In Newquay, a startup called Bennamann is pioneering another type of clean energy – and it comes from cow poo. We spoke to Bennamann’s business development engineer Kate Dibble about how it works, how she got involved, and why renewables is such an exciting area to work in.
Kate, tell us a bit about Bennamann – what does the company do, and why is it important?
We’re all about turning methane into clean energy.
Every dairy farm has a slurry pit, where farmers store cow poo to turn it into fertiliser. The problem is that as the poo decomposes, it releases methane into the atmosphere. And methane is a really harmful greenhouse gas – it’s up to 86 times more harmful than CO2.
If we can capture that methane, we can stop it getting into the atmosphere and heating the planet.
So Bennamann has developed technology to turn methane from slurry into clean biofuel.
That sounds brilliant – how does it work?
The first part is simple. Our technology covers the slurry pit, captures the methane, and processes it to filter out some of the nasties.
The other bit is more difficult. Methane is a gas at room temperature, but to be used as fuel, it needs to be liquid. That means you have to cool it down to -160˚ C. And you have to keep it at that temperature while you transport it and store it wherever it’s going to be used.
So Bennamann has a patent for a ‘non-venting liquid methane storage tank’. It's like the vacuum flask you use to keep your coffee hot. There’s an inner vessel and an outer vessel with a vacuum in between. The liquid methane is in the middle, and as very little heat can get in, it should stay liquid.
But in reality it's not perfect. Some heat always gets in, the methane starts to turn into gas, and the pressure increases. You have to let the gas out, but we don’t want it getting into the atmosphere. So we designed technology that takes the boiled-off gas and uses it to re-cool the liquid in the tank.
Watch how Bennamann's methane recycling technology works
It’s simple but effective, because it means you can liquefy methane at the farm and then transport it to wherever it’s needed.
And where might it be needed – who uses liquid methane, and what for?
You can use it in vehicles, or to power a generator to create electricity. That’s a real advantage because it means you can have clean electricity in places that are off-grid. So you could use it to power an electric vehicle charger in a remote location, for example.
We’re actually running a project with Cornwall Council to capture methane from six of their dairy farms, and use it to power Cormac’s road repair vehicles. It’s a really nice closed loop – and it’s carbon-negative because it’s preventing methane emissions and cutting down on fossil fuels.
We’re running a project with Cornwall Council to capture methane from six of their dairy farms, and use it to power Cormac’s road repair vehicles. It’s a really nice closed loop – and it's carbon negative."
It’s a really impressive use of a very abundant resource! What’s your role in all of this?
My job is a mix of business development and project management. On the business development side, I look at who’s interested in using our technology, and help them to work out how it could save them money. I might also help them plan a pilot project or apply for funding to use the technology.
In terms of project management, I work with my colleagues to make sure we're on track in terms of scope and cost for projects like the one with Cornwall Council, so that we deliver the best results.
And as Bennamann is a small startup, I’ve had opportunities to get involved in other areas too. I love being part of a small team that achieve big things. There’s a real focus on innovation and it's really cool when the team produces a new bit of kit – seeing it go from nothing to something that works.
"I love being part of a small team that achieve big things. There’s a real focus on innovation and it's really cool when the team produces a new bit of kit"
It's the kind of place where you can share your ideas and your ideas will be supported. And you’ll get your name on a patent if you contributed to the design. It's really nice.
And what's your background more generally – what brought you to Bennamann?
My background is in engineering – I studied a really nice course at Warwick University called Engineering Design and Appropriate Technology. It was basically mechanical engineering for hippies, with a real bent towards renewable energy.
I studied a really nice course at Warwick University called Engineering Design and Appropriate Technology. It was basically mechanical engineering for hippies!
Then I did graduate training with Scottish Power, where I got to see the energy industry up close. I was excited about it because I wanted to get involved with wind power. But the reality wasn’t what I expected – I wanted to be designing wind turbines, but the job was more about getting planning permission to put up poles.
So I moved on to work at the Carbon Trust on the marine energy side, which was a great opportunity to get involved with a new area of renewable technology. And then we moved back to Cornwall and I was very lucky to get this job at Bennamann.
What drew you to study engineering? Did something set you off down the track of being interested in renewable energy?
As a child I loved making things, and I’ve always been interested in nature and conservation. At school I was always more sciencey, so when it came to A levels, I chose Physics, Chemistry and Design Technology.
It was actually my Design Tech teacher who looked at my A levels and asked me if I’d thought about engineering. It literally wasn't on my radar, I had no clue what I was going to do at that point.
So I looked into it, and found it ticked all the boxes for me in terms of making things. And then I found that fantastic degree, which is what really sold it to me. It meant I could do something in renewables rather than just straight engineering, which I thought looked a bit boring.
It's interesting that you'd never thought about engineering. In our research at TECgirls, we found that very few girls choose engineering subjects at school. Do you have a view as to why that is?
I think engineering isn’t marketed well to women. On my degree, everyone doing mechanical engineering did the same first year, and then we specialised in the second year.
When we specialised, my course was 50-50 men and women. I think it appealed to women because it was positioned in a slightly different way. The emphasis wasn’t on making big noisy things, it was on what we can do to help society.
I think my engineering course at university appealed to women because the emphasis wasn’t on making big noisy things – it was on what we can do to help society.
One thing I’d also say. I went to an all-girls grammar school and there were 20 or 30 girls in my A level maths class. But my friend went to the local comprehensive in Tavistock, and in her A level maths class she was the only girl.
That really terrified me, actually. Because if I hadn't done maths. I couldn’t have done engineering. I don't know if that's still the case. I hope not, because that quite staggers me.
What would you say to an 8-12 year old girl about engineering as a career?
I’d say you're never going to be bored. It’s really interesting work. And there's so much you can do with engineering. I wish I’d known about it when I was younger, but it just wasn’t on my radar. It was never pointed out to me that I could design and build things.
I wish I’d known about engineering when I was younger. It was never pointed out to me that I could design and build things.
But now there’s Arduino coming through – there’s all this really accessible, fun stuff you can do in your living room. So I’d say do that, and just do what you love. If you do what you love, you'll end up with work you love. So focus on that and don't worry too much about what you’re going to study.