Most electricity in the US is produced using steam turbines in power plants. Coal is commonly burned to heat water and produce steam, which spins the turbine and generates electricity. This electricity is sent through transformers to increase the voltage for long distance transmission on power lines before being stepped down for local distribution and use in homes and businesses. Implementing a "smart grid" that uses sensors and two-way communication could help modernize the aging electrical infrastructure to reduce waste and better incorporate renewable energy sources.