Episode #123  Beautiful Methane: Powering the transformation with Will Llewellyn

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We all know that methane is a far more dangerous greenhouse gas than CO2. But what if we could harness it and put it to good use? What if it we could power our cars and heat our homes on waste food? Will Llewellyn of Red Kite Management explains the potential and how to apply it.

Will has worked in the renewables industry for decades. Now he advises individuals and firms on the use of food waste, animal slurry and human effluent as feedstocks for biodigesters which can both reduce the leakage of fugitive methane into the atmosphere where it acts as a greenhouse gas and provide a power source for vehicles, a heating source for buildings and a potential baseline load filler in power generation.

In Conversation

Manda:  My guest this week is a friend and a neighbour. Will Llewellyn is director of Red Kite Management, which is an energy consultancy company that focuses on renewable methane. For all the time I’ve known him, Will has been a passionate advocate of the use of renewable methane as a way to fill the gap that is inevitable when we give up fossil fuels. It’s not the only answer, but it’s a significant part of the answer to how we’re going to power our cars or heat our homes or create electricity when we no longer want to burn coal and oil and gas from Russia. And Will is one of those people who is working at the front end. He knows so much. The depth and breadth of his knowledge is always breathtaking, and he’s making it happen. He’s going out there and he’s installing the plants or buying up the trucks or creating the networks to change the world around us. And he has ideas for how we can take agency to change the world ourselves. So people of the podcast. Please do welcome my friend and neighbour and a real hero of the renewable movement. Will Llewellyn of Red Kite Management.

 Manda: So Will Llewellyn, Director of Red Kite Management, thank you so much for taking time off on this beautiful spring morning to come on to Accidental Gods. How are you?

 Will: I’m very well, thanks, Manda. How are you? And thanks for having me.

 Manda: You’re welcome. I have an eye now. I was down to one eye this time last week. It was extremely unpleasant, but I am back to having two eyes now. It’s great. Good. So thank you. You are a couple of villages away. There was a time when I first met you and we lived in adjacent villages and then we both moved in opposite directions. So now there’s a couple of villages between us. But at the time when we met and ever since, you have always struck me as somebody who completely gets the climate and ecological emergency and is doing everything that you can in a practical level to make things different and to help other people make things different. And I’m wondering, how did you get into this? How did it become the defining feature of your life? If I’m right, that it is?

 Will: Well, nothing is ever straightforward. And so I grew up in rural Herefordshire, and I had a workshop. And so ever since I was about 12, I was always making things, whether it was old cars or things that interested me. And in about maybe 1999, I went to a festival that was called the Big Green Gathering, and I built a wind turbine that stood on a five metre pole with a truck alternator that charged batteries, so we could power our band using a 12 volt truck battery through an inverter, because there was no fossil fuel power allowed on that site. So that switched me on to other ways of generating electricity or producing useful energy. I studied science at university. I did biology and French at Manchester and quite by accident I was at a rave and I was talking to a guy about an interesting process that he’d come across in about 2008, that used the contents of animals guts after they’d been slaughtered to turn into renewable electricity and renewable heat, via methane. And I thought, My goodness, that sounds like anaerobic digestion; because I’d studied that through university and, you know, it’s just a part of science. And it sounded quite interesting. And at the time I was working in the City of London, working in the shipping business, working for some ship owners who were carrying refined products, including biofuels, which I was very interested in. And I thought, well, that’s my ticket out of London, because by that time in my life, I had one child.

 Will: I had no desire to spend the rest of my life sort of grinding away in London, running hard to stand still. And I thought I’d better find out more. And so I got my first job in AD in Ludlow in 2009, working for a company called Green Finch Ltd, where I was the assistant to the technology director, a guy called Michael Cheshire, and I effectively did the equivalent of an apprenticeship. So using my rather diverse set of experiences and skills from deal making through to science to being able to drive a MiG welder, through to being able to talk other languages, to get things done. I started working in AD and since then I’ve been doing it ever since. And the common denominator in all the work that I do is renewable methane. And so whether that comes out of a biogas plant on a farm or a food waste digester or out of a landfill site, it’s all the same molecule CH4. It’s all an extremely versatile energy vector. And there are applications where if you don’t harness methane and you let it go into the atmosphere, like through uncovered slurry lagoons or uncapped landfill sites, for example, it’s a really potent greenhouse gas with the carbon intensity 34 times that of carbon dioxide. So while making a good source of versatile renewable energy, which is a drop in replacement for compressed natural gas or electricity for export into the grid, you’re also preventing these fugitive methane emissions, and that’s actually what it’s all about.

 Manda: Wow. Okay. There is so much in there I want to unpick, starting with I had no idea you had a band. I’ve known you for decade and a half and you had a band back then. Do you wanna, tell us if you still got a band?

 Will: Well, we’re still good friends and we play together. But sometimes the you know, having gone from the powers of The Mighty Organ, which was the name of the band, playing out probably twice a week when we all lived in London and didn’t have children. And life was easy. We play a bit from time to time, but it’s rather like sort of kicking a corpse. But, you know, the spirit is still there and it’s good fun, but we’re not as good as we were.

