Communicating the Cause

CAT is currently recruiting for some lovely long-term volunteers to join us here in mid-Wales. Are you looking to gain experience in woodland management, horticulture or marketing? CAT has five or six-month placements in these areas and we are recruiting in a rolling basis. If you are interested in applying then check out our volunteering website.

Yesterday we looked at the role of the Gardens Volunteer and the day before that it was the turn of the Water and Natural Resources Volunteers. Up today:

Media and Marketing Volunteer

Who better to discuss the role than Richard, a former Media & Marketing / ZCB Communications volunteer:

Richard, a former Media and Marketing volunteer

“I’ve always been interested in environmental issues and actually visited CAT back in the early nineties! I was a little shorter then though. So, having lived in London for almost seven years, I decided to move to mid-Wales and get involved as a long-term volunteer.

It proved to be an unforgettable but somewhat surreal experience…

I volunteered as media and marketing liaison for the Zero Carbon Britain (ZCB) project. My average day, if you can call any day at CAT average, involved working closely with the ZCB researchers, meeting like-minded individuals and leaving for home with my pockets stuffed full of organic vegetables – yum! I certainly wasn’t expecting to be sharing my desk-space with an overly curious robin. It’s not something that tends to happen in an office unless you’re Doctor Doolittle, Santa Claus or Batman.

Volunteering at CAT offered a great chance to be directly involved in promoting sustainable living. I learnt so much that I never expected. This is undoubtedly because of all the different disciplines that CAT is involved with. It’s a holistic hot-pot!

A great benefit for volunteers is getting involved in the short courses that CAT runs. Taking part in the sustainable woodland management course got me hooked on learning as much as I could. So much so that I still help in CAT’s woods when I can, despite working five days a week at CAT’s visitor centre.

Donating my time for the ZCB project also exposed me to so much amazing information about climate change and energy issues. The team isn’t enclosed in a stuffy research faculty but are communicating with the public on a daily basis, be it graduate students or visitors. The team take their research seriously and working in this unique environment lends the project a strong sense of community.

It is this aspect of environmentalism that gets forgotten all too often in research: community. The change towards renewable energy can benefit local communities and if the shift can also create jobs then the transition will be a lot smoother.

When you sit down – or should that be stand up – and look at the technology that already exists, it suddenly becomes clear that a completely renewable infrastructure is not just possible, but a necessity.

CAT has a unique role to play. Why not get involved yourself? I promise the robins aren’t that bad!”

Visit the volunteering website for more information about this placement.


Should Britain look forward to a new wave of tidal power?

Last week, an influential House of Commons committee announced serious concerns over Hafren Power’s proposed Severn barrage. It has been claimed that the facility could provide up to 5% of Britain’s electricity demand but critics warn that wildlife could be deeply affected. What does this mean for the future of tidal energy in the UK?

In theory, tidal energy offers huge potential for the UK’s power mix. Tides are incredibly predictable, more so than wind energy and solar power. But the sheer power contained in Britain’s seas come at a cost. The damage that seawater causes to materials and machinery makes maintenance an issue.

Tidal projects have always been difficult to fund, despite the fact that the UK has great locations for wave and tidal energy projects. The upfront cost of constructing these renewable energy projects has put many off. The other major downside to tidal barrages is the somewhat unpredictable ecological impact.

Peter Hain, former Welsh Secretary of State, has been a strong advocate of the Severn Barrage. Hain’s website states: ‘The barrage makes sense environmentally’. But is this really the case?

The current proposal is a 18km fixed tidal barrage across the Severn estuary. MPs on the energy and climate change parliamentary select committee have been examining the proposal. The report said that while a barrage might help tackle climate change, the environmental and economic case is not strong enough. The committee did however urge the Government to consider developing smaller tidal facilities.

Hafren Power responded to the report by saying ‘We believe the environmental and economic issues can be solved with everyone working together’. They claim that the Severn Barrage will protect against storm surges and save the UK billions in flooding costs. Critics, such as RSPB and WWF, fear that it will endanger the ecosystem, particularly birds and fish.

Peter Hain claims ‘the Rance Barrage in France suggests that there would be a significant increase in faunal abundance and biodiversity. The barrage would slow down the fearsome Severn tide, introducing more light and oxygen and therefore improving the water quality, attracting more fish which will support greater and more diverse birdlife.’

The Rance Barrage is one of the biggest tidal power stations in the world. Development costs were extremely high but these have now been recovered and it produces around 600 GWh a year.

Research shows that the dam has clearly modified the currents of the estuary and caused progressive silting. Sand-eels and plaice have all but disappeared, though sea bass and cuttlefish have returned. There have been large changes to the aquatic ecosystem of the Rance estuary but it continues to be varied.

So what about alternative schemes in the UK?

