With the US overtaking Germany last year as the world's largest producer of wind power, the market for wind turbines in the US is clearly significant and with lucrative rewards at stake, technology developers and manufacturers often turn to their intellectual property rights as a means of preventing rivals from taking advantage of new markets.

The US market for wind turbines is currently dominated by General Electric and by Vestas and Mitsubishi is trying to increase its presence in the lucrative US market. In an ongoing case, GE has complained to the US International Trade Commission that turbines manufactured by Mitsubishi heavy industries infringe three of GE's patents. GE is seeking a ruling to prevent Mitsubishi importing infringing turbines into the United States.

GE is the proprietor of three patents which relate to variable speed turbines. These turbines can adjust to provide a consistent power supply to the electrical grid without damage to the turbines. GE alleges that the turbines sold by Mitsubishi infringe GE's patents and therefore that Mitsubishi's import of turbines should be blocked. An initial ruling is set to be issued by the ITC on 7 August. The initial ruling will be issued by one judge (Carl Charneski) and, once the initial ruling has been issued, the full US ITC then has until 7 December to complete its investigation and either modify, accept or reject the initial ruling. Any order to block imports could, however, ultimately be overturned by the US trade representative Ron Kirk for policy reasons.

Intellectual property rights can be a powerful tool in the armoury of technology companies. It is worth bearing in mind that patents prevent the import of technology into territories where patent protection is in place, as well as preventing manufacture. Developers who depend on manufacturers to supply turbines will doubtless have clear delivery obligations on suppliers which would assist in a situation where a supplier was prevented from importing infringing technology, but developers should also ensure that supply agreements contain clauses relating to patent infringement. An indemnity covering claims for intellectual property infringement is important if developers purchase equipment and are then exposed to risk by importing that technology into a country where a rival manufacturer holds a blocking patent.