 Manda: All right, guys, go find The Mighty Organ, listeners. That’s your new thing for this week. So we talked about the fact that methane is 34 times more potent than CO2. I’d like you to explain kind of how we get to that, because it seems to me that people often bandy around a lot of stats and we don’t really know where we get them. Particularly, I have to say, when it comes to farming and they talk utter nonsense about cattle producing huge quantities of methane, when the the stats were derived from US feedlot cattle who are fed huge cereals exclusively and live on concrete. And it’s different when they aren’t fed cereals and don’t live on concrete. But we’ll get to that eventually. But then let’s have a look at methane, what it is and how it can become part of the solution instead of part of the problem. Is that too big an idea or can we head into that?

 Will: No, I think we’ll we’ll let’s grapple it and give it a start and stop me when you want me to elaborate on any particular aspect.

 Manda: I shall put my hand in the air. Yes, go for it.

 Will: Right. So methane, it’s  a gas at room temperature. It has a chemical structure CH4. So it’s a hydrocarbon. It can be liquefied at about -164 or it can be compressed to 250 bar for safe transportation utilisation, or it can be recovered in a dilute form in a mixture of gases, which is called biogas, which is produced by microorganisms. And then it can be used directly at lower concentrations to run gas engines or to power boilers, to produce point sources of heat and electricity, which in some cases can be very small. So some people will build a small anaerobic digester or biogas plant, and these are all over the developing world. So India, China, Africa, where they’re they’re literally run on dung from their livestock. And while there’s very little food waste in those in those countries, but it’s to provide gas to cook on because one of the major causes of deforestation and desertification is actually people going out to look for wood to cook on. And so the further they go from their village, the further they have to walk, the more they struggle. And then also the other problem of that is that where people are cooking over open fires, they get all sorts of respiratory and an eye diseases. So, you know, at a very small scale, biogas can produce enough clean cooking gas for one or two or three households. And then at the other end of the scale, a large anaerobic digestion plant might produce enough biomethane injected into the grid to heat 10,000 households, or it might produce enough gas to run a fleet of heavy lorries on the motorway network of any country. Or it might produce enough electricity for several thousand households, depending on what the application of the biogas is. So it’s all the same core process. But getting to the end result is slightly different depending on what the feedstocks are and depending on what’s the chosen application for the for the energy is.

 Manda: So just on an empirical basis, if it is the case that we could be running fleets of lorries with this, why are we not? Is it a feedstock issue, a distribution issue? Is it just that the fossil fuel companies are sitting on people so that they can’t?

 Will: No, it’s not as cynical as that, actually. There has been an impasse within the OEM. So the original equipment manufacturers and the deployment of a refuelling infrastructure, for all vehicles, actually. And so I think the best way to do this is to kind of give an example and to explain. For reasons unknown to myself, being an avid Europhile, we happen to drive with the steering wheel on the right hand side of our vehicle where the rest of the world drives with their steering wheel on the left hand side of their vehicle.

 Manda: Do you want to know why that is?

 Will: I’d love to.

 Manda: We drive on the left hand side because you hold a sword in your right hand and you needed to meet the oncoming guys with your sword. So from Roman times, if you were on a dual carriageway, you needed to stay on the left, because most of us are right handed. When Napoleon decided that he wanted to do things differently to England, then he switched France. And because Napoleon switched, the rest of Europe switched and America went the other way for exactly the same reason. And then everybody followed the majority and we were left with our sword hands on our right. Anyway, there we go.

 Will: Ah! OK. No, I mean that explains it. And I mean, I think I like the context of a dual carriageway, because sometimes when I’m driving down the A303, it feels a bit like a dual carriageway, but with an E rather than an A because of the way things go there. But in all seriousness, the the impasse is to do with the availability of vehicles. So compressed natural gas has been used since the Italians, Fiat were using it in the 1930s. And then there’s been a huge growth in infrastructure throughout Europe, led predominantly by Germany, Finland and Sweden, to develop a network of refuelling stations. And so that then, there was a technological solution from the likes of Volkswagen and Mercedes and the big vehicle manufacturers. And they tried to deploy their gas vehicles into the UK market. But because of the fact that people drive on the on the other side of the road, it wasn’t deemed to be economically attractive to them to produce small production runs of right hand drive gas variants. And so what happened was there was effectively a chicken and egg scenario, where the deployment of the refuelling infrastructure was held back because there was a shortage of suitable right hand drive vehicles. And then when the right hand drive vehicle lot were asked if they wanted to produce more right hand drive vehicles, they said no, they didn’t because there wasn’t the refuelling infrastructure. So what was what was very interesting was I actually bought up, my business Red Kite Management, bought up all of the right hand drive, Volkswagen Caddy vans and Mercedes sprinter vans, which were factory built gas variants.

 Will: Because we trawled the second hand market; they were introduced from 2008. We bought them all up and we put them out on contract higher in London where there was a refuelling station just north of Kings Cross where they could refuel these vehicles. So they’re very low emissions and it worked a treat. And so when I went to Milton Keynes, which is the head office of Volkswagen Corporate and the head office of Mercedes Corporate, to ask them for a trifling 500 Volkswagen caddies that was deemed to be not a big enough production run to be worthwhile putting it in right hand drive. So that was the end of the sub three and a half tonne vans going into gas, because the focus has been on electrification actually of the smaller vehicles now. But when it comes to heavy trucks, it’s a very different story. Because the only way to decarbonise the logistics supply chain is via biomethane, because effectively hydrogen is a long way away. I think that it’s seen to be the silver bullet. It’s politically very attractive to talk about hydrogen, even if people don’t really know what they’re talking about from a policy perspective. And electrification is difficult on heavy trucks because your payload suffers, because you’ve got you’re carrying so much battery that if your gross vehicle weight is 44 tonnes and you’ve got 38 tonnes of battery on board, so that’s not enough for them for for cargo. So. Given that biomethane offers the cargo owners the opportunity to green up their supply chain, the market is being driven by the carbon reduction requirements of the cargo owners and their imposing that on their supply chain contractors, which is why we see the likes of Stobarts or who else?

