Fossil fuels such as oil, natural gas, and coal are examples of nonrenewable resources. Renewable resources are the opposite: Their supply replenishes naturally or can be sustained. The sunlight used in solar power and the wind used to power wind turbines replenish themselves.

Renewable resources are replenished naturally and over relatively short periods of time. The five major renewable energy resources are solar, wind, water (hydro), biomass, and geothermal.

In conventional natural gas deposits, the natural gas generally flows easily up through wells to the surface. In the United States and in a few other countries, natural gas is produced from shale and other types of sedimentary rock formations by forcing water, chemicals, and sand down a well under high pressure.

Nationally, fracking produces two-thirds (67 percent) of the natural gas in the United States, according to the US Energy Information Administration, and approximately 50 percent of the nation’s oil.

About 21% of the natural gas consumed in the United States during 2013 went to homes [1]. This gas is delivered to homes through pipelines or in tanks as CNG (compressed natural gas). Most of the natural gas consumed in homes is used for space heating and water heating.

Natural gas can be used in two different forms – CNG and LNG.

Compared to oil, natural gas is less expensive. The average natural gas bill in winter 2014 to 2015 was $642, and natural gas tends to be one of the least expensive fuel options overall. The efficiency of natural gas systems varies. The best quality systems are more than 90 percent efficient.