Army Solar Hot Water Project To Reap Big Savings
By Jan Ten Bruggencate
Source: Honolulu Advertiser http://the.honoluluadvertiser.com/article/2001/Sep/01/ln/ln04a.html
The Army will save $250,000 annually in electrical
costs for water heating under a massive new solar water heating
project that is a joint venture with Hawaiian Electric Co.
The utility says it is the nation's largest project
involving the installation of solar water heating units.
The project will place 650 solar water heating units
on the roofs of Helemano military housing units and on buildings
at the Wai'anae Recreational Center.
Solar water heaters generally consist of a serpentine
array of piping in a black box behind a glass surface. During the
day, the sun heats the rooftop box and the water inside the pipes.
The water is stored in an insulated water tank like the ones normally
used in electric and gas water heating installations.
Properly sized units can generally meet all water
heating requirements for families, except during extended periods
of cloudy weather or periods of high use, such as when house guests
add to the number of showers and laundry loads.
The overall project is expected to cost about $1.9
million, but Hawaiian Electric rebates will reduce the cost to the
Army to about $1.7 million. Two models of solar water heaters will
be used, one from Inter Island Solar Supply and the other from R&R
Hawaiian Electric account manager Steve Luckett said
construction is expected to begin soon and may be completed by the
end of the year.
Water heating is usually the largest single cost item
in an electric bill. The savings after installation of the units,
which cost between $3,000 and $3,500 apiece before rebates, should
pay for the entire project within about seven years.
The solar heating systems have life expectancies of
10 to 25 years, Hawaiian Electric said.