 Will: John Lewis are running on gas. There’s a whole load of hauliers which are running on gas. And if you get into it, you look for gas tractor units. They’re quite easy to spot when you get into it. But what that’s driven is the growth of the biomethane refuelling infrastructure built by private companies such as CNG fuels, because they know that they will get a base load core business of contract offtake work from this, let’s say, core haulage. And so they’ll build open access refuelling stations at strategically useful locations knowing that the base load will be met by whatever contracts they’ve got with whatever carriers. And then people like me are involved in the second hand truck market. So when trucks get sold after being five or seven years in a fleet, those gas trucks will get sold into the second hand market. So I’ll be able to find a buyer who will then be able to buy two or three trucks and then to fill them all of the CNG fuel’s refuelling infrastructure or gas recs or liquids. And so what we’ve done is we’ve effectively broken this impasse. But the reason why the impasse is broken is it’s been driven by the, first of all, the technological development of getting biomethane into the gas network and into trucks and onto roads. And I can talk about that process in a minute, but also by the market driven need to decarbonise supply chain.

 Manda: Okay. So many different things there. Yes. So you said about things being a silver bullet. And I listened to somebody the other day saying there is no silver bullet, but there might be silver buckshot and that this is… There’s lots of little different things. So first question: if we can create a refuelling infrastructure and if it’s starting, is it the case that most of us would be better to take our existing cars and make them run on gas rather than heading for electric vehicles With all of the problems of rare earths? Is it is it that liquid gas is actually a better option? Is the feedstock there or would we end up, this is probably a slightly different route, but my concern, fed by friends in Germany, is that Germany ended up putting tens of thousands of hectares into monoculture-growing of green stuff to feed reactors that otherwise would have been feeding people. And it was taking up huge amounts of land and water. Is that something that we would end up having to balance? Or are there ways of creating the feedstock that we could all be running our cars on biofuels and it would be better than electric vehicles?

 Will: Well, I think that’s a very good question. So let’s take it a step at a time. So there are a range of feedstocks which are good for the production of biogas and or biomethane. We’ll take a few extremes because it’s always worth taking extremes and everything else tends to sit in the middle. So cow slurry, for example. Your average high yielding dairy cow produces 68 litres per day of slurry. Very useful point source of feedstock for a biogas plant. And let’s say that the reality is of intensive dairy production is that you might have 1000 of these cows in a shed somewhere producing a lot of slurry. So just so that’s I’ll just work it out.

 Manda: 68,000.

 Will: 68000 litres per day of dairy slurry.

 Manda: So that’s a lot of slurry.

 Will: Well actually I don’t think it is that much. I’d call it 68 cubic metres and it sounds a lot more manageable. I mean 68 cubes. Yeah. That’s doable. That’s two road tankers a day.

 Manda: Well, just hang on. What happens to that? Because I hadn’t really done that maths in my head and I’ve seen the slurry lagoons at the dairy farms and I mean, this stuff is part of the reason we have toxic oceans that are killing all the phytoplankton. Is that we just chuck it into the sea. What normally happens to this?

 Will: Yeah. Okay. So their slurry will be held in a tank and then it will be spread at particular times of the year according to what the ground conditions are and what the meteorological conditions are. Or, for example, if there’s a NVZ, which is a nitrogen vulnerable zone, the slurry can’t be spreads at times where it could be leached straight into watercourses. And actually, by and large, most dairy farmers are very conscious of not spreading through NVZ closed periods. Because you have to remember that a well run farm, is a holistic relationship between land production and management. And so I think it’s very easy to see major problems in everything, but ultimately there is… I spoke at a conference at the University of Edinburgh a few years ago that was called sustainable intensification. Bigger is not always bad. And so what it was talking about was how if you gather up all these points source; let’s say. production of slurry, etc. then  you can actually collect it and do something useful with it. So back to your question, what happens to the slurry? Very often it’ll go into open lagoons and then it’ll gas. A tonne of slurry produces about 20 cubic metres of biogas per day at 60% methane.

 Will: And so that methane will go into the atmosphere and that’s called a fugitive methane emission. And that’s not a good thing. Okay. That slurry, if it was put into a biogas plant, which is a covered reactor, basically; with a heating system and a mixing system in it. To keep the mixture homogenous and to you heat it up to typically about 40 degrees in order to give the microbes the optimum temperature for  metabolism to take place. You know, that’s going to produce a fairly steady supply of bio gas, which you can do something useful with. And so just using round numbers with our 1000 cow dairy farm, producing 68 tons of slurry a day, that’ll produce about 56 cubic metres per hour of biogas.

 Manda: Wow.

 Will: Okay. So if you were to take that 56 cubic metres of biogas per hour, you could, if you were to turn that all into electricity, provide enough electricity for about 250 typical households. If you were to export that electricity to the grid. Or, and this is what really gets me going, you could produce the equivalent amount of vehicle fuel to about 450 litres of diesel per day.

 Manda: Wow.

 Will: So that’s pretty cool.

