Does solar suit every house?

Black_Knight

Regularly toyed with the thoughts of solar for our house, but given our orientation and house setup I never thought it was worth it (or certainly the payback time was very long).

Our house:

3 bed semi detached. 2 adults, 2 kids. No hot tank for excess power to heat water. No room for batteries (I hear they take up decent space). Rear faces East but has a Velux in the middle of it, side (hipped roof) faces south but it's the smallest of the 3 roof areas and hard to access. We've an electric car, so utilising solar would require an investment for a new charger.

Our usage:

~300-350W during a WFH day, with spikes for cooking, kettle etc. Washes, dishwasher are all done on a night rate at the moment. Using about 13kWh per day on a normal day. Multiples more when we charge the car.

So after all that, my question is does solar work for everyone?

I feel like with our setup, we can get panels and either top up the car with any excess (several hundred euro to change the car charger though), or send it back to the grid. Having an array that provides much more than our base load seems like waste. And given our orientation I'd expect our payback period to be maybe double what those with 100% South facing would expect.

Thoughts?

It will save on electricity and therefore your bills.

Payback is probably 7 to 10 years. Most have a 25 year warranty.

I've a 3.24kw system and am saving a fiver a week over winter. I cooked on solar today and it wasn't particularly bright all day. I'm west facing. You have some south facing.

There is a company offering solar as a service with a 2.9kw system at 29.50 per month over 10 years after the grant is paid to them.

It's worth considering

Snugbugrug28

Do you have panels both east and west?

Im about to move into a west facing house and would consider it if there was any kind of decent payback time. Anything for energy independence.

https://www.boards.ie/discussion/comment/118754250#Comment_118754250

Mine are west facing

Black_Knight

https://www.boards.ie/discussion/comment/118754250#Comment_118754250

I've no panels. Yet to be convinced it's worth the investment. Not sure we'll be in this same house in 10 years time.

Black_Knight

https://www.boards.ie/discussion/comment/118754195#Comment_118754195

What power are you generating at peak with that array these days?

Our bills aren't too bad, and assuming 8 hours of solar a day we'll cover our base load ok, and some cooking/Kettles too.

Our day rate usage is ~8kWh per day. About 4kWh of that is the base load, so the other 4kWh would mostly be during daylight (solar) hours. Probably 2kWh of the base load is during daylight hours, and maybe 3kWh of the other usage is in solar hours.

Base load during solar is about €140 for the year saved. The rest is about €210 a year. €350 saved a year (at today's rates) isn't much. Even plugging in the car during the day and got 20kWh a week into it it is only saving me against the cheap night rate I'm on, so that's €50 saved a year maybe?

Maybe I'm being conservative with solar hours (I don't know tbh) and energy rates will only rise, but spending 4-5k on solar to save €4-500 a year feels a pretty slow payback.

https://www.boards.ie/discussion/comment/118754435#Comment_118754435

350 a year over 10 years and the rest is profit for the next 15 years.

Got 6.6kw today. Winter was around 2kw a day

This is how it went since September

bullit_dodger

Everyone's value system will be different, a 10 year payback for one person would be too long and yet for another person be totally fine.

What I can say is that unless your a real outlier, there's a solar configuration where you'll get a decent return on investment. I've a East/West split myself and with 5.3Kwp in panels, the forecasted yield for the array that I have is 291 Kwhr for March. In fact the expected yield for my installation is....

So from March to Sept, your average household should be fairly well covered. Winter as you can note (Nov-Feb) it's not great. For that you'd need south facing panel.

Apr - Jun you could plug in your EV via the "granny-cable" and put 10Kwhr into it a day easy enough. I don't have an EV, but I'm sure the EV owners on the forums would tell you how feasible that is. I mention this as you were worried about the expenditure of a new charger. I don't think you do need one.

Most systems would pay for themselves (at the current electricity rates) in 10-12 years. After that of course your "quid's in", where it's saving you €500-750 a year. Sometimes payback is less, if your a heavy user. Of course if electricity rates rise (probably likely!) then your payback again would be shorter.

Typical installation that I think is "a good start" for an EV owner would be 5Kwp in panels and 5Kwhr battery. Probably about €8k after the grant taken off.

Alkers

https://www.boards.ie/discussion/comment/118754435#Comment_118754435

The solar as a service mentioned above is a monthly fee (for ten years). It seems in your case, the cost per annum is roughly equal to what you'd save financially. So it would be close to zero cost for you for ten years and everything after that would save you money, plus you have the environmental benefits.

If energy costs increase, you save more. If you end up with a decent fit, you save more.

