Offshore Wind Energy

Is offshore wind power cost effective?

The fundamentals for offshore wind along the northeastern US are strong: consistent wind resources relatively close to shore and close to high population centerslack of alternatives for other technologies; and the need  to replace older fossil and nuclear plants with new clean renewable generation.   

States are procuring offshore wind energy because of its contributions to affordability and grid reliability.  Wind power provides a stable, cost-competitive price while helping to achieve environmental and renewable energy goals.   

What happens when the wind stops blowing? Do the lights go off?

Electricity generated from the project will feed into the grid in coordination with other sources. The electricity grid is a complex system that is built to match various sources of generation and changing demand patterns. If the project does not generate at full capacity additional sources of generation will be used to meet demand.  

Wind integration studies by grid operators have found that wind energy can grow to reliably support at least 20-30% of total electricity on an annual basis, with some studies finding wind energy can provide more than 40% or more of total electricity.  Four interior states today reliably generate more than 30% of their electricity from onshore wind (Iowa, Kansas, Oklahoma, and South Dakota). 

Do turbines have back-up generators to provide energy for basic functions when the wind dies?

Grid operators have the technology and experience to forecast and prepare for output changes in a manner that maintains grid reliability. Grid operators use day ahead forecasting to choose which power stations to make up demand each hour of the next day, and they adjust this forecast at intervals as short as hourly or every fifteen minutes to accommodate any changes. 

How does offshore wind’s high capacity factor impact power generation?

Capacity factor for a power plant is a measure of how often an electric generator runs for a specific period of time.  It compares how much electricity a generator actually produces with the maximum it could produce at continuous full power operation during the same period. 

For a wind farm, the capacity factor is determined by the availability of wind, the swept area of the turbine, and the size of the generator.  Improvements in wind turbine design have not only helped to increase the maximum power they can produce (generating capacity), but also their capacity factor. 

The high capacity factors of wind in the offshore lease area help lower the levelized cost of energy (LCOE), a typically used measure of the competitiveness of different generating technologies.  Technological innovation continues to drive down costs and improve performance.   

Why do we need offshore wind?

The Massachusetts Global Warming Solutions Act of 2008 established economy-wide targets for greenhouse gas emissions (GHG) reductions below 1990 levels of between 10-25% by 2020 and 80% by 2050.  The Massachusetts Executive Office of Energy and Environmental Affairs (EOEEA) has set a 2050 statewide limit of net zero emissions, and identified offshore wind as the least-cost pathway to decarbonization   A law passed in 2016 (Act to Promote Energy Diversity) allows for the procurement of up to 1,600 megawatts (MW) of offshore wind energy by 2027.  Mayflower Wind was awarded the second solicitation for 804 MW under that law.  The Mayflower Wind project will be one of the single highest impact contributors to achieving the Commonwealth’s GHG emissions reduction goals.    Harnessing offshore wind resources supports tens of thousands of jobs, billions in economic output, and investment in critical coastal infrastructure. 

Are there other companies and leasing areas with proposed projects?

The US Bureau of Ocean Energy Management (BOEM) has issued competitive leases for Atlantic Outer Continental Shelf (OCS) areas off the coast of New England to four other developers, including Equinor, Orsted/Eversource, and Vineyard Wind. 

How does offshore wind enhance reliability?

Offshore wind diversifies the overall fuel generation mix, offsetting significant generation unit retirements within the Commonwealth, including the shutdowns of the Brayton Point station in 2017 and Pilgrim nuclear station in 2019. The location of strong and consistent winds close to shore mitigates natural gas demand and reduces threats to grid reliability due to  gas pipeline constraints.  

As a part of its regional system planning, the regional grid operator ISO-NE conducted an economic study in 2015-2016 of the impact of interconnecting 1,000 to 2,000 megawatts  of offshore wind capacity into New England’s wholesale electricity markets and operations. ISO-NE’s simulation results show that as offshore wind is added to the system, less energy is required to to serve southern New England load, achieving positive impacts for Massachusetts through less constrained interfaces and reduced transmission congestion. 

How does offshore wind contribute to reducing winter peak prices?

The strong and consistent wind speeds in the federal office lease areas are projected to provide significant energy generation during all seasons of the year and hours of the day, with highest generation periods during the winter months when natural gas prices surge from heating demand.