Transcript Jan 2008
Gareth Mitchell: From the World’s fifth best university, this is the official podcast of Imperial College London. And I’m Gareth Mitchell. Happy New Year and welcome to the January podcast. And we have a special edition for you today. On the back of last month’s climate change conference in Bali, thoughts on this podcast turn to a technology that might help reduce the environmental footprint of power stations. It’s based on a bamboo like plant called miscanthus, or more commonly elephant grass. Could it be an alternative to CO2 emitting coal or gas as a fuel for power stations? Amid increasing interest in so called energy crops science media production MSc student Neil Strawson set out to investigate whether they really can help power a new greener economy. And here’s his special report.
Neil Strawson: The need for a sustainable carbon neutral power source has never been greater. Currently just 4.7 per cent of our energy is generated from renewable sources. The government plans to increase this figure to 10 per cent by 2010. But a recently leaked dossier suggests that we’ll be lucky to reach 5 per cent by 2020. Nearly 75 per cent of our energy comes from fossil fuels like coal and gas. Other EU countries like Germany and France have more than doubled the UK figure on renewables while for Sweden, they make up more than half. The majority of energy generated from renewables in the UK comes from burning landfill gas and waste but a third comes from biomass. Put quite simply, biomass energy is burning anything that comes from a biological source whether it be plant or animal. But what’s so novel about that? People have been burning wood and other plant material for heating and cooking ever since humans discovered fire. In modern terms we mean using so called energy crops for powering vehicles or, as we report in this programme, firing power stations at present highly dependent on greenhouse gas emitting fossil fuels. Biomass can be in either liquid or solid form. Dr Frank Rosillo-Calle is a research fellow specialising in biomass energy at Imperial College London.
Frank Rosillo-Calle: Well, biomass is a very broad area. I mean, biomass, you talk about two different types of biomass. You talk about solid biomass which is normally crops. And then you’ve got the liquid biomass which is actually bio-diesel, bio-ethanol. So you have very different types of biomass and also many applications. The motor biomass, which is basically either using combustion plants or to use as a liquid biofuel as ethanol on a large scale, as is the case with Brazil. Also you use bio-diesel which is used [ ]. It’s also biomass because it’s all organic matter.
NS: Liquid biomass is widely used in countries such as Brazil and the USA for ethanol and diesel production. But here in the UK there’s been a big focus on using solid biomass as a fuel source for generating electricity. Advocates of biomass hope that it will play a significant role in helping the UK play catch up when it comes to renewable energy. Like any fuel, it gives off CO2 when it’s burnt but that’s just the carbon dioxide it soaked up when it was grown in the first place. So compared to burning fossil fuels it’s practically carbon neutral. What’s needed then is a crop that’s easy to plant and maintain, grows quickly in large volumes giving plenty of mass to burn and doesn’t disrupt the ecology of the regions where it grows. Here in the Lincolnshire countryside I’m trudging towards a field full of a crop called elephant grass, also known as miscanthus. But could this tropical grass be the ideal energy crop? Just to give you an indication of what this crop actually looks like. I’m stood in front of one now and it’s really quite tall. There are some younger ones that are about as tall as I am, and I’m six foot two. But then generally there’s a lot of them just completely and utterly towering over me. They’re mainly consisted of a stem that feels almost like bamboo. It’s quite firm. And that then shoots up from the ground. There seems to be very little foliage actually near the ground but as you get close to the top, to the canopy, it’s a mass of green long leaves. Almost like little whips if you actually walk through them.
Rudy Humphries: It’s grass. The upshot of it is it’s a grass. It’s a cereal crop. It’s not some strange variety of new crop that we’ve previously not encountered. It’s just a grass.
NS: Rudy Humphries, Biomass Officer with the Forestry Commission, is viewing this field of miscanthus with me. We’re at Fowler Farms, one of the sites in the UK where farmers are trying the crop out.
RH: It’s very similar to the grasses that you buy in garden centres and things that people grow in their gardens. You know, you can buy Miscanthus Giganticus in garden centres and grow it as an ornamental grass. In terms of the production it will make 15 feet in a really good yielding ground. You cut that every year. You should get somewhere between 10 and 15, maybe 18, tonnes a hectare of dry material to take away to be burnt. It is a grass but it’s just 15 feet tall, on good land anyway.
NS: But there are plenty of plants that grow in large volumes and could surely fit the bill as energy crops so why does miscanthus stand out?
