CAT Volunteer Open Day

Tuesday 7th June 2011 11am til 4pm

Come and find out more about volunteering opportunities at CAT and previous, current and potential volunteers are invited up for lunch, 1pm.

Volunteering opportunities are flexible – some people come and volunteer full-time, some come up for just a few hours per month.

People from the area are invited to come up to CAT on Tuesday 7th June to a volunteer open day. Entrance is free, and we’ll have a free lunch on offer at 1pm. You can take a look around the site, meet staff, meet new and old volunteers, and chat about opportunities at CAT.

For more information, or if a weekend or evening meeting is more convenient, please contact Candy Bedworth on 01654 704971 or email:


Discover a new Wales at the Welsh Living Landscape Festival Sunday 29th and Monday 30th May – 10am to 17.30pm

Visitors are being invited to discover a new Wales at the Welsh Living Landscape Festival, May 29th-30th.

This vibrant and informative weekend event, which is open from 10am to 5.30pm on both days, is packed with fun activities, workshops, arts, talks and entertainment for all the family.

Local experts will bring the local landscape alive, explaining its geology and the fascinating history that has shaped it. From farming to forestry, slate quarries to sustainable building, visitors will be able to experience the magic of the Welsh landscape through new eyes.If you’ve ever wanted to explore the varied and wondrous ecosystems around us and to find out about the people who depend on them, this is your opportunity.

Grace Crabb, Ecologist and woodland manager at CAT said:
“Landscapes are incredibly important in Wales. How we manage our landscapes it vital to our rural economy and is also vital to protecting the incredible biodiversity we have here. We’re putting on the Living Landscapes Festival to help the public understand the unique landscapes we have here”

Julie Bromilow, Education Officer at CAT said:
“It’s vital that we begin to understand how landscapes might change as we adapt to climate change. The Living Landscapes festival is all about helping people explore what landscapes mean to them and why they are important”

CAT shortlisted for the prestigious Ashden Awards. CAT’s courses in renewable energy and sustainability shortlisted for sustainable energy award

The Centre for Alternative Technology has been shortlisted for the prestigious Ashden Awards for Sustainable Energy

CAT’s courses in renewable energy and sustainability have been recognised as a vital part of moving the UK towards a low carbon future by the judges of the Ashden Awards.

Paul Allen, Outreach Director at CAT said: “Being shortlisted for the Ashden Awards is a huge honour. Our educational and training programmes in renewable energy and energy efficiency are vitally important as we move to a low carbon society. We are delighted that the Ashden Award judges have recognised this and shortlisted CAT.”

CAT has been shortlisted for the award in recognition of its education and training work. The centre runs courses aimed at training people in the skills the country will need to make the transition to sustainable energy. These cover a variety of renewable energy technologies and sustainable building techniques, and take place in CAT’s newly-constructed Wales Institute for Sustainable Education.

CAT’s postgraduate programmes cover renewable energy and sustainable building techniques. They are designed for professionals wanting to work in the development of renewable energy and sustainable building projects, and combine both theoretical and practical components. CAT’s renewable energy postgraduate course covers all renewable energy technologies. During the course students work on real, functioning renewable energy installations that power the teaching facilities at CAT.

CAT’s unique sustainable architecture course covers both the theory and practice of sustainable building. Students gain hands-on experience working with low impact building materials such as earth, hemp and clay. CAT’s postgraduate students leave able to gain employment in a wide variety of sustainability, ecological building and renewables projects.

CAT also runs courses for plumbers and electricians to gain the qualifications they need to become renewable energy installers. CAT is one of the few places in the country where people can come and learn to install solar water heating, solar electric and wood heating systems.

The Centre for Alternative Technology (CAT) teams up with Shambala festival to demonstrate sustainable buildings to festival goers.

For the last three years CAT and Shambala have been working together to make Shambala the greenest UK festival by producing the most detailed carbon audit of any UK event. This year, Shambala achieved the highest ever rating from the Industry Green assessment, and, alongside CAT, have been working with Julie’s Bicycle ( to make changes at Industry level.

