Environmental issues
Natural gas is the environmentally friendly fuel. Of all the fossil fuels available, natural gas creates the least greenhouse gas emissions and so contributes to the improvement of New Zealand’s energy efficiency.
It is highly flammable, burns almost completely and is considered a clean fuel as it does not produce any ash, dust or smoke. When natural gas burns efficiently in the air it produces energy, water and carbon dioxide.
Environmental concerns are also addressed in the design of modern gas appliances which feature sophisticated burner systems. These produce fewer emissions and are more energy efficient, often 80 – 90 percent more, than their electrical equivalent. Typically, new heaters have economy settings and thermostats that save energy consumption without affecting the heat output.
Efficiencies through direct use
Natural gas is nearly three times more efficient when used as a direct fuel rather than as a source of fuel to generate electricity. This is because electricity generation plants generally operate at as little as 28 percent of their available efficiency, therefore wasting much of the energy available in gas.
An example of the efficiency of using gas as a direct energy source is the difference in gas consumption to boil water using an electric kettle compared to a kettle on a gas hob. The electric kettle uses 2.8 times more gas than a kettle boiled using a gas hob, as illustrated in the diagram below.
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