A contentious new measure that will require wind generators to install devices that help control voltage levels on the grid has been approved by the ERCOT Board of Directors.

The devices produce what is known as “reactive” power, which is different from the “real” power used to light homes and businesses. But while not actually consumed by end-users, reactive power must always be present on the grid in order to maintain voltage levels and reliability. Another characteristic of reactive power is that it does not transport well, which means it must be produced near where it is needed.

Unlike traditional generators and even wires companies, very few wind farms are equipped with full reactive power capabilities. As a result, other parties end up making up the difference. When regulated wires utilities (like Oncor, for example) provide these devices, the cost gets shifted to all their customers in the form of higher transmission rates. Since reactive power cannot be transported effectively, the wires companies are the only market participants with the ability to place reactive devices in close proximity to wind farms.

Protocol Revision Request (“PRR”) 830 — which was adopted during the November ERCOT board meeting — requires that wind generators provide full reactive capability on par with requirements for traditional generators. Cities Served by Oncor supported the measure, arguing that it fairly allocated a portion of the cost of maintaining the integrity of the grid to wind generators. Wind developers opposed the PRR, and a coalition of such generators is widely expected to appeal to the PUC.