Does anyone know which one is more efficient given the same amount of space to operate, and both at optimal levels?

From a raw peak kilowatts or kilowatt-hours delivered per square meter of real estate displaced it's, wind by far (including low temperature solar-thermal.)

But that's assuming truly optimal conditions, and fully optimal wind conditions are quite rare (and NEVER at anything as low as residential rooftop levels.) Without a wind survey and analysis indicating at least an adequate wind resource you'll be unlikely to make the correct decision for particular location by going with wind. Wind also has factors the work in favor of larger turbines, and against micro-scale wind, whereas efficiencies of solar work about the same from 10watt installations to megawatt levels.

But solar doesn't work so well at night, eh? There is no equivalency between the different technologies.

Another thing to keep in mind is you typically want a wind generator at least 10 meters above anything within 300 meters. And most locations have a minimum of clearance of the height of the tower around the base. So if you have a 25 meter high wind generator you need a 25 meter in any direction clear of anything around its base, so you need lots of horizontal space as well as vertical tower with wind

My understanding is that PV generally gives more bang for the buck. Less maintenance costs than wind. But obviously you need to determine cost/benefit based upon your specific location conditions and available systems.

Hi guys. Cool topic to discuss. Personal opinion only.... wind is great for wind farms and can help urban areas by bringing it in across distance and plugging it into a proper smart grid. Solar is great for actual on-site application. Even with its limitations, having it in place sends a signal to inhabitants.

A little late on the response, however I think it needs to be noted that truly an ideal system will be a hybrid of the two generation sources.  If the location is ideal for wind generation, you will be able to produce wind power in those times that the sun is not typically out (i.e. stormy conditions).  And visa verse with the ability to harvest the sun's energy.  The two systems blend perfectly to provide the best possible solution at times all throughout the year. 

In comparing the two, wind is the cheapest form of energy production, however it is not reliable.  As it was mentioned earlier in the posts, you will need to collect data on your possible locations, and doing so with a anemometer.  And as mentioned, to capture your wind speed at 30 m above "clear" ground level will give you hard numbers that will allow you size your system accordingly to generate the highest, most cost productive energy generation.  (Wind generators need to be sized according to the average amount of wind speed).

Success to you in your design!

Great point biebs. Is there a commercial hybrid installation that is worth looking at? Residential?

Posted By Whitcheepooh on 19 Apr 2010 05:29 AM
Great point biebs. Is there a commercial hybrid installation that is worth looking at? Residential?

Very few residential situations have sufficient available wind resource to get a net return on investment for wind (the upfront costs & maintenance exceed the lifetime output of the turbine even in simple-return analyses.)  Many, possibly even most single family residences in the lower 48 have sufficient available solar resource to more than break-even in lifecycle costs in a simple-return analysis, but without subsidy most of those would still be an investment loser from a net-present-value point of view.

The situation for solar is mostly similar in commercial space, but with a sufficiently large load there are economies of scale.  Building a 500' tower for a mega-watt turbine would be ridiculous for single residences, but for a large enough commercial entity the costs may be reasonable.  The taller the tower the more wind is garnered, and the larger the turbine, the more sophisticated the design, for more optimized efficiency.  (Building a hundred 10kw turbines on 50-100' towers is both more expensive, and has lower net output than a single megawatt installation.)  No wind project (of any scale) should be undertaken without a substantial wind survey to verify the resource.   Solar surveys are much quicker easier to execute than wind based on site solar-geometry & shading and regional historical weather data for humidity & cloud cover.  Wind-shadowing & local conditions are much more fickle & varied, and need site-specific monitoring over time to verify.

Some good discussion here, love to see it! From what I have read for a large scale projects wind seems to be a bit more efficient as well as being more environmentally friendly (not covering as much land that would hurt the habitat, less water usage, etc) but that is rapidly changing as new technologies are developed every day. On a small scale (like residential or small commercial projects) solar is almost always the better option as it can be used in urban areas or in places where a turbine just can't be built. Despite your view, the exciting thing is that solar and wind are involved in this conversation!!