Advice on PV panels and system.

[SharkT]

We are looking at getting PV panels and are looking to get a quote. Before we do I want to understand better what the options are. We have a detached bungalow of approx 2400 sq feet. It's a C3 rating. We have plenty of roof space for panels.

Our heating is gas heating and it is split into radiators in the older part of the house and underfloor heating in the newer extension. Both are a similar size. Our annual usage is approx 5000 kw for electricity and 4000 kw for gas. We have a couple of fuse boxes in the house with a couple more in the garage and shed. But we have one electricity meter which is not a smart meter.

We have separate controls for heating the water, the radiators and the underfloor heating.

We would like to get panels for the electricity and also to heat the water both for showers and for the rads/underfloor heating.

We would also like to a battery for storage. We are based in Kildare.

Could anyone advise whether what I am looking for is possible as I don't know how the panels work with water heating and underfloor/rads? Is there also an issue with us not having a smart meter? Also could anyone recommend a company to request a quote from covering Kildare area.

Any other suggestions or advice welcome. Many thanks in advance.

 

[newirishman]

With a C3 energy rating I'd use the money to improve this as much as possible. This is not a great rating.
This will give you most likely a much better return

 

[SharkT]

@newirishman. Thanks. I'm looking into that separately. Though because of some of the large open spaces, number or Windows and type of build (1970s raised bungalow), the costs of remedying some of these would be prohibitively expensive. Hence I'm looking into PV panels to try to reduce energy costs.

 

[FANTANA]

Now with the FIT would recommend you avoid a battery, just go for a standard inverter (get a 6kw to future proof it) which is half the price of a hybrid (needed for a battery) and spend the extra money on more panels. It’s also a good time to upgrade your hot water tank if needed.

An eddi is now questionable with the FIT as it will be better to send back to the grid and then heat the water on night rate. This of course is just looking at it purely from the financials, it can be quiet a nice feel good factor to heat water on solar and from a carbon reduction point of view self consumption is best.

If you want a battery in future you can always add one with a second smaller standard inverter and this will give you more control than bi a hybrid.

A C3 is a bit low and you will not be able to realistically use the PV for space heating but your gas consumption seems very low (average house is 11k kwh per year). So you haven’t a lot to gain by spending big on heat loss reduction. Are you spending a lot on solid fuel for open fires?

 

[Peanuts]

Now with the FIT would recommend you avoid a battery, just go for a standard inverter (get a 6kw to future proof it) which is half the price of a hybrid (needed for a battery) and spend the extra money on more panels. It’s also a good time to upgrade your hot water tank if needed.

An eddi is now questionable with the FIT as it will be better to send back to the grid and then heat the water on night rate. This of course is just looking at it purely from the financials, it can be quiet a nice feel good factor to heat water on solar and from a carbon reduction point of view self consumption is best.

If you want a battery in future you can always add one with a second smaller standard inverter and this will give you more control than bi a hybrid.

A C3 is a bit low and you will not be able to realistically use the PV for space heating but your gas consumption seems very low (average house is 11kwh per year). So you haven’t a lot to gain by spending big on heat loss reduction. Are you spending a lot on solid fuel for open fires?

Is that the generally accepted best approach now? Most people I know that have installed a solar PV system recently have included battery storage.

 

[FANTANA]

Is that the generally accepted best approach now? Most people I know that have installed a solar PV system recently have included battery storage.

Not sure if it’s widely accepted but remember the battery grant is only recently gone and FIT is very recent in this country (not one cent yet paid) so will take awhile to break the battery mindset.

If you run the numbers now though a battery does not make financial sense. While FIT is higher than the night rate a battery or water diverter will never pay for itself.

I would probably still get an eddi though if replacing the hot water tank as the eddi outlay is small and having a large very efficient hot water tank is very important as you have a thermal store which will not degrade (like a battery).

The most expensive part of solar is getting the installer up on the roof. A battery and a hybrid inverter is a great money maker for the installer compared to the roofing section of the job so unless you are very clued in you will probably go with what they advise. I often see the battery being sold that it will cover cooking etc during peak energy times but most battery systems cannot cover the load of the oven.

Go for as many panels as possible, after a year; with a years data run your numbers yourself and if you still want a battery then go for it with a storage inverter.

 

[Alkers86]

We are looking at getting PV panels and are looking to get a quote. Before we do I want to understand better what the options are. We have a detached bungalow of approx 2400 sq feet. It's a C3 rating. We have plenty of roof space for panels.

Our heating is gas heating and it is split into radiators in the older part of the house and underfloor heating in the newer extension. Both are a similar size. Our annual usage is approx 5000 kw for electricity and 4000 kw for gas. We have a couple of fuse boxes in the house with a couple more in the garage and shed. But we have one electricity meter which is not a smart meter.

We have separate controls for heating the water, the radiators and the underfloor heating.

We would like to get panels for the electricity and also to heat the water both for showers and for the rads/underfloor heating.

We would also like to a battery for storage. We are based in Kildare.

Could anyone advise whether what I am looking for is possible as I don't know how the panels work with water heating and underfloor/rads? Is there also an issue with us not having a smart meter? Also could anyone recommend a company to request a quote from covering Kildare area.

Any other suggestions or advice welcome. Many thanks in advance.

All of what you're looking for is readily achieveable. How is your roof orientation, being a bungalow, what way do your roof pitches face? South facing is best in terms of pure generation but east and west link in better with early morning and evening usage to get production over a longer period.

What sort of a hot water cylinder do you have?

If I was you, I would get solar thermal panels to heat your hot water and possibly also your heating system buffer tank and also a small enough solar PV system - maybe 3kWp - 4kWp. The solar thermal panels are more efficient than PV panels and seeing as you have lots of roof space they are a good option.

