Domestic Solar power? The figures..

css

Ok I'm looking into a simple system, and throwing figures at it.

Take for example, I look at running 10 20w lights off a 12v system, powered by Solar PV panels.

So thats 200w/hr and supposing I run them for 10hr's a day, thats 2KWh a day.

Put them on every day, and multiply them by ESB's rate and you get

2 x 365 x 14.44885 = €105.47 saved per year.

Now I know i am being simplistic here, but a basic PV system including batteries would cost close to €3000, which is not really beneficial in my books. Considering you'll see a performance decrease in your PV panels over time. Close to 30 years payback, not even counting interest rates (if you wanted to be an accountant about it!!)

What's the general consensus on the solar PV route? Am I alone in thinking it's a no-brainer-stay-away ?


PS: I'm not 100% on the price for the setup and i know there are deals out there, but it's the payback period i'm on about more than anything!

irishguy

Did a bit of reading about this. It seems solar power for heating water is economically feasible in Ireland/UK, but using solar power for electricity is not. You should use wind/water for generating electricity and solar for heating water.

rooferPete

Hi,

My understanding is PV can and does work, also is particularily suited to Ireland because PV does not need direct sun light, even on a cloudy day the panels perform the same.

The problem appears to be the initial outlay / cost of manufacturing the units and the cost of the batteries for storing the power generated.

Perhaps in time the technology will be available to make PV cost effective, one of the biggest investors in research and development of PV is British Petroleoum (BP).

Companies of that size are not run as independents, they have shareholders to answer to maybe even our own pension funds have invested in them or similar companies.

The fact that they are profit motivated should mean that they see a future for PV, so it maybe not today but I expect the point where they will have perfected a cost effective panel is not too far away.

Of course the rising cost of oil due to the limited supplies may be enough to make PV viable in it's present format.

.

Dirk Gently

many thanks pete, hoping to make the time to pop out to your showrooms in dunboye sometime, regarding the pellet boilers.

Have an issue with the 6 cubic metres of space recommended for storage. i'm hoping that for a small house (96metres sq) i wont need that much storage space and hopefully wont require the 3 tonnes to heat the house yearly. have a very small garden as it is and would like a grassed area free from storage tanks, this is why i have drawn in an interal room in the house( 2 metres x 1 metre) with acess at the side enterance with the hope that this will provide my storage requirements.

Anyway i can talk about this further to you or someone in your showroom when i get off me arse and go out there. Put the house on the back foot over the past few weeks so time to get stuck in again. really want to work out my heating and storage issues so i can get planning permission asap.then i can concentrate on builders while the drawings are in the planning stage.

* just realised this isn't my thread, just one with a near identical title. got more replies than my one anyway so ill leave the post and thanks again pete.

probe

css wrote:

Ok I'm looking into a simple system, and throwing figures at it.

Take for example, I look at running 10 20w lights off a 12v system, powered by Solar PV panels.

So thats 200w/hr and supposing I run them for 10hr's a day, thats 2KWh a day.

Put them on every day, and multiply them by ESB's rate and you get

2 x 365 x 14.44885 = €105.47 saved per year.

If you are looking at photovoltaic (PV) or similar technologies to save money compared with conventional energy delivery systems at current electricity prices, you are pissing into the wind! If PV was cheaper per kw at today’s prices who’d be bothered with the ESB mafia?

It is essential to factor in energy price inflation, which is going to be exceptionally high over the expected life of an alternative technology purchase such as PV. Natural gas is the main source of electricity in Ireland. Kinsale gas is on its last legs. Any new gas finds in Ireland are unlikely to be usable due to NIMBYism, arrogance and management incompetence a la Shell*, ill conceived planning regulations and lack of political direction.

GB is already running out of gas and is now the largest gas importer in Europe. Norway, GB’s main gas supplier, gave notice a few months ago that it expected its supplies to be exhausted within seven years. Russia’s Gazprom (the largest gas supplier in Europe) warned the EU yesterday to stop interfering with its plans or it would cut off supplies to the EU and divert them to China and India, where there is a ready market for every kW of gas Russia can supply. Anyone watching the interviews with Brussels officials on the threat story on CNBC on Thursday might conclude that the Brussels lot don’t understand the plain English from Moscow.

Energy price inflation will hit Ireland the hardest because it is the only EU-15 state that has done nothing materially serious to harness the alternatives. Not to mention the only country in Europe without an electrified national rail infrastructure (aside from Iceland). Spain is heading for 30 GW of wind electricity capacity, up from a current 10 GW. (Ireland’s peak electricity need is under 5 GW). Spain is not a very windy country. Ireland is among the windiest – with huge territorial waters surrounding it.

