Prices of Solar PV V wind Turbine

holdfast

Anyone an a rough idea of PV v Wind turbine cost per kW installed. I want to have a rough idea before i totally rule of PV for my place.

regards

rockabaloo

I'd say turbine is about 3 times more expensive than PV. And then you've got the hassle and expense of annual maintenance on top of that. But you will generate more power with the turbine.

freddyuk

You may be better off with a little of both? Depends very much on your location and what you have planned. Anyone quoting €/ kWh is going to over price it unless they have done a proper survey.

holdfast

Cheers lads

freddyuk

rockabaloo wrote: »

I'd say turbine is about 3 times more expensive than PV. And then you've got the hassle and expense of annual maintenance on top of that. But you will generate more power with the turbine.

You need to quantify statements such as this backed up by fact otherwise the OP is being misled. Commonly called BS.

Solar PV is kicking butt, hands down winner unless you have a wonderfully windy site.
Last I saw cells were €0.30 per watt compared to €1.00 per watt wind (DIY costs, not including sundries or towers)
Wind requires more electronics, much higher maintenance and constant loads.
Solar is a pretty feeble in the Winter, so a small turbine can keep things ticking over.
I'm going 5:1 on solar.

rockabaloo

freddyuk wrote: »

You need to quantify statements such as this backed up by fact otherwise the OP is being misled. Commonly called BS.

A 5kW turbine costs around £20,000. A 5kW PV array costs about £7,000. So there is some quantification for you.

And the annual turbine maintenance is a fact. They are too dangerous to leave to chance.

So BS to you sir.

hugo habicht

You should also keep in mind at what time of the year you need the energy. More electricity is used in winter when you have the least amount of sunshine hours and the highest amount of wind.

Also at night your PV output is guaranteed to be 0W while you still may have wind. I know you had asked for cost per kW installed but for cost/gain calculations you have to use energy output per average year (Watt hours) not peak or nominal power (Watt) of the system.

I am planning on using wind (5kW nom. 10kW max.) and put the excess energy in winter into house heating. Imho for electricity alone both systems are too expensive; ESB is still too cheap (this will change in the future though).

quentingargan

I have both here. 2.5kw wind turbine as a legacy from days when PV was €10 per watt, and 2kw solar PV. There is a rough seasonal mix but I still end up importing a lot of electricity at 19c and selling it back at other times for 9c. However, I would have to say that PV is simple, trouble free and if you work from home, or have a daytime baseload, it makes sense.

More importantly, if you are exporting the surplus, the PV is more likely to be really useful because Ireland already has quite a bit of wind power on the grid. Really, the ESB should be paying more for solar than it does for wind for this reason.

I can understand Hugo wanting to use the surplus as heat, but you can export this power for 9c, and you can get heat from other sources for less than that price, so it isn't really economical to set up the intelligent diversion facilities to do that IMHO.

A really good 5kw turbine will probably cost €30k installed, and on a really good site it will generate about 18,000 KwHrs per year (assuming no turbulence and average at 7m/sec - at 5 m/sec it is about half that).

The same money would get you about 20kw of PV, maybe more, which will generate about 17,000KwHrs per year, but as has been pointed out, it will be maintenance free.

Either way, assuming you use half of this power at a saving of 19c and sell the rest to the grid for 9c (a very optimistic mix), your income is €2380 per year tops. So this would be for environmental and ethical reasons, not as a money-making venture at this stage.

MicktheMan

quentingargan wrote: »

Either way, assuming you use half of this power at a saving of 19c and sell the rest to the grid for 9c (a very optimistic mix), your income is €2380 per year tops. So this would be for environmental and ethical reasons, not as a money-making venture at this stage.

On a 30K investment, that's a return of nearly 8%, tax free and safe. Not too shabby!

