
Image shows capped Victorian gas light wall fitting next to a modern electric standard lamp. | Gas fuels are, and will continue to be, important in global energy, despite the projected exponential rise in renewable electricity generation from solar and wind power. Natural Gas has a far lower carbon dioxide emissions profile than coal or oil, and is providing increasing amounts of heat, light and power to industrialised countries. Gas may be regarded as competition to renewable energy, but in fact, gas of different kinds will be an enabler of the renewable energy future, filling in the sawtooth gaps in variable renewable electricity generation, and providing essential transport fuels. |
Traditional methods of producing energy gas include mining and pumping the Earth’s fossil fuel resources. The good quality, easily accessible gas is coming to an end, and so-called “unconventional” sources are beginning to be exploited – gas locked in dense sediment and strata, in shales, coal seams and deepwater seabeds. To make energy takes energy, and unconventional gas fuels are becoming more costly to produce. Since the expense of going after poorer density, more inaccessible resources could become prohibitive, exploitation of gas from under the ground will most likely gradually be usurped by methods of making gas fuels above ground. These will need to be from sustainable resources, and so lighter-than-air fuels of the future will be Renewable Gas.
To dig deeper into how important gas is, here’s a little data disclosure on my personal home energy consumption, leaving out food, goods and transport – much of which is virtually Zero Carbon :-
May 2012 Household Domestic Utility Energy Consumption
Natural Gas 137.3 kWh
Electricity 54.0 kWh
Water 5.2 kWh (estimate for 2.4 m3 water from Thames Water)
May 2012 Household Domestic Utility Energy Production
Electricity 293.2 kWh (home photovoltaic generation)
Biomethane 1.8 kWh (estimate for 2.4 m3 sewage digested by Thames Water)
For the first time since having the solar electricity panels fitted, my house has become a net energy producer. The house was already producing more electricity than it used in March 2012, but the thing that kept it a net energy consumer was Natural Gas consumption – mostly used for space heating.
The house used less than half the Natural Gas in March than it did in February or January, but the solar power generated was much less then than it is now – owing to the season – and so did not overtake gas demand. Hopefully now, the house will remain a net energy producer until November.
Two things can be drawn from looking at all the data – first that energy consumption swings can be significant from season to season – and secondly that Natural Gas use is by far the largest part of energy consumption for most of the year. In fact, Natural Gas use is an order of magnitude larger than electricity in winter, even when some of the localised space heating is electrical.
I have taken measures to reduce my space heating needs, such as only using the gas central heating when critical, and keeping the thermostat at 17 degrees C when it’s on, and installing various kinds of insulation and draught exclusion. Thermal adjustment of the home is an ongoing process of improvement, but despite all my efforts, gas use is still ten times higher in the cold months than all the power consumption. On the other hand, in the warm months, I sometimes use less gas energy than electricity.
I aim to change some of the home gas appliances to electrical power, in order to further reduce my dependence on gas. However, even though I have a green electricity account, some of my power will still be coming from gas-fired power stations. Plus, it could be argued that my burning gas to heat water is more efficient than using electricity, because of the losses of conversion in the power supply grid system. Heating by electricity is almost certainly less efficient – which is why I must continue to insulate my home further. Of note, my domestic production of energy will not ever match winter consumption without utilising a new resource, as solar insolation is at its ebb then, and so moving away from gas to power will perhaps take me farther away from an overall balance between energy supply and demand.
Until the United Kingdom is powered entirely by green electricity and given comfort by insulation and green heating and cooling, we will continue to be dependent on gas fuels, not just because of the variable nature of renewable energy, which gas backs up, but because it will take time to convert everything that can be converted from gas to power. This is especially important in the field of transport, where the first conversion will need to be from oil-refined fuels to gas-refined fuels as a first stage – as replacing all the vehicles with electric drive models will take a gargantuan effort, and much economic turnover.
The importance of gas fuels in the next few decades during the green energy transition means that it is worthwhile to develop sustainable Renewable Gas supplies, particularly considering that once developed they can continue to be of use long into the future. |