Hello

I plan to install two MINI-750 wind turbines and some solar panels from the supplier called EnergieVair (Energie V'air - Energies Renouvelables / Renewable energies). I have planned my whole system could provide me more than 2000 watts per hours. It would cost me less than 4000$. That makes 2$ per watts. What do you think about this? Does anyone have any other ideas to share with me?

Thanks for your help.

PS : have a look at this website
Energie V'air - Energies Renouvelables / Renewable energies

[DPinBucks]

Fred,

Going from your figures and the website, I think you’re being a trifle optimistic.

For $4,000, you’ll get 2 MINI 750s ($1,770), I think just 1 inverter ($765), and about 300 watts-worth of solar panels. This doesn’t include installation and other bits & pieces I may have forgotten.

You have to take into account the average wind speeds and sunshine at your location, but the 750 is only giving 175 watts at 24km/h, which is a very high average speed. I think you’ll be very lucky to achieve an average 100 continuous watts per unit.

And let’s assume 12 hours daylight per day, and that the panel works nearly as well on shady days as bright sunshine, so let’s say 250 watts per half day = 125 continuous watts per unit.

So the total year-on-year electricity production is 325 continuous watts = about 2,800 kWh per year. At current UK marginal costs of 12p per kWh, that is about $500 a year saving, or break-even in 8 years.

These are my guesstimates: others may wish to offer different figures.

Don't get me wrong: I'm not saying you shouldn't do it, but I do suggest you look at your figures a bit more.

[robh2002]

Originally Posted by DPinBucks

Fred,

Going from your figures and the website, I think you’re being a trifle optimistic.

For $4,000, you’ll get 2 MINI 750s ($1,770), I think just 1 inverter ($765), and about 300 watts-worth of solar panels. This doesn’t include installation and other bits & pieces I may have forgotten.

You have to take into account the average wind speeds and sunshine at your location, but the 750 is only giving 175 watts at 24km/h, which is a very high average speed. I think you’ll be very lucky to achieve an average 100 continuous watts per unit.

And let’s assume 12 hours daylight per day, and that the panel works nearly as well on shady days as bright sunshine, so let’s say 250 watts per half day = 125 continuous watts per unit.

So the total year-on-year electricity production is 325 continuous watts = about 2,800 kWh per year. At current UK marginal costs of 12p per kWh, that is about $500 a year saving, or break-even in 8 years.

These are my guesstimates: others may wish to offer different figures.

Don't get me wrong: I'm not saying you shouldn't do it, but I do suggest you look at your figures a bit more.

I would tend to agree with the above - be very careful (ignore?) with the numbers supplied by the manufacturers and installers. I have seen many wind turbines with a rated power output of 1kW actually produce close to nothing in reality because of where they were sited and inadequate wind speed. See here:

Warwick Wind Trials - Briefings and reports

I am also an enthusiastic supporter for renewable energy particularly wind, but ONLY if sited in a suitable location. Get a proper wind survey carried out - preferable for a whole year before committing money.

Hope this helps.

[johntheexpat]

There was an interesting letter in New scientist recently from someone who had paid £7,500 (and then add in grants etc grants) on solar panels after being persuaded to buy some by slick salesmanship. After getting enough 'real' results, the pay0-back period was going to be 37 years. Not very impressive. I bought a solar panel (5W, 40€) to charge a lead acid battery in the shed which powers some lights when needed. I am lucky to get 2W at midday if it is blue sky at this time of year, less for the rest of the day. That's still enough for my needs, but way down on 5W!

[robh2002]

I suppose what we are all saying is make sure you have ALL the information you need before committing to any power generation. I have a couple of panels which generate above their rated power on sunny days, but there aren't that many of those in Sheffield!

Try the "greenbuildingform" for advice and real world measurements of PV panels and wind.

We changed our fridge freezer to an A++ rated model and saved 25% on our electricity usage...