Contractor Cianbro casts lightweight, seaworthy, wind turbine foundation

Sources: Cianbro Corp., Pittsfield, Me.; Maine Maritime Academy, Castine; U.S. Department of Energy; CP staff

Cianbro hosted a late-May launch of North America’s first grid-connected, offshore wind turbine, bearing on a three-leg, floating concrete foundation the ENR 400 contractor fabricated at its Eastern Manufacturing Facility in Brewer, Me.

Crews hoisted the VolturnUS prototype with 60-ft. turbine into the Penobscot River for a two-day journey to anchorage off the Castine coast, Maine Maritime Academy tugboats leading the deployment. The first floating turbine of its kind in the world, the prototype is dubbed VolturnUS1:8, reflecting its scale of a commercial, 6-MW, 423-ft. rotor diameter structure.

The VolturnUS’s advanced material systems and floating concrete hull technology stem from five-plus years of research and development under the University of Maine-led DeepCwind Consortium Research Program. The public-private partnership is funded by the U.S. Department of Energy, National Science Foundation-Partnerships for Innovation, Maine Technology Institute, State of Maine, UMaine and more than 30 industrial partners.

UMaine Advanced Structures and Composites Center will use data from the VolturnUS1:8 deployment to optimize the design of its patent-pending floating wind turbine system. The Center has partnered with industry leaders to invest nearly $100 million in a 12-MW, pilot offshore farm in preparation for connecting a full-scale floating unit to the grid in 2016. The goal behind the VolturnUS development and testing is to reduce the cost of offshore wind to 10 cents/kWh by 2020, in order to compete with other forms of electricity generation without subsidies.