I've never understood that logic myself. Buy a new car for the same and you lose €5000 putting 50 miles on it.
I've no problem paying over the going rate for electrons, makes me appreciate them more. Also means I don't get power cuts.
If I was connected to a grid my standing charges would be higher than my annual consumption...easy justify buying new gizmos at this logic.
Addition by subtraction will get you further than any one technology.

quentingargan

Sir Liamalot wrote: »

I've never understood that logic myself. Buy a new car for the same and you lose €5000 putting 50 miles on it.

Like you Sir Liamalot and Mick the Man, I agree totally. Hence I have made those investments to ensure that my electricity comes from clean sources where possible, and I am willing to pay a bit extra for both the security of supply and the knowledge that my house (and car) are powered by clean energy where possible. Ten years ago when I spent €20K on my wind turbine, friends spent more than that on their cars. I spent €500 on a car that year, and I still have the turbine.

I personally think that this is a good investment, but most people don't. I'm not as agin it as I seem..

hugo habicht

quentingargan wrote: »

... but you can export this power for 9c, and you can get heat from other sources for less than that price

Yes, I agree 100%. At the moment. But I can get the wind turbine now for very little money (because energy is so cheap now) and have much bigger savings later (likely scenario; not guaranteed). With nowadays prices for oil and gas it doesn't pay.

I forgot to say I want to be off the grid that's why I won't be able to get money from ESB for excess electricity. I am planning on PV later as an addition for those (rare ) weeks in summer with plenty sunshine and no wind.

If you are planning based on current PV prices you better buy them fast. China is closing 3/4 of their factories because the price is too low.

quentingargan

China is closing moving a lot of its factories offshore because of import tariffs imposed on the assumption that there was below-cost dumping of PVs. Not sure myself if that wasn't a bit of protectionism, but the prices seem to be holding at a low level at present.

Of course energy is a component price in any hardware and if you believe that energy prices will rise, then yes, that component will rise too, but may be offset by further mass production.

I was offgrid for a long time, but the cost of cycling batteries is very high. I reckon it is about the same price as buying the electricity. So I now use my batteries as a stand-by and keep them on trickle charge and export my surplus. I still think that is more economical. It is also more useful from an energy perspective than the dump load heaters I had to run on windy nights or sunny days when I was offgrid.

hugo habicht

What I read (just recently) was that they are planning on closing down about 3/4 of the factories due to low prices. This will not have affected the prices now but may well within a year or so. I think I found the web site again: http://asia.nikkei.com/Business/Trends/China-hands-death-sentence-to-75-of-solar-cell-makers

hugo habicht

hugo habicht wrote: »

I am planning on PV later as an addition for those (rare ) weeks in summer with plenty sunshine and no wind.

With half-decent mono panels, a top MPPT charge controller, sensible orientation or tracking, no shading and over-spec'ed stranded cable on direct runs you'd be surprised what you can harvest in the rain.

All wonderfully silently and without fear of a blade flying into orbit or the like at any point.

holdfast

Really good posts here. I am probably going to go with with PV. They only thing is possible overshading in the late afternoon 3pm on. AS the gargrge roof is lower than the house roof. Need to measure this some way.

About batteries, I think the safety issue DC would stop me from going with them. Also the management of them as quentingargan said in terms of cost, ensuring they meet the not damaged by poor charging/ discharging.

On a side note, I read that the cost of RE technologies are likely to drop as the us military plan to spend nearly 20billion between here and 2030 on them. Both for home bases and the likes of afgan. It will make there home bases more seure from grid problems. For bases in afgan it reduces the cost in lives as fuel transportation convoys are easier hit, also the cost of fuel and the end point of the bases is reckoned at 10 times cost of the purchase price. Sorry to bore ye

hugo habicht

Double post due to system not displaying original message.

hugo habicht

Sir Liamalot wrote: »

...you'd be surprised what you can harvest in the rain.

No, I won't be surprised how little comes out when it's overcast. The live data (and cost of system) is all out there: http://www.solar-yield.eu/home/main

Sir Liamalot wrote: »

All wonderfully silently and without fear of a blade flying into orbit or the like at any point.

