All calculations in the following analyses are expressed as a present value of money, energy and emissions. Measures are assumed to be financed at a real after-tax interest rate of 4%. Cash flow and any associated energy benefits are discounted to a present value at a discount rate of 4%. Future emissions are not discounted. The Hermiston project is expected to last 30 years. Since the PP&L contract is only for 15 years, the net present value (NPV) of total emissions may need to be adjusted accordingly. The relative economics of most of the mitigation/attenuation options presented here do not change significantly.
The value of any electric energy benefits resulting from mitigation/attenuation options discussed here is assumed to be 35 mills/kWh in real levelized terms. This is consistent with current regional estimates of the value of new energy resources, and well within the range of actual costs of electricity from Hermiston
Average MW output for Hermiston is based on PP&L contract estimates. Since the efficacy of several mitigation and attenuation options is dependent in part on which fossil fuel generating resources are being displaced, values are sometimes expressed both in terms of displacing Hermiston, and in terms of displacing a prototype coal plant burning low-sulfur coal. In the latter case, it is assumed that US Generating (USGC) has implemented this option as part of an overall strategy of environmental dispatch, and that the marginal resource being displaced is a coal project somewhere in the Western regional grid.
Estimates of the global warming potential (GWP) of various emissions or displaceable mitigation options relative to CO2 are expressed in terms of their 100 year impact on a weight basis.
| Real Finance Rate | 4% |
| Cash/Energy Discount Rate | 4% |
| Emissions Discount Rate | 0% |
| Coyote Springs Heat Rate (BTU/kWh) | 7,367 |
| NSPS Coal Plant Heat Rate (BTU/kWh) | 10,856 |
| T&D Losses | 7% |
| Net Coyote Springs Heat Rate (BTU/kWh) | 7,883 |
| Net NSPS Coal Plant Heat Rate (BTU/kWh) | 11,616 |
| Coyote Springs Project Life (years) | 30 |
| Average MW Output | 401 |
| Annual Fuel Use (MMBTU, Gas only) | 25,899,543 |
| Annual CO2 Emissions (Tons, Gas only) | 1,528,073 |
| Value of Energy ($/kWh) | $ 0.035 |
© Convergence Research - 2/14/96