Plastic energy – Making hydrogen easier and safer to use

An Interview with Professor Stephen Bennington of Cella Energy
Plastic energy – Making hydrogen easier and safer to use

Cella Energy has developed a proprietary process that combines hydrogen-rich material with a polymer in order to create a solid form of hydrogen that resembles plastic. In its solid state, this material is more stable and therefore is easier to use as a clean power source for a whole range of applications, from UAVs to airplaces to cars. The material was developed during an extensive research programme in Oxford, UK, and the NASA Kennedy Space Centre in the US. Hydrogen’s low emissions and high energy density means it is an ideal energy source. However, transportation and infrastructure challenges have been a deterrent in its widespread use so far. Cella Energy’s solid form of hydrogen should now be able to change all that so that it can be widely deployed for clean energy applications.

REM talked to Professor Stephen Bennington, the co-founder of the technology, to find out more about it.

Tell me a bit more about Cella and what it does?

Well, we were founded in Oxfordshire in 2011. Around that time I had been working as an academic at UCL and at the Rutherford Labs looking to use nanotechnology to improve existing hydrogen storage. My team and I knew other materials have existed for years, but none have been stable enough for broader use and distribution. That was the problem we set out to solve.

Through our experimentation, we found a way to combine hydrogen-rich materials with a particular polymer that resulted in a plastic-like material you can compress and hold the hydrogen within. When heated to temperatures above 100 degrees Celsius, the material is able kick out hydrogen to be used as fuel. When exposed to air, the technology remains stable and can be tossed around without worry. We essentially created a safe way to store large quantities of hydrogen energy.

We then began looking into marketing the technology, but it became evident that people aren’t sold on the notion of hydrogen or green technology. What people want is a large amount of energy already installed within a device, so we developed power supplies using our hydrogen storage to replace batteries. After a few years of work, we have come up with a gas generator that heats up individual pellets one by one and feeds them into a fuel cell to get electricity. We also have power systems a third of the weight of a lithium ion battery with equal performance standards. Overall, we’ve created a super light- weight, portable power with no emissions.

What applications can this be used for? And how would it be incorporated into vehicles and aircraft?

One of our primary markets is within unmanned aerial vehicle systems, specifically the smaller scale UAVs used for surveillance, coast guard, security and agricultural work. All those drones are electrically powered, so we want to replace their fuel source with our proprietary system. Using Cella’s hydrogen fuel cells, UAVs will be able to fly three times longer then on standard lithium-ion batteries.

Our other big market is aerospace. We have been working with Safran, a French aerospace company, to adapt Cella’s technology for use onboard aircraft, powering galley and auxiliary power units. By replacing batteries and powering the APU onboard, our technology can replace anything up to 5% of the total energy used on the aircraft and reduce the take-off weight, which has the added benefit of decreasing emissions.

We’re also working in the automotive sector. We currently have range extenders for electric vehicles. When you run out of fuel, you simply switch it on and the extra range will be produced by a small compact system that powers a fuel cell. A few companies are interested in picking that up at the end of this year and taking it on as a project. We are also currently working with manufacturers to co-develop other products.

What are the advantages of this over other green technologies, such as Li-ion?

With lithium-ion batteries, you are mostly limited due to their heavy weight. Our technology is one third of the weight of a lithium-ion. The standard lithium-ion battery is also very flammable when exposed to air whereas our technology is completely stable. Consider these advantages within a real-world scenario, say, a soldier carrying a lithium-ion battery into battle. If they’re being fired at, and the battery is hit, it will explode. Our technology aims to reduce that safety risk as well as tackle the weight-load soldiers have to carry.  Our hydrogen storage is also stable, and does not lose power in storage, eliminating the need for continuous recharging.

What are the main challenges to be overcome?

The main challenges we’ve had to overcome are financial and commercial. The technology has been proven in the lab and we know people are willing to scale up, but we just need to find the right partners to fund the development of the technology and show that it works well in versatile applications. We have been working with Safran in the aerospace sector and we have a partner on the drone side. We are now looking for a partner in the automotive industry.

What are the predicted costs of this technology compared to other transport technology/fuels?

Within 4-5 years, we do expect the price to drop as the scale of manufacturing changes.  Once that happens, we should be providing the technology for things like scooters where each of our cartridges will cost around $20. It may still sound costly, but there are also the longer range times to consider.

In the future, we would like to get the price down to a few dollars per kg at wholesale. At that point the total cost of operating an EV will be roughly the same. We still have a way to go before we can see the technology in wider commercial use, but we hope that it happens within the next few years.

What are the next steps in the development in this technology?

We would at some point want to develop a pellet system to fuel cars, but we are a long way from that technology. We discovered early on that the transport sector is cost-sensitive and a hard market to enter as a new technology. Right now, we can't make a business model around it, but it’s part of our future once we can manufacture pellets in the tens of thousands of tons. We envision the technology as a competitor with both batteries and compressed hydrogen gas, which is not as safe.. 

Another project we want to work on is finding a way to feed the hydrogen into diesel engines to reduce particulate emissions. We’re working with University College London and it looks like it can reduce the number of particles by a factor of 1000, maybe 10,000. The clean air legislations from the EU are switching to focus on total particle count, so it could be an important task for us to have a solution for the issue.

Cella Energy Ltd is a UK registered company based in Oxfordshire with a wholly owned subsidiary, Cella Energy US Inc., registered in Delaware, USA. Cella has offices and a laboratory at the Rutherford Appleton Laboratory and similar facilities located in the Space Life Sciences Laboratory at the NASA Kennedy Space Center in Florida, USA.

For additional information:

Cella Energy

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