Wind power is a free, clean, renewable energy source that can sharply reduce greenhouse gas emissions. But, like any naturally-occurring energy source, the availability of on-demand wind power is a prime concern facing its wide-scale implementation.
This challenge leads the industry offshore. Though the supply of wind is technically variable, the long coastlines in the United States offer a strong and consistent enough wind source that can provide more than 2,000 gigawatts (GW) of electricity generation per year to the 50% of the U.S. population living within 50 miles of a coast. This energy rate is nearly double the current U.S. electricity use.
Because of these benefits, New York state just signed the largest renewable energy procurement contract in US history for 1.7 GW of wind power. The field is young, but some projects have successfully gotten off the ground in the U.S., and they offer lessons for current and future projects.
Block Island Wind Farm
To date, the Block Island Wind Farm (BIWF) in Rhode Island is the only operating U.S. offshore wind installation, coming online in 2016. The Deepwater Wind-backed project supplies 30 megawatts (MW) of power from five turbines to an island previously powered by diesel fuel.
The project established an electrical path to the mainland—a connection that allows transfer of power between wind- and grid-powered sites. The wind farm also helped to establish new jobs and demand for multiple disciplines of workers. New jobs created by offshore wind include specialized wind turbine maintenance and construction jobs, along with electrical and mechanical engineering research and development roles that specialize in developing turbine improvements to increase both the amount of electricity delivered and the overall process efficiency.
“The Block Island Wind Farm set the standard for responsible offshore wind development in the U.S.,” said Paul Murphy, head of engineering at Orsted U.S. Offshore Wind, which operates Block Island. “The lessons we learned in the design and installation of the wind farm will help guide our work on the larger offshore wind farms we have planned from Massachusetts to Virginia."
Challenges remain, though, as even more sustained coastal winds do not produce constant wind power. The offshore turbines can produce power 50–60% of the time, meaning that some grid power is still needed to cover the total energy demand. Regulations will define placement and amount of turbines available, and will be needed to govern infrastructure upgrades to transmit the power load. From a safety perspective, regulations will focus on ensuring the equipment will be rated to the increased amount of power created by the wind energy.
"While each project and site are unique, we’re confident we can design solutions that work for each wind farm," Murphy said.
Vineyard Wind is a Massachusetts-based equal partnership between Copenhagen Infrastructure Partners and Avangrid Renewables. It has kicked off two projects aimed at providing clean energy to population-dense and high energy usage application. While BIWF provides 30 MW to a defined area, the Vineyard projects plan to deliver up to 800 MW to Massachusetts homes.
Though the project is not completed, some favorable developments have come out of project. The Northeast, with its dense population densities and abundant coastline, is a strong proponent of the technology. New York passed legislation to generate 9 GW of wind power, following Massachusetts and New Jersey committing to a combined 6.7 GW between them. Additionally, tax credits have helped offset the cost of the process, which facilitates mass adoption.
Vineyard has still experienced challenges even early in development. They hit a roadblock in obtaining permits in Massachusetts for the transmission cable along the ocean floor, and experienced a delay in an environmental assessment that pushed out project timing. Though manageable, working through the details of the transmission paths may dictate a longer timeframe to bring the facility online than initially planned.
Also, the cost of wind power would come under pressure if existing tax credits and subsidies expired. And as always, political climate could accelerate or halt any momentum in either direction.
Wind power is experiencing increased attention as a viable renewable energy alternative. Offshore wind is garnering extra focus because the high U.S. coastal population and more consistent wind source create a lower cost, more reliable electricity product than the on-shore variety. Lessons learned from the BIWF and Vineyard Wind can help provide the blueprint for future projects aiming to take advantage of advancements in wind turbine technology.