RH: Miscanthus has probably benefits over some of the energy crops in that a farmer who is used to growing cereals, it’s a cereal based crop, he can use pretty much his own machinery. He can harvest it with a forage harvester, which he would have for sugar beet production. He can handle the crop with a teleporter, which he would have for handling bails. He can use a Heston Bailer, which he would have for bailing cereal crops. So there’s a familiarity which means the farmers can do it. It’s an annual crop which means there’s an annual income for the farmer much the same as growing cereals. It also has benefits in that power stations and things that are using the fuel are surrounded by agricultural land. So it can be produced here in the UK, grown as a crop; harvested here and shipped direct to the power source. It’s locally provided. It provides a link, if you like, between the agricultural community and the power producing community that the land surrounds. So it has several benefits. It’s essentially half the calorific value to coal so it has the ideal benefit of two tonnes of miscanthus is a tonne of coal. So it gives a relatively high proportion of calorific value available to use as a fuel source.
NS: In 1992 the Integrated Administration and Control System, also known as IACS, was introduced as a result of a reform in the EU Common Agricultural Policy. The IACS forced farmers to leave a certain percentage of their land out of food production. But Ambrose Fowler, the owner here at Fowler Farms, sees this set aside land as an opportunity to generate a little extra revenue through growing energy crops, like a species called short rotation coppice and more recently miscanthus.
Ambrose Fowler: When the IACS regulations were first brought in we recognised that we had sufficient area on our land to permanently set aside the required 10 per cent, as it was then, and so we thought if we’re going to permanently set this land aside why not try and generate a small income from it as well? Which is what led us to first go into short rotation coppice as an energy crop, which you were then allowed to grow on set aside land. The miscanthus particularly is an interesting crop in that once it’s established that’s it. Well, you don’t fertilise it or spray it or anything. The same with the coppice actually. Once they’re estab lished that’s it. You just let them get on with growing and they regenerate themselves. The leaf fall from the miscanthus acts as a sort of compost, if you like, for the next year’s crop. So they are self generating. And environment ally what could be better than that?
NS: Ambrose Fowler has a tall healthy crop but just down the road Jonathon Hall, another farmer in the area, has had mixed experiences with the grass.
Jonathan Hall: Probably two-thirds of the crop has been fine and it’s been well established and got away well. Other areas have been slightly tricky. They’ve had slight replants and areas of crop failure really, which probably need addressing fairly soon.
NS: And what would be the reasons for crop failure on that scale?
JH: Possibly down to weather conditions. Dry seed beds. We can’t actually point our finger at any one thing at the moment to suggest exactly what caused the crop to fail in these areas. We’ve had two springs of quite strange weather patterns of either huge amounts of rain or long dry spells. They have more than likely had some affect upon this.
NS: But the way that miscanthus is planted has also caused problems for Jonathan. Unlike other kinds of grass, like that on your lawn, miscanthus isn’t grown from seeds but from rhizomes. These are the main stem of the plant, similar to ginger root. The visible part of the plant then grows from small lumps or nodes on the rhizome.
JH: There are issues with some of the rhizomes. It’s noticeable that it grows better in certain places then it does with others. Field types also. Land types. You know, very, very variable. I think on the whole though most people are quite happy with their crop. We seem to have reasonable establishment in most areas.
Mike Carver: You’re dealing with a rhizome, an underground stem, which is not the easiest sort of planting propagule to work with.
NS: Dr Mike Carver knows all about that. He’s a technical consultant at Bical, a firm founded to produce miscanthus on a commercial scale. The grass is easy to grow once it’s established but the tricky bit is getting it planted in the first place. Setting up a successful crop is time consuming and costly. Bical says it’s cracked a technique which is important. Nobody is going to invest in growing miscanthus without a reliable way of adapting agricultural land for it.
MC: Bical had to do a great deal of work to try to understand how you actually harvested the best rhizomes from underground, how you process them and then how you replanted them on a commercial scale to create cane crops. The fundamental concept is we’re trying to get the increased margin back in the hands of the farmer. And the farming community is always the one where all of the profits are taken by people outside of farming. What we’re trying to create is a structure whereby the enhanced value is actually in the pocket of the farmer not in some middle man upstream.
NS: But you can’t just grow miscanthus anywhere so how exactly do the farmers get the green light? Peter Hayman, a senior specialist with Natural England, explains how the England Rural Development Programme run by Defra is giving the opportunity for farmers to get into energy crop production through its Energy Crops Scheme, or ECS, that offers grants that help with the high cost of establishing miscanthus.