 Manda: That really is. Given that I read something about a year ago that every litre of diesel or other fuel that we burn has the warming potential to melt one ton of Arctic ice. And given that the Arctic ice is currently falling into the oceans as we speak, saving 450 tons of Arctic ice every day would be a really good thing. You’re also then not sending this fugitive methane into the sky, so there’s going to be an even greater balance to be done with that. So 250 households or 450 litres of diesel or. And that’s just with one dairy farm.

 Will: Yeah, that’s with one dairy farm. Okay. And so the question is, why aren’t we doing this everywhere?

 Manda: That was my question.

 Will: Right. And so there two main reasons. One is  about identifying the right farm, because any successful anaerobic digestion project is a three point interdependency between a source of viable feedstock, an outlet for the energy that you’re going to produce and then a land bank to spread the digestate. Now the Digestate application is extremely important. Most people forget about Digestate and generally people will only think of Digestate for the wrong reasons. Anaerobic digestion is a natural biological process whereby sugars and proteins fats are converted into biogas, which is carbon dioxide and methane. And then there’s the residual NPK and whatever else is left in the soup, which is not methane CH4 or carbon dioxide CO2. There’s no NPK in any of that gas. There might be a little…

 Manda: So all of the mineral content, is like an ash then.

 Will: It’s right. Yeah, but it’s a slurry. Typically it’s about 7% dry matter. So it can be carried in a tanker and it can be applied to land and it’s extremely useful for bio fertiliser. So what does that mean for the big picture? It means that there’s a reduced dependency on inorganic imported fertilisers as a reduced dependency on imported phosphates. Phosphate’s a finite resource. No one talks about phosphates, but they are.

 Manda: But we’re already exceeding the planetary boundaries of nitrogen and phosphate. So that’s one of the nine boundaries that the Stockholm’s system produced. So we’ve got to stop spreading it as much. Part of the regenerative farming is to wean people off needing to spread stuff by having plants that actually send the roots down and take it up from the soil.

 Will: Yeah, that’s exactly right. But if you look at… I’m no expert agronomist, but I know that the amount of organic material that you spread back into the land, i.e. the carbon that you can sequester back into the soil through the application of digestate, it means that you’ve got a nutrient cycling. So if you imagine you’re growing crops to feed into cows which you’re then anaerobically digesting the cow slurry; the carbon, nitrogen and phosphate goes back into the same soil. So you don’t have to import.

 Manda: Okay. So you’ve got a cycle.

 Will: Yep. Yeah, exactly. So that’s the digestate. And it’s really important because most biogas plants work on what’s called a continually stirred tank reactive basis. So you have a tank which has got, let’s say, 1800 cubic metre working volume, okay? The contents are kept at 38 degrees and they’re mixed, so there’s no stratification in there. It’s bubbling away. The way that the process works is you feed in material at a flow rate, which is calculated against the discharge rate to, if you have a a bell shaped, Gaussian distribution curve, you’re aiming to have the maximum amount of particles in that tank for the maximum amount of time. Because each different feedstock has a different what’s called hydraulic retention time, which is the amount of time it takes to yield its biogas under particular temperature conditions. So for example, slurry, it’ll produce it’s 20 cubic metres per fresh tonne. You don’t want to keep it in a tank any more than about… For any more than about 25 days, because by that point it will have yielded all its gas. Whereas a forage crop like maize, for example, you want to design for a 60 day retention time. So you see, it’s actually a relatively straightforward process. And so that’s the feedstock element. Is the feedstock suitable for the plant? If we’re going to take the example of the slurry plant, we’re going to say, yes, it is, it’s fine. We can pump that. It’s good. It’s good and thick. It’s not too watery. The digestate has to be understood from a chemical and environmental perspective. But if you can’t get the digestate away from the plant, you’re not going to be able to feed any fresh material in.

 Manda: So a very quick intervention question on there, which is if we’re trying to create circularity, let’s assume that our plant is producing our 450 litres of diesel equivalent. How much of that 450 litres diesel equivalent is required, first of all, to power part of the plant and second to remove the digestate a distance formula that we can’t do. But let’s assume it’s not going more than 20 miles because there’s another dairy farm more than 20 miles away. So we’re losing a certain amount of what we take out in the spreading of Digestate. As anybody kind of run those numbers through to see what the actual net positive?

 Will: Yeah, well this is all part of the design process. When I was talking about how suitable are the projects for the, you know, how suitable is the application of the technology. Yeah, these are all things that you look at. So, you know, there’s a good old cliché don’t lump it, pump it. If you can pump digestate around, like an irrigation distribution circuit around the land, that means that you’re not hauling digestate on the road. And it’s quite, if it’s 7% dry matter, it’s 93% water.

 Manda: So so it weighs a kilogram per litre and it’s heavy stuff.

 Will: Yeah, that’s exactly right. But okay. But then you go and I do a lot of work with New Holland, so I’ve got a tractor that runs exclusively on biomethane. Their Gas tractor.

 Manda: Right.

 Will: And so if you were to use a New Holland Gas tractor to haul your digestate, then you’ve got a carbon negative feedstock employed in the production of your energy process. So that’s good. And then there are other kind of parasitic energy requirements such as heating and electricity to run pumps and mixers and that kind of thing. So because slurry is quite wet, it has a high specific heat capacity. So it might require 15% of the overall energy production in the parasitic heat requirement of that material. But it doesn’t require any mechanical pre-processing and maceration because the cows have already done a pretty good job of macerating it. So you don’t need a heavy duty front end to pre-treat it before it gets into the tank. So you could say that depending on the scale of the plant, you might be using 15% of your gross energy production to run it.

