Technology could cut cost of offshore wind electricity by 15%

Since Edison, electrical engineers at GE have recognized the effectiveness of DC in the transmission of electricity from the sites where it is generated to the homes and businesses where it is needed. Modern power electronics have made it possible to realize that efficiency gain for power transmission, and PassiveBoost extends its potential for use in the distribution or collection grid.

The trials, performed at the company’s full-scale power system test site near Leicester, in the U.K., brought together new technologies, which GE has been introducing over the past four years. The solution on test provides a straight replacement, on the same footprint, for the AC transformer inside every wind turbine and allows direct connection to an efficient, high-voltage, DC power collection grid while reducing cable cost and without the need for an expensive and complex DC breaker.

Keiran Coulton, senior executive, global industry at GE Power Conversion said, “Whether extracting fossil fuels or capitalizing on renewable energy resources, we find ourselves working further offshore or in inhospitable desert locations. In either case, the energy wasted in AC transmission systems is costing the energy consumer too much. The technologies behind PassiveBoost will enable these costs to be cut.”

In PassiveBoost, GE has used a new power device packaging technique with a novel cooling system. Crucially, GE also has its ActiveFoldback™ fault protection system, which has allowed it to protect the DC network at equivalent or lower cost compared to AC.

“Like all electronics, the cost of power conversion is coming down while the prices of materials in a conventional transformer are rising,” explained Coulton.

The PassiveBoost project has been supported by Scottish Enterprise, with parts of the trial system being manufactured in GE’s Glasgow plant.

Seoniad Vass, director of renewable energy and low carbon technologies at Scottish Enterprise, which was involved in the early stages of the project, said, “Reducing the cost of electricity generated by offshore wind is a vitally important factor in realizing the significant economic potential of the technology. As a result, the development of innovative technologies such as this is key to the sector’s ongoing development, and we look forward to continuing to work with GE in this important field.”

Research and development was undertaken by teams from GE Power Conversion’s Advanced Technology Group at the University of Edinburgh and in Rugby, Warwickshire, in the U.K.