Question

Explain the difference between energy and power. If a household has an average annual energy consumption of 7,500 kWh, what is the average daily and hourly power demand. How would you expect this to vary during the day and year?

Answer 1

Energy is ability to do work. In electrical circuits energy is due to flow of current. Current has abilty to light up your bulb, fan etc that it has ability to do electrical work and hence it has energy. Units of energy is Joules

Power is energy consumed per unit time. Power is rate of doing work . Power = Energy/Time units are Watt

So Watt hr is units of energy.

Energy = 7500KWh in one year.     Energy in 1 hr = 7500/8760 = 0.86KWh

Power consumption in 1 hr =0.86/1 = 0.86 KW    Power consumption in 1 day= 0.86 * 24 = 20.64watt

Power consumption will be usually less during days because less lights will be used than nights. Also consumtion in summers will be more because appliances like Air conditioners and fans wil be more. So in months of summer power consumption will be more.