Wind energy is a form of solar energy. As the sun's energy differentially heats different surfaces, such as water and land, it causes the atmosphere to warm differentially. As hotter air rises, air is pulled from cooler locations to displace it, causing wind. Wind, as air in motion, has kinetic energy, which can be converted to other forms of energy that we can use.
The power available from wind increases with the cube of the wind speed. This means that there is much more kinetic energy in windier areas and that a small increase in wind speed can mean a dramatically more attractive location for wind power development. For example, a 25% increase in wind speed (for instance, from an average of 12 to 15 mph) corresponds to about twice the wind power. For more information on the physics of the power and energy in wind, see the description of "Power & Energy in Wind" (PDF 350 KB) Download Adobe Reader in this fact sheet from the Renewable Energy Research Laboratory, University of Massachusetts at Amherst.
Looking for Good Locations?
The first step in planning a wind turbine or wind farm is determining whether the wind resource in a specific location is sufficient. The economics of a wind power plant are extremely sensitive to the local wind regime. A site's wind regime can be extremely site-specific, influenced by regional weather, local topography, elevation, orientation, land cover, and nearby structures.
Timing Isn't Everything, But It Does Matter
Wind as a resource is anything but steady. Wind speed, direction, and turbulence vary on an hourly, daily, and seasonal basis. As a result, wind power cannot be the only resource supplying the power grid, but it can contribute to a similar degree as many other generation sources as part of a portfolio. For example, Denmark relies on wind power for 20% of its electric supply mix. Although the wind availability at any given time beyond the immediate future cannot be predicted with precision, there are time-of-day and seasonal patterns that are reasonably reliable over the course of time. Electricity at some peak times of day or year has greater value than at others. This variability impacts the value of the wind power; when the wind blows matters as much as how much it blows. The wind's variability gives rise to some technical challenges. One reason for the growing interest in off-shore wind development is the presence of steadier (less variable) winds.
New England has a number of locations with strong winds suitable for commercial-scale wind power development. However, unlike many other regions of the country, such as those with windy farm land, the windiest areas in New England — typically mountain ridges and shorelines — are densely populated, highly valued for other uses, or challenging to access. As a result, New England's true wind power potential will be limited to a subset of locations where the land use is most compatible and where other siting considerations are met. Regional New England wind maps can provide a screening tool prior to investment in site-specific resource assessment are available.
Wind Maps of New England
Wind resource maps can help determine whether a specific area merits further exploration. The wind resources of New England — Connecticut, Massachusetts, Maine, New Hampshire, Rhode Island, and Vermont — were validated and mapped by NREL using data produced by TrueWind Solutions, LLC under a project sponsored by the Massachusetts Technology Collaborative's Renewable Energy Trust, the Connecticut Clean Energy Fund, and Northeast Utilities. In addition, the Massachusetts Technology Collaborative has made available a variety of other searchable map configurations, including maps of onshore and offshore wind resources, transmission lines, ocean depth, and other features for Massachusetts and for rest of New England, as well as community-scale wind maps of both wind resource and open space for each city and town in Massachusetts. The Vermont Department of Public Service has also funded the creation of wind resource maps for each of Vermont's 14 counties. [another link: http://publicservice.vermont.gov/energy-efficiency/ee_files/wind/ee-wind.htm]
Site-Specific Field Measurements
Because site-specific conditions can cause average wind speed and direction to vary from those suggested in the best regional mapping efforts, and because of the importance of timing in establishing the value of the wind plant's output, understanding the wind resource at a site-specific resolution is critical to a successful wind power project. Although some local historical wind data is available, much of this data has been collected at urban airport weather stations in locations not representative of the more varied topography of New England — and it is rarely indicative of the most probable sites for wind power development. While rules of thumb (elevation and orientation of ridgelines) and local visual clues ("flagging" of trees) can help in screening prospective wind sites, without a site-specific wind assessment, it is difficult to tell whether any given site will be a good one for wind development.
The Renewable Energy Research Lab at the University of Massachusetts provides additional information on resource assessment (PDF 689 KB), including why it is important to assess wind resources, how wind resources should be assessed, and how to site wind meteorological towers. Also, several states have anemometer loan programs (see state-specific pages).
Wind Data Links
After collection of several months of site-specific data, that datset can often be enhanced through correlation with measurements at other nearby sites, if available. Publicly available wind measurement data are available for a number of sites throughout the region from:
If you are aware of additional, publicly available wind data sets, please contact us so we can make them more widely available.