Page 242 - Alternative Energy Systems in Building Design

218 ENERGY CONSERVATION

At present, power-production capability of the aggregate solar power cogeneration
system is designed to meet approximately 70 percent of the calculated demand load of
the net meter, which is effectively 48 percent above the 20 percent maximum qualifi-
cation requirement for USGBC 3-point credit. From the April 2006 commissioning
date until December 2006, while the project was while under construction, solar power
system generated over 550 MWh of electric power, which translates into approxi-
mately 8 percent of the net invested capital.
With 50 percent of the CEC solar power rebate received and projected escalation of
electric energy cost, the solar power cogeneration system investment is expected to
recover its cost in fewer than 5 years. In view of the 25-year guaranteed life span of
the solar power panels and minimal maintenance cost of the system, the power cogen-
eration system, in addition to saving significant amounts of energy, will prevent
atmospheric pollution by avoiding the dumping of millions of tons of carbon dioxide
into the air.

ENGINEERED BY VECTOR DELTA DESIGN GROUP

Projected economic contribution Considering maximum performance degra-
dation over the life span of the solar power system, projected ac electrical output
power throughout the system life span under worst-case performance conditions is
expected to be as follows:

Energy Production
Daily energy production = 350 kWh (worst-case hourly energy output)
× 5.5 (hours of average daily insolation) = 1925 kWh

Yearly energy production = 1925 kWh × 365 days = 702,625 kWh

System lifetime (25 years) energy production = 702,625 kWh × 25 years
= 17,565,625 kWh or = 17.7 MWh

Assuming an optimistic rate of increase in electric energy cost escalation over
25 years of system life, at a mean value of $0.75/kWh, projected saving contributions
by the solar power system could be approximately $13,174,218. If we assume a rate
of 1 percent of the solar power system cost for general maintenance, the net energy
savings over the life span of the system could be about $13 million.

Air pollution prevention When generating electric power by burning fossil fuels,
the carbon dioxide emitted into the atmosphere per kilowatt of electric energy ranges
from 0.8 lb for natural gas to 2.2 lb for coal. The variation depends on the type of fossil
fuel used, such as natural gas, crude oil, or coal. In view of this, pollution-abatement
measures resulting from the use of the solar power at the Water and Life Museum over
the life span of 25 years is estimated to be 28 million pounds of CO that will be prevented
2
from polluting the atmosphere.