Solar Panels

FANTANA said:
As a rule of thumb you should try aim for €1k per 1kw system and €1k for 2.5 kWh of battery storage, this is after grants.
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Could you gross this up for those of us who aren't eligible for any grants, please?
 
Shirazman said:
Could you gross this up for those of us who aren't eligible for any grants, please?
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Max grant for solar panels is €2,400 up to 4kw. Then the battery grant is €600. If you are not grant eligible I would drop the battery idea and just go for panels with a a standard inverter instead of hybrid. You could go down the hot water diverter route for €500 and store your energy that way. Can be a good time to upgrade the hot water tank it but as your house is 2011 or newer I doubt that will be needed.
 
Forgot to add, if you are getting an EV soon between this and the hot water diverter you will use a good chunk of your excess and you can get this installed same time as the panels with a €600 grant. A FIT system is coming soon too which will also help.
 
Is it correct to say that the more roof space you have the more panels you can install the more electricity you can generate the more you will save?

Is there any way to calculate what your rebate might be if you were able to sell excess back to the grid?

For example roof area is approx 115 meter sq facing east/west and living in the west.

Trying to figure out how worth my while it might be to install panels.

Thanks
 
No, not really.

The more panels you have the more you can generate absolutely.

But even with a small system, circa 2.5kW of panels, for a typical household on bright days you will generate more electricity than you can use. If you get a large array, you will typically generate much more electricity than you can use. Obviously, the panels won't generate anything when it's dark and during the winter when the days are dull, even a big array can actually end up prodcuing quite little. For example, we have a 2.5kW array in south Dublin, facing due south. In the summer we can get up to 16kWh (about €4 worth of electricity) generated on good days, in the winter the lowest I've seen is 0.9kWh (about 22.5c worth of electricty). This is when the batteries become relevant but they add significantly to the cost. If you go with a battery, you also need a hrbrid inverter which is more expensive than a standard one.

The FIT has kind of been announced but the amount has been left for the individual providers to determine. To give you an idea of the money invovled, a €200 amount has been allowed for in the budget, tax free. Anything above this will need to be declared as income and treated as such.

If you are doing this for purely financial reasons, the best option is to install the cheapest small system you can find. This will result in you self-consuming as much of the electricity as possible and result in the quickest payback. You should be able to get 2.5kW installed for €3,600 after all grants. However, if there is no-one at home during the day, you won't save much money with a system like this. Note that the grants are going to decrease by €300 per year starting in 2023.

If you spend €10,000 on a large array with battery storage and a hot water diverter, you may well end up with a very low electricity bill and be able to run your house off-grid for six months of the year, however it may well take you 15 years to recoup the €10,000 in outlay.

TLDR - it depends on your electricty usage profile as much as it does the size of the system.
 
jim said:
Is it correct to say that the more roof space you have the more panels you can install the more electricity you can generate the more you will save?
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Only if you can use it, or feed it back to the grid once the Clean Export Guarantee scheme comes online. The maximum you will be able to feed back to the grid will be limited by the supply line to your property.
 
Apologies for thread hijacking but I’d love to get some independent advice

my house has a geothermal heat pump and lots of down lighters.. i paid 4.5k in electricity bills last year

house is 2004 build but well very well insulated for time ( could do with new windows though to improve things)

last BER was b3 for what its worth

i switch electricity provide every year so 4.5k would be closer to 6k if I didn’t

So my question is should I get solar panels and if so how much would it reduce my bills buy.?

Ive got one quote of 13k(panels and battery) where the sale guy Said it would reduce bills by 50%..

as Above would love some independent advice on this

the heat pump was installed in 2004 so is probably coming to end of life. Whilst a newer system is no doubt more efficient I’d prefer to see how long it lasts; it’s a NIBE system and has been very low maintenance so far

would appreciate any pointers on what research I should be doing

thanks

other info.

house has a large slate directly south facing roof so I assume this would improve efficiency
i expect we’ll get at least one EV in the near future
we’ve a day and night electricity meter
 
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Cameo said:
So my question is should I get solar panels and if so how much would it reduce my bills buy.?