Yes, PV is silent. But I yet have to see a wind turbine that is noisier than the wind around buildings and trees close by. The problem with wind is not the noise but the shadow of the blades. This knowledge finally seems to have found it's way into Dublin Castle: http://www.irishtimes.com/news/environment/new-planning-guidelines-for-wind-turbines-include-setback-distance-1.1624679

And not all is positive about PV either. Do you know that, for example, the fire brigade in Germany is simply watching your house burn down if you have a PV system on the roof: http://www.welt.de/finanzen/immobilien/article8856358/Feuerwehr-laesst-Haeuser-mit-Solardach-abbrennen.html? I wonder what your house insurance will say about that. And have you heard about compulsory 50.2Hz retrofit for all inverters for grid stability? And cleaning of the panels? And compulsory yearly inspection for fire safety? Not here yet, but will all come to Ireland sooner or later.

I see no reason why a blade would come off if the rotor and the wind turbine controls are designed, tested and manufactured to accepted engineering practice.

I did the measurements, I did the calculations weighed with seasonal variations of supply and demand, installation and maintenance cost and based on those facts a wind turbine combined with house heating is the optimum investment. This is of course only applicable for myself and on this location; so you cannot generally say one thing is better than the other.

And off the grid due to ESB reliability problems and the simple answer to the question: what if everybody installs a PV or wind energy system and wants to feed into the grid?

touchdown77

I'm reading this with interest and I'm trying to get a handle on the big picture;

Solar PV;
-prices much lower than before so it needs a fresh look at pricing

-cap on selling units to ESB is about €240 pa

-day time solar power production will contribute to household usage (thus reducing electricity bill, but varies enormously from home to home)

-very low maintenance required on equipment, long warranties on panels.

-if ESB buy rate ever changed then its it would be a major game changer (likely-hood of that?)


What am I missing or have wrong?

quentingargan

touchdown77 wrote: »

Solar PV;
-prices much lower than before so it needs a fresh look at pricing

-cap on selling units to ESB is about €240 pa
-day time solar power production will contribute to household usage (thus reducing electricity bill, but varies enormously from home to home)
-very low maintenance required on equipment, long warranties on panels.
-if ESB buy rate ever changed then its it would be a major game changer (likely-hood of that?)

What am I missing or have wrong?

Not missing much there. I think the cap of 3000 units (what you show as about €240) was a cap on the 10p subsidy which was withdraw a few years back. AFAIK, there is no cap on the 9c export tariff.

I don't see much prospect of the 9c changing much. They had the nerve to eliminate the 10c top-up a few years back, and nobody has been for turning on that. I think the attitude is "We can buy green energy from wind farms for about 7c why should we pay small scale household producers much more?"

hugo habicht

Is this forum censored? I posted something this morning and I got a message regarding moderator approval. Post still not here.

holdfast

holdfast wrote: »

They only thing is possible overshading in the late afternoon 3pm on. AS the gargrge roof is lower than the house roof. Need to measure this some way.

Then mount them elsewhere. Solar incidence changes year round, that shadow could cost you half a days harvest in the Winter. Mounting them with shading problems is much like changing 3 tyres on your car and keeping a bald one.

DC is no less dangerous than AC. Besides all panels are DC they're just inverted at the inverter. As long as you install a few fail-safes and don't make a habit of completing live circuits with your body then you'll be ok.

holdfast

holdfast wrote: »

Need to measure this some way.

I just whipped this from an American website to give you an idea, ideally you ought to verify the angles with a latitude of 53° North.
The idea is there's nothing between the sun and the panels greater than 15° from the edge of the nearest panel (midday sun angles shown).

If you keep them adjustable you can just focus the tilt every few months with an clamp ammeter.

BryanF

hugo habicht wrote: »

Is this forum censored? I posted something this morning and I got a message regarding moderator approval. Post still not here.

