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Department of General Services, Office of Energy and Sustainability

About Solar

Why Solar?

Solar panels on County facilities make good sense. Through grants and power purchase agreements, Montgomery County benefits from clean, renewable solar energy with no upfront costs. Among their many benefits, solar energy systems:

  • Reduce greenhouse gas emissions
  • Stabilize the utility grid by generating extra power on hot, sunny days when energy demands are typically high
  • Create job opportunities and drive economic development
  • Reduce the need for new power plants or transmission lines
  • Lower the cost of County operations by cutting energy bills

Learn more about the benefits of the County’s solar projects.

How Solar Works

Solar energy systems convert sunlight into electricity or heat that can be used to meet energy needs.

Solar Thermal Systems: Otherwise known as solar water heaters, these systems convert sunlight into heat that can be used to warm water or buildings. This heat can even be converted into cooling using an absorption chiller. Learn how Solar Thermal Works at Office of Energy Efficiency & Renewable Energy, Department of Energy.

Solar Photovoltaic Systems: Convert sunlight into electricity that can offset energy generated from fossil fuels and distant power plants. Solar photovoltaic systems can be distributed on buildings, parking lots and open space. Learn more about how Solar Photovoltaics work at National Renewable Energy Laboratory.

Montgomery County Government facilities are using photovoltaic systems. We also are actively evaluating solar thermal systems.

A photovoltaic (PV) panel is usually made of silicon-based semiconducting material placed between two electrical contacts. Glass protects the panel’s components from the weather and wildlife.

To make sure PV panels have access to direct sunlight for most of the day, it is best to mount them on a sloping, south-facing roof or to mount them in a sloped, south-facing fashion on a flat roof or on the ground. Also, the semiconductor is coated in an antireflective substance to make sure it absorbs sunlight rather than scattering it away. As the panel absorbs sunlight, electrons are freed from the atoms that make up the semiconductor and an electrical current is created.

PV panels generate direct current, which is run through an inverter to change the electricity to alternating current so it can be used to power the building.

A utility meter measures how much electricity the solar panels are generating. During the day the solar panels often can produce more power than the facility needs, so excess power is sent to the electric grid to power homes and businesses. At night or on cloudy days, the facility uses power from the grid.

Types of Solar Photovoltaic Installations:

Roof mount solar panel
Roof Mounts: Solar photovoltaic panels are installed on open space on building roofs, making use of otherwise unusable space. The panels can even help keep the building cooler by shading the roof.
Canopy Mounts: Solar photovoltaic panels are mounted on canopies above parking, making double use of parking facilities. Canopy systems typically have integrated light emitting diode (LED) lighting under the canopy decking. Canopy systems provide shaded parking and help reduce heat islands.
Canopy mount solar panel
Ground mount solar panel
Ground Mounts: Panels are mounted on scaffolding installed in open fields or space adjacent to buildings. Grasses and ground cover vegetation can grow beneath the panels, allowing for rain water to soak into the ground and reduce flooding and pollution in streams.

Take Advantage of Solar at Home

To learn more about how to use solar for your home or business, including any available incentives, visit the Department of Environmental Protection's Solar Energy page.

About Combined Heat and Power

Why Combined Heat and Power?

Combined Heat and Power (CHP), sometimes referred to as cogeneration, helps stabilize the utility grid by generating electricity close to the site of use. These systems save energy by using the waste heat from on-site electricity generation to heat the building or to provide hot water. CHP installations help reduce the need for additional power plants and transmission lines. CHP can generate electricity cleanly and efficiently when powered with natural gas or renewable fuels.

How CHP Works

CHP systems use combustion or thermochemical processes to convert fuels into electricity and heat which can be used near the point of generation (e.g., a building). CHP systems are most commonly fueled by natural gas. Because CHP uses both the electricity and heat locally, they are very efficient. CHP systems also can be coupled with batteries and advanced controls to provide emergency power during a blackout. Learn more about CHP from the U.S. Department of Energy.

Montgomery County has installed CHP at the Pre-Release Center and is investigating the potential for CHP in several additional facilities. In addition, Montgomery County has joined the U.S. Department of Energy’s Better Buildings Initiative accelerator to promote the adoption and expansion of combined heat and power systems across the country.

Types of CHP Systems

Microturbines: Small turbines that convert natural gas and other fuels to electricity and heat. These systems can be installed in groups to generate larger amounts of energy. Microturbines can use more than 65% of the energy of a fuel (compared to the 45% average efficiency of traditional power plants and boilers).
Fuel Cells: Use electrochemical processes to convert natural gas, hydrogen, and other fuels to electricity and heat. Because they convert fuel using electrochemical processes, as opposed to combustion, fuel cells are extremely efficient.
Fuel Cell

Reciprocating Engines: Similar to the engine in a car, these systems combust fuel to drive pistons generating electricity. Heat is recovered off the exhaust and cooling systems.

About Microgrids

Why Microgrids?

Microgrids are small scale power grids that can operate independently of the local utility. Microgrids combine a variety of technologies such as solar, combined heat and power, batteries, and advanced controllers to allow self-sufficient operations. Microgrids improve the resiliency of buildings and communities to utility interruption, help stabilize the overall grid by generating electricity during periods of peak demand, and can reduce greenhouse gas emissions. Learn more about Microgrids at the U.S. Department of Energy.

How a Microgrid Works

Microgrids use advanced smart grid controls to combine the electricity output of sources such as solar, combined heat and power, batteries and other technologies to power facilities and operations locally.


During normal operations the microgrid balances the electricity generated on site with grid supplied electricity, selecting the most economical operating mode. A microgrid may even generate electricity for export to the grid, increasing the amount of electricity available to the community and helping to reduce grid strain during periods of peak demand.

During an outage, the microgrid disconnects from the utility grid and operates independently. Microgrids provide an advantage over traditional generators as they can operate independently for extended periods of time. Learn more about how microgrids work at the U.S Department of Energy.

Montgomery County is exploring the use of microgrids at key facilities to provide uninterrupted public safety services during major storms and power outages.