Question

Between 12 and 4 PM a utility anticipates its solar farm will generate 2000 kWh of excess power. In

an effort to make money with that power, the utility is considering two options: Option 1) Sell the

power to a neighboring utility (who is hoping to increase the percentage of their power sourced

renewably) for $0.10 / kWh. Option 2) Use that energy to pump water up a hill (with 90% efficiency) into

a tank. Then, between the peak hours of 4 and 8 PM, run that water downhill through a turbine (with

85% efficiency) and sell the power to customers for $0.20 / kWh. Which option should the utility pick to

maximize profit? and why?

Answer 1

Excess power generated from Solar firm =p=2000kwh. option: Cost per kWhich $0.10 Total Sold Lost &- cx P = 0.18 2000. >$200 option 2 pump = 0.9 ; Cost Perkob 0.2 kech Power Required to Pump = 2000ked available Head generated by pump = 0.9x2000 keah 0.85 turbine - Power generated from turbine = 0.85x09x2000 P = 1530 kWh Total Revenue = Px a $0.2 x 1530 = $306 option is preferable. We are getting profit More