Can anyone who gets this message. Make themselves known to the mods by PM thanks

hugo habicht

Hi Bryan,
post displayed now, but at original position in time (7 posts up for anybody interested).
Thank you!

hugo habicht

hmmm.... corrected a typo and it's gone again....

@BryanF: Is this because of the external links in the post? Should I avoid them?

hugo habicht

Sir Liamalot wrote: »

...and over-spec'ed stranded cable on direct runs you'd be surprised what you can harvest in the rain.

P ~ I ^ 2 so with about 10% current flowing the cable losses are only 1% what they would be in full sun conditions. So paying extra for better cables brings you neglectable advantage for overcast days. Comparing inverter power losses a no load or low load conditions gives you better pay back here.

I'd be rating for < 3% power loss at 100% capacity.
If you want to cheap out carry on, most people do seem to think cable and monitoring are areas to save a few bob. Personally I think it's a false economy.
You'll rarely find an accurate voltage drop chart because it's quite hard know what the exact cable alloy is. By overspec-ed I'm only suggesting 2 grades higher than recommended.
Cable's cheaper than any other component in the rig if you want higher efficiency, start there. It's 100% reliable and far down the line should you have problems with your equipment and require decommissioning you'll find that cable has increased in value.
It also allows you to add more panels at a later date without too much grief.

hugo habicht

Sir Liamalot wrote: »

I'd be rating for < 3% power loss at 100% capacity.

Sounds reasonable; I would call that minimum spec. So cable losses at 100% output would be normally higher than 3% if you order a system from an installer ?

quentingargan

hugo habicht wrote: »

Sounds reasonable; I would call that minimum spec. So cable losses at 100% output would be normally higher than 3% if you order a system from an installer ?

It is a bit more nuanced than that. Depends on how many modules you are putting in series, which in turn depends on the maximum open circuit voltage (at minimum temperature) tolerated by the inverter. Designing these systems for optimum performance is sometimes not done very well. A high voltage system will have lower current and lower cable losses, and 6mm may do fine - especially if it is a short cable run. 10mm cable isn't much more expensive though.

There are design assist programmes which can do the calculations for inverters, cable losses etc. Some of them are free on the web.

hugo habicht

I know how to design a system and how to calculate the losses.

What surprised me here was that it seems that in a "normal" installation more than 3% of the losses are in the cables. The cell and inverter design engineers fight for every tenth of a percent efficiency and then the installer wastes a few percent to maximise his/her profit.

Cable cross section depends on the maximum current, length, cable temperature and accepted losses; stating fixed figures here is misleading. Also cable optimisation has to have system life time and extra cable cost versus energy gains in the equation.

hugo habicht

hugo habicht wrote: »

Sounds reasonable; I would call that minimum spec.

I agree.

I've 0.5% loss roof to controller @ 100% installed capacity.
0.06% loss controller to batteries @ installed solar capacity, 25% controller capacity.
0.4% loss on distribution @ nominal capacity 5% of rated.
I don't use AC....much.

Figures are just re-hashed cable voltage drop charts, I haven't measured the line resistance, and contact/control resistance not factored.

I'd accept higher losses on a large system.

hugo habicht wrote: »

So cable losses at 100% output would be normally higher than 3% if you order a system from an installer ?

I've no idea what's normal, I am my installer. I can't justify the expense of "certifiable" equipment and installers. My system is isolated.

[Edit]: No offense to installers....I can't justify the expense of mechanics either...

ggtrixibell

This has been very informative , thanks .

Does anyone know of any Pv suppliers in the cork city area ? If you were to invest in a system to include heating the house :
A) What is a rough estimate of price (including water pump and installation)for a normal 3bed semi d?
we are renovating and are replacing the hot water tank , can this system be used with a normal copper hot water tank?
C) does it keep the hot water hot until the evening time ?
D) roughy ( I know it's a guide here dependent on usage ) if your on the grid , what kind of bills can you expect.