 Manda: Okay. But that’s still an 85% net energy use.

 Will: Yeah, that’s correct.

 Manda: So we live in a world where at the time of recording last week, our government decided to sell our National Grid to an Australian asset stripping company. I’m assuming so that when the power goes down they can pretend it’s got nothing to do with them. It’s all the market deciding that rural areas didn’t really need power or they just triple the prices. Let’s assume that we managed to wrest that back and if necessary we do it with a revolution first. It seems to me that what we’re looking at is weaning ourselves off big central power production and onto a distributed network of local production and local microgrids, where our dairy farm combines with a hydro unit and solar panels and things, and the dairy farms or the anaerobic digesters, whatever the feedstock is, could be providing the baseload that everybody says is the difficult thing with renewables because they all depend on the sun shining and the wind blowing. Am I right or is that just me being fantastical?

 Will: No, that’s exactly right. So what what we’re looking at is the smart grid concept. Now, the smart grid concept has been around for a long time and it’s been something that’s been facilitated by technology. And so we put solar panels and AD is called distributed microgeneration. So it’s a diffuse of small points of microgeneration going into a network. In terms of baseload, you’re absolutely right. There’s 8760 hours in the year. Okay. When you do the financial modelling on a anaerobic digestion facility, typically you’d calculate that thing running at 90% of flat out for the whole time, which is about just under 8000 hours per year. Okay. So for example, if I had a 500 kilowatt anaerobic digestion facility, I’d expect it to be running at a minimum of 90% of that 500 kilowatts. 24/7, 365. If I had a five kilowatt photovoltaic array on my roof, I would probably if I was lucky, I might get 20% of that.

 Manda: What about wind, local wind as opposed to big wind.

 Will: Wind I think it’s similar. I mean, I was at a show in 2010 called Energy Now at the three county showgrounds. And it was when AD was really kind of…it was great… We were kind of giving presentations back then about what is anaerobic digestion. You know, it’s very kind of big picture stuff. But someone had set up a wind turbine outside the show and there was a speaker from DECC, the Department of Energy and Climate Change, who was on stage. And he was talking about how wind power, onshore wind power is going to revolutionise everything. And I stopped him and asked him how that could be the case when the windmill that was set up outside the show wasn’t turning quite yet. And so where I’m going with this, is back to our portfolio of renewable technologies. There is no one silver bullet. So AD will provide the baseload, that’s granted. When it’s generating electricity. But what I think is more likely to happen, is the bulk of anaerobic digestion facilities that are, I would say, small and on farm were built between about 2010 and 2016.

 Manda: Was there a grant? Is that why that happened?

 Will: Yeah. Yeah, they were they were built to match a particular feed in tariff, which is paid against the gross amount of electricity you generate, and then you get a power sale price on top of that. Now that feed in tariff ended or became commercially unviable for small projects. And bear in mind, in different parts of the country there are different scales of agricultural operations. So we live in the west here and typically there are mixed farms which are much smaller than the sort of arable plains of East Anglia. Okay. So the smaller sort of baseload type producing plants which are built, there are substantial amounts of them through the country, but there aren’t any new ones being built. And it’s highly unlikely that power generation from biogas will be re supported after the current feed in tariff expires. And the reason why is..

 Manda: Why?

 Will: Well, no, it’s very obvious, actually. It’s because generating electricity from methane is a waste of good methane because of the electrical conversion efficiency of an engine.

 Manda: Okay.

 Will: So 35% of the useful energy in the methane will be converted into electricity through a power generation. Through inefficiency.

 Manda: Yeah, but how much is it from coal or oil or the gas that we’re burning anyway?

 Will: Oh, no, no. You’ve got to let me get to the point. This is quite a complex sort of thing to grasp. So imagine there’s a lot of efficiency… That energy you’ve got, 65% is, if you’re not capturing the heat and using it usefully, which a lot of plants do, but there are some that don’t, then you’ve only got 35% of the energy in your gas is being used for something useful. Where the technology has moved on and back to the microgrid thing, is it’s about energy production and storage. Okay. So if you can have a photovoltaic array that is on your shed roof or on your roof, and that is also charging a couple of batteries. When the sun’s not shining, the batteries are connected to your inverter and they’re downloading into your inverter, which is stepping up the power to 240 volts and is effectively powering your house. And then.

 Manda: I wish.

 Will: Well, I’ve just bought one of these arrays.

 Manda: Okay. You and I need to talk offline about that because ours doesn’t do that. But anyway. Yes, that’s..

 Will: I was very particular about getting one of those, because I think energy storage is the answer. And the reason why I’m talking about this in this way is because, yeah, you’ve got the micro-grids distributed energy generation and the, the base load from anaerobic digestion is great because of its 8000 operating hours in the year at flat out. But if other renewables can effectively contribute to energy storage and then the  instantaneous generation, plus the stored generation will then contribute more to that baseload. Then, rather than burning the bio gas in an engine that’s not very efficient, you could upgrade it and turn it into vehicle fuel. Then that’s a much better use of biomethane because you’re directly replacing diesel and petrol.

 Manda: What’s the loss in the upgrade? You said upgrade it. How much power does that take?