Peter Hayman: Basically the scheme is there to encourage the planting of energy crops. And it applies to two types of crops: short rotation coppice and miscanthus. What happens is a farmer applies for a grant and he then has to submit an application which is subject to an environmental impact assessment. Once he’s gone through that environmental impact assessment, which looks at crop position sitings, whether there’s public footpaths, power cables, the negotiation starts. And clearly if we’re happy with it then he’s awarded a grant. Now, that grant enables him to plant the crop. Because the establishment costs; one of the big problems with energy crops is actually the establishment costs are very high. And therefore it’s an encouragement by the government to kick start the industry. And that’s why it’s there.
NS: Has the ETS come to being, as it were, from the government drive in increasing power generated from renewables?
PH: Yes, it has, very much so, and to get the farming industry focused and encourage them to grow crops for power generation. And there are many ways you can do it. I mean the particular benefit of the producer groups with miscanthus is that it’s a full contract job from planting to harvesting right the way through. So the farmer can actually belong to the producer group, he can influence its direction, but in terms of an operation on the farm there’s not very much for him to actually do. So that is one of the benefits. And it is another option for a farmer to actually try and diversify his cropping.
NS: Whilst miscanthus is another option on the farm is it the most profitable? After the farmers have established an energy crop shifts in the market might make other harvests more lucrative.
PH: I think one of the problems that we’ve actually seen, and we’re going to run into now, is that miscanthus is a crop for the sort of arable areas and, again, the economics have to stand up for it. And we are seeing surging cereals prices at the moment which clearly is going to put some people off. So in this region we feel that we have the framework in place to develop it. But, as I say, it is going to be slow. It’s not going to be massive because, again, there is competition for what you actually grow on the land and I’m afraid the economics actually determine that.
NS: But the cost may not only be financial but also ecological. It may seem that putting crops on land marked out for biodiversity defeats the object of that set aside land. This certainly concerns Mark Latinum, a Science Policy Research Fellow at the University of Sussex.
Mark Latinum: The first worry would be that we take into to use so called set aside land which has been set aside precisely in order to recover some of the lost biodiversity values that had been lost because of the intensive agriculture we have had in the past. So in that sense it would be a step backwards.
RH: One of the benefits of set aside has been increases in biodiversity. However, biodiversity increases are a result of set aside and was not the reason why set aside was created in the first place. Set aside was created to reduce food production and to combat things like the food mountain and the wine lakes and all of those things. And the increases in biodiversity have occurred more by luck than by judgement, it would appear to me. And as a result I think that biodiversity, yes, could suffer from the planting of set aside. However, the results from research that has been done on the biodiversity gains of using miscanthus over monoculture cereal crops are significantly in the favour of miscanthus. So, yes, it could affect biodiversity but that’s not the reason that set aside was created in the first place. Whether we want to look at set aside in terms of biodiversity and paying people for biodiversity is a whole other issue. That isn’t the reason that set aside was created initially.
NS: Well that’s the theory at least from the Forestry Commission’s Rudy Humphries. But I’m keen to find out how the local ecology is faring back amongst the miscanthus on the farm with Ambrose Fowler.
AF: I know people talk about the barley barons and things and no hedges and all this and devastating the wildlife but I can hand on heart say our wildlife has increased dramatically in all our energy crops. From the smallest of insects and butterflies, bees, through to song birds, game birds and mammals, you know, hares and particularly small deer and this sort of thing it’s just an astonishing increase in our wildlife.
NS: But the true impact on biodiversity in miscanthus crops won’t be known until they’ve been grown on a truly large scale. However, we’re already getting an insight into how the crop addresses another environmental concern and that’s soil erosion. For Rudy Humphries this isn’t a problem because of the way miscanthus grows.
RH: So the rhizome is essentially the seed but it’s a rhizome rather than a seed. It’s in the top soil. That stays in the top soil and you’re cutting the cane, the dry matter that’s died off over the winter, in the springtime. You’re cutting early spring and because the top 30 centimetres in which the root structure sits is fibrous, much like a pot bound houseplant, that forms a kind of raft in the top of the soil, binding the soil together, meaning that you can get on and do your harvesting and those kinds of treatments in the early spring meaning you’re not suffering the same soil erosion as you would, say, with harvesting sugar beet.
NS: Farmers applying to grow miscanthus through the Energy Crops Scheme have to go though a rigorous application process to get the go ahead. Conservationists, environmentalist impact assessors and local planning councils all have to be consulted before an application is approved. It’s a longwinded process. But even then there’s yet another barrier before miscanthus can finally take root.