“Shambala is 99% powered by wind, sun and waste vegetable oil and has been judged the greenest outdoor event by Industry Green and A Greener Festival ” Sidharth Sharma, Director & Creative Coordinator of Shambala festival

This year CAT is teaming up with Shambala to demonstrate sustainable building to festival goers. As part of a shared commitment to sustainable futures (and having fun), the CAT team will be on-site showing what can be constructed with natural raw materials.

“Houses out of hemp, Walls out of willow, Towers out of timber, Structures out of straw and Arches out of earth – Come and help us explore the new worlds of zero-carbon building!” said Peter Harper from CAT.


The Shambala Festival has blended music, art, creativity and participation all in into perfect bite size chunks of brilliance for well over a decade. It is now firmly established and respected as being one of the most innovative, creative and environmentally conscious festivals in the industry.

Set across 4 days on the August Bank Holiday weekend, the variety and quality of entertainment on offer is staggering for a festival of its size. With over 200 diverse musical acts across 12 live stages, world-class cabaret, stand-up comedy, inspirational talks and debates, jaw dropping circus and acrobatics, interactive theatre and nationally acclaimed poetry all housed in beautifully crafted venues.


Woodland management

At CAT we manage the woodlands to enhance their biodiversity and maintain a range of habitats for wildlife. We thin the trees to keep a continuous canopy, favouring certain species and removing others. This provides us with a range of sizes and species of trees that we can covert in to different products. Part of my job is developing the uses of our timber and trying to create marketable products such as rustic furniture, turnery and garden products, gaining a sustainable economic benefit along side the environmental and social functions of our lovely woodland.

When the trees are cut down, usually in the winter period when the sap is low, the wood is graded in to levels of usefulness. Small diameter straight stems for bean poles and plant supports and slightly larger stems for hedge stakes. Any other small diameter stems go to make charcoal in our retort. Medium diameter straight logs of ash, willow, beech, sycamore, lime and birch are kept for green woodworking and rustic furniture and large straight logs of oak, beech, douglas fir, western red cedar and larch for milling in to sawn timber or are split for fencing or construction. Any wood that can not be converted in to woodland products we leave for firewood. It is left in logs, or ‘in the round’, for a year then split, chopped and stacked for another year so it is very well seasoned. On site we have used a variety of different stacking methods including the rather attractive round German woodpile called a Holzhaufen.


Over the few months or so we have provided poles for some of the courses run on site, supplied Chloe and Roger with bean poles and pea sticks for the gardens and made some door knobs for the renovations in site community. I have also made a gate, a simple bench and a few items of turnery out of green wood on our pole lathe, including rounders bats, honey spoons and garden dibbers. The list of items to make is set to grow as long as I can keep escaping from the office to the bodger’s shelter!

Reedbeds and Sewage

The Eco cabins at CAT have their own reed bed systems which are used to treat sewage. Reed bed  sewage systems use a series of natural filtration systems to treat waste water. Discharging of raw wastewater has a negative impact on the environment such as eutrophication of receiving water bodies, pollution of groundwater and odor. What is more, wastewater contains pathogenic organisms which transmit disease to animals and human. For these reasons it is crucial to have an effective sewage management system and operate it in proper way. This is what our biology department does.


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A comparison of two methods of mushrooms cultivation

Today I would like to talk more specifically about how we cultivate our mushrooms here at CAT. Currently, we are testing out 2 different methods so as to compare the results. One method uses straw or cardboard while the other method uses sawdust. In both cases, the straw/cardboard or sawdust must be pasteurised in order to clear them from micro-organisms so that the mushrooms can proliferate easily. This is done by putting them in boiling water for about 2 hours.

In the first method, the straw/cardboard is put in layers in a box with a small mycelium culture (i.e. spore culture), closed in a plastic bag and left in a hot room for about 2 weeks until it is completely colonised by mycelium. The straw is then put into a fruiting room, which is much colder. The cold shock that the mycelia undergo at this stage, make them start fruiting, i.e. growing into mushrooms. This process should take about 2 weeks as well.


The second method uses sawdust, is easier but takes longer. In this case, the mycelium culture is put into the sawdust and in an incubator until the mycelium culture colonises the whole container. The saw dust is then taken out and packed into pre-drilled holes in logs that have been kept on the ground for 2 years (this is to replicate the natural decomposition process). The logs are then left for about 6 month and should, hopefully, grow oyster mushrooms.


