A Cornish Experiment in Sustainable Power
With your help, we aim to build and test an experimental engine fuelled by wood chips to power a lightweight vehicle. We've been developing this new concept of biomass-fuelled engine, based on a combination of old and new ideas, and are now at the point where we can integrate our designs into a first complete engine. This will be an exciting next step after many years of research and practical experimentation.
We are a small team based in West Cornwall and like many forward-thinking people we are interested in renewable energy. With particular regard to engine fuels, the current mainstream approach is to grow monoculture crops that are then extensively processed into a format suitable for existing engines. For example, sugarcane is grown and then fermented to produce bio-ethanol as a petrol replacement fuel. We think that a far better approach would be to develop new engines designed specifically to run on a broad range of minimally processed plant matter, typically woodchips.
“I can’t resist getting behind these guys, if only so I can get a step closer to my dream of a carbon neutral wood-chip powered flail mower for River Cottage. And maybe an eco-jet ski to get me a bit quicker to my favourite inshore fishing marks…"
Hugh Fearnley Whittingstall - River Cottage
Historically, Cornwall is the birthplace of high pressure steam power, and a very appropriate place to develop a new form of wood-gas fuelled steam engine. Our engine will be compatible with forestry brash, scrap wood, hedge trimmings, crop residues, and so on, which need only be dried and chipped. This engine could be used in all sorts of ways, but our first one will be used to power a modified recumbent trike.
We will use our powered trike prototype for practical trials and for demonstrations. It will be a form of power-assist vehicle but with an important difference. Instead of having pedals, the rider will use leg power to pump air into the engine's combustion chamber to generate the heat needed to raise steam. The harder the rider pumps, the more steam pressure will be created and the faster the trike will go.
As far as we know, this concept has never been explored, and is actually more like a form of 'muscle-power amplification' (rather than power-assist). The engine and rider will have to work together to power the trike, and this makes for an unusually simple mechanical system.
Our engine will basically consist of:
1. A high efficiency gravity-fed wood chip gasification/combustion system of our own design.
2. A monotube boiler
3. Our unique rotary expansion motor that uses flexible tube 'muscles' instead of pistons and cylinders.
4. A steam condenser
5. A circulation pump
6. Foot-operated high-flow air pumps.
The technical spec for our engine will be:
Top operating pressure - 110psi
Combustion chamber exit temp - about 1000 degrees C (raising superheated steam to approx 250 degrees C)
Maximum power output - 1 horsepower (roughly three times more powerful than an average cyclist)
Warm up time from cold - around 5 minutes
Thermal efficiency - estimated between 15% - 20%
Fuel efficiency - we hope for about 25 miles per kg of wood chips
Given that we will be running on locally grown fuel, we expect the 'twig to wheel' efficiency to be unbeatably high!
We hope to validate this new concept as possibly the simplest engine yet devised capable of powering a vehicle using biomass. Variations of our engine may prove to be useful in many other ways (such as to power small boats, or generate electricity, etc.). Wood is an important renewable energy source - when grown and managed sensibly - and we aim to demonstrate that when it is burned correctly and in optimal conditions, it can also be a very clean and powerful fuel.
Please explore the rewards offered for pledges to this project and help us if you can. See the budget section of our project website for a full breakdown of how we will use your money.
Our particular expertise is in the adaptation of existing and recycled parts and materials for the building of components; a methodology we refer to as shoestring durch technik. We expect the building and preliminary testing of the trike-with-engine to take 4 months.
If the project is successful we hope to build bespoke engines for anyone who wants to commission one. We may develop kits and plans to enable others to build them too, and it may help us to find government and/or private backing to develop our engine concept more seriously. We also hope to encourage the involvement of universities with our ideas.
Please enjoy our film and support our project!
Graham Waldren, Mat Thompson & Richard Blackborow
The Zennor Phoenix Team
How crowdfunding works
You pledge using the options on the right of the screen. Only if enough people pledge and we reach our target of £7,000 by our deadline will our campaign be deemed 'successful'. Then pledges will be collected and rewards distributed. We will thank and post the names of all our funders on our website. Those of you receiving willow cuttings will be contacted to find out when you'd like them, or if you'd like us to plant a tree for you. We will then enjoy the midwinter festivities before beginning our 4-month project on Monday 5th January.
January and February will be spent building the engine and adapting the trike. Those of you taking a tour of the woodland workshops and seeing developments will be invited towards the end of this period. In March we aim to be testing and refining the trike and by April finish the short film 'The Making of the Zennor Phoenix'. At this point we will honour all outstanding rewards.
There are two ways to pledge to make this project happen, via Paypal or Go Cardless. If you use PayPal, your donated amount will be debited from your account immediately and held by Crowdfunder until we reach our target, at which point it'll be given to us to start our project. If we fail to meet our target, the money will immediately be returned to your account. If you pay using Go Cardless, the amount you pledge is not debited from you account until such time as we reach our target. If we don't, the money is never debited. We hope that makes sense! Please contact us if you need any further clarification. Both payment options are safe and simple to use, and we thank you in advance for your generosity.
We will keep you all updated with our progress at key stages and send you all a report on the project at the end.
You can also pledge money to help support us and opt out of the offered rewards!
International pledges are accepted but additional postage will be added.
If you would like to know more about the rewards, or want to ask for something else, please use the 'send message' button. Let us know what you might like and how much you can pledge, and we will do our best to accommodate your ideas. We think that this is a really worthwhile ecological project and aim to make it interesting and entertaining too.
Click on the image to visit the Zennor Phoenix Website, where you'll find more information about our project.