You can probably fit a much larger PV system than 3 or 4 kWp but the larger a system you install, the more expensive it is and the harder it is to self-utilise the energy you produce, which affects the pay back negatively. Some people go all out with as many panels as they can and battery storage etc but to me, this is way overkill and the sweet spot is a smaller system which will pay for itself much sooner.

 

[AJAM]

I wouldn't bother with solar thermal panels at all. Like FANTANA suggests, max out your solar PV panels. You can always use the excess electricity to heat water if you want. Or sell to the grid, or charge your car, or phone, or batteries, or run the washing machine etc. Whereas once solar thermal panels heat your hot water, there is nothing you can do with the excess.

While FIT is higher than the night rate a battery or water diverter will never pay for itself.

That is a really good point, I never thought of that. I have an Eddi and it has been happily providing all my hot water since April. Yesterday was the first day the gas had to kick back in to heat up the tank. But you are correct, once the FIT comes in (I know technically it is in) but once they actually start paying you, it would make more sense to sell the excess solar at 18c and use nighttime at 9c.

 

[Micks'r]

@SharkT 4000 kWHr's for a C3 rated 2400 sqft bungalow appears very low to me! Are you sure there isn't a typo?

 

[SharkT]

Thanks all for your replies. That is really helpful and increased my knowledge. I'll do some research on the suggestions.

As many of you pointed out there is a major typo. My annual gas usage which is in fact approx 45,000 kWh. So quite a considerable difference!! It is the gas heating that is the biggest usage and cost here.

Our house orientation is south west but because of the extension, we have roof space at the back of the house facing south east and north west.

Our hot water cylinder is a coppercraft 200 lr 33kw rating.

I will look into the Eddi and the FIT scheme also.

If anyone has recommendations for an installer to get a quote in the Kildare area please let me know. Or PM me please if not allowed on the thread.

Thanks again for taking the time to reply. Much appreciated.

 

[Leo]

Most people I know that have installed a solar PV system recently have included battery storage.

Anything I've been reading suggests the the payback just isn't there for the battery systems even without the FIT.

Unless people are considering battery systems as backup in the event of power outages, but that adds to the complexity of the installation.

 

[Leo]

If anyone has recommendations for an installer to get a quote in the Kildare area please let me know. Or PM me please if not allowed on the thread.

We encourage people to post recommendations publicly so that others can benefit.

 

[Peanuts]

Anything I've been reading suggests the the payback just isn't there for the battery systems even without the FIT.

Unless people are considering battery systems as backup in the event of power outages, but that adds to the complexity of the installation.

Will it also add to the cost of the installation?

 

[cremeegg]

While FIT is higher than the night rate a battery or water diverter will never pay for itself.

I am told that currently you can charge the battery from the mains at night for 8 cent and get 14 cent on the feed in tariff during the day ?

 

[Leo]

Will it also add to the cost of the installation?

Yeah, you'll need the system to be able to split from the grid while still powering the house, or perhaps just selected appliances for the duration of the outage.

 

[Micks'r]

Thanks all for your replies. That is really helpful and increased my knowledge. I'll do some research on the suggestions.

As many of you pointed out there is a major typo. My annual gas usage which is in fact approx 45,000 kWh. So quite a considerable difference!! It is the gas heating that is the biggest usage and cost here.

You've answered your own question!
If I were you I would invest whatever funds I have to make a significant dent in my gas usage by addressing my heat loss rather than considering Solar.
There has to be big wins there.

 

[Zenith63]

I am told that currently you can charge the battery from the mains at night for 8 cent and get 14 cent on the feed in tariff during the day ?

Technically you can charge at night then discharge to the grid during the day, it makes little sense to do so though. Firstly I’m not sure anybody is doing an 8c night rate any more, mine is now 16c. Even if you could get it at 8c, the 6c profit would take years to pay off the cost of the battery, many many years more than the battery will actually last. It makes more sense to charge the battery at night and then just use it during the day to offset your normal usage which you’ll be paying 30c+ for.

 

[Alkers86]

I wouldn't bother with solar thermal panels at all. Like FANTANA suggests, max out your solar PV panels. You can always use the excess electricity to heat water if you want. Or sell to the grid, or charge your car, or phone, or batteries, or run the washing machine etc. Whereas once solar thermal panels heat your hot water, there is nothing you can do with the excess.

Im only recommending the solar thermal as there is so much roof space on a bungalow, one or two panels is all that's requried to cover summer hot water needs and they're relatively inexpensive. The cost of the PV diverter to heat water from the excess solar doesn't make sense anymore with FIT being so high and this taking so much electricity compared to heating water with gas. Ditto batteries but to a lesser extent likely with peak tarrifs beign rolled out to all.

Covering a bungalow with PV panels will run up the cost so significantly the OP will never recoup it, also your capped at a 6kW inverter by ESB so it's diminishing returns after you go above a certain array size.

Selling to the grid is capped at €200 tax free so it's not the be all and end all, everything after that taxed as per extra income.

 

[Lamps]

Rather than pay for a hot water diverter I plan on putting the immersion on in the late morning from April to September to heat my hot water when I install my solar. I don't usually be cooking or using the washing machine/dryer/dishwasher then so it seems like the best approach for me. Then I'll have hot water and I'll be feeding back to the grid when I have excess, instead of heating the water again like I would with a diverter.

 

[Leo]

The cost of the PV diverter to heat water from the excess solar doesn't make sense anymore with FIT being so high and this taking so much electricity compared to heating water with gas.

Very true, especially for those with zoned heating where there is a separate hot water circuit. We have oil heating which is more expensive than gas, my water heating for the 4 months of June to September last year (no space heating used during that time) consumed ~170l of oil, ~€230 at today's prices.