Sustainable Energy

Sustainable Energy

From its inception, EnergyXchange has explored sustainable energy resources to make a positive impact on the local economy, environment, and educational opportunities. Initially, landfill gas was the focus for development and use.  Since then, EnergyXchange has explored solar, wind, and wood waste as viable fuels for future operation of the EnergyXchange campus and continuation of its mission.

Landfill gas

As the municipal solid waste decomposes beneath the surface of the Yancey-Mitchell landfill cap, landfill gas is created. Landfill gas consists of about 50% methane (the primary component of natural gas), 50% carbon dioxide, and a small amount of other organic compounds. Ordinarily, without a collection system, the landfill gas moves upward and escapes into the air. The collection and combustion of the landfill gas drastically lowers greenhouse gas emissions. At EnergyXchange, the landfill gas is captured and used as an energy source, thereby reducing local smog and global climate change. Methane gas from the decomposing trash supplies radiant heat for the greenhouses, classrooms, office, and rented studios.

The system is expected to save over a $1 million in energy costs over the landfill’s conservatively estimated 20-year reuse cycle. Methane, when burned, combines with oxygen to form carbon dioxide. Methane is a greenhouse gas that is 21 times more effective at holding heat in the atmosphere than carbon dioxide. According to the EPA’s feasibility study, the environmental impact of the Yancey-Mitchell County landfill Reuse Project is equivalent to planting 14,000 acres of trees or taking 21,000 cars off the road in North Carolina each year!

Solar

Solar energy is the heat and light radiated from the Sun that powers Earth's climate and supports life. Solar technologies allow controlled use of this energy resource, through conversion of sunlight into electricity by photovoltaics (PV) or conversion into thermal energy. EnergyXchange uses solar energy for both electricity and thermal heat.

 

Photovoltaic Systems

Currently the EnergyXchange campus has over eight kilowatts (kW) of photovoltaic generating capacity. The three arrangements of modules or arrays, follow the sun with a non-motorized tracking device. The tracker uses only the sun’s heating of Freon inside the device, converting it from a liquid to gas to liquid it as moves and settles as a counter weight. This tracking increases the systems’ electrical generation by 20-30% and negates electrical losses that occur during the conversion and transmission processes. The electricity generated by the solar PV supplements the electricity in one of the buildings, and also feeds back into the electrical grid.

Thermal Systems

While PV systems convert sunlight into electricity, thermal systems convert sunlight into thermal energy, most often providing heated water. EnergyXchange has ten solar thermal panels that can provide heat for aquaponics fish tanks. Heated water and glycol are circulated from the thermal panels through coils in the fish tank and back to the thermal panels. In this manner, the water in the fish tanks can be maintained above 60 degrees even in the winter.  

For more information on solar energy, check out these links:

http://nccleantech.ncsu.edu/go-solar-nc

http://nccleantech.ncsu.edu

http://www.ases.org