The aim for the product ratings section is to simply to provide an idea of the opinions of people who are familiar with those products.
In the example of wind power, it has been broken down into blade, drivetrain, wind manufacturer and overall design. The scale goes from -10 to 10 and the default is zero.
If you think a particular manufacturer has terrible customer service but their turbine design is good and reliable, then you might say -8 for the company and 8 for the blade. -10 is very bad. 10 is very good. It is as simple as that. If you don't feel one way or the other. Or you simply don't know. Leave it on zero. See the content guidelines at the bottom of the page for more information on this.
The scores for each product are aggregated and contribute to the overall ranking for the manufacturer.
Additionally, you are able to vote for news stories. This is on the basis of whether it is good for the industry or the manufacturer, rather than the style of the story. As stated elsewhere, news stories are designed to be short and easy to digest.
Long form stories can be voted on. These are not connected to manufacturers or products and voting is intended to be a indicator of whether the story, in the traditional sense, is worth reading.
Be warned, these are early days for the site - at the time of writing this is still supposed to be in beta - and things may well change.