Emissions: displaced, but not avoided

It is fundamental that the benefits of any proposed wind energy facility outweigh its impacts. Since there are no intrinsic environmental benefits to erecting wind turbines on ridge lines, prairie lands or coastal areas, the benefits of wind-powered electricity are expected to accrue through the displacement of fossil fuel generation, and the offsetting of associated CO2 emissions and other pollutants.

In September, the ISO-NE, which holds responsibility for managing the electric grid system for the New England area, released its 2006 New England Marginal Emission Rate Analysis where it analyzed the annual marginal emission rates of the New England Generation System. The 2006 marginal emission rate values were calculated using actual 2006 hourly generation. 

Table 5.9 of the report states the average CO2 emissions for the entire six-state region was 993 lbs per megawatt hour (lbs/MWh) generated. Put another way 993 lbs/MWh of CO2 could be offset should electricity from wind-generation or other renewable energy sources displace the electricity which otherwise would be produced on the grid from power plants operating on the "margin". The ISO defines “marginal units” for energy and emissions purposes as largely oil and gas units that are needed in the event of higher load on the system.

Given that New England power plants emitted nearly 52-million tons of CO2 in 2006, according to the ISO, it would require nearly 10,000 MW of installed wind energy capacity -- more than 4,500 massive towers -- to offset or displace just 25% of New England's annual power plant emissions of CO2 for 2006.

However, the overriding issue is whether wind turbines will significantly REDUCE the CO2 emissions in New England.

Under New England's cap and trade program (Regional Greenhouse Gas Initiative - RGGI), owners of wind energy facilities could displace any CO2 emissions produced from another power source, and the generator may sell and/or transfer his unused emissions credits to another source. Thus CO2 emissions which are regulated under the RGGI cap and trade program may be transferred  but are never avoided.

Wind proponents are quick to proclaim the effect of wind generation on greenhouse gas emissions but Windaction.org warns these benefits are less apparent in the New England region for two important reasons:

1) New England relies heavily on clean natural gas for its marginal fuel source, which produces far less CO2 emissions than coal, for example. Any displacement of CO2 due to wind energy generation in the region would be far less than in other parts of the U.S.  which are more dependent on coal. Yet the negative environment, economic, and social impacts of a wind facility can be enormous.

2) Under the region’s cap and trade scheme, emissions are displaced but will never be avoided.