Not very big news – three FSADs equal one FGW. (It’s about fracking, by the way).


Also while we’re on the subject of Shale gas and today’s hoo-ha, it’s probably worth disinterring and updating the piece I produced on shale gas and biogas some time ago (here).

What I said in that piece was that it might be worth comparing and contrasting what you might get out of a farm size anaerobic digester by way of useable biogas (with just a little bit of cleaning up you can inject biogas into the grid, use it to produce electricity or as a fuel for vehicles) and what you might get out of the lifetime of a drilled and fracked gas well (same provisions, same use).

The two methods of producing gas can be summarised thus:

Biogas                                                                                                   Fracked gas

Costs about  £2 million to build a farm plant Costs £6-10 million to drill a well
Needs lots of cow poo etc. Needs 6 million gallons of water to frack
Lasts as long as cows keep on producing Lasts about seven years
Emits about 11g CO2 per kwh of electricity produced Emits about 400g per kwh of  electricity produced
Doesn’t look that great at the end of your road Doesn’t look that great at the end of your road
Can be used to store hay if you don’t produce Needs to be capped and made safe when exhausted
Good for energy security Good for energy security


Well I was a bit wrong in my estimates on the relationship between farm sized AD plants (FSAD) and fracked gas wells (FGW).  My original projection was that the output over 20 years of four FSADs would equal the output of one FGW.  Not a bad comparison – about the same overall price range and much cleaner gas. However, looking at some of the detailed literature on the results of fracked well lives over a period from the US (e.g.  Arthur Berman 2009) I was a bit out. Berman suggests that the average life of horizontal wells is far less than initially suggested by promoters – in fact about 7.5 years, during which time an average well in Barnett shale will produce  about 0.81 billion cubic feet, which translates as about 22.6 million cubic metres of gas.

A farm AD plant, on the other hand will produce about 6.2 million cubic metres of gas over a 20 year period.  True, you can drill another well after 7.5 year if we want to make strictly fair comparisons, but that does double your cost.

So, here’s the metric:   three farm sized AD plants at the bottom of three lanes give you slightly under the likely production of one fracked well at the end of one lane.  I’m not sure the residents of the respective lanes would really take to either, but at least with the AD plants they would be able to rest in the knowledge that they would be contributing to low carbon energy, rather than participating in forcing a lot more high carbon energy out of the ground.  Oh, and some of the farmers and their families down the lane might keep the income from the digesters  instead of having to be sweetened up to allow someone else to walk off with it.

Of course, though, there won’t be any development and production allowances to assist with the development of farm AD, because, well, it’s just not strategic or exciting is it?  So I guess the cows will go on doing what they do and the frackers what they do. Shame really.

Exclusive: (not the) Gas Strategy Revealed

The Government is about to publish a ‘Gas Strategy’ alongside the imminent Energy Bill. In that strategy, if reports are to be believed and if the pact between Treasury and DECC is followed through, we will hear a lot about unabated gas, gas hubs, gas into the 2030s, shale gas and so on. I doubt somehow, that we will hear much about a strategy for the development of ‘green gas’ which, estimates suggest, could support as much gas into our grids over the next twenty years as the much vaunted ‘shale gas revolution’ that may well feature in the gas strategy in the form of a green light for fracking.

So in case you don’t,  here’s a brief note on at least a component of what an alternative gas strategy might look like.  The key points of the strategy go something like this:

  1. Support the rapid expansion of Anaerobic Digestion plants of all sizes (the plant pictured above is sited on a large dairy farm) able to produce biogas from an input of animal, food and plant waste
  2. Inject the proceeds into the gas grid (or produce road fuel for large trucks)
  3. Save thousands of tons of CO2 emissions  (the biogas comes in at about net 11g CO2 per kwh  compared with a minimum of about 400g for shale gas)
  4. Replace fracked gas or imported liquid natural gas with a locally produced secure supply
  5. Er, that’s it.

I think that stands up quite well as a strategy, don’t you think? And it gets a bit better when you compare it with proposals now under way to drill and ‘frack’ for relatively high carbon mineral gas.

There is something of a co-incidence here, in that the claims for anaerobic digestion and shale gas in the UK are not that far apart.  Utilising much of the UKs biodegradable waste for AD they could supply about 10% of the country’s domestic gas requirements; utilising most of the recoverable shale gas could supply, subject to depletion, about 10% of the UKs overall gas requirement.  But compare, for a moment, the economics of the two methods of putting that gas into the grid, setting aside all the other issues about carbon, etc.

One shale gas well costs between £6 -10 million to drill and frack (Cuadrilla’s test plant near Blackpool is costing about £10 million). It is difficult to assess total output of gas, but the average well in Texas at the moment is producing about 2 million cubic meters of gas per year, with much of it depleting fast as drilled wells tend to do after about five years of production.

