One of the major news stories in Scottish energy policy in recent weeks was the announcement that the 2.4 GW coal fired power station at Longannet would be shutdown next year. Longannet is Scotland’s largest thermal power station and thus largest source of carbon emissions, so on the one hand this is good news. It may be stating the obvious, but if we want to cut carbon emissions that means shutting down fossil fuel plants, particularly those still running on coal. And obviously it is another indicator of the growing strength of renewables in Scotland, with 49.5% of Scottish electricity now coming from renewables. However, as I will discuss it also reveals a number of worrying factors and a lack of joined up thinking.
Obviously one of the issues with renewables such as wind and solar is that they are variable and aren’t necessarily on all the time. Admittedly opponents of renewables can use this as something of a red herring. Largely because they seem to assume that wind and solar power advocates are some sort of sun worshipping hippies, praying before stone circles in the hope of good winds and light cloud. They seem to be unfamiliar with this thing called “weather forecasts” which can tell you days (if not weeks) in advance whether or not it will be windy or sunny, allowing measures to be taken to ensure there’s enough power on the grid.
Take the recent solar eclipse in Scotland which led to much silliness about “how will renewables like solar cope?”…hmmm perhaps because we can predict an eclipse like a couple of decades (if not centuries!) in advance? The only people for whom this is actually an issue are those who don’t trust this thing called “science”, although admittedly this is part of the problem.
But suffice to say, you need something in place to back up such energy sources when the wind drops, particularly in winter. Longer term there are various ideas, such as upgrading Scotland’s dams to perform more pumped storage. Portugal recently demonstrated that it was capable of producing 70% of its electricity from a combination of wind, hydro and pumped storage. Development of more advanced forms of energy storage (hydrogen from wind, advanced battery storage, Liquid Air Energy Storage) would also help. As would the increased use of biomass and CHP systems (as I’ll discuss in a minute) and a host of other ideas.
Its also worth remembering that not all renewable energy systems are as variable as wind. Tidal energy, hydro, CSP (Concentrating Solar Power) or blue sky ideas such as airborne wind turbines all offer much greater capacity factors and reliability. But certainly in the short to medium term, some fossil fuel based power capacity needs to be kept on the grid to provide the necessary load capacity, until these other options are fully developed. The problem has been however that many of these alternatives haven’t really materialised.
Because its not as if there haven’t been efforts to keep Longannet open. One short term quick fix that gets banded around is carbon capture and storage (CCS). Longannet was originally selected as the likely site for the first of these projects in the UK. However this fell through, largely for practical and economic reasons. In order for CCS to work you need to either separate the oxygen from the air and burn fuel in pure oxygen, or separate the hydrogen and hydrocarbon content from the rest of the fuel. Failure to do this will result in large quantities of other combustion products, mostly composed of nitrogen, which will greatly increase the volume of gas you need to get rid of.
The problem is that such separation policy is difficult to implement with a plant as old as Longannet, unless you’re prepared to spend a lot of money upgrading it, which wasn’t the case. Furthermore, since we’re discussing back up of renewables, I’d also throw in the point that an ageing coal plant designed for baseload power is not the best type of energy plant to be doing this sort of job. Tying it up to a CCS system would only make the problem worse. In truth, this CCS plan was only ever going to work if the knocked the Longannet down and built a new power station on the same site.
Alternatively, there’s been the idea of burning biomass instead and operating large thermal plants on a dual fuel load. However, this again requires a high level of system efficiency. And one has to be careful where the biomass is sourced. Otherwise you could well find you’re simply moving emissions from the chimney to the production and transport of the biomass. Plus if trees aren’t regrown quicker than they are consumed, then it ain’t really a renewable source.
Combustion of waste is another idea. About 2.5 millions of tons of household waste is generated in the central belt of Scotland each year, of which only 42% is recycled. Thus large quantities still find their way into landfill. Burning it for fuel is certainly preferable to burial, particularly from a carbon footprinting point of view (otherwise it rots and produces methane).
But again, if one wishes to control emissions, then the plant in question needs to meet the appropriate standards (i.e. expensive upgrade, if not a brand new power station). Furthermore there is a lot of opposition to incinerators, everyone seems to think they are a good idea if built in someone else’s back garden. However, if say 50% of the 55% of waste in Scotland that is currently sent to landfill were instead burnt at an average calorific value of 11-16 MJ/kg, this would imply that you could meet about a third of Longannet’s fuel needs for a year (assuming a capacity factor of 40%, which would be normal for a peak load power station).
