Energy ≠ Electricity, Part 963

It's The Economist's turn to be hit repeatedly with a big stick on which we have painted the inequation: Energy ≠ Electricity.

Their leader, "How long till the lights go out?" is on an important subject and makes quite a lot of important and correct points. But it is underpinned by the usual myopia. They are concerned about fossil fuels as an input, but only about electricity as an output, as though that's what we mainly use our fossil fuels for.

So let's try once again:

  • Of the 154.9 million tonnes of oil equivalent (mtoe) total final consumption of energy in the UK in 2007, 29.4 mtoe (19.0%) was consumed as electricity.
  • Of the 235.8 mtoe of primary demand for energy (i.e. before conversion and supply to customers), 80.1 mtoe (34.0%) went to the production of electricity.
  • Of the 90.9 mtoe of primary demand for gas, 30.4 mtoe (33.4%) went to the production of electricity. Most of the rest went to the production of heat (for heating buildings or for industrial purposes).
  • Of the 84.4 mtoe of primary demand for oil, 0.7 mtoe (0.8%) went to the production of electricity.
  • Of the 29.4 mtoe of final consumption of energy in the form of electricity, 79.8 mtoe of primary energy was used in its production, of which 30.4 mtoe (38.1%) was gas, 33.8 mtoe (42.4%) was coal, 14.0 mtoe (17.5%) was nuclear, and 0.9 mtoe (1.1%) was renewable.
  • Of the 59.8 mtoe final consumption of energy for transport, 59.1 mtoe (98.8%) was oil, and 0.7 mtoe (1.2%) was electricity.
  • Of the 65.7 mtoe of other final energy consumption (besides transport and electricity), primarily heat, 50.4 mtoe (76.7%) used gas, 11.3 mtoe (17.2%) used oil, 1.7 mtoe (2.6%) used coal, and 2.2 mtoe (3.3%) was from other sources (heat supplied direct, converted fuels like LPG and coke, renewables, etc). Some of the electricity excluded from these figures was also used to produce heat.

From these figures, it isn't hard to work out that:

  1. Much more gas is used for heat than for electricity.
  2. Electricity has much more diverse sources of energy than heat or transport.
  3. Electricity has almost nothing to do with our dependence on imported oil.
  4. Electricity is nowhere near as important as heat to our dependence on imported gas.

And here's another simple calculation that we've pointed out before. Gas and biomass are the two fuels that are commonly used for producing both heat and electricity. To make the most of either of them, we would maximise efficiency through Combined Heat and Power where there is suitable demand for heat and electricity. But such opportunities are scarcer than would be ideal (at least until heat is treated equally to electricity and transport in government interventions). Failing that, we have to choose whether to use them to produce heat or electricity. At the moment, the incentives encourage the use of biomass for electricity and gas for heat. In modern equipment, the gas is converted to heat at around 90% efficiency, and the biomass is converted to electricity at around 15-30% efficiency (depending on scale). If we switch that, so the gas is producing electricity and the biomass is producing heat, the biomass will be converted to heat at around 90% efficiency and the gas will be converted to electricity at around 50-60% efficiency. For a given resource of the two fuels, you get far more bang for your buck using gas for electricity and biomass for heat, rather than vice versa.

That will help the storage issue too. The Economist rightly thinks we need to increase our storage capacity. We need storage particularly to cope with seasonally-variable demand, because the fossil fuels tend to be produced constantly, but some demand varies significantly over the year. And which demand is most seasonal? Heat, of course. Electricity varies too, but nowhere near as much. And transport varies in the opposite way (we do more of it in summer). Electricity and transport balance nicely against each other in terms of flattening out demand that varies according to time of day and time of year. But heat doesn't. Heat is needed mainly in winter. It's hard to store most forms of energy for 6 months. But gas is harder than most (though not as hard as electricity). It's a high-volume fuel relative to solid and liquid fuels, so you need either very large volumes of storage, or expensive and energy-intensive high-pressure storage. On the other hand, biomass is nature's way of storing energy. Wood will happily sit in a pile somewhere for 6 months. Just one more reason to use biomass to produce heat, and gas to produce electricity.

If we want to reduce our dependence on imported gas (and reduce our carbon emissions most efficiently), we will encourage the displacement of gas-fired heating by biomass-fired heating, and use some of the gas that is thereby released to produce electricity. So naturally our politicians think we should encourage exactly the opposite. Extending our gas network to encourage ever more houses to switch to gas is the name of their game.

Once more:

If the Russians turn off the taps again next winter, we don't have to worry about the lights going out, we have to worry about people freezing to death. Why do you think they do it in winter?

And if the Arabs close the spigots, very few homes will even notice, but we'll all be getting very familiar with our homes, because we won't be going anywhere.

If you want to deal with our increasing dependence on imports of oil and gas from unfriendly countries, give people incentives to cut their use of gas for heat and oil for transport. We need to get our electricity supplies sorted too, but to focus on that to the exclusion of the other two more-vulnerable uses is blinkered to the point of blindness.