Wind–SCC Green Power Partners

1. Basic Concept
Wind power is an "intermittent" energy resource because electricity is generated only for certain wind conditions. These conditions are present approximately 20% to 40% of the time. A wind turbine is also a "non-dispatchable" resource, to use the term given to it by grid operators, because the amount of electricity that can be generated at any given time is not under their control. For these reasons, it is recognized that wind power must be complemented (firmed up) with a natural gas power plant that picks up the slack when the wind turbines are not generating electricity.

Furthermore, the cost of wind generated electricity is at the present higher than that of a baseload plant such as coal.

However, combining wind power with a natural gas plant equipped with POWER's Simplified Combined Cycle (SCC) results in a hybrid wind-natural gas power plant, Wind-SCC, that provides firm (not intermittent) power, is dispatchable, and produces electricity that is competitive with that of a coal plant.

Priority would be given to the wind turbines. When the wind turbines are able to produce power, they do so. When wind speeds fall below the minimum, a control signal is sent to the gas turbine to immediately produce the desired electricity. The SCC technology enables a fast acting but otherwise inefficient simple cycle gas turbine to quickly ramp up to the desired power level and continue operating there economically. Furthermore, if conditions call for instantaneous response to changes in wind output, the SCC plant can operate in a spinning reserve mode without consuming enormous amounts of natural gas. The SCC technology has economics better than a combined cycle plant. Wind and a SCC plant are a “natural” fit.

2. A Green Baseload Project
Imagine Wind-SCC as an alternative to a 300 MW coal plant. To generate this amount of electricity, the Wind-SCC Program would include 170 wind turbines and five combustion turbines equipped with SCC. A GE LM6000 with the SCC technology would be able to produce 60 MWs each at a plant efficiency of 49% (LHV).

The project schedule is about 3 years from the notice to proceed to commercial operation.

• Wind: 5.5 cents per kWh x 35%
• SCC: 10.1 cents per kWh x 65%
• Total: 8.5 cents per kWh

Natural gas was assumed to cost $9.0 per million Btu. Without the Production Tax Credit, the cost would increase by approximately 1.0 cent/kWh.

This number, which is a realistic estimate based upon POWER's experience in developing natural gas plants, is competitive with today's coal costs.

In a carbon constrained world, the cost of coal would almost certainly be higher and perhaps much higher than that of Wind-SCC. This should hold true even though natural gas prices may periodically spike. A $1.0 per million Btu hike in natural gas prices, which would represent a significant increase, adds just 0.50 cents/kWh to the cost of electricity generated by the plant. In other words, the wind portion of the project is a significant hedge against fuel price increases.