Navitron Renewable Energy and Sustainability Forum

Energy/Electricity Storage and Use/Grid Connection => Grid-connected Renewables => Topic started by: voiceofreason on June 16, 2006, 10:01:57 PM

Title: What are the costs per kwh of electricity produced and variables.
Post by: voiceofreason on June 16, 2006, 10:01:57 PM
Do you have information about the cost per kWh of electricity produced by the various windturbines?

Title: Re: What are the costs per kwh of electricity produced and variables.
Post by: Ian on June 18, 2006, 09:46:44 PM
A Good question ! - But almost impossible to answer.

Any quality response is bound to start "It depends......"

There are so many variables that to get a meaningful answer the question will have to be re-defined with all but one or two of the variables omitted or held constant.

The biggest variable is the wind itself. It varies by the time of year / season, where you are, the size of the tower, and many of the structures around you. However, you could "assume" that the wind blew constantly at, say, 5 m/s all the time and that would eliminate that variable. (However, saying that, as it is the biggest and most influentiual variable, would probably make any eventual comparison pretty meanignless !). If you chose a different constant wind speed the economics of the different turbines would be different.

Other variables are :
What you do with the output (do you use all of it all the time ?)
The equipment you attach to the generator (in all likelihood, you will attach different equipment dependent upon the size and type and voltage of generator installed - and that even applies to inverters if you use one at all).
The consequences of what happens (or not!) when there is no wind.
The limitations of the equipment you attach to it and any failsafe devices you install to protect that equipment.
Cost of ALL the preparation and installation work as well as the kit
Assumptions about maintenance.
Timescale to amortise the costs
And I am sure there are many more....

Sorry for the negative approach (I did not mean it to be). There are many helpful people around the forum and I am sure that if I am wrong and there is a way of answering the question - it will be pointed out to me !


Title: Re: What are the costs per kwh of electricity produced and variables.
Post by: martin on June 18, 2006, 10:48:02 PM
as Ian said, an entirely reasonable sounding question - the sort of figures that allow you to make a fair comparison!
What really is not helping is the appalling "smoke and mirrors" being employed in certain sectors of the turbine market today - I would pull out of the air some recent hilarious "performance figures" for a very well known and highly touted roof mounted jobbie - 1kw at rated speed 12m/s...........(that's about 28mph, force 5-6) - furls at 8m/s................  ??? (in other words, it's a rewound washing machine motor that is more realistically rated at around 350-400w tops!)
They will insist on using the confusing "m/s" instead of  mph/knots/beaufort scale as well, (12m/s sound SO much less than 28mph)
What's important ultimately is how many kw/h it generates in your conditions - that is often more to do with low wind speed performance than the "performance figures at high wind speeds" that are quoted instead!  8)