Yet another Solar installation quote post!

ABrass

Screwdriva said:

Alnat1 said:

I used this calculator Solar Panel & Battery Storage Calculator - Great Home (great-home.co.uk)
which I found a couple of months or so ago and appears to be able to factor in better variables than any other out there.

My ROI without a battery comes out at 6.6 years. With the battery I have, it claims 7.2 years so not a huge difference. 

Thanks for sharing! Such a relief to see someone post actual numbers (vs. amateurish opinion) . In the case of our household, the difference is far more substantial (6 year vs. 11 with battery, assuming it lasts that long)

Perhaps the more pertinent question to ask is what could one do with the funds instead? The opportunity cost could instead supply a heat pump or better insulation, both of which may have the potential to reduce environmental and financial costs more than a battery could!

That had to be a spectacularly bad deal on the battery. Wasn't your system 4kW for about £7k including battery ready kit. Dropping another 8(?) grand on a battery would be pretty significant. Way off on the value for money curves too as it'd be far too big to make sense.

But, congrats on the improved economics. The last full year you reported was a 20 year ROI.

Heat pumps don't save money, but insulation is good.

Screwdriva

£7.5K for a 10 kW battery was my assumed cost.

Don’t want to open Pandora’s heat pump box but I think you get the point I’ve been trying to make :-:smile:

ABrass

Screwdriva said:

£7.5K for a 10 kW battery was my assumed cost.

Don’t want to open Pandora’s heat pump box but I think you get the point I’ve been trying to make :-:smile:

That's a really bad deal. You were right to avoid it.

94JDH

Screwdriva said:

QrizB said

Not wishing to rain on anyone's parade, but basing a 10-year-plus investment decision on a peculiar condition of the market that has lasted barely 12 months is a bold choice.

It's is exactly because the battery is a significant 10 year plus investment that I would prefer that potential purchasers consider all inputs to their decision as they exist today, not an outdated viewpoint from a less volatile time.

Said another way, if Outgoing Agile's export prices somehow crash, one can always add on a newer generation, more capable battery a year or two later, while benefitting from disproportionately high export tariffs of the foreseeable future. However, if the inflationary trend continues and export of solar continues to be rewarding, the potential battery owner would have spent significant upwards of £5K for an add on that may never return its original investment. And for some buyers, a battery is all about return on investment. 

uk1 said:

I’m not sure you have fully understood the full discussion.  

A perfectly rational view of “the battery” is that during the months when PV output is inadequate then the possibility of off-peak battery charging is a potential advantage and has a viable place in the consideration. So on days that export is available and the price is right, then you export.  On those days when you aren’t producing enough then you charge at cheap rates.  It sounds rational to me.  

Both sides of the battery discussion cannot base their decision on certainties. It’s about instinct and risk assessments and the different sets of considerations that different people find most important.

From your post, I'm not certain you have understood the full discussion. You can export on Outgoing Agile OR benefit from a cheap, battery charging nighttime tariff, but not both. 

Or if you're clever use Agile in the summer and swap to Go in the Winter, best of both worlds IF you've invested in a battery.

uk1

Screwdriva said:

£7.5K for a 10 kW battery was my assumed cost.

You do know that this is extraordinarily bad value don’t you. 

rew81

Nice to see a debate with good arguments supporting each personal opinion. 
Doing the maths in the current situation it is  better without a battery even if you are using less from what you are producing. Obviously this is valid as long as the exporting price is above 25p and not 5p as I will have if I stay with Shell energy. 
I see the battery more as an insurance for future price increases. 
My system has a 9.5kwh battery which will add a few years to the break even point but according to my electricity usage profile it is better with it. 
Unfortunatly there isn't a single solution that will work for everyone. So many variables to take in consideration. 
But if you are considering a solar system and you are ready  to spend a few thousands then for sure, in my opinion, you are able to educate yourself and play with a simple equation to see the outcome of different scenarios. 

Screwdriva

94JDH said:

Or if you're clever use Agile in the summer and swap to Go in the Winter, best of both worlds IF you've invested in a battery.

I suspect I'm not that clever. I also lack an EV and therefore don't quality for Octopus Go.

rew81 said:

I see the battery more as an insurance for future price increases. 

My point really was that a better battery can always be added later, should the price of solar export crash for some reason. Given the recent fixed SEG tariff increase to 0.15p, I would suggest that is a remote possibility. 

ABrass said:

That's a really bad deal. You were right to avoid it.

Even assuming a 10kWh SolarEdge or LG battery for £6K (impossibly hard to get at this price today), the economics for a battery still don't add up for us.

ABrass

Screwdriva said:

94JDH said:

Or if you're clever use Agile in the summer and swap to Go in the Winter, best of both worlds IF you've invested in a battery.

I suspect I'm not that clever. I also lack an EV and therefore don't quality for Octopus Go.

rew81 said:

I see the battery more as an insurance for future price increases. 

My point really was that a better battery can always be added later, should the price of solar export crash for some reason. Given the recent fixed SEG tariff increase to 0.15p, I would suggest that is a remote possibility. 

ABrass said:

That's a really bad deal. You were right to avoid it.

Even assuming a 10kWh SolarEdge or LG battery for £6K (impossibly hard to get at this price today), the economics for a battery still don't add up for us.

Of course not, that's too big and still too expensive.

If you've got a battery ready hybrid inverter then 10kWh of Pylontechs would cost £4,000 - £4,500 Inc vat. And a more sensible size of 4-8kWh would be proportionally less. You get the most saving from the first few kW.

If you were buying it as part of your solar installation you'd have saved 20% on the VAT.

Niv

Alnat1 said:

I used this calculator Solar Panel & Battery Storage Calculator - Great Home (great-home.co.uk)
which I found a couple of months or so ago and appears to be able to factor in better variables than any other out there.

My ROI without a battery comes out at 6.6 years. With the battery I have, it claims 7.2 years so not a huge difference. 

This is a useful calculator.

I plugged in the numbers form my solar quote and get a 12 year payback.

If I factor in a 6kW battery costing £4k I get a 12.2 year payback - I have no idea if this is a sensible guessed price for this size battery but think its worth checking with my installation company to get a better estimate. 

ggmf

Plugged in my numbers, it suggests a current payback of 8.4 years, taking into account the new electricity rates from 01/10/22 this then comes down to 7.1 years.

My actual figures suggest a ROI of just under 7 years currently, taking into account the rise on 01/10/22 then its under 6 years.

Should our Son who has had to move back home, and his girlfriend who is here half of the time, manage to save enough for a mortgage, and then get one, then our utilisation will drop significantly and hence the ROI will reduce further.