Mushrooms propagation or how to grow valuable protein resources

My name is Ariana, I am a long term volunteer in the biology department and today I would like to tell you more about our recent forays in the realm of fungi, that special kingdom not quite plant not quite animal.

Mushrooms are divided into different categories according to the substrate they live on; saprophytic mushrooms that break down organic matter and replenish the soils, parasitic mushrooms that colonize living organisms and mycorrhizal mushrooms that form symbiotic associations with plant roots.

Aside from performing important functions in nature like decomposing and recycling nutrients, mushrooms have a wide range of applications very useful for humanity. In Europe they are most famous for their culinary use, whereas in the East they are most widely employed in medicinal use; in Japan most cancer treating drugs are derived from mushrooms, and in China a huge variety are sold dry as health tonics.

Mushrooms have also been successfully used as barriers for excess nutrient in a process known as mycofiltration, as cleaning agents for toxic pollutant contamination (mycoremediation), and as inhibitors of undesired plant growth (mycopesticides). Mushroom propagation is a low impact very accessible technology that can be adapted to a range of climates, skills, time and materials available.

To propagate mushrooms here at CAT we use, an incubator to keep a stable warm temperature so that the original culture becomes established, an autoclave for sterilization of cheap grains (which the culture can use as a food source to get stronger), and a variety of woody wastes from CAT as substrate for mushroom fruiting.

Hardwood logs plugged with mushroom spawn have been part of the displays of the biology department as an example of ways to grow valuable protein sources on a shady corner of a garden or a forest. This year however, we are conducting experiments to increase the viability of the crop, and hopefully establish a production system that might allow us to do some more research on other exciting applications of fungi. To start with we are collecting different waste products from the many activities that go on at CAT (glass bottles and coffe grounds from the restaurant, bits of straws and hemp from the graduate school, woodchip and sawdust from the building department, cardboards…) and testing them for their suitability as substrate for oyster mushroom production, a species that will be a welcome addition to the restaurant kitchen.

Stay tuned for fruiting developments!


Vole family in our gardens

Morning Everyone, Keeping Roger our gardener and his volunteers company in the garden is a family of voles which seem to have set up home under one of the tarpaulin sheets. They are probably Field Voles, although Bank Voles are very similar and to add to the confusion Field voles sometimes frequent hedgerows and Bank voles can be found in scrubland as well! The Field vole is slightly larger and less reddish and has a shorter tale but as a fleeting glimpse is usually all you get it is difficult to identify with any certainty.

Most of us have seen voles but sometimes you are not quite sure what you’ve see – if you spot something that looks a bit like a small sausage with tiny legs suddenly shoot across the path or lane in front of you it is probably a vole. They are in fact one of our commonest small mammals with a phenomonel breeding rate–a single female can have up to 6 or 7 litters a year and the young become sexually mature at a few weeks old. Mind you they have to reproduce so prolifically as the poor old vole is preyed on relentlessly and is the main food source for many predators–it is the staple diet of Barn Owls (some owl pellets I’m dissecting at the moment contain practically nothing else but vole bones) and foxes like nothing better than a couple of tasty vole snacks as an appetiser before their main course.

In fact it is likely that very few voles live their full lifespan–most of these inoffensive and rather cute little creatures end up as a food item for some hungry predator. The other species of vole found in this country is the much larger Water Vole (the Ratty of Wind in the Willows) which lives as the name suggests in and around inland rivers. You have to work quite hard to observe most of our native mammals but it is worth the effort – so make the most of any chance encounters you have.


From Bristol to CAT: Countryfile takes on Sustrans

On the 4th of May, the Countryfile Magazine editorial team and Rich from Sustrans are racing from Bristol to the Centre for Alternative Technolgy in Machynlleth, mid Wales using a variety of different travel methods. They aim to explore the trials and the triumphs of travelling in rural areas. Each person will take different routes and judge how efficient it is a way to travel based on time, cost, experience, environmental impact and the effort (calories/ energy/ stress)


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