Natural gas is the world’s third biggest energy source after oil and coal. Natural gas is a fossil fuel that emits lower contents of environmentally harmful substances during combustion than oil, but it is a finite source, just like oil.
Natural gas is currently a heating alternative only for those who live along the natural gas pipelines in southern Sweden.
Natural gas is a fossil fuel that was formed over several hundred million years. Energy gases also include biogas that is formed continually when an organic material decomposes in an oxygen-free environment, such as in landfill sites and sewage treatment plants. Unlike fossil gases, biogas is renewable.
A network of town gas is also available in the three biggest Swedish cities. Town gas is produced by cracking light petroleum. In Stockholm, town gas is distributed in the town gas network, but in Gothenburg and Malmö, it is natural gas that is mixed with air so that it is similar to the town gas distributed in a town gas network.
Demands a network of pipes
In Sweden, natural gas is distributed along a main pipeline between Malmö and Gothenburg. The gas is imported from Denmark and accounts for 2 percent of Sweden’s energy supply, although the percentage is much higher in municipalities in which gas is available. The spread of gas as a source of energy is principally dependent on decisions to extend the pipe network.
More environmentally friendly than oil - worse than pellets
When natural gas is burned, its negative effect on the environment is lower than that of oil. The carbon dioxide emissions from a natural gas-fired domestic boiler are 25 – 50 percent lower than from an oil-fired domestic boiler. Compared with pellet firing, natural gas is a poorer alternative as regards greenhouse gas emissions, since it is a fossil fuel. However, the emissions of sulphur from gas firing are negligible and the nitrogen dioxide emissions are just over half of those from oil firing.
Boiler and burner
Gas can be fired in an existing oil-fired boiler, although the boiler must be fitted with a special gas burner. The efficiency is affected to some extent by the design and condition of the boiler. A modern gas-fired boiler has an efficiency of around 90 percent, which is somewhat higher than that of an oil-fired boiler, since soot formation is lower and the flue gas temperature can be kept lower, and the need for oil vaporization before combustion is eliminated.
Biogas in farms
Biogas production based principally on livestock droppings may be employed in livestock farms. Heating may then be a simple and inexpensive way of using the biogas. The design and performance of a biogas-fired boiler is exactly the same as that of a boiler for solid or liquid fuels. The difference is that the burner is specially designed for gas.
A problem associated with generating heat from biogas is that the heat demand varies over the year, but the biogas production does not. Gas consumption is therefore irregular and the biogas needs to be stored, which may be costly.
Natural gas prices have increased substantially. The price per kWh has more than doubled between 2000 and 2006.
The natural gas market was deregulated in July 2007. This means that you as a customer can choose any gas supplier, just as you can today on the electricity market.
Advantages and disadvantages
+ the fuel cost may be lower than that of oil or electricity
+ high efficiency
+ low work input
+ lower emissions of environmentally harmful substances than oil
- available only to certain houses in southern-western Sweden
- is a fossil fuel and is thus not renewable