Of the fossil fuels, natural gas is considerably better than either oil or coal. This is because natural gas, CH4, is partly hydrogen which burns to form water rather than carbon dioxide. It produces about 70% of the CO2Carbon dioxide is a gas which is given off when carbon based materials such as fossil fuels (coal, oil, and natural gas) are burned. It is called a greenhouse gas because it works like the glazing of a greenhouse and causes global warming compared with oil. However it is still a major polluter and if supply networks are not well maintained and become leaky then methane is a potent greenhouse gas.
On the positive side
- is its ability to burn very cleanly (in terms of particulates), producing little sulphur dioxide and NOx. Also very little ash.
- It can be burnt very efficiently.
- Gas is very storable compared with electricity so it is more efficient at coping with short term variations in demand.
- There is also a considerable future potential for feeding renewable methane produced from land fill sites into the gas supply network and this could supply nearly half the domestic heating needs of the UK if a report from National Grid is to be believed. See this BBC article. (There is of course also the Ambridge scenario)
- There is also potential for the direct gasification of materials such as waste timber and household waste, a technique which has been almost ignored in the UK. See the report by Juniper Consulting
- Furthermore there is the possibility that hydrogen, maybe powered from renewables such as solar or wind, could be fed into a converted national gas supply network in the future.
For the self builder who is on the gas supply network there are a few points to consider.
- Gas requires no on-site storage so this saves on building costs compared with say burning wood.
- Gas boilers are relatively cheap to purchase and easy to install
- Maintenance contracts are reasonably economical
- Combination boilers maintain water pressure through the hot side of the system. This may be useful for showers on top floors (and removes the need for header tank space).
- The PassivhausSee more on the Passivhaus standard. The PassivHaus Institute has pioneered a standard for low energy buildings. It includes very low energy usage and ways of achieving this. The word is derived from the idea of buildings which are fundamentally low energy and passive solar heated rather than using extra gadgets to heat them. See Passivhaus for the UK branch of the organisation. design approach has not favoured gas heating. Rather it incorporates electric heating directly into the air supply.
- Co-generation, or CHP Combined heat and power - where the heat which is produced when electricity is generated is used within a heating system rather than wasted. This can happen at different levels - within a single house, a housing development, a town etc. , is a possibility with gas and although the internal and external combustion engine approach to this has been slow in taking off, the emerging fuel cell technology for achieving CHP is currently about to hit the market.
Building regulationsThese are the legal regulations which govern how a house is constructed. (not to be confused with Planning Permission which is about whether you are allowed to build the house at all or what it might look like) see Building Regulations)
see Gas Safe registered engineers