1-The power generated by photovoltaic cells in an array ________________.

A. is alternating current and can be directly used by the power company

B. is direct current power

C. can be increased by having the array track the movement of the sun

D. both B and

2-When water vapor in a boiler’s stack gas gives up latent heat to the water returning to the boiler, the boiler is said to be a _________.

A. non-condensing boiler

B. condensing boiler

C. fire tube boiler

D. water tube boiler

3-Ice storage systems _______________________________.

A. can reduce chiller tonnage by 40 to 50 percent

B. don’t save energy directly, but they improve the efficiency of the power utility’s delivery of power

C. shift electric load to off-peak periods

D. all of the above