Thanks in advance for any info

quentingargan

ggtrixibell wrote: »

This has been very informative , thanks .

Does anyone know of any Pv suppliers in the cork city area ? If you were to invest in a system to include heating the house :
A) What is a rough estimate of price (including water pump and installation)for a normal 3bed semi d?
we are renovating and are replacing the hot water tank , can this system be used with a normal copper hot water tank?
C) does it keep the hot water hot until the evening time ?
D) roughy ( I know it's a guide here dependent on usage ) if your on the grid , what kind of bills can you expect.

Thanks in advance for any info

You appear to be confusing two different systems - solar thermal, which heats water, and solar PV which generates electricity. Though some people use solar PV to provide their electricity, and then use a device to switch on the water heater to use up any surplus power.

If you avail of a grant, you could get a reasonable solar thermal system for about €3,000 to €3500 - this would include changing your cylinder for a well insulated one which would keep water hot until the following day. The size of your system depends on your family size and water use (whether you use a lot of hot water or not).

PV systems are entirely dependent on the size of system you want and working out the savings depends on your consumption trends.

ggtrixibell

quentingargan wrote: »

You appear to be confusing two different systems - solar thermal, which heats water, and solar PV which generates electricity. Though some people use solar PV to provide their electricity, and then use a device to switch on the water heater to use up any surplus power.

If you avail of a grant, you could get a reasonable solar thermal system for about €3,000 to €3500 - this would include changing your cylinder for a well insulated one which would keep water hot until the following day. The size of your system depends on your family size and water use (whether you use a lot of hot water or not).

PV systems are entirely dependent on the size of system you want and working out the savings depends on your consumption trends.

Thanks for that . I was speaking to a PV sales person in the ideal homes show in the rds , and they said that the PV system would not only generate electricity , but also heat the house and water , so I was wondering if this was sales patter, or are people successfully using it for these purpose ? Also, if it's true , what do I need to consider water heater wise , and can it work in conjunction with an oil based heating system as a top up ?

quentingargan

ggtrixibell wrote: »

Thanks for that . I was speaking to a PV sales person in the ideal homes show in the rds , and they said that the PV system would not only generate electricity , but also heat the house and water , so I was wondering if this was sales patter, or are people successfully using it for these purpose ? Also, if it's true , what do I need to consider water heater wise , and can it work in conjunction with an oil based heating system as a top up ?

I always regard the notion that solar PV can economically heat your house as bs. It is a total mismatch - lots of heat in summer. If they said it works the air-con, I'd be a bit more charitable. But yes - you can use PV to heat your water in the summer instead of having a solar thermal system. HOWEVER, it requires a complex controller which sends power to your cylinder in proportion to the surplus amount of energy being exported. Since you are getting paid 9c for exports, you can, with such a controller, use that electricity yourself to heat your water for 9c. But hey, you can do it off-peak at night for 8c. So not sure where the savings are there.

I like solar PV as a low maintenance way of producing a premium form of energy (electricity). The power stations burn oil to produce heat to produce power at an efficiency of about 40%. Turing that electricity back into heat seems wasteful compared to the other uses it can be put to.

Solar PV as a heat source is fairly pointless imho. Everytime you change an energy's form you get losses. Unless it's required as a fail-safe I can't see the point. Electric heat has never been a practical idea. The most efficient way to produce heat is burning/heating something or utilising waste heat. Thinking about getting the ESB to burn something on your behalf to turn it into steam, into mechanical labour, into induction, into high voltage transformers, transmission losses, more transformers, domestic power. Typically what comes out of the socket in your house is 30% to 60% of what was originally spent at the national power generator.
Similarly on a well designed system your solar excess can be put to more useful tasks than making a volume of water tepid in the late afternoon off-grid. On-grid where you don't have the problem of over-generation it makes even less sense.
Immersion heating from wind turbines however I can see the merit as they are a valuable part of over-spin control.

