Wednesday, 6 August 2008

Wasting energy

We have a classic example of the failure of government to act in a 'joined-up' way on climate change with the proposal to build a LNG-fired power plant at Pembroke, and probably another one on the other side of the Haven near Milford Haven.

Natural Gas is promoted as being a 'clean' fuel. It is certainly cleaner than say coal or oil, but burning it still produces massive amounts of Carbon Dioxide - about 6 million tonnes per year for each of the two stations. To put it in context, 6 million tonnes would be adding around 15% to Wales' annual CO2 emissions, at a time when we have governments in both Cardiff and London which claim to be committed to reducing emissions.

Worse than that, the type of power station proposed is extremely wasteful in the way the gas is burned. In fact, less than half of the energy content of the gas will be turned into electricity - the rest will just be wasted. Most of what will be lost will be lost as heat, probably dissipated into the Haven by use of water for cooling. FoE Pembrokeshire have calculated that the amount of heat wasted from two such power stations will be equivalent to around 80% of Wales' total electricity demand - a staggering waste of scarce energy resources – and roughly equivalent to the potential output from a barrage across the Severn.

Does it have to be this way? No, of course not. It would be possible to build a larger number (3-4) of smaller Combined Heat and Power stations. If some of these were sited closer to the Natural Gas terminals in the Haven, the 'waste heat' could be used to re-gassify LNG imports. Others could be sited in other locations where the heat could be used for other purposes. Using the waste heat in this way would increase the energy efficiency of the use of the gas from less than 50% to possibly 85%. Put simply, we could get twice as much useful energy out of the same volume of gas; and that would halve the CO2 emissions per unit of energy.

So why aren't we doing that? Simply because the government has abdicated its responsibility for energy policy. Since the Electricity and Gas industries were fragmented and privatised by the Tories, decisions on which power stations to build where are taken not in the interests of the overall energy needs of the country, nor on the basis of a plan for reducing our carbon footprint, but in the interests of the profits of the energy companies. If they can make more profit by building the most wasteful type of power station, then that is what they will do.

The underlying message here is that no government can ever achieve the changes which are needed in our patterns of energy generation and use as long as they leave the key decisions to individual companies competing with each other. We need a clear national strategy for energy, and the government must be prepared to enforce it. As long as Labour-Tory politicians simply welcome the construction of wasteful power stations because of the jobs they will bring, we are unlikely to get a sensible or coherent energy policy. And their commitment to action on climate change is shown to be a very shallow one.


Draig said...

The question is though - is THIS gas cleaner than, say, coal, which attracts so much ire from climate change protesters?

In the case of LNG, it has to be pumped out of the ground, liquefied, transported halfway across the world, and then piped to it's final destination. As you point out, FoE have already done good work highlighting the waste inherent in this process.

Compare this to coal, which we have, quite literally, under our feet. It can be used at the point of extraction, or transported minimal distances when compared to LNG. Clean coal technology, meanwhile, mitigates some of the damage damage caused from emissions. I don't know if any studies have been done to compare the two in this way.

Compared to LNG - is there a case to be made for coal?

ardibeltza said...

CHPs are far more efficient as you point out, but there's another problem in terms of efficiency - the amount of electricity lost in transportation along the National Grid.
CHPs should be sited close to energy needs, i.e. industry and homes, rather than remote locations in West Wales. Of course this would mean ugly power stations in S E England so it won't happen.

Draig's case is worth examining - if we're saying no to nuclear and the gas is running out, we have to get serious about energy conservation, renewables (offshore windfarms, solar, hydro, tidal lagoons, you name it) or we have to accept that there is a bridging need for coal.

Long-term, Wales has to go 100% renewable and start planning now for a post-oil economy. Our universities need to researching hydrogen technology for transport and energy use. It's possible if the political will is there.

John Dixon said...


I don't think that there's much doubt that, even after shipping LNG half way round the world and taking into account the liquefaction, regasification, and piping, burning LNG is still 'cleaner' than burning coal to achieve the same amount of useful energy. And coal doesn't just produce CO2 when burned; there are other gases as well.

However, paradoxically, the fact that the CO2 output from burning coal is higher than from burning methane actually makes it more viable for the application of CCS (Carbon Capture and Storage) solutions, because a given investment will have a greater impact on total carbon emissions. For that reason alone, it is worth considering the use of clean coal technology.

There are always caveats, however. My first is that CCS only deals with the CO2 emissions; as stated above, there are other by-products which also need to be dealt with. And my second is that, for all the hype, CCS technology is nowhere near as ready for implementation on a wide scale as some of its supporters claim. It is not yet a proven solution; so my assessment would be that research should continue, but we cannot depend on it yet.

One of my concerns about the whole energy debate is that too much attention is focussed on the supply side of the equation, and not enough on the demand side. We have to do more to reduce demand for energy by better energy conservation, more efficient use of energy, and changing patterns of energy usage. Emphasising the supply side - which is what the big players (and the government, much of the time) seem to be doing - carries the danger of encouraging people to believe that our profligate use of energy can continue unchecked because there will be a technological or engineering 'fix' for the problem. I believe that to be wholly unrealistic.


I agree that CHPs need to be sited close to energy needs. I agree that we need to get serious about energy conservation and renewables. And I agree that we have to be planning for a post-oil economy; although I think I'd extend that to 'post-hydrocarbon' economy.

Above all, we need a coherent plan for energy, and that means government taking much more of a lead than it has done to date.

Draig said...


It's true that there are other gases in the coal-burning process. The most notable of which is sulphur. That's why power stations like Aberthaw have been retrofitted to screen out most of the sulphur under the EU emissions directive. So CCS technology, as you say, is still relatively unproven, but other aspects of clean coal technology are proven, and in widespread use, including here in Wales.

It should also be noted that Methane gas is 20 times more potent as a greenhouse gas than CO2,and even the Stern report noted that Gas transmission and production was THE most carbon intensive sector of the economy today.

The final point I'd make revolves around who the gas is for. It needs to be borne in mind that what we have in Milford is geared towards English demand - hence the rationale behind piping it to Gloucester. If it WAS geared just towards Welsh demand, it would obviously be a lot smaller, and hence a lot less carbon intensive.

The fundamental question has to be asked - which is more carbon intensive; gas geared towards English demand, or coal geared towards Welsh demand? If coal demand is going to be ramped up again in Wales, then who is it going to be for, and what are we going to do to ensure that our interests here in Wales are served thereby?

John Dixon said...


The issue of 'who is the gas for' is a very relevant question when we look at the installations being built in Wales and the impact of them on us here in Wales.

But in terms of the dangers of climate change, siting them in England would merely have moved a part of the human carbon footprint from one country to another; it doesn't reduce it.

Clearly, if the natural resources of Wales are going to be exploited, we need to make sure that Wales derives maximum benefit, in a way which didn't happen in the past. But I remain far from convinced that we should be looking at ramping up the use of coal for electricity production at this stage.