Assessing a site for a wind turbine is easier these days with good, cheap, loggers available. But the anemometer needs to be at a suitable height above buildings, trees etc, and not just mounted on a rooftop.
Here are three web links to telescopic masts that can be used for anemometers.
www.radioworld.co.uk/catalog/masts-c-632.html
http://www.radiozing.co.uk/masts_detail.php
http://www.spiderbeam.com/index.php?cat=c12_Aluminium%20Masts.html
and here is a good installation guide page http://www.spiderbeam.com/documents/index.php?coID=37