Ive got one quote of 13k(panels and battery) where the sale guy Said it would reduce bills by 50%..
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50% is far too optimistic I would say. In my case since my panels and battery went in I’ve generated about 7000kWh of the 16000kWh my house has consumed, so 43%. But that doesn’t mean my bills are down by 43% because there are all the bits of the bill that are not the unit cost. Also in your case I’d guess you’re consuming most of that electricity in the winter months when you’ll be generating very little solar. Taking a complete stab in the dark a decent sized system might bring your bill down 25-30%?

The best thing you could do would be to get an energy monitor (like the Efergy units on Amazon) and start to see how much power you’re consuming when.

€13k sound expensive for a solar system but it totally depends on how many panels and the size of the battery, if you share some more details others can comment.
 
Cameo said:
So my question is should I get solar panels
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If it was my house I would take a fabric first approach and invest to reduce the need for so much energy rather than change how the energy is supplied.
Also, keep in mind that when your hp needs the energy most there is least solar available.
 
Cameo said:
i switch electricity provide every year so 4.5k would be closer to 6k if I didn’t

So my question is should I get solar panels and if so how much would it reduce my bills buy.?
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I think you are asking the wrong question. €4.5k in bills must be 20k units or more per year. That is an exceptionally high usage.

So either your house is enormous (~3000sqft) or you have very high temperature settings throughout your house.

In my opinion, solar is never a good pairing with heat pumps because (as others have said) solar provides very little in winter when heat pumps require a heavy load.

I would start with trying to understand your usage habits are, for example:
  • How many units did you use last year and what is the day/night split?
  • Are all of your stats set unnecessarily high (above 21°C)
  • Are there rooms or sections of your home that get very little use?
  • Have you other energy intensive equipment that is a significant contribution to your bill (eg. Power tools related to your profession)
  • Are you overheating water?
It is very likely that you can significantly reduce your usage and bill with some changes to your behaviour. Only then can you properly quantify the impact solar will have and what size system you would actually need
 
Thanks for the reply

House is about 3500 square foot (double height ceilings; think Celtic tiger,we bought but didn't design and original owner would have a lot more means than us so energy efficiency was probably not high up in terms of priorities)

Downstairs we aim for 20 degrees in main living areas, rest of house is 17(upstairs) or 18 hall etc.

Not sure how many units we use annually but must be 20k kwh or so

Nearly all usage is on daytime metre too

Details of the set up I was quoted for shown below :

  • High power output of 6.8kWp
  • Top of the range 18-panel system
  • Includes Inverter
  • 10 kWh Battery
  • Solar Generation: ~6,200kW
I dont know much about solar but it given our usage is mostly Nov to Feb I'd question how much wed get back from solar
 
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Micks'r said:
If it was my house I would take a fabric first approach and invest to reduce the need for so much energy rather than change how the energy is supplied.
Also, keep in mind that when your hp needs the energy most there is least solar available.
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Thanks, without knowing too much about it your suggestion makes sense.
 
I agree there is a timing mismatch between when solar generates power and when wed use it; given we probably use 20kwh each year I'd guess we'd want a very large capacity battery
 
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Another thought struck me I assume there are no regulations around sales people for solar panel companies and the like making outlandish claims as to savings that could be achieved?
 
Cameo said:
Another thought struck me I assume there are no regulations around sales people for solar panel companies and the like making outlandish claims as to savings that could be achieved?
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It is critical to get multiple quotes and I'd also post your best one here or on the boards.ie Renewable Energies Forum to see if others have found better deals. Some of the most professional and polished solar companies are charging twice or more for the same systems. But there are some really great companies out there that are a pleasure to work with.
 
Cameo said:
Another thought struck me I assume there are no regulations around sales people for solar panel companies and the like making outlandish claims as to savings that could be achieved?
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Ask them to put their claims in writing and provide a guarantee...see how quickly they back-peddle.
 
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