Elaine Willett: My name is Elaine Willett. I am the Rural Development Officer for ALGAO, which stands for the Association of Local Government Archaeological Officers. In terms of biomass the whole policy driver behind it is a sustainable approach to the way in which we live. And the historic environment is an intrinsic part of our natural environment. Without the historic environment, without what has come before, we don’t have our existing natural environment. You’re dealing with deposits and features which are finite and irreplaceable. Once they’re damaged and destroyed they can’t ever regenerate. They can’t grow back. And the evidence that they contain is of extreme value. There are deposits beneath the ground within archaeological features that are perhaps waterlogged and contain very valuable paleo-environmental information and evidence which when analysed can tell us a vast amount about how climate change has already taken place and how mankind has already adapted through hundreds of thousands of years since the last Ice Age or before. In terms of how come archaeology and archaeologists are involved in the biomass scheme and the application process, that’s due to the fact that the crops that we’re planting a) are normally on a massive scale, a landscape scale, and they would impact upon the historic landscape character and the way in which we perceive our natural environment. So we would comment from that perspective. But we would also comment on whether or not we know there to be or suspect there to be a very high potential for buried archaeological deposits beneath the fields which are included within the application. Planting these crops in order to use our environment sustainably, we need to make sure that we don’t inadvertently damage the very fabric that has created that environment in the first place and destroy these finite and irreplaceable resources that we have.
NS: So as long as Tony Robinson isn’t lurking around the corner then farmers should be able to go ahead with planting their energy crop safe in the knowledge that they’re doing their bit for a carbon neutral future. Of course few means of energy production can be totally carbon neutral. However, Rudy Humphries gives me the low down on miscanthus’ green credentials.
RH: You’re using fewer passes of farm machinery is one of the big wins. You’re not spraying with pesticides and herbicides. You’re not ploughing annually. You’re not essentially doing as many passes with your tractor over the crop as you were with cereal production. So you’re not ploughing annually. You’re not tilling annually. You’re not spraying annually. And you’re just doing one pass a year, which is your harvest essentially, once the crop is established. So you’ve got a reduction in fuel use there on top of which you’re not actually using any agrochemicals on the crop because it doesn’t need it. The leaf litter falls to the ground. It creates its own mulch suppressing weeds. Pesticides and herbicides aren’t required. There are currently no known pests for the crop. And also it’s not requiring any additional additives because it’s getting that from its leaf litter. So you’re getting a reduction in the use of agrochemical crops as well. The reduction in passes per machinery and the fact that you’re not adding any additives or chemical additives to the plant is one of its main benefits.
NS: So compared to growing conventional cereals energy crops require fewer agrochemicals cutting down on the fuel guzzling farm machinery and it’s associated CO2. But the crops still have to be transported to the power stations where they’ll be burnt. However, Mike Carver and his colleagues at Bical have already given it some thought.
MC: Scattered round the whole of England now there are what we call production footprints where farmers can qualify for the Energy Crop Scheme and supply miscanthus to a relatively local power station. We’ve now taken that a step further in that moving cane around the country, large bails of cane weighing perhaps 350 kilos, maybe even more, is not the most efficient way of moving energy crop. So we’re now building compression plants where the cane is compressed and then it can be moved greater distances much more efficiently. It’s having an impact on the overall figure. In the biomass sector it would be the main contributor. Because at the moment if you talk biomass market to people here and they talk about wood pellets the majority of those are imported from all sorts of distant lands, even Eastern Europe and South America. So it’s difficult to argue a sensible carbon footprint for that. If you have home produced miscanthus that’s produced in cubes or pellets, that is making a huge contribution to the whole argument of carbon footprints and Kyoto compliance and reaching energy targets.
NS: But even whist trying to make energy crops as carbon neutral as possible how much of a contribution can they make in reaching ambitious government targets on renewables? Peter Hayman from Natural England says we need to look at other options too.
PH: In terms of renewables there are lots of ways of doing it. And I think one has to look at a bit of everything. And certainly energy crops are not the total answer. They are one part of it and it’s an opportunity for the farming industry. Certainly wind power, tidal power and solar power are other options. And clearly as we progress there will be new technologies that come out.
NS: Scientists are already looking at more advanced uses for biomass than merely chopping it up and burning it. Experts are divided on how green biofuels really are especially when increasing demand for palm oil is threatening Indonesian rain forests in order to make bio-diesel. Perhaps the biofuel industry is due for a makeover. Policy researcher Mark Latinum believes that second generation biofuels are the solution.
