Biomass Feasibility Project Final Report - Xcel Energy

conversion of Volatile Organic Solids to biogas, and the electrical efficiency of the combustion
of biogas by the genset. The values used to arrive at the efficiency are: 85% of total solids are
VOCs, 35% of VOCs are converted to biogas, and the genset has a 40% electrical efficiency.
These values are average values, however, and are known to vary significantly with the manure
management practices, the digestion technology, and the generation technology employed.
The other income included in the template includes fertilizer and pesticide savings resulting from
manure digestion, as well as propane savings arising from heat recovered from the genset’s
jacket.
Power Plants Summary
Below is a summary of assumptions used.
Table VIII-1: Power Plant Characteristics
Scenario Capital Cost ($) Plant Capacity
(kW)
Capacity
Factor
(%)
Electrical
Efficiency
(%)
50 MW Biomass $150,000,000 50,000 85.0% 24.4%
Co-Firing (Incremental) $15,400,000 35,000 85.0% 36.4%
600 MW Coal w/ 5% Co-Fire $1,100,000,000 600,000 85.0% 36.4%
5.4 MW Gasification w/ CHP $15,300,000 5,392 85.0% 23.8%
135 kW w/ Manure Digester $424,000 135 85.0% 11.9%
Table VIII-2: Power Plant Income (Other) and Expenses
Scenario
Other Income
($/year)
Total Expenses
($/yr)
50 MW Biomass $0 $2,179,487
Co-Firing (Incremental) $0 $1,266,766
600 MW Coal w/ 5% Co-Fire $0 $17,604,724
5.4 MW Gasification w/ CHP $3,547,606 $894,308
135 kW w/ Manure Digester $74,000 $31,374
Capacity Payment
($/kW - yr)
Table VIII-3: Power Plant Income and Taxes for All Scenarios
Interest Rate on
Debt Reserve
(%)
Federal Tax
Rate (%)
State Tax
Rate (%)
Production Tax Credit
($/kWh)
$0.00 5.00% 34.00% 0.00% $0.0000
Page 130
Identifying Effective Biomass Strategies:
Quantifying Minnesota’s Resources and Evaluating Future Opportunities