Turning all that high tech PV energy into the simplest and most basic form of energy; heat is an affrontment to the technology and a misunderstanding of it's capabilities. There are systems out there that can do this for you, it may work, unlikely it's very effective unless you have more PV modules than sense.

samsclub

hi guys this in my mind is the best model out there . he seems really nice to talk to people about his concept and low wind coming in from all angles . very practical.
http://www.youtube.com/watch?v=8MQaT9EbMDQ

Hugh Piggott amongst many others...

VAWTs are just ornamental. They don't produce anywhere near the useful power a HAWT can. For some reason most people are attracted to VAWTs first, myself included, doesn't take long to realise who uses what and why though.

Hugh Piggott amongst many others... wrote:

Vertical axis wind turbines (VAWTs)

‘Vertical axis’ turbines have a vertical shaft that is driven by blades that move horizontally like a roundabout. ‘Horizontal axis’ describes the more conventional windmill which has to face itself into the wind and whose blades revolve in a vertical plane. The vertical axis wind turbine idea is popular even though it is thousands of years old and has long ago been superseded technically by the horizontal axis blade rotor.

Attractive features of the VAWT include the ability to take wind from any direction, and the ability to drive a generator at ground level. But in spite of a huge amount of research, vertical axis wind turbines have failed to become widely successful. They can be hard to start, hard to stop, and they have inherently lower efficiency than horizontal axis turbines. (They convert less of the energy that is in the wind). Putting them on lower towers means that they have also got access to less wind. It is often hard to mount a VAWT on a tall enough tower where it can get a good wind. Low speed vertical axis wind turbines of the 'Savonius' type are useful for really basic simple rugged machines with low efficiency, and low rpm. But the same amount of effort put into a horizontal axis machine will yield much greater returns. Low speed alternators are very heavy and expensive.
High speed Darrieus 'egg-beater' or alternatively H-rotor type vertical axis (VAWT) wind turbines are popular in university engineering departments but have never been successful in the marketplace, except for a few years in the 1980s in California. In brief, the main problem with high speed vertical axis wind turbines is the fact that the blades suffer from reverse buffeting by the wind every single revolution. This causes severe fatigue loading which shortens the life expectancy of blades. This is usually the main reason why they fail to become commercially viable.

There are numerous small VAWTs appearing in the marketplace these days but none of them seem to have any sort of track record. In fact none of them seem to be able to offer any real world measured data for energy production. Beware of computer-generated predictions of output!

In a desert I'd have thought PV was the sensible choice...

Villain

Has anyone installed a PV system of about 5kw recently, what was the cost?

samsclub

im really of no idea what the difference of the kw of these units but what would run standard on the lighting of a home . and regular appliences etc? in kw

quentingargan

I installed my own 2kw system. For a 5kw system I would expect to pay about €1.20 per watt for hardware including normal roof mounts and inverter. But do you have a large enough baseload to use this amount of power during the day? The problem in Ireland is that you only get paid 9c per KwHr for your exports.

freddyuk

On average:
5kw will give you 350- 400watts on the worst Irish day (dark and rainy)
Average cloudy day will give you 1-2kw
Bright day 3kw+
Sunny day 4-5kw all depending on time of year and temperatures and how well it is installed.
It all depends on the amount of light hitting the panels.
So for the average home with base load of 400-500w it should cover it each day. Winter short days/summer long days. Of course you will not be able to get free power as your usage will fluctuate so if you put the kettle on you will be importing power unless it is sunny. Do not put high loads on together but stagger usage to make best use of free power.

The Gambler 101

Can anyone help me here?

I am looking to start a new build shortly for a 3200 sq ft house. Looking at installing an Air to Water or Geothermal (still undecided) Heat Pump (both approx 12kW) with under floor heating.

I have been told that the above systems would have an estimated annual electrical cost around €1200+.

