
272 Shipboard Electrical Power Systems
If the equipment saves S
kW
in power loss and costs ∆P more, it will save money over
30 years only if ∆P < S
kW
× PLCR. A case where ∆P = S
kW
× PLCR
will result in
breakeven. However, 30 years is too long for most managers, who would be gener-
ally interested in 1 kW loss saving advantage only if the additional capital cost ∆P
<
1
/
3
S
kW
× PLCR.
Example 11.1
A 1000 kVA transformer is open for procurement. Vendor A offers 97% efficiency
at $90,000 price and vendor B offers 98% efficiency at $100,000 price. Determine
the profitability of buying the high-efficiency transformer. Assume that (i) quoted
efficiency is a ...