One large farm size Anaerobic Digestion plant costs about £2million to build (the BV dairy plant  pictured cost £2.3 million) and then provides a steady stream of gas from then onwards, varying only to the extent that cows stop producing manure or people stop eating food. The first plant currently operational and injecting gas into the grid (the Poundbury plant in Dorchester produced about 850 cu mtrs of gas in a day in November, which grossed up over a year, represents a bit more gas produced over a period than the average shale gas well.

Oh, and by the way, you have to factor in the by-products.  A shale gas well will consume between two and seven million gallons of water and around five thousand gallons of chemicals per frack,  much of which (the ‘flowback’  water) has to be treated and adds to the cost of the well drill. An AD plant produces varying amounts of digestate, depending on its size, which has to be disposed of by, er, spreading on land as a soil improver at a cost of….nothing, and some water, which goes back into water courses.

So I think we can come to the somewhat startling conclusion that it might well be a better long term business proposition for Cuadrilla, if they wish to invest in gas in Britain, to fund and build four AD plants rather than drill a large hole near Blackpool. And it certainly would get the alternative gas strategy seriously under way. Somehow though I don’t think it will happen: not immediately, anyway.

Another modest proposal……

Littlebrook power station in Kent. Could there be a bigger role for it in the future energy market?

Some more on Electricity Market Reform, I’m afraid. Well, it is connected, but I guess it comes more under the ‘why, oh why hasn’t someone done this’ heading. I hope someone might be able to explain to me why it can’t be done.

Bear in mind that Ofgem are now telling us that the total cost of re-equipping energy networks for future low carbon production will come to the order of £200 billion by the early 2020s, and that it will be very difficult to see where £90 billion of that will come from, after the investment capitalization of the main companies that are likely to contribute is taken into account (see the Buchanan evidence 18th Jan DECC select committee).  Also bear in mind that the  Electricity Market Reform  proposals (ah, there they are….) currently envisage a capacity payment regime to secure capacity ready to  put power onto the grid, rather than rely just on the half-hour bidding system to underpin marginal power supply as is the case at present.  The main reason for this is, of course, the concern that, as the UKs capacity portfolio become more populated by renewables, and in particular by wind, there will need to be a greater degree of capacity in the system to back up the inherent variability of a large part of it.

So capacity payments (or at least some of them) will be paying for energy companies to build new plants which will, pretty much from the word go, be standing idle most of the time, awaiting the call to generate and back the system up, unless and until we have mastered storage, demand management and interconnection to the extent that they won’t be needed.  This new capacity will be needed also because large amounts of existing capacity, some of which presently performs the task of standing around waiting to generate will be closed under European Emissions Directives by 2016.

You might think, then, that strenuous efforts would be under way to get additional life out of plants that are already in existence to provide for future stand-by: but you’d be wrong. Plants will close: new plants costing perhaps £3 billion will be built to replace them.

A prime example of plants that will close but conceivably could be reused is provided by the five oil-fired, 1GW plus power stations presently providing a few hours a year of supply at the top of demand peaks. They are not, between them particularly old, and, since they have not been run very hard during their existence, they are like the fabled Austin A35 found in the garage of a little old lady  who brought it forty years ago and has only used it to drive to church on Sunday ever since.  They are also equipped with ‘black start’ facilities which enable them to provide power for the grid almost instantaneously, unlike most other supply.

Keeping them performing this useful standby role into the 2020s would, obviously save a lot of new investment in new plants – perhaps £15 billion out of the £90bn Alistair Buchanan worries about. But, you will say, they’re oil-fired; terrible for Carbon emissions; just as well they’re being closed (what not to say: ‘keep the oilers burning!’ as a witness expostulated in front of Select Committee the other week).

Setting aside the argument that, since they’re running only a few hours a year their emissions wouldn’t be serious, (because they would,  and could be used more extensively, as was coal during the very cold period of a few years ago)  they certainly could be refurbished and given much longer life burning  biofuel. I believe they could run on biogas, but certainly could on biodiesel. Indeed there have been some experiments in alternative fuel burn conducted recently at Littlebrook D power station, in Kent.  Clearly there isn’t enough biodiesel or biogas to go around for a full on programme of power production, but there certainly could be an adequate supply for the production of  a few hours power a year as is provided at present.

Despite the fuel trials, I gather that Littlebrook, along with the others, are still scheduled to close in 2016. That seems quite perverse in view of the imperatives that are now ahead of us. Perhaps capacity payment arrangements should include a ‘refurbishment’ element, to allow cheaper stand-by plants like Littlebrook, Fawley and elsewhere to remain standing whilst bringing new clean fuel. That makes sense to me. Is there a good reason why it can’t be done?