 Will: Oh, well, you probably get about 1% methane slip.

 Manda: Did you say methane slip, 1% loss then? So it’s a 99% efficient production process.

 Will: Yeah, about 99% methane recovery through the process.

 Manda: Okay. All right. And then we can stop this rush to electric vehicles, which is creating a dearth of rare earths. John Whitelegg, who lives in Shrewsbury near us, who’s one of the most switched on transport people I’ve ever met, said there isn’t enough cobalt in the entire planet to even replace the UK fleet, never mind the world’s fleet with electric vehicles. So why are we doing this? But if we could use the vehicles that we’ve got and the designs that we’ve got and just put methane into the tanks instead of diesel, then we’re on. Does it require…so this is presumably liquefied methane. Does it have to be under pressure? Do you have to really redesign the whole tank system and the delivery system?

 Will: Yes, you do. So methane or compressed natural gas is stored at, for cars and small vans at 200 bar and for bigger trucks and buses at 250 bars. So that’s a substantial pressure if you think that a typical car tyre is at 1.2 bar.

 Manda: Yeah, yeah, yeah. I remember from my anaesthetist days we used to store oxygen at 60 bar and you did not want to be near a cylinder if it blew. So 200 bar, you don’t want to be near your car if it blows. But presumably there’s reasonable safety constraints that people know about to make sure that you’re not just driving around in a bomb.

 Will: Well, of course. I mean, I would sooner be driving in a gas vehicle than a petrol vehicle if there was an accident, because methane is lighter than air goes up into the air. Whereas if you’ve got your petrol tank ruptures and you’ve got a pool of petrol around your vehicle, that’s a far more frightening prospect to be in.

 Manda: Okay.

 Will: And you know, there’s very strict rules and regulations concerning the storage and the infrastructure to manage compressed gases in vehicles. So, yeah, I think that what we have to look at is do we use the existing cars that we’ve got and retrofit them? Well, retrofitting is always a little bit difficult because… There are some very, very good retrofit kits in the market. But there is an element if you’ve got a vehicle that’s made by number one, which has got its own engine management system, etc., etc., and then you’ve got some aftermarket equipment, even if it’s very good. That can it dovetail into the sophisticated engine management software of the OEM vehicle? Probably not. So you’re going to be running at a slight compromise. And this is really extremely important because the truck market looked at dual fuel retrofit for diesel and gas. And what happened with dual fuel kits was there was actually a substantial volume of methane that was not being burnt in the engines and coming out of the exhaust because of this.

 Manda: Oh, no disaster.

 Will: Which is why all gas trucks now which are being used are all dedicated gas engines. They don’t slip any methane. So what’s the best thing to do for the transport solution? I’ll be honest. I don’t really know. I mean, my policy is to have well maintained old diesel cars because they just work extremely well and living in rural areas. I mean, what you didn’t mention is the what’s the weight on the electricity grid going to be to charge up all this supposed electric cars when if you want to have a decent fast charger, you need a three phase electric supply with a cable about as thick as your arm. And so I really don’t know what the answer is. But within the agricultural context and with the community transport context and with kind of back to base fleets, if there’s a point source of biomethane on a farm, for example, then, you know, that’s great, make sure it gets used locally. But there’s also the opportunity to inject biomethane into the gas network at somewhere else, let’s say, in Lincolnshire. And then that biomethane goes into the gas network. And then if one has a filling station that’s connected to the gas main in Ludlow, for example, and a contract is signed, there’s a deal done between the producer who’s injecting energy into the grid at Site A and someone who’s taking energy out of the grid at site B. And the deal effectively says, right, you inject 100 megawatt hours at your site, then we’ll take out 100 megawatt hours of energy. Then, while the molecule is not the same as was injected as being taken out, it’s the energy that counts. And that’s called a mass balance. And that mass balance application of Biomethane injection and taking out somewhere else, is the whole driver for this deployment of CNG biomethane refuelling infrastructure.

 Manda: So hang on a minute. Are we still talking fuelling cars or are we now talking a gas network for heating houses? Because I’m guessing it’s different.

 Will: This is for fuelling vehicles, but it’s exactly the same principle as for heating houses.

 Manda: But there’s a gas network, there’s a kind of gas grid.

 Will: Yeah, correct.

 Manda: That covers the whole country. Whereas for fuel is there a grid? Or is it there’s a huge tank at the filling station and a truck comes up and  pumps it in.

 Will: So I would recommend your listeners go and have a look at CNG

 Manda: I will put it in the show notes.

 Will: Yeah. Just to have a look. They’ve got some good pictures. They run a very efficient network of CNG stations or biomethane stations, I should say. So it works like this, Manda. There is a network of gas distribution pipework that covers the whole country. If you want to build a refuelling station, you connect to that. So you have a compressor that sucks gas out of that gas network and then it compresses it to usually to 300 bar and stores it in racks of high pressure storage cylinders. And then the vehicle comes up to a dispenser, which is just like a diesel pump, plugs in its nozzle onto its special nipple that’s on the side, which is called a receptacle, presses the go button and then the the dispenser manages the flow of gas into the vehicle until the vehicle reaches 200 or 250 bar. And then on it goes. I mean, it’s really straightforward.

 Manda: Thank you. And I found CNG fuels and I will I will stick it into the show notes.

 Will: Thank you.

