Power Plans for a Submarine Gallery

Electricity for an Underwater Adventure

A science museum is planning a submarine gallery. Visitors will use pretend controls and lighted displays to explore deep-ocean discoveries. The gallery needs electricity, but electricity is not a fuel that workers dig from the ground. The museum must choose how natural resources will supply its electricity. Planners compare three plans that would provide the same amount of electricity on one sample day.

Coal and natural gas are fossil fuels found underground. They formed from ancient living things over millions of years. People use these fuels much faster than nature replaces them. Workers mine coal and drill wells for natural gas. Mining can remove plants and disturb land. Gas wells and pipelines can also disturb habitats. At power plants, burning these fuels helps produce electricity. Burning them releases carbon dioxide, a gas that contributes to Earth's warming, and can release other air pollutants.

Solar panels use sunlight to produce electricity without burning fuel during operation. Making panels requires materials from Earth and produces some waste. Moving river water can turn machines that generate electricity without burning fuel during operation. Sunlight and flowing water are naturally replenished resources. However, building a river dam can flood land upstream and make it harder for fish to reach parts of a river.

The planners estimate that the gallery will need 12 kilowatt-hours of electricity on the sample day. A kilowatt-hour, or kWh, is a unit of electrical energy. Plan A supplies 12 kWh from an existing coal power plant. Plan B supplies 8 kWh from panels on the museum's existing roof and 4 kWh from a natural-gas power plant. Plan C supplies 6 kWh from a proposed river dam and 6 kWh from a natural-gas power plant. The proposed dam would flood a nearby wetland. The roof panels would not require clearing land beside the museum. These estimates describe the sample day; sunlight and river flow can change.