Selling Wind Power
Owners of wind turbines interconnected directly to the transmission or distribution grid, or that produce more power than the host consumes, can sell wind power as well as other generation attributes.
Wind-Generated Electricity
Electricity generated by wind turbines can be used to cover on-site energy needs (interconnected behind a retail customer’s meter), or it can be sold and transmitted over the electric grid.
On-site or distributed generation can displace a portion of a customer’s purchases of electricity from the grid. In addition, state net metering rules sometimes allow generation in excess of on-site load on a monthly or annual basis to be sold back to the local utility (see the DSIRE website for net metering specifics).
For sales over the electricity grid, an Independent System Operator (ISO) creates and manages a wholesale market for electric energy, capacity, and ancillary services (services that support transmitting electricity to the end users). Wind generators may sell their electric energy and capacity in spot markets organized by the ISO, or they may contract with wholesale buyers to sell these products for any term to utilities or other buyers operating in the ISO marketplace.
Electric utilities and energy cooperatives may also install their own wind turbines as a way to supply renewable energy to their customers. Modern wind generators may also provide other marketable ancillary services, such as the ability to provide voltage support on weak distribution lines.
Generation Attributes
Generation attributes are performance characteristics of each unit of energy produced by a particular generator and can include the generation technology, fuel source, location of plant, time of generation, emissions (if any), and other ancillary services. Zero-emission wind generators have additional attributes reflecting indirect or derived benefits to the power system, which could include displaced emissions. These can be sold directly as Renewable Energy Certificates (RECs) or tradable property rights such as emission allowances or emission reduction credits that may be created for various emissions under state or regional emission “cap-and-trade” or similar programs.
RECs, also known as green certificates or green tags, are terms used to describe the embodiment of rights to generation attributes that can be bought and sold separately from electricity service or together with electricity as “green power.”
Emissions markets are a practice used on a state, regional, national, or global basis to limit emissions of various pollutants and greenhouse gases. In some of these programs, a wind generator can apply for and receive a form of tradable emission rights in recognition of emissions a wind generator displaces on the system; in other programs limited to emitters, they cannot directly participate. For more information, see:
- Regional Greenhouse Gas Initiative
- Northeast States for Coordinated Air Use Management (NESCAUM)
- Environmental Protection Agency: Clean Air Markets.