While Irish consumers wallow in "cheap" electricity today at about 14c/kW (compared with about 9c/kW elsewhere in Europe!), expect it to be heading for 20c/kW within a few years. Petrol was about 6c a litre in Ireland in 1960. Today it is heading for 120c+. Given the huge energy conversion inefficiencies in the incompetent way electricity is generated in Ireland expect to see even higher electrical energy price inflation in the state over the coming decades.

probe




*http://www.xsd.ie/comsites/Corrib_SOS/Fiosru_2_LOW_RES_Final.pdf

rooferPete

Hi Probe,

I know I'm only backing up your figures but an example of how serious this should be taken but appears to gone un-noticed here is our Italian suppliers are pushed out to September for deliveries.

The reason given to me is the rest of Europe sat up and took notice at the Russia > Ukraine gas conflict earlier in the year and Every European country has been buying more products than Ireland even since the grants were announced.

An example is we can't get a product brochure and they have no intention of ordering more because in Europe the consumers know what they want from experience.

In Ireland a substantial number of consumers don't even know what Pellet Fuel, Wood Chip or Solar Panels look like.

Appears there is going to be a program of intense education needed very soon.

.

css

Good point there probe. My only concern is that if you write the equipment off over 8 years, or whatever your expected lifetime of the equipment, it's still not economically viable, even if you double the price of electricity. And that's not counting maintenance at all!!

As rooferpete said it's still in its infancy i suppose...

boomshackala

'Natural gas is the main source of electricity in Ireland. Kinsale gas is on its last legs. Any new gas finds in Ireland are unlikely to be usable due to NIMBYism, arrogance and management incompetence a la Shell*, ill conceived planning regulations and lack of political direction'

Check this out;
http://www.rte.ie/business/2006/0210/finavera.html

This will be 10 times thwe size of Kinsale, and not troubled by the high pressure issues associated with corrib. It looks like Irelands gas needs are sorted for the next 20 years.....unfortunately this will keep us back in terms of getting our sustainable fingers out...

Jaden

If it's any use to you, I've worked out that for me, Wind power is about 8 times cheaper to generate than Solar PV.

Capt'n Midnight

Yeah gotta agree that wind beats solar hands down here in every area here.
It's really only used for lower power applications because unlike wind it has moving parts and is virtually maintainance free.

I've posted links to hours of sunshine in this country before. We are quite a bit up from the equator so in winter you are down to about 6 hours sunlight on a crips winters day. So you'd need twice the area even if you could get cloudless winter days. IIRC the average here is 3 or 4 hours sunlight per day. So at a guesstimate you'd get twice that on average during good summer weather and half that during winter. You'd also need battery storage for a few days in case we get really bad weather.

Of course wind power works best in bad weather

IIRC you are talking about 4W per square foot in bright summer sunshine.
So say 2 hours sunshine on a winter day - you'd need maybe 250 Square foot And 6000WHr battery backup for 3 days = 12v x 50 Ah x 10 Batteries (car battery size - you'd have to use deep discharge batteries - car batteries will go low a few times but then they die.) The replacement cost of the batteries might cost more than the cost saving and they are made of Lead etc so no benefit to the environment

With wind power you'd need far fewer batteries because only need to supply a few hours at most.

CJhaughey

I am toying with the idea of setting up a simple PV system mainly to run lights.
The new LED lights consume so little (4w) that it becomes feasible to run lights from batteries.

css

CJhaughey wrote:

I am toying with the idea of setting up a simple PV system mainly to run lights.
The new LED lights consume so little (4w) that it becomes feasible to run lights from batteries.

I've been told by an electrician to be wary of them, as he said some of these low watt lights take ages to come up to the brightness of a normal bulb. He reckoned that they would be fine for places where you leave the light on all the time or for a long time, but on a room that you go into and out of, turning off the light each time, it would get annoying! I've no idea how accurate this is btw, so correct me if i was told wrong!

css

Jaden wrote:

If it's any use to you, I've worked out that for me, Wind power is about 8 times cheaper to generate than Solar PV.

It's only of use, Jaden, if you can put some figures in front of me! There are SO many sales blurbs out there, saying that this is 10 times less than ESB, bla bla..

Is there any chance you can even give a few sample figures and then we can compare?

PS: Not getting at you or anything, I'm just trying to be objective about the whole alternative energy thing!

CJhaughey

CSS
These are replacement bulbs for the GU10 fitment, they are instant on and off and consume very little power , your spark is probably talking about CFL lights which can have the drawbacks you mentioned.

css

CJhaughey wrote:

CSS
These are replacement bulbs for the GU10 fitment, they are instant on and off and consume very little power , your spark is probably talking about CFL lights which can have the drawbacks you mentioned.

Cool thanks CJ, I'll check into those so!