Natural Gas 101  

What is Natural Gas?

Natural gas is an energy fuel that provides heat. It is difficult to envision what this energy commodity is since we can’t see or touch it but is typically used in most homes for heating and / or cooking. Natural gas can be stored, is often transported underground through pipelines, and is easily burned. It is usually found beneath the surface of the earth and ENSTAR currently receives 100 percent of its natural gas from producers here in the Cook Inlet.

A complex process exists in order for you to be able to turn on your gas heater, your gas grill, or any other appliance fueled by natural gas. There are several participants in Alaska’s market today including:


Producer – Any entity owning, controlling, managing, or leasing natural gas here in Cook Inlet.

Transporter – Any party that has the ability to move or provide the service of transporting natural gas. These typically include pipeline companies, gathering companies, and local distribution companies (ENSTAR). ENSTAR takes ownership of the natural gas at certain receiving points along the natural gas transmission system.  These receipt points are different depending on the contract and producer selling the gas. Those receipt points are the location where gas changes ownership from one party to another.

End-user – The ultimate consumer of the natural gas. This is you, the customer!

The Origin of Natural Gas

When we refer to the word "gas," our present-day use of the word is often confusing. Gas is one of the three states of matter, as opposed to solids and liquids. While we often use the word "gas" to refer to gasoline, our vehicular fuel, this is technically incorrect because gasoline is a liquid and not a gas.

When the gas industry uses the word "gas," it can also be confusing because members of the American Gas Association generally mean either natural gas, which is truly in a gaseous state, or propane gas, which is also known as liquid petroleum gas.

Natural gas is lighter than air, colorless, odorless and tasteless. For this reason, odorant is added to the gas to make it noticeable and objectionable for safety reasons. Natural gas can be compressed and, therefore, transmitted in large quantities through relatively small pipe diameters when under high pressure.

Natural gas is primarily composed of methane, although also present are other chemicals such as propane, butane, isobutane, pentane and heptane.

Important Properties of Natural Gas:

  • Flammability range 5% to 15%
  • No color, odor or taste
  • Mercaptan is added for odor
  • Non-toxic
  • Burns with a blue flame
  • Liquefies at - 260 °F
  • Heating Value 800 to 1200 BTU's per cubic foot


BTU - British Thermal Unit, a measure of heat energy, it represents the amount of heat necessary to raise one pound of water one degree Fahrenheit at sea level.

CFH - Cubic foot an hour

Therm - One therm is equal to 100,000 BTUs or 100 CF (Cubic Feet) = 0.1 MCF

CCF - Natural gas is measured by volume. One CCF means one hundred cubic feet of natural gas.

MCF - Another volume measure, one MCF means one thousand cubic feet of natural gas.

Customer charge - A monthly charge that recovers a portion of customer related costs that do not vary with the amount of gas you use. Examples of these costs include meter reading, record-keeping, billing, collections and costs associated with the service line and meter used to serve you.

Base rate - Recovers operating expenses and investment in physical plant.

Gas Cost Adjustment (GCA) - Recovers the cost ENSTAR pays to purchase gas. This rate is adjusted at least annually.

Gas Supply Agreement approval charge (GSA) - Recovers costs of obtaining regulatory approval of gas supply contracts.

Regulatory cost charge (RCC) - A charge provided for by Alaska Statute to fund the Regulatory Commission of Alaska.