ML: Well, basically first generation is the technology that we use today which is based on converting sugars or starches into ethanol or plant oil into bio-diesel. Whereas in the future with second generation technologies we could convert cellulose into ethanol or bio-diesel.
NS: Current biofuel technology uses either plant oils or plant sugars to produce transport fuels but second generation biofuels will use cellulose and lignin. These are the structural materials found in the cell walls of green plants and are the two most abundant organic substances on Earth. Together they account for most of the dry weight of woody plants. The benefits of using so called lignocellulolytic technology would be considerable as almost any plant waste could be used to make fuel for our cars making us less dependent on fossil fuels.
ML: The way in which energy crops are grown today is not very efficient in Europe and in the US. Tropical countries have a great advantage of having crops and climatic conditions that allow much more efficient production. But if we achieve the kind of technological breakthroughs in the kind of technologies that would allow us to use cellulose material in order to produce, for instance, ethanol out of forest waste and all kinds of cellulose material that might be a solution. And at the same time that could provide a bridge from the present first generation biofuels, as we call them, to the second generation biofuels with convert cellulose into fuel. But this is a technology that’s not commercially available and technically not developed enough at the moment. The most optimistic estimates are that within five to ten years we’d have commercial applications of second generation technologies.
NS: As for miscanthus, Bical’s Mike Carver says it has a role of its own to play in a brave new second generation world of biofuel production.
MC: The bio-ethanol market has been the one that people have got excited about which is using the carbohydrate to create ethanol. What you’ll find is a lot of those initial ventures are not now going to be built. Because second generation biofuel, which is lignocellulolytic enzymes, is now clearly a better opportunity. And it’s believed by many scientists that after sugar cane the second most likely plant to feature in this technique will in fact be miscanthus. And so that’s another reason why there’s an awful lot of interest in the crops from various countries around the world.
NS: And for Rudy Humphries a crop that grows in large volumes with hardly any need for chemical additives is ideal for uses alongside energy production.
RH: There is quite a lucrative cattle bedding and horse bedding market that can be used for miscanthus shredding and using it as horse bedding or animal bedding. There are in Holland moves to use it as recyclable plant pots or biodegradable plant pot material. So pressing it into shapes and using the lignin in it to make plant pots that are biodegradable. And also there is some work being done on looking at it as a very finely chopped fibre to use in children’s nappies so to make children’s nappies biodegradable. So there are other outlets for it, although quite embryonic at this time.
MC: We’re not yet at the stage where people are targeting the bio-composite market because that’s a developing market. But miscanthus is now recognised by a lot of authorities as a very, very good fibre to include in composites with either straight plastics or more excitingly products which are totally genuinely bio-renewable. No fossil fuel in them whatsoever.
NS: Well, that’s miscanthus then. An all purpose, all singing, all dancing energy crop. But if it’s going to become successful in the bioenergy market, as the experts hope, it’ll need greater support from renewables legislation. Energy crops like miscanthus aren’t without their problems. They’re fiddly and expensive to establish and are only economically viable when they’re not competing with other lucrative crops like wheat. But their advocates see fields of gently swaying grassy plants as playing an important role in a greener, lower carbon emission future.
Frank Rosillo-Calle: I’m not thinking that we’re going to solve the whole problem with biofuels. Fossil fuel will remain with us for many, many years.
PH: And certainly energy crops are not the total answer. They are one part of it. Certainly wind power, tidal power and solar power are other options.
RH: The Energy Crop Scheme and the growing of miscanthus and short rotation coppice single-handedly isn’t going to address carbon fuels. It’s one slice of the pie, if you like, of a very large scale operation.
ML: Yes, they can contribute to reducing greenhouse gas emissions. They can play an important role but they are not a magic bullet.
GM: That special edition of the Imperial College podcast was produced and presented by Neil Strawson, recently graduated from our MSc in Science Media Production. Well, I’ll be back with more next month in the February edition. On the menu, one of our translation specialists in the humanities department reveals the delights of Chinese literature. And of course we’ll have the latest news from around the campus. This podcast is a co-production of the Imperial Press Office and the Science Communication Group and is available on the first working day of each month. This theme music is called Lila and it’s composed by Ozgur Buldum. You can hear more of his work at ozgurbuldum.com. And whilst I’m giving out addresses, do keep an eye on breaking news from Imperial via our Press Office website at imperial.ac.uk/news. Well, that’ll be it for now then. Thanks very much for listening but until next month from me, Gareth Mitchell, it’s goodbye for now.