do you get several quotes on a reply post, I've even seen quotes from different folkies on a reply post.

I normally open a duplicate tab in my browser (right click on the tab to show the option, at least in MS Edge, Chrome, Firefox and Opera, on Windows). Then I go to the post I want to quote from, reply to it, but instead of submitting, just copy the relevant segment (including the quote brackets) and paste it into my original tab where I am writing the post I intend to submit.

Alternatively, scroll down through the posts (below where you're preparing your draft) and copy the text of interest, then paste it into your reply, but add {quote="insert_name_of_author_here"} at the start and put {/quote} at the end, but use [] brackets instead of {}. Make sure that "insert_name_of_author_here" is replaced by the correct name (case sensitive I think) of the person you are quoting (which is why I normally open the duplicate tab, as the copy/paste avoids that error).

Using the preview option is really helpful when doing this, as any mismatched brackets or unexpected results can be addressed before going public.

VRD

[funduffer]

I purchased my 4.225kW solar array in December 2020, so I have had it for just over a year.

I have split the 13 panels across 2 roofs facing ESE and SSW respectively. I live in West Yorkshire.

The system cost £4k and generated 3700kWh in the first year. I think the cost of solar panels is starting to rise now, but you may find, as I did, that smaller suppliers offer better value for money than the big electricity supply companies. Aim to pay £1k per kWp installed.

The projection I have from my supplier is cash payback in 8 years. (Note, this takes account of inflation but is not a proper NPV calculation). Their projections with a storage battery were longer - more like 15 years. I didn't get the battery as I have a plug-in car (BEV) which I got last September.

The SEG (Smart Export Guarantee) is very important in delivering returns. (SEG is the replacement to the old FIT scheme). I have signed up to a SEG with OVO which pays me 4p per kWh for exported power, but the plug-in car has reduced the amount I export. Without a battery, you should expect to export maybe 2/3rds of the power produced, unless you have some other way to soak up all the power during the day in the summer months. I am about to switch the SEG to Scottish Power who pay 5.5p per kWh. (Octopus offer even more but I have an EV tariff with them so I can't use their SEG.). You may need to keep switching SEGs to get the best rates. I would hope SEG rates rise as the cost of electricity rises, but I am not holding my breath!

So far I am delighted with the system I have purchased, and it works well with my plug-in car. It has been 100% reliable and delivered what I expected, even in not-so-sunny Yorkshire.

FD