Chapter 17, Problem 9P

The demand for electric power is usually much higher during the day than it is at night, and utility companies often sell power at night at much lower prices to encourage consumers to use the available power generation capacity and to avoid building new expensive power plants that will be used only a short time during peak periods. Utilities are also willing to purchase power produced during the day from private parties at a high price. Suppose a utility company is selling electric power for $0.06/kWh at night and is willing to pay $0.13/kWh for power produced during the day. To take advantage of this opportunity, an entrepreneur is considering building a large reservoir 50 m above the lake level, pumping water from the lake to the reservoir at night using cheap power, and letting the water flow from the reservoir back to the lake during the day, producing power as the pump–motor operates as a turbine–generator during reverse flow. Preliminary analysis shows that a water flow rate of 2…

Manufacturers make backup batteries for computer systems available to Batteries+ dealers through privately owned distributorships. In general, batteries are stored throughout the year, and a 5% cost increase is added each year to cover the inventory carrying charge for the dis- tributorship owner. Assume you own the City Center Batteries+ outlet. Make the calculations necessary to show which of the following statements are true and which are false about battery costs. (a) The amount of S$98 now is equivalent to a cost of $105.60 one year from now. (b) A truck battery cost of $200 one year ago is equivalent to $205 now. (c) A $38 cost now is equivalent to $39.90 one year from now. (d) A $3000 cost now is equivalent to $2887.14 one year earlier. (e) The carrying charge accumulated in 1 year on an investment of $20,000 worth of batteries is $1000.

Why some diesel vehicles have battery-driven attached to the fuel tanks in order to be able to power them with natural oil? How does this affect?   Why some diesel vehicles have two tanks, one with petrodiesel and the other one with vegetable oil? How does this affect?