Natural gas is a fossil fuel and as such is not a renewable energy source. Natural gas can be found in various geological formations (U.S. EIA, 2018);
Conventional Natural Gas – Found in the large cracks or spaces between layers of overlying rock.
Unconventional Natural Gas (tight gas or shale gas) – Found in tiny pores within some shale, sandstone and sedimentary rock formations
Associated Natural Gas – Found with deposits of crude oil
Like any fossil fuel, combustion of natural gas results in emissions of Carbon Dioxide (CO2) though at lower levels than oil and coal. Emissions of CO2 are around 40% lower than coal and around 20% lower than oil. However another major area where this source beats oil and coal is in emissions of the other main air pollutants. Natural gas has the smallest share of total energy-related emissions of air pollutants (Gould, 2017);
This graph compares the emissions of three fossil fuels for the main air pollutants in 2015. Gas is the clear winner in each category particularly Sulfur Dioxide (SO2) and fine Particulate matter (PM2.5).
One area in particular where natural gas shows the greatest promise is the continued evolution of cogeneration or Combined Heat and Power (CHP). When combining a CHP system with absorption refrigeration systems, year round efficiency of the CHP can be dramatically increased. This is known as a trigeneration system or Combined Cooling, Heat and Power (CCHP) (Clarke Energy, n.d.);
Gould, T. (October 2017). Commentary: The environmental case for natural gas. Retrieved from https://www.iea.org/newsroom/news/2017/october/commentary-the-environmental-case-for-natural-gas.html
Natural gas explained. (December 2018). U.S. Energy Information Administration. Retrieved from https://www.eia.gov/energyexplained/index.php?page=natural_gas_home
Trigeneration/ CCHP. (n.d.). Clarke Energy. Retrieved from https://www.clarke-energy.com/gas-engines/trigeneration/