Solar Panels - Am I missing something?

[fromdownwest]

I am looking at the option of a solar install via Octpus.

I have been quoted £16k for 24 Panels and Tesla Powerwall3 and Tesla Invertor
Panels are JAM45441 LB 440W

12 Panels at 60 deg
12 Panels at 120 Deg

The current tariff is Octopus Wholesale tracker circa 4,500 annual usage.
Generates circa 8,000 - so offsets my usage with the sale back on the rest

Will be an EV in 2 years time added to the above

Showing about half of generate being exported at about £700 a year.

So in essence no electricity bill except the standing charge.

I am struggling to see that this is a good value investment, or am I missing something?

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Updated by MNHQ
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You'll still be paying for electricity during the winter as you probably wont generate enough to cover your usage.

Also if your load exceeds what your generating or capacity of inverter you'll be importing from the grid

They seem to be expensive panels.

How much is your current annual electricity cost?
You can then assess how long it would take to pay back.

The code means the panel is a JA Solar 440w.

If you can get the right tariff overnight especially in winter you charge the battery from the grid at a lower tariff and use it during the day when a higher tariff is in place.

The return you're getting is the £700 plus not having to pay for the 4,500 you consume.

Looking at the Octopus Tracker it seems to be around 20p p/kWh at the moment (in August figures have varied from 14.4p to 22.7p).

The Octopus Outgoing Fixed rate is 15 p/kWh.

So, 4,500 x £0.20 = £900 which you're saving by having the panels and storage

On top of that you get 3,500 x £0.15 = £525 for electricity that you export

So, the total amount you get from doing this is 900 + 525 = £1,425

If it costs you £16k then that is an 11.2 year payback . Whether you think that is a good deal or not is down to you.

Ultimately, it doesn't really cost in. Most quotes don't take into account the degradation of the solar panels either.

You will get a nice fuzzy feeling for saving the planet, but it isn't a financially sound investment or anything. Especially if you aren't likely to stay in the house for at least 25 years.

I think you could have fewer panels. 24 is a lot. 16 should do it.
Octopus also offers free energy in windy days in some post codes….winter or summer.

The way the solar panels connect to the batteries is an issue. They can switch off a whole set if one isn't generating enough. They are a decent investment if you get it set up right, but we decided Tesla batteries weren't worth it due to the connections...

Thanks, all, I was just ensuring I wasn't missing anything.

So benefits are no electricity bills ( bar standing Charge) and around £700 in credit for excess.

So around £1,568 based on the provider's assumptions, so ROI is just under 10 years, assuming no degradation of panels or other issues.

Add an EV into this in 2 years, saving Circa £200 in fuel costs

So £3,968 is closer to 4 years break even.

I think it may be prudent to wait until I have the EV.

Do you think the VAT free will continue?

A fair chunk of that investment is the battery. Run the numbers without the battery as a comparison.

Take the battery out of the equation and recalculate. They are not yet at a cost effective price for domestic users, usually.

It’s not always helpful to look at ‘how long will it take to recoup the cost’ - it partly depends on the price of electricity and on how much you use, but the payback period is likely to be years in any event.

I had solar panels for two reasons, firstly because I think it’s better for the planet and secondly because I wanted to reduce my outgoings. I have eight panels and a 10 kw battery, and I haven’t paid for hot water since the day they were installed. Even in winter it generates enough power to heat the tank. However, I live on my own, if I had two teenagers in the house I’m sure I would need to top it up.

The price you get for exporting it is minimal, but most days in the summer I generate more than I use. I can sometimes charge my car entirely on solar, but an overnight charge on Intelligent Octopus is less than £2.00.

Why not get some alternative quotes, that does sound like a lot of panels and you may not need such a large installation.

We got 14 panels WSW facing. And 2x 5kw batteries (not Tesla). We also have 2x EVs
When I bought them it looked like a 7 year pay back.
And that is what we are achieving.
Some of the saving has come from switching to Octopus Go so we get 5 hours of v cheap energy overnight. This is when we charge the car (on a timer). The day rate is higher but because of the panels I hardly draw from the grid in the day. I run washer and dishwasher (one at a time) in the day time on sunny days or overnight in cheap electric period when not enough solar is being produced.
In the summer when I produce more in a day than I use and the batteries are full, I plug the EV in on Eco mode which shifts the spare solar to the car, but only the spare solar, it doesn't also draw from the grid. So the car also acts as an extra battery. Without the EV payback would be longer.
Even in the winter I tend to get most of my non EV usage covered by solar except on really dismal days. We are SE of country.
I am now looking at getting an immersion (ours isn't wired in) and a switch so spare solar can also be diverted to the hot water. If there are gas shortages or my boiler breaks this will be a godsend. And a much cheaper way to heat water.

Thanks all - the battery takes up around £6,550.00 of the £16k.

The number of panels was maxed, as I would rather do a one-and-done installation, and not add at a later date.

Looking, relatively unfavourable based on the numbers as it stands, again based on the current prices.

You are missing something - if you store the electricity that you generate in a battery you do not export back to the grid. So either battery and you keep and use all the electricity that you generate or no battery and export back to the grid.

PS You don't need to have your panels installed by Octopus to take advantage of their tariffs. I would recommend obtaining another installation quote from another company.

Thank you, I have had a few quotes, and surprisingly, Octopus are the lower end of the quote range. I assume some economies of scale are at play.

but once your battery is full, then you do export any excess back to the grid, @catndogslife , it's not an either/or. However the income from this is minimal.

24 panels sounds like a 10KW install, and thene there's a Tesla powerbank. So £16k is probably about right. But, I'd be running the economcis without the powerbank as well, particularly if I was going to get an electric car as the future is probably using the cars battery to manage load.

doesnt seem like a very good incentive at the moment or payback time

A friend has solar panels. Had them for about 3 years. Wants to do a loft conversion/extension but is unable to as the panels cannot be removed to do the work as this is considered theft.
Read the small print. It’s been an absolute eye opener.

24 x 440W panels is alot, over 10kW peak! Batteries are never cost effective.
Solar companies seem to assume people can afford a solar install cost of about 15K, then scale the installed kit to match this, irrespective of what you actually need.

For comparison, we have the equivalent of about 10 panels, no battery, EV. Almost all self consumed, little export, payback was in 2-3 years,

£6 - £7k without the battery, bringing the ROI down to around 4 years-ish.

Better, but still not convinced!

I've had a similar set up to what you are proposing (but not a Tesla powerwall) for 2.5 years now. What is harder to calculate are the savings around low and negative pricing (with Agile). When you get an EV you'll be able to occasionally charge and get paid for it. Or charge when costs are low. We make our battery work for us, discharging back to grid and recharging when cheap. It's a mental load but I find it fun. We're very happy with the cost savings (which wasn't our primary reason for installing them). Your quote is comparable to what we paid.

I would not install without a battery. You need to store the electricity to get through the more expensive peak times (4-7pm).