Handbook of Energy Storage for Transmission or ... - W2agz.com
Handbook of Energy Storage for Transmission or ... - W2agz.com
Handbook of Energy Storage for Transmission or ... - W2agz.com
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EPRI Proprietary Licensed Material<br />
cost/benefit analysis<br />
Wind Generation, MW<br />
25<br />
20<br />
15<br />
10<br />
5<br />
0<br />
Jun<br />
Aug<br />
Oct<br />
Dec<br />
Feb<br />
Apr<br />
June 2001 thru May 2002<br />
100%<br />
80%<br />
60%<br />
40%<br />
20%<br />
0%<br />
% Time Wind Available<br />
Max Pw r/month<br />
Avg Pw r/month<br />
% Hrs Wind>0<br />
Annual Avg: 5MW<br />
Jun-Sep Avg: 2.4MW<br />
Oct-May Avg: 6.3MW<br />
Figure 4-1. Summary <strong>of</strong> Hourly, Year-long Wind Test Data<br />
To ascertain the value <strong>of</strong> inc<strong>or</strong>p<strong>or</strong>ating energy st<strong>or</strong>age within the wind farm, an optimization<br />
calculation using hourly wind data and the above electricity rates was conducted to first identify<br />
the maximum revenue stream <strong>f<strong>or</strong></strong> the wind farm without inc<strong>or</strong>p<strong>or</strong>ating energy st<strong>or</strong>age (windonly),<br />
and then with energy st<strong>or</strong>age (wind+ES). This process showed that the wind generat<strong>or</strong><br />
would maximize revenue with an on-peak firm power supply contract <strong>of</strong> 1.9MW <strong>f<strong>or</strong></strong> wind-only.<br />
The optimal on-peak contract amount is increased to 4.4MW when 17.2MWh energy st<strong>or</strong>age<br />
capacity per cycle is inc<strong>or</strong>p<strong>or</strong>ated. The value <strong>of</strong> energy st<strong>or</strong>age <strong>f<strong>or</strong></strong> these conditions is<br />
represented by the incremental benefit in annual revenue summarized in Table 4-5.<br />
Table 4-8. Economic Benefit <strong>of</strong> <strong>Energy</strong> <strong>St<strong>or</strong>age</strong> <strong>f<strong>or</strong></strong> Wind Stabilization<br />
<strong>Energy</strong> Rates<br />
Rates, Wind-Only, Wind+ES, ES Benefit,<br />
$/MWh MWh/yr MWh/yr K$/yr<br />
On-Peak <strong>Energy</strong> (sell) 120 6242 14454 986<br />
On-Peak <strong>Energy</strong> (buy) 144 (3140) (3717) (83)<br />
On-Peak Non-Firm <strong>Energy</strong> (sell) 60 9468 5963 (210)<br />
Off-Peak <strong>Energy</strong> (sell) 20 22015 17921 (82)<br />
Off-Peak <strong>Energy</strong> (buy) 21 0 (1319) (28)<br />
Semi-Peak <strong>Energy</strong> (sell) 40 9041 9041 0<br />
<strong>Transmission</strong> Charges Rates, Wind-Only, Wind+ES, ES Benefit,<br />
$/kW-mo MWh/yr kW-mo K$/yr<br />
<strong>Transmission</strong> Tariff 3 (22800) (52800) (90)<br />
Net <strong>Energy</strong> <strong>St<strong>or</strong>age</strong> Benefit, K$/yr 493<br />
Since examination <strong>of</strong> data also shows that the energy st<strong>or</strong>age system is not being used about 25%<br />
<strong>of</strong> the time, including AGC functions during those periods can further increase its value. This<br />
value element would increase annual revenue by $58K, assuming operation in AGC mode <strong>f<strong>or</strong></strong> 16<br />
hours per day, 90 days per year. On this basis, the NPV <strong>of</strong> the NAS system without<br />
consideration <strong>of</strong> AGC is negative ($0.1M) and with AGC it is positive ($0.6M). Costs and<br />
benefits <strong>f<strong>or</strong></strong> these options are summarized as follows:<br />
4-6
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