What are solar panels doing on the site of an old Pierce County landfill?

In March, contractors finished installing a large array of solar panels on the southern part of the Purdy Landfill, near the waste and recycling center. The panels are expected to generate over 1 million kilowatt-hours of energy each year, which is “enough to power approximately 100 homes, or to drive an electric car around the Earth 120 times,” according to Pierce County’s website.