Is solar a good option for me?

cubatahavana · 11-12-2021 9:26am #1

Hi all, I’ve been looking around and getting a couple of quotes for solar.

I live in a 2020 A-rated semiD in South Dublin. We have 4 solar panels installed in our SE roof at about 30 degrees angle. We have used about 4500 kWh of electricity since we moved in last December (full year). The last figure from my inverter has been 650kw generated, but I only realized a couple of months ago that while moving some boxes beside the inverter, I had the solar switch off, so I’m not sure of the yearly solar production.

The quotes that I’ve received for a 5kw system and 5kw battery are around 10-11k. I would need to replace my system.

Do you guys think it is justified to spend so much in a brand new system? Will I save enough with my yearly electricity usage?

All installers have said that the old system needs to go. I don’t need hot water heating as the gas heats it very efficiently. I am planning to get an electric car soon (1-2 years). Would it be better not getting a battery if they introduce the feed-in tariff?

I’ve been thinking as well to add a battery to our solar system, but it’s so small that I don’t think it’ll be justified.

bullit_dodger · 11-12-2021 2:03pm

4500 units / per year is in about the average for a house in Ireland. This will invariably rise tp 7,000-8,000 in a few years when we all start buying EV's. The government has decreed that no internal combustion engines to be sold from 2030 onwards. So it's probably important to precursor this info as it's not just how much you are using today, but really what you'll be using tomorrow and the cost of that electricity will be at the time. That figures into the whole return on investment.

I think your ballpark 5Kwp of panels and 5Kwhr battery is at the "sweet spot" for most houses. More is always better of course, but more panels = more cost.....so there is that. In todays market, you shouldn't be paying no more than about €7K-€8K for that, but considering that you wouldn't qualify for the €3k grant, that would put the quotes of about €10-11k as "competitive". (Your not being ripped off anyway)

Without knowing more details I'd hazzard a guess that your a marginal case at best to do away with your existing system and replace it. I guess what would help is if you could give details of your existing kit (make/models/etc) to the forum and then people would be able to advise you better. For example, if your inverter make doesn't support a battery, then you would know that that option is off the table.

4x panels is probably about 1.5Kwp or there abouts. Sure, it's better than nothing, but really a house needs 4-5Kwp in panels (more if the roof supports it)

cubatahavana · 11-12-2021 11:27pm

https://www.boards.ie/discussion/comment/118305033#Comment_118305033

Thanks for the answer! I suppose when you take the electric car into account it makes quite a bit of sense. I’ll think about it during Christmas

Bobeagleburger · 12-12-2021 12:00am

10-11k for a 5kWp system is nuts. Basically a rip off. You should hopefully be able to get much better.

The grant system is unfair for the likes of yourself. There should be a better way to entice people. A lot of installers just whack the grant price onto your bill and wrap it up as a good deal. They'll even take care of the paperwork.. 😄

If the grant system was discontinued in the morning you can bet your life installer prices would drop.

Good luck, hopefully you get some realistic offers

cubatahavana · 12-12-2021 9:45am

I thought the quote wasn’t too bad, but I need to compare more. The way I see it is:

4500 kWh in a 20c contract (to round off, I pay around 16c) is 900-ish euros per year. If my system generates half of what I use (what is the average?), we’re talking about 450 euro saved per year, meaning 22 years for return of investment at this rate. This seems a bit excessive, but maybe I’m getting something wrong.

bullit_dodger · 12-12-2021 4:16pm

The quote wasn't too bad, but your being shafted there by not getting the grant. It's a failing of the SEAI grant system if you ask me that people like yourself aren't eligible for it.... even though it's clear that a bigger system would serve you well. There are savings calculators up there on the web such as

Solar Electricity Calculator (seai.ie)

or

Solar Calculator (electricireland.ie)

and a few others. Some more sophisticated than others - but they tend to assume certain things that may/may not be applicable to your scenario. I think the average home will save about €500-800 depending on the amount used and the usage profile, such as is there someone in the house during the day etc. Some people like myself will save more, but that's because my consumption is substantially "non-average".

Another option would be to just get in the 5-6 Kwp in panels and hybrid inverter this year, (you need a hybrid inverter to support a battery so make sure you get them to quote you for one) and you can add in a battery very easily in a years time.

Is solar a good option for me?

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