The fancy car charger to use excess solar will likely never pay the cost of itself back in solar fed into the car. You have to make sure the car is home when there is solar excess being generated, while the car hasn't got a full battery (useless if you've charged the night before) and many cars won't charge until you've about 1.2kW of excess, further limiting the charge you will get.

KCross

https://www.boards.ie/discussion/comment/118754299#Comment_118754299

Not sure we'll be in this same house in 10 years time.

if the financials are any way important to you I think that statement would rule you out.

with what you’ve described you’ll be lucky to break even.

if you’re looking at environmental and happy to pay it forward for the next owner then maybe worth considering. It will certainly make the house more sellable!

Deagol

https://www.boards.ie/discussion/2058236479/does-solar-suit-every-house

To be honest, I don't really want to engage with someone like you. And apologies if I've got you wrong but you remind me of one of my best friends. He seems to have already made up his mind that no amount of solar or any other tech is right for him. As if I have to 'sell' him it. I've told him what I'll say to you.

Do all the maths you want- but no one know can predict energy prices in the future. BUT! I'll be willing to bet they will be up not down.....

If you can admit this one simple premise than you can see point one?

Second point I make to him. Are you so certain you are much cleverer than other people? If not... then why are they getting solar etc??

End of the day though, I'm not a solar sales man and neither is anyone else here. Get them or not, we make no money from you decision either way!

Good luck.

Black_Knight

https://www.boards.ie/discussion/comment/118754568#Comment_118754568

What size array have you got? All South facing?

https://www.boards.ie/discussion/comment/118755186#Comment_118755186

3.24kw west but that's in my first 2 posts

Black_Knight

https://www.boards.ie/discussion/comment/118754900#Comment_118754900

You've got me wrong alright. Sure aren't I here trying to justify solar for ourselves?

If you're in a house for the longer term is a no brainer. Our next house is 100% having solar, but anything I spend on this house takes from what I can spend on the next house. If that next house is <10 years away it might not be worth investing in our current house.

Might be best to just get some quotes and experts in to see

Snugbugrug28

The service option sounds ideal. I might look at it myself once I've moved in.

Black_Knight

https://www.boards.ie/discussion/comment/118754610#Comment_118754610

Solar as a service does sound pretty good actually. Wonder what €30 a month gets you panels wise. It's only €3600 over 10 years! If it were that cost at our current day rate of electricity it'd only have to supply 5kWh a day to the house to save us more money a month than it's costing. Energy prices only going up so it paying for itself every* month seems very attainable.

*Obviously solar isn't linear, so winter won't pay for itself, but summer should cover a bit extra when we're pulling it.

I'll give them a shout.

graememk

https://www.boards.ie/discussion/comment/118755375#Comment_118755375

I think its about 3kw of panels Id say its about 7-8 panels?

I know their prices had gone up at the new year (to the 30 a month) but now with the grant change for solar only (1800 to 2400)

Alkers

https://www.boards.ie/discussion/comment/118755375#Comment_118755375

I have 2.5kW from them, 7 panels which I have about 16months or so. We pay €19.99 per month but their prices have increased since (although the system they give you now is also bigger).

@Black_Knight

https://www.boards.ie/discussion/comment/118756110#Comment_118756110

@Black_Knight

Their system is now 8 panels at 2.9 kW.

I got 9 panels off them on the old deal

Paid up front for the extra 2 panels.

Over winter I paid the 20 a month and saved that on my bill so it broke even in that respect.

pjproby

Appreciate if. someone would PM me the name of the "solar as a sevice" company mentioned here.

Snugbugrug28

https://www.boards.ie/discussion/comment/118758473#Comment_118758473

For me aswell would be great

Sent a pm to you both

Gerard93

https://www.boards.ie/discussion/comment/118759507#Comment_118759507

Would you mind sending me a PM also with their details - Thanks

WestWicklow1

https://www.boards.ie/discussion/comment/118759507#Comment_118759507

https://www.boards.ie/discussion/comment/118759507#Comment_118759507

Can you send me a PM with that info please?

https://www.boards.ie/discussion/comment/118767969#Comment_118767969

You don't have permission set

unkel

If you are not fairly sure you are going to be in the house longer term and / or you can't do the install mostly DIY (with well bought parts), then I wouldn't do it.

Also, if you already have an EV charge point then DO NOT replace it with a smart charge point so you can charge your car with excess solar. Particularly not if you are not going to install a big array and / or your car isn't at home plugged in a lot. This upgrade will never pay for itself

WestWicklow1

https://www.boards.ie/discussion/comment/118768070#Comment_118768070

Can you try again please?

slave1

Re 10 years payback not worthwhile, show me an alternative guaranteed return on investment currently available

valy1972

https://www.boards.ie/discussion/comment/118759507#Comment_118759507

Me too please.

thanks