(a) To calculate the total electricity produced by the power plant in a year, we can use the following formula:
Total electricity produced = Power plant capacity x Hours of operation per year
Total electricity produced = 12 MW x 8,000 hrs/yr
Total electricity produced = 96,000 MWh
Therefore, the power plant can produce 96,000 MWh of electricity in a year.
(b) To calculate the total energy consumed by the community in a year, we can multiply the average energy consumed per household by the total number of households:
Total energy consumed = Average energy consumption per household x Number of households
Total energy consumed = 8,000 kWh/yr x 3,000
Total energy consumed = 24,000,000 kWh/yr
Therefore, the community consumes 24,000,000 kWh of energy in a year.