Domestic Solar PV: "Eco Bling" or does 10+ year payback make sense?

ECO_Mental · 20-06-2022 11:29am

I have my system 6.1kWp (no battery) installed from last November, at the moment its saving me about €100/month (since March) I am estimating that it will save me about €800 for the year. My system cost me €7000 so its looking like a payback of 8.75 years. Now I put in my system as part of a new build so I reckon I got it cheaper than if it was retrofitted ( But I also didn't get a grant ) I am only using about 40% of my PV output

I am also getting an EV on the next few weeks to soak up more of my excess so I reckon the payback will be substantially less than 8.75 years. Before you say but you bought an EV and that cost you thousands more. I was on a PCP with VW and the payments are actually €150/month less that the Tiguan I have and the petrol saving will be €200-300/month I am hopeful. My PV system pushed me into getting the EV

In my opinion Solar PV is certainly not eco bling its highly cost positive in my situation and I would imagine for a lot of other people as well. €0.30 per unit cost of electricity changes the game in a big way also

yankinlk · 20-06-2022 8:40pm

I borrowed my install money. Small loan paid back after 2 years. Hoping to have 10 to 18 years of free electricity. That's how I look at it.

I don't have the exact math, but the loan is offset by the immediate savings (and the grant obviously) so I always saw this as smart investment in my home.

If you aren't in a position to afford PV please at least load shift and switch providers annually.

con747 · 20-06-2022 9:17pm

Also don't just think of the electric car as the only other saving after the Eddi, I bought all battery operated garden and DIY stuff so no petrol needed for that now. I used to go through enough petrol with the amount of trees and hedges that need trimming and large garden to mow. All free now with the solar when you need it in summer. Not a huge saving but it all adds up.

graememk · 20-06-2022 11:01pm

https://www.boards.ie/discussion/comment/119228563#Comment_119228563

Not to mention starting them damned 2 stroke engines. now its pickup, turn on and just go.

yankinlk · 21-06-2022 10:31pm

Anyone that wants to find an argument against Solar PV - using a neighbours bill as "proof" is really just trying to justify their already biased decision that they feel its just not worth it.

I looked back at my bills before researching solar and i was doing ALL the wrong things. Never switching providers for years on end, staying on a standard 24 hour rate. I never even considered or knew what night rate was - so used my electricity at peak times without a care in the world. I used gasp the electric shower for hours on end never even thinking about what it took to run it! In summer i burned oil to heat water on a timer - without really considering was it being done effciently or not. (often the tank was cold anyway!)

When i DID research here - i quickly was able to reduce my monthly bills BEFORE i ever deployed a solar array. I could have stopped there and not ever bothered putting up solar tbh and i would have been at least twice better off my old ways... but i drive on with my investment.

Comparing the OLD me with the new SOlar me is not apples to apples.

BoxerX · 22-06-2022 4:59pm

I've only been live for just over a week, and yes; I know it's midsummer and the days are longest and its been sunny etc. The house was B2 rated prior to 4.5kWh panels being fitted. All appliances are (at purchase) A rated or higher with the TV a B rating. All lighting is LED, house is highly insulated etc. No EV.

There has been a couple of cloudy days with low generation, but overall, I am still exporting a lot of power, that's after Eddi uses what it needs to heat the hot water tank. I do all the washing during daylight hours and bake bread, run the dishwasher and anything else I can do with the excess.

SolarPV is not just the reduction of the amount of electricity used. We have a newish condensing oil boiler with copper tank, but the main solar panel usage in winter (after powering the house idling needs) will be that of heating the same tank using Eddi. Even the smallest amount of heat produced by solar through Eddi will help reduce our oil consumption, something to be considered if you have a hot water cylinder fed by a gas or oil boiler. Eddi is clever in that it can use the smallest amount of power to feed the immersion, turning off when there is not enough power. Without Eddi, the immersion would use grid power if left on (even if you have SolarPV), negating any savings. This is the key to our savings over winter when we don't expect solar to supply all our power needs like it does in the summer months. We will also adjust the heating timer to utilise the hot water before the sun sets.

We don't want solar to order our lives, but it is sensible to make a few adjustments to what you use and when, and to keep an eye on any excess and use that before it exports to the grid, or even to the battery if you have one, as any power transferred will always incur a loss. It's also worth looking to see if you can reduce the house idle tickover as that will be pulling from your battery or the grid by unplugging all the unnecessary devices. I managed to get my overnight tickover down to under 300 Watts from 450 just by unplugging chargers, my hifi system and turning off appliances not used and by applying a sleep period to my TV and music server.

I'll shut up now!

MATTYON · 27-06-2022 4:27pm

https://www.boards.ie/discussion/2058171977/domestic-solar-pv-eco-bling-or-does-10-year-payback-make-sense

here is my 2 cents for what they are worth

i have had solar in since December (4.5kw system)

so far looking at our usage versus the rising electricity rates i have worked out that i have saved around 350 euro (not including 200 gov payment) , i expect i will at least match that in the remainder of the year which will bring it slightly ahead of the 10 year payback.

people tell me we can save even more by changing our habits but with 2 teenage kids it is not worth the arguments (maybe when they move out).

despite that it has absolutely been worth it.

once i decided to take the leap and make the initial investment then it is the benefits it provides that make it worth it.

getting a bill for 110 euro when other same size families are getting bills for 300 is great

plus my initial motivation to start the process was an alternative source of hot water in the summertime (when the heating is not on) to get my teenage kids out of our en-suite. Now it provides 90% of our hot water (not every day as we are in the west of Ireland) and we only have a small tank

Also, someone mentioned in an earlier thread that all you are doing is paying up front for the electricity that you will have to pay for anyway and if electricity keeps going up then you will shorten that pay back time, plus i see airtricity are going to offer 14cent per unit buy back so combined with a regular supplier change, this should also speed things up

so i would recommend it .

KCross · 27-06-2022 6:51pm

https://www.boards.ie/discussion/comment/119257916#Comment_119257916

so far looking at our usage versus the rising electricity rates i have worked out that i have saved around 350 euro

could you share the figures?

how many kWh’s has your system generated since Dec?

what unit rate are you paying to get to the €350 figure?

thanks.

MATTYON · 27-06-2022 9:07pm

I was able to work it out by taking the price per unit from the bill and applying it the the consumption rate from the Solis app. It is not exact but if anything I have saved more than 350 as the Solis app tends to under report

So far this year I have generated 2mhw

Alkers · 29-06-2022 12:04am

I am on the original SAAS 20e per month deal.

If the currently publicised 14c per kWh FIT materialises, my 2021 generation is sufficient to cover my 20e per month + 50% over even if I export ALL of my PV generated electricity.

0 payback period, saving more money than it costs.

Domestic Solar PV: "Eco Bling" or does 10+ year payback make sense?

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