 Manda: So that we can see it. Okay. So just for my own interest, we’re back to as I understand it, it’s more efficient to be using biogas, methane for fuels. If we still want to power houses, what’s our base load? Is Boris Johnson right? That’s a sentence that doesn’t sit well in my mouth with the idea that we need 15 new nuclear power stations urgently to provide the baseload, because that does seem to be the issue with renewables. Unless we’ve got a lot of batteries which are going to hit the same rare earth issues unless the seawater batteries have come on a lot in the last few months that I didn’t know about. How are we going to create electrical baseload for people? Or is this beyond your your remit?

 Will: Yeah, I think that is beyond my remit. I just don’t know. I think that one thing which politicians are very bad at doing is telling people to use less energy. And that is one of the first things that I say. I mean, if you asked about how can people be given agency over climate change the way they can be given agency over climate change is being told to turn their thermostat down by five degrees and wear a sweater if it’s cold.

 Manda: Yeah, I know. And and yes, people are doing that. But I’m also listening to people who because of the fuel price rises, I was listening to an old couple yesterday. They haven’t turned their heating on for weeks. And she says we’re wearing, they’re both in their eighties. They’re wearing every item of clothing they got. Even in bed. The air is still crisp and and white when they breathe out. I think there’s a limit to how much we can tell people to do that. And it would be nice to be able to provide these people with heating that they could afford that wasn’t crippling the planet.

 Will: So the other the other way that people can have agency over this is we would we were talking about feed stocks and I told you that I was going to talk about extremes. And so we talked about slurry, which has 20 cubic metres per ton by 20 cubic metres.

 Manda: And then we must have human slurry.

 Will: I think that human slurry is great if you are living in a place connected to Mains drains.

 Manda: London, any city.

 Will: Yeah, a city, exactly. So if you look at the likes of Wessex Water, they’ve got a renewable energy production branch called Geneco. Where on any sewage treatment plants, the sewage sludge, which is the solid matter which I’m going to use, is the faecal material. Is digested anaerobically to yield biogas, sewage gas. Traditionally it was used just to heat the heat the digesters. Then it was used in combined heat and power units which are gas engines with heat recovery on the exhaust in the oil on the charger at the intercooler to produce electricity, to run the plants. And whatever spare would go into the grid plus heat. But more recently, they are using this sewage sludge to produce biomethane for injection into the grid. So Geneco, do this where they co digest sewage sludge and food waste and Severn Trent do it at Minworth, which is an enormous sewage treatment plant near Coleshill, that’s just southeast of Birmingham, where they are flowing substantial volumes of biomethane into the grid.

 Will: What I was really about to talk about in the context of agency is food waste, because food waste is an excellent source of biogas feedstock. And food waste, I think is the least acceptable part of the modern just in time consumer culture. And I don’t like general statistics, but I’ve been to food waste digestion facilities and I’ve seen the material that comes in and you could eat it all. You could eat, probably 60% of it.

 Manda: So is this a supermarket deciding that the three tons of cabbages are a day out of their sell by date? So we have to throw them all away in spite of the fact they’ve been wrapped in plastic individually.

 Will: Yeah, that’s correct. So I went into an anaerobic digester that was taking food waste from a major supermarket chain. I won’t say which one it was. About ten years ago, I saw rainbow trout in a box with the sell by date was the day after I was there and I was nearly made me cry actually, it was a disgrace. And then a curtain-sider arctic lorry backed into this reception hall and the sides went back and it was full of pallets of canned tomatoes. Now, I think canned tomatoes are things that you’re advised to put in a nuclear fallout shelter to last you for years and years and years. So this was you know, this was sell by dates.

 Manda: And how much use are canned tomatoes for a biogas generator? You have to crush them?

 Will: Oh, I mean, they’ll make reasonable amounts of gas.

 Manda: But how do you…do you have to individually get them out the cans or do you just put them in a great big crusher and smash them and then put all the cans and…

 Will: Know this is the great black art of what’s called de-packaging machinery to separate the packaging and the inserts from the feedstock. And actually, it’s really extraordinary the technology that’s used to do that.

 Manda: But surely somebody somewhere along the line going, this shouldn’t be happening…to cut that cycle before the pallets of tinned tomatoes end up being crushed and opened and think of the waste of energy and resources and everything.

 Will: So 30% of all food produced is thrown away at some point during its cycle, whether that’s out of grade, straight on the field or through to stuff that’s been chucked out because the sell by date has gone. You know, it’s a disgrace. And so ultimately, the best thing to do is to reduce food waste. And I think that that could be done by… You have high profile people like Hugh Fearnley Whittingstall was advocating people being less fussy about how bumpy a courgette was or something like that. I mean, it’s completely absurd that people believe that the taste is going to be affected by whether it’s a little bit lumpier than the next one, whatever. But ultimately it’s there. And so while I absolutely think it’s laudable, the attempts people are making to reduce food waste on a sort of individual or corporate level. Where there is food waste, it’s extremely important that if people want to have agency over it, they, they take their source separation seriously, in order to produce clean streams of food waste that will be collected. And they are collected actually in lots of big cities from the little food caddy, I would say virtually all of that goes to anaerobic digestion.

 Manda: I thought it went to making compost. Is the compost after the digestion?