So the real reason why Longannet is closing is more because these various policies have failed than because of any deliberate attempt to cut back on carbon emissions. Faced with an ageing plant that seems to have no real purpose, Scottish power seem to have finally decided enough is enough, its time to turn off the life support. Which is somewhat more worrying.
And again, its not as if we’re short of options to replace Longannet and other large thermal power stations. To return to the issue of CHP. Scotland is an ideal location for CHP, given that we have a relatively long heating season (my boilers been on some sort of a cycle since October and only got turned off that cycle a few days ago). In many other Northern European countries CHP can represent +70% of heat generation and +40% of all electricity generating capacity, yet the figure in Scotland its under 5% of electrical capacity and only 4.1% of heat is coming from renewable sources (CHP, biomass, GSHP’s and solar thermal).
Such schemes could be applied to large facilities (such as Longannet). Or better still lots of medium to micro-scale CHP units could be used to eliminate the need for large thermal power stations. The fact that the time the UK grid is most vulnerable to shortages (in winter) happens to be the very time the CHP units will be running, makes for a useful match between CHP heat generation and electrical needs.
However CHP requires careful long term planning to implement, as the capital costs are high, even thought the long term fuel and energy savings can pay for themselves over the lifetime of the plant. But, as it was pointed out to me once by someone in the industry the vast majority of boiler replacements are “distressed purchases”, i.e. its winter, the boiler has broken down, you need a new one pronto and don’t have time for long term planning. Hence, without sufficient support for CHP from government (a situation not helped by energy related decisions being taken down south rather than in Scotland) such schemes haven’t been pursued with the vigor and urgency needed.
And before anyone brings up nuclear, by the time Hinkley C comes online (or perhaps I should say if) in the mid 2020’s (if we’re lucky!), the UK will have shut down all but 1 of its historical fleet of 19 reactors. Replacing 18 reactors with 2, neither of which will be in Scotland, (which will be nuclear free from about 2023 at current estimates), is hardly favourable. Indeed it means that most of the growth in renewable capacity in the UK in recent years has been devoted to replacing lost nuclear capacity, rather than reducing the number of fossil fuel plants.
But it is the nature of the half assed measures proposed to replace Longannet, despite the fact that there are plenty of other sensible options (as discussed), that has me worried. At one point there was talk of using temporary power barges moored in the Firth of Forth instead of a fixed power station. Obviously such measures are only taken if you’re desperate for power, as its not a long term solution and works out as both inefficient and expensive.
However, a lack of joined up thinking means nobody is willing to put up the money to build any permanent power stations in the UK. This is largely due to failures in the privatisation of the UK energy industry which has seen several defacto monopolies created, with no real incentive for them to build power stations, as they have nothing to loose if capacity levels fall and electricity prices rise…..indeed they have a perverse financial incentive to create an artificial shortage (anyone remember ENRON’s in California?).
The situation is starting to resemble the mess otherwise known as the British railways. Privatisation of these has resulted in a situation where the UK government now spends five times more subsidising the UK railways than it did under a nationally owned system, despite a massive inflation in ticket prices, which have nearly tripled. This is largely because the UK private train companies have been granted a defacto monopoly in their area, they have lots of commuters who depend on the train to get to work and the train companies know they can charge the most ridiculous fees and commuters will pay them, with some now paying over £5,000 a year just to get into and home from work.
With no incentive to compete, nor to build new infrastructure, they’ve been literally running the UK’s railway network into the ground. The UK railway system is now so antiquated that many lines still use manual signal boxes, with someone having to manually switch train signals (most European lines have been electronically operated for some time). Consequently the UK government, realising that the rail companies aren’t going to do anything, have been forced to step and commit an estimated £40 billion to build a new high speed line to relieve capacity on the overstretched West Coast line.
Similarly the energy companies are basically running down the UK’s energy infrastructure into the ground, no doubt confident that the government will have no choice but to bail them out when the inevitable happens and there’s power cuts. About the only capacity they are growing is renewables, in part due to subsidies, but mostly due to the fact that they see them as a hedge against future spikes in gas prices.
Certainly, there has been significant growth in the renewables, particularly wind. And the message seems to be that older coal plants can’t compete with wind in Scotland, which is certainly good news. However we still face a lack of joined up thinking, something that needs to be resolved. This isn’t to say we’ve too much wind on the grid, its how the wind power is being used that’s important. Its also important that we recognise the failure of the Thatcher era policy of privatisation.