This device is unnecessary since most European wind turbines, "being of the asynchronous inductive type already have functionally similar features built in," says the EC in a document submitted to the Japanese government. The EC's Tokyo office says the matter has been taken up by MITI ,which has asked for time to gather necessary documentation. The indication is that MITI will relax its rules. "It is my impression that there is no opposition to this proposal in MITI," says an EC official. "But we will follow up on the case."
The safety requirement at issue is a device which makes it impossible to accidentally feed power into a grid which has been turned off for maintenance work. But since most wind turbines need to be excited by power from the grid before starting, they cannot generate power if the grid is closed. The EC also points out that most wind turbines have built-in safety systems to ensure that current will not be fed into a grid when the grid is down.
"All of the countries in the European Union recognise the special features of inductive generators and allow for either fused based systems or, in a few cases, for circuit breaker systems," says the EC document. "In Japan this distinction between asynchronous inductive generators and other types is not recognised." The resulting extra cost for grid connection for wind turbines is upwards of ¥20,000,000.
The impact is especially acute in Japan because the construction of large wind farms is hindered by the weakness of the grid in the country's windiest regions, restricting development of wind turbines to small clusters, each of which must bear the considerable cost of a superfluous grid safety device. Wind power is thus made unnecessarily expensive.
"By ignoring the advantages of inductive generators, the power companies are in effect keeping a significant price barrier on the largest windmill producers in the world. Given the current attention Japan is getting in respect to reduction of emissions, it seems odd that such a barrier remains in place," concludes the EC.