Suppose that the main street of a town has 30 lamp posts each containing two 175 W mercury vapour lamps. A town has a street lighting system consisting of 30 lamp posts each containing two 150 W incandescent lamps. The town council has decided to reduce the number of lamp posts to 15 and to place one 150 W sodium light on each post. Explain your answer. State the annual savings provided by the new system.
Most homes use kinds of energy other than electrical.
Name some other kinds of energy used in your home and say how they are used. Also, suggest ways to reduce your consumption of these kinds of energy.