Over the past decade, Montgomery County Public Schools (MCPS) has become a leader among Maryland school districts in hosting net-metered solar power purchase agreements (PPA). The Department of Facilities Management has PPA contracts that allow MCPS to host the operation of solar photovoltaic (PV) structures at no cost to the school system. As part of the agreements, a solar developer installs, owns, and maintains the solar array and sells power at a reduced rate directly to MCPS. Sites have been selected based on roof age, roof shading, building orientation, and financial considerations. Currently, MCPS has 17 solar PV locations with a total estimated capacity of 4.1 megawatts (MW) direct current installed.
On a hot summer afternoon, solar panels can supply 20–50% of a host school’s energy needs. Each year, MCPS saves more than $300,000 thanks to the solar energy agreements.
Renewable energy credits (RECs) represent carbon offsets from clean or renewable energy sources, primarily wind and solar generators. Since 2005, MCPS has purchased clean RECs and will continue to increase this amount in future years. As of 2021, MCPS purchases 38% of our electricity from renewable energy sources.
Montgomery County Public Schools piloted the first geothermal system in 2001. Currently, 32 schools are being heated and cooled with the geothermal systems. Geothermal, also known as geo-exchange, heating, and cooling systems, is one of the most energy-efficient and environmentally safe space-conditioning systems available. While temperatures above ground change a lot from day to day and season to season, the temperature 10 feet below the earth’s surface holds nearly constant between 50 and 60 degrees Fahrenheit. For most areas, this means that the soil temperatures are usually warmer than the air in winter and cooler than the air in summer. The geothermal system harvests the constant ground temperature and uses the earth’s mass to store energy to heat and cool buildings. Energy is transferred through an underground piping system between the building and ground to provide year-round heating and cooling.