Page 216 - Sustainable Cities and Communities Design Handbook

190 Sustainable Cities and Communities Design Handbook

discounted stream of cumulative revenue impacts does not equal the
LRI RIM )
NPV RIM ¼ NPV levels
BCR RIM ¼ BCR for rate levels
B RIM ¼ Benefits to rate levels or customer bills
C RIM ¼ Costs to rate levels or customer bills
E ¼ Discounted stream of system energy sales (kWh or therms) or demand
sales (kW) or first-year customers. (See Appendix C for a description of the
derivation and use of this term in the LRI RIM test.)
The B RIM and C RIM terms are further defined as follows:
N N
X X
UAC t þ RG t UAC at
B RIM ¼ þ
t 1 t 1
t¼1 ð1 þ dÞ t¼1 ð1 þ dÞ
N N
UIC t þ RL t þ PRC t þ INC t RL at
X X
C RIM ¼ þ
t 1 t 1
t¼1 ð1 þ dÞ t¼1 ð1 þ dÞ
N
E t
X
E ¼
t 1
t¼1 ð1 þ dÞ
where
UAC t ¼ Utility avoided supply costs in year t
UIC t ¼ Utility increased supply costs in year t
RG t ¼ Revenue gain from increased sales in year t
RL t ¼ Revenue loss from reduced sales in year t
PRC t ¼ Program administrator program costs in year t
E t ¼ System sales in kWh, kW, or therms in year t or first-year customers
UAC at ¼ Utility-avoided supply costs for the alternative fuel in year t
RL at ¼ Revenue loss from avoided bill payments for alternate fuel in year t
(i.e., device not chosen in a fuel substitution program).
For fuel substitution programs, the first term in the B RIM and C RIM equa-
tions represents the sponsoring utility (electric or gas) and the second term
represents the alternative utility. The RIM Test should be calculated separately
for electric, gas, and combined electric and gas.
The utility-avoided cost terms (UAC t ,UIC t , and UAC at ) are further
determined by costing period to reflect time-variant costs of supply:
I I
X X
UAC t ¼ ðDEN it MC: E it ðK it ÞÞ þ ðDDN it MC: D it K it Þ
i¼1 i¼1
UAC at ¼ UAC t formula, but with marginal costs and costing periods appro-
priate for the alternate fuel utility.