The Woods family uses about 10,000 kilowatt-hours of electricity annually.Coal-fired power plants release about 2 lbs.of carbon dioxide per kilowatt-hour of electricity produced.Wanting to be more environmentally "friendly," the family installs a solar photovoltaic PV)system on their roof.They notice that the amount of electricity provided to them by their utility company has decreased by 60%.Assuming all of the utility company's electricity is generated from coal,how much less carbon dioxide is being produced annually as a result of the Woods installing their PV system?

Question

Quizplus · Accepted Answer

The Woods family uses 10,000 kWh of electricity annually, which would result in the release of 20,000 lbs of carbon dioxide (2 lbs/kWh x 10,000 kWh). However, with their PV system providing 60% of their electricity needs, they are reducing their electricity consumption from the utility by 6,000 kWh (60% of 10,000 kWh). This means they are now only using 4,000 kWh of electricity from the utility, resulting in a carbon dioxide release of 8,000 lbs (2 lbs/kWh x 4,000 kWh). Therefore, the Woods family is reducing the carbon dioxide released annually by 12,000 lbs (20,000 lbs - 8,000 lbs) by installing their PV system.

The Woods Family Uses About 10,000 Kilowatt-Hours of Electricity Annually