Would it be worthwhile investing in PV to offset this annual costs, would there be a good return on an investment or am I missing the point completely?

quentingargan

The Gambler 101 wrote: »

Can anyone help me here?

I am looking to start a new build shortly for a 3200 sq ft house. Looking at installing an Air to Water or Geothermal (still undecided) Heat Pump (both approx 12kW) with under floor heating.

I have been told that the above systems would have an estimated annual electrical cost around €1200+.

Would it be worthwhile investing in PV to offset this annual costs, would there be a good return on an investment or am I missing the point completely?

I am afraid that this would be a bit of a mismatch. I would suggest you include Solar PV as a very low-cost way of meeting the Part L renewables requirement on a building of this size, and it will reduce your electricity bill, but it will produce most of its power at a time when the heat pump isn't required.

You will only get paid 9c by ESB for surplus electricity that you export. If you have thermal mass, UFH / buffer tank, and can run the heat pump at night, you would be better off doing that using off-peak costs.

If the house is occupied and you are using a lot of electricity during the day, you will be saving 19c on any power you are using, but in most domestic situations, you will be exporting most. So ESB will be buying this power from you for 9c and sending it down two wires to your neighbour who buys it for 19c. In terms of profit margins, this must be one of their most profitable activities :rolleyes:

The Gambler 101

Would Solar PV generate enough electricity to power a house and also a surplus that could be exported?

If so, what size of unit/panels would be required and also approx costs.

Cheers

BryanF

The Gambler 101 wrote: »

Would Solar PV generate enough electricity to power a house and also a surplus that could be exported?

If so, what size of unit/panels would be required and also approx costs.

Cheers

What's your kWh/per year expected demand?
You do accept that on a summers day you export and on a winters day you'll buy from elec supplier?

Answer the above and you've some hope of a reasonable response

The Gambler 101

BryanF wrote: »

What's your kWh/per year expected demand?
You do accept that on a summers day you export and on a winters day you'll buy from elec supplier?

Answer the above and you've some hope of a reasonable response

I honestly don't know Bryan, I wouldn't have the best understanding of how to calculate the expected demand. Would 14,000kWh in the year be an expected demand for the heat pump and all other electrical requirements?

Yes, exporting in the summer and buying in the winter would be fine.

quentingargan

The Gambler 101 wrote: »

I honestly don't know Bryan, I wouldn't have the best understanding of how to calculate the expected demand. Would 14,000kWh in the year be an expected demand for the heat pump and all other electrical requirements?

Yes, exporting in the summer and buying in the winter would be fine.

Most simulations would suggest that you need about 16kw of PV to make this amount of electricity. The problem is that most of the time you will be exporting electricity for 9c per KwHr. If you want to make the house carbon neutral, you're on the right track - in fact you are being very helpful to the grid, because you are producing power during the day when it is used by industry, and your heat pump can run at night off wind that isn't needed. So you are facilitating renewables on the grid.

If you are doing it to save money, then the payback on a PV system at 9c per KwHr is poor enough. You can reckon on a hardware cost of slightly under €1 per watt so at 9c you would get €1260 back per year on a €16k outlay.

By the way, the standard max size for connection to the grid is 6kw for single phase. You would need special permission to go above that.

gtg60

freddyuk wrote: »

On average:
5kw will give you 350- 400watts on the worst Irish day (dark and rainy)
Average cloudy day will give you 1-2kw
Bright day 3kw+
Sunny day 4-5kw all depending on time of year and temperatures and how well it is installed.
It all depends on the amount of light hitting the panels.
So for the average home with base load of 400-500w it should cover it each day. Winter short days/summer long days. Of course you will not be able to get free power as your usage will fluctuate so if you put the kettle on you will be importing power unless it is sunny. Do not put high loads on together but stagger usage to make best use of free power.

I'm assuming these figures are the amount of power generated per hour of daylight, yes?

Just to make my calculations simple (a top of your head guesstimate is fine) but for a 1kw setup how much power would be generated in a year?