Customers buy the gas at this rate and then compress it at the customer's designated premises. The cost of each therm for the G-NVG2 rate varies each month. With the growing concern in the United States for improving air quality, alternative transportation fuels have received increased interest. Because of its emissions benefits and ample domestic supplies, natural gas is emerging as the alternative fuel of choice for our country. Everyone in the United States is familiar with the measurement of conventional liquid fuels like gasoline and diesel.
Fuel is dispensed and sold by the gallon, with no adjustments made for variable energy content.
For example, gasoline sold in many areas in California was traditionally oxygenated through the addition of alcohol-based fuels in winter months, providing better emissions performance in older vehicles. This oxygenated fuel had a lower energy value than the fuel sold in summer months. In 1997, California set a standard for oxygen content in gasoline sold throughout the state, year-round. According to the California Air Resources Board , this standard has also had the effect of standardizing the energy content of gasoline. Natural gas delivered by utilities is measured in standard cubic feet, a volumetric measurement, then converted by the utility into Therms, directly reflecting the amount of energy that was delivered.