Domestic solar panels/wind turbines?

Freiheit

:)Are they expensive to install? are they likely to generate much electrcity? how long would it take to make my money back and are they likely to increase the value of a property?.

Any feedback gratefuly received

Danke
F

quentingargan

Freiheit wrote: »

:)Are they expensive to install? are they likely to generate much electrcity? how long would it take to make my money back and are they likely to increase the value of a property?.

Solar PVs are still relatively expensive for the amount of power they produce. Looking at, lets say 1.2KW, the panels will cost you about €2K plus VAT, and the inverter another €1K. Plus roof fittings and VAT, lets say €4.5k. That will give you roughly 1,200 Kw Hrs per year depending on your location. At, lets say, 15c per Kw Hr, thats €180 a year back on your €4.5K. Unless energy prices rise quite a bit, that's a 25 year payback on a panel that is guaranteed for about 25 years, and an inverter that's guaranteed for five.

In practice, you will get 19c for the power you export for the first 3,000 units per annum for 5 years, and PVs won't be displacing the cheap night rate electricity. So maybe the figures are a little better, depending on what the ESB does with the tariff after five years.

Wind turbines can be a lot more viable, but only if you have a good windy site. For example a site with a mean wind speed of 7m/sec will produce over twice the power of a 5m/sec site. You really need to assess your site and do an assessment of the likely output. It isn't an exact science either. Even if you go to the expense of putting an anemometer on your site for a year, that won't take into effect issues like turbulence and non-horizontal winds.

PM me if you want details of how to assess your site using online wind maps etc. Its a simple desktop procedure that will give some indication as a starting point.

If you like the idea of having clean electricity, then it may not matter whether it is "profitable" or not. I would always say that payback cannot be the main reason for buying a turbine or a solar PV. It has to be something that you want to do, and if it turns out to be profitable, then so much the better.

And of course, as energy prices rise, the payback time will fall - depends on how you view peak oil etc.

Bens

Dont forget to factor in maintenance over the lifetime of the panels/turbine.
You dont think its going to last for 25 years without you having to pay for maintenance, do you?
And what if you move in the meantime?

These things, unless the up front prices come down significantly, are not viable.

quentingargan

Bens wrote: »

Dont forget to factor in maintenance over the lifetime of the panels/turbine.
You dont think its going to last for 25 years without you having to pay for maintenance, do you?
And what if you move in the meantime?

These things, unless the up front prices come down significantly, are not viable.

Yes - maintenance is a factor, particularly with some of the more complex wind turbine designs out there, but there is zero maintenance on solar PVs.

I wouldn't say carte blanche that they aren't viable. There are windy sites where domestic scale turbines make a lot of sense. Arguably, leaving money locked up for a year in a dodgy bank earning 3.7% less DIRT gives, at best, a payback time of over 30 years.

gizmo555

quentingargan wrote: »

I wouldn't say carte blanche that they aren't viable. There are windy sites where domestic scale turbines make a lot of sense. Arguably, leaving money locked up for a year in a dodgy bank earning 3.7% less DIRT gives, at best, a payback time of over 30 years.

Really poor comparison - at that rate of interest and current rates of DIRT, you would double your money in 26 years and you would still have your capital intact. (Not to mention that at a time when interest rates are near historic lows, you're assuming no increase in deposit rates over the next 26 years . . .)

By contrast, after 26 years you might have recovered the initial cost of your turbine or PV panels, which would by then be at the end of their working life and effectively worthless.

As you rightly say,

quentingargan wrote: »

If you like the idea of having clean electricity, then it may not matter whether it is "profitable" or not.

but in purely cash terms, there's no case for them.

As for peak oil and the likely future cost of energy, in the opinion of many, it's at least as likely that shale oil and gas will result in cheaper real prices in 26 years (after adjusting for inflation) than today. But that's pure speculation and if any of us knew for sure, we'd be making our fortune trading oil futures.

quentingargan

gizmo555 wrote: »

By contrast, after 26 years you might have recovered the initial cost of your turbine or PV panels, which would by then be at the end of their working life and effectively worthless.

I agree totally in relation to PV. However, with a wind turbine on a good site, the payback is shorter, and with a decent turbine, the lifespan is longer. The base and a wel made tower should last 60 years. Generators should only need bearings after 20 years, and blades after 5 to 10 years.

Bens

quentingargan wrote: »

Yes - maintenance is a factor, particularly with some of the more complex wind turbine designs out there, but there is zero maintenance on solar PVs.

I wouldn't say carte blanche that they aren't viable. There are windy sites where domestic scale turbines make a lot of sense. Arguably, leaving money locked up for a year in a dodgy bank earning 3.7% less DIRT gives, at best, a payback time of over 30 years.

Over 25 years? Dont think so.

quentingargan

Bens wrote: »

Over 25 years? Dont think so.

Inverter? Yes - I did say 5 years warranty on that, but they should last the pace. Panels will last 25 years OK and are guaranteed to still produce 80% of their rating at that time. There are some near Cork that are pushing 35 and still working.

But I'm not arguing for the viability of PVs. The general thrust of this thread that they're still non-viable holds true.

Needler

quentingargan wrote: »

Inverter? Yes - I did say 5 years warranty on that, but they should last the pace. Panels will last 25 years OK and are guaranteed to still produce 80% of their rating at that time. There are some near Cork that are pushing 35 and still working.

But I'm not arguing for the viability of PVs. The general thrust of this thread that they're still non-viable holds true.

If you source a decent second hand grid tie inverter or go off grid using old car batteries you can get the cost down quite a bit. your cost for the panels themselves seems fairly accurate maybe even a bit low but the rest can be cut down a good bit

it would be interesting to see what components fail in a grid tie inverter and how easy they can be repaired. or what percentage of failed inverters can be repaired