 Will: No, the composting used to be the preferred route to dispose of organics because it effectively composting stabilises the organics, but it’s aerobic so it produces carbon dioxide and doesn’t yield any energy. Whereas if you anaerobically digest the food waste, you get methane, which is a great energy, an energy vector, and you get the bio fertiliser which goes back to land, so that you’re effectively nutrient recycling back to the farms. And so there was a really great experiment that was done in Ludlow, that was commissioned in 2008 where there was a 220 kilowatt food waste digester that was built on the industrial estate just inside the A49. Where it was designed to run on food waste from Ludlow, Church Stretton, a little bit into Mid Wales and it was the perfect sort of prototype for a small to medium scale community integrated food waste plant. And so if we’re talking kind of how it used to work, there was a couple of little collection vehicles that would go round and they would pick up food waste caddies. There was extremely good community engagement. I mean, if you go to Ludlow, you’ll still see window stickers that say We support the Ludlow bio digester. There was an electric milk float that used to get charged up on the electricity and would go round the small streets collecting food waste. And it worked extremely well until the South Shropshire District Council basically dissolved, because Shropshire became unitised. And then the food waste collection contract was let to a private third party, which meant that, for reasons that I don’t fully understand, the food waste collection around the locality stopped being done. Because the food waste was then diverted somewhere else. Which meant that this little AD plant, which was designed to serve a community, no longer had its kind of modus operandi.

 Will: And what was a real pity about that, was at the time it was pioneering because it it demonstrated that you could run a biogas plant just on food waste. It also had really good community engagement. So people were very proud of the fact that their food waste was going to something useful. It also supplied Digestate to a group of farms within about a ten mile radius, so the amount of ton miles of digestate was kept to a minimum. And now if that plant was still going, again using round numbers, if it had a 220 kilowatt chp on it, which would have pulled about 110 cubic metres an hour of biogas. So that would have made about 600 litres of diesel equivalent per day. If we were running that through an upgrader to produce biomethane, which could quite happily look after a major chunk of either municipal vehicle movements around Ludlow or some kind of community transport scheme. So those are the questions that I think, if people want agency over how can they do something useful? And for reasons we’ve discussed, they haven’t got room for solar panels or the capital investment or whatever, it’s to lobby their MP for some sensible use of their food waste, which shouldn’t be considered to be a waste. It should be considered to be a valuable resource.

 Manda: Brilliant. Ok, I’m aware that we’re over the time we said we would be and I could talk to you for several more hours about this because it feels like you know so much and there is so much in this that’s really, really valuable. But I think leaving people with something that they can do, and the understanding that methane used right is not bad. We’ve all got this kind of idea that methane is toxic and fugitive methane clearly is. But that used right and used by people who know what they’re doing, and there are people who know what they’re doing. It’s part of the overall solution. So we’ll leave people with, lobby your MP, see if you can get local food waste to be a thing. See if you can get local energy production to be a thing. See if you can get them to buy back the National Grid, because selling it off is functionally insane. I said that, not Will. Is there any other one thing that people could do that would be useful? What would people do with their cars other than use them less from now if they want to stop using fossil fuels?

 Will: I think to use them less and to really think about where they’re going and what they’re doing, I think that’s the best way to do it. And I speak as someone who has lived…I grew up in the countryside. I lived in London before I came back, and I was an avid user of bicycle and public transport. But the reality is of rural life, is there is a pitiful form of public transport. And again, lobby the MP for improved public transport links. But just use your cars as frugally as possible.

 Manda: Brilliant. Okay. We’ll go with that. So Will Llewellyn {four L’s and a Y), of Red Kite Management. Thank you so much for your time and your expertise and your enthusiasm. And just for a ray of light, I think. It feels like things are surmountable if we actually all got our heads around the ways that they could be surmounted. So thank you so much for coming on to the Accidental Gods podcast.

 Will: Well, thank you very much, Manda. That’s great. Thanks for having me.

 Manda: And that’s it for another week. Enormous thanks to Will for the passion and enthusiasm and depth of his knowledge. And for his practical action; getting out there in the world and changing things. So if all you do is write to your MP and enthuse about anaerobic digestion and the use of local food waste, then that’s a good thing. But you can also look at setting up things in your local area. We absolutely need to be generating our own heat and power and creating fuel for our cars. As ever, with these podcasts, the conversation continues when we switch off. And so if I got this right, one tonne of food waste will produce enough biogas to propel a two litre vehicle a thousand kilometres, and there are potentially 15 million tonnes of food waste in the UK per year. So that, if I get my arithmetic right, is 15 billion miles driven. Now having looked up the summary statistics of our government, we currently drive around 280 billion miles per year. So 15 billion isn’t going to wipe that out, but it’s going to make a significant chunk in what we can do. And I’m not suggesting that you rush out and get your car to run on biofuel, because if nothing else, the problem is going to be how to fill it. But talk to people, get people aware of what’s happening. Find out if there’s anaerobic digestion plants in your area. A lot of farms are running them. So it may be that there are ways you can do that.

 Manda: Can you convert your local area of town, your local area of village to some kind of anaerobic digestion use? Human slurry is a source of power instead of a way of completely contaminating our rivers as our local water company did. And for the sake of brevity, and because you’ve heard it all before, I have just deleted the quite long rant about our government conducting a fire sale of all our remaining assets. I will say I genuinely have no idea why selling our National Grid to an asset stripping company was a good idea. If anybody out there thinks they know the answer to that, please do let me know. Otherwise, your mission for this week is to write to your MP and your local council and anybody else that you think will listen and see if you can begin the move towards a more regenerative power production system in your area, wherever you are in the world.

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