In a photovoltaic (PV) system, solar panels absorb sunlight and convert it directly into electricity. This visible part of the system is also called a solar array. The electricity it generates may be used right away, carried to a grid or stored in batteries. PV systems range in scale from tiny individual low power systems to large utility-scale power plants. They operate silently and without any moving parts to supply zero-emission renewable energy.

Community solar is a model in which a shared PV system, also called a solar farm or garden, benefits a group of participants. An optimal site is found for the solar garden, which generates power that is fed back into the grid. Subscribers purchase shares of the power and receive credit on their utility bill. This model makes solar power accessible to individuals that may not have suitable space for a solar array – about half of the businesses and households in the US.

The earth’s surface is a powerful vessel for solar energy, and the temperature below ground stays fairly constant regardless of the season and climate. Ground source heat pumps (GSHPs) are electrically powered systems that transfer heat to or from the ground to provide heating, cooling, and hot water for residential and commercial buildings. When it’s cold outside, a GSHP pulls heat from an underground loop of piping and redistributes it through air ducts, a radiant floor system, or into a hot water heater. This process is reversed to cool indoor temperatures by extracting heat from the air and moving it either back into the underground loop or into a hot water tank.

In modern wind power systems, natural airflow engages turbines that generate electricity. Wind power can be used on a small scale to provide power for individual homes or businesses. On an industrial scale, large wind farms connect to the grid and provide power to large communities. Wind is a plentiful and widely distributed renewable resource that can be harnessed to generate clean, zero-emission electricity.

Many different technologies fall under the energy storage umbrella, including batteries, compressed air and pumped hydro systems. What these technologies all have in common is that they represent potential energy resources that can be made available at a moment’s notice. And while battery back-up systems can provide power when the grid is down, “smart” storage can also act as a sponge to absorb excess energy at times when production is high but demand is low. By combining innovative energy storage solutions with renewable energy supplies like wind and solar, micro grids can quickly come online at times- or in places- that grid power is simply not available.