The Swansea Bay tidal lagoon is one such project. An ambitious tidal power station, it is seeking £10m of funding from the public. The scheme claims it could power 107,000 homes and generate 250MW of renewable energy. Small-scale investors have being offered a 55% stake in the company.

Traditional barrage designs consist of two different types. Ebb generation allows water to fill an enclosed area until full tide. Once the sea level has fallen enough, to create sufficient head, turbines generate power from the water leaving the enclosed area. Two-way generation allows water to flow through the turbines as the tide goes in and out. This energy produced is usually less than ebb generation but electricity is produced over a longer period.

The Zero Carbon Britain report recommends that tidal and hydro should supply 4% of the UK’s energy.

Tidal energy is still in its infancy compared with wind and solar, which have a proven track record. But with the crown estate investing £20m in the UK’s wave and tidal energy, this industry could soon begin to contribute. Ongoing advances in designs like SeaGen and VIVACE mean that the UK could be on the crest of a new wave of possibilities.

Taking the Pressure Off Your Water Use

Water conservation is a fantastic way to reduce your ‘water footprint’. It has a positive impact on waste, reduces the need to pump water over long distances and protects against water shortages.

CAT recommends connection to mains sewerage where possible because it provides an efficient way of disposing of material that is difficult to treat on a small scale. However, you can still easily reduce your water usage using these tips:


Use less!

Mains water provides a clean and safe supply of drinking water but it is vital that we all reduce the waste. Using less of this resource is a better option than trying to find more of it so consider simple methods of water conservation in your home. By replacing washers and installing flow control valves you can use less water.

Many properties already use a simple rainwater butt to save water for watering the garden. This can save significant amounts of water if you’re not doing this already.

The energy used to heat water has a bigger impact than the delivery of mains water so only boil as much water as you need. Using less hot water has a large positive impact on your energy efficiency.


Recycle your greywater for the garden!

Greywater is any household waste water that has not been produced from the toilet. As summer approaches, you can easily recycle your greywater for the garden and reclaim some of the nutrients you might currently flush away.

You can’t store greywater because it contains fats, bacteria and other pathogens. However, a simple way to filter your water whilst reclaiming nutrients for composting is to use a straw trap. This is a basket of straw inserted into your kitchen drain. It will filter large debris and some fat from your waste water. Routinely empty the contents of the trap into your compost and replace with fresh straw.

After filtering, greywater for the garden can be left untreated, but only if biodegradable, non-toxic household cleaning and toiletry products are used in the water system. Make sure to apply the dirty water onto the soil, not the plants.


Compost Toilets

The average person uses 50 litres each day to flush the toilet! Recycling water for flushing toilets can save domestic water but requires treatment such as filtering and disinfectant to remove biological material and bacteria. This will probably increase your environmental impact. Installing a low flush device is much more effective. The EA has a very useful guide on re-using and harvesting water.

Another option is a dry or compost toilet. These don’t use water to flush the sewage away and composts the waste instead. A range of choices are available, either to buy or DIY. Adding the right amount of carbon-typical materials gives good decomposition and creates perfect compost for the garden. You can use sawdust, straw & earth to this effect.

Keeping urine separate is key to a successful composting toilet, otherwise they can become anaerobic and smelly. CAT runs a one-day course on composting toilets, which serves as the perfect introduction to dry toilet systems.


Check out CAT’s information service for more tips!

You can find loads more info about sustainable living on our website. As well as our short courses, CAT offers a free information service on all aspects of rainwater harvesting & domestic water efficiency. You can contact us by phone at 01654 705989.

There are a number of great books available. Judith Thornton’s book, Choosing Ecological Water Supply and Treatment, is a fully revised new edition of CAT’s previous publication The Water Book. Choosing Ecological Sewage Treatments is also a great resource for anyone considering off-mains treatment systems.

How to make the most of longer days in the woods

If you manage woodlands you’ll know that spring heralds the time to reduce your timber harvesting. Richard and the CAT woodland team look at what opportunities the break in late spring and summer offers sustainable woodlands.

After what seemed like a long cold winter of rain and snow, some of you might have been worried that we’d never see spring! But with the first buds of blossom and the wild garlic flowering it seems that spring is finally upon us – though the rain is still here!

So what now for your woodlands?

Harvesting in April to May should be avoided in most native woodlands, especially those with dense ground flora. Indeed, it is best to avoid it in any managed woodlands until the autumn. This means spring provides the perfect time to start thinking about what products your woodlands can provide.

One of the easiest is to bind together Birch brash to create traditional “besom” brooms. Other uses for brash include bundling it up to create faggots for firing clay ovens. Long bundles of brash can also be used to stablise riverbanks and muddy footpaths. Willow can also provide the perfect charcoal for artists.

Chairs and gates are other potential products. They can be relatively quickly produced from green wood. Green wood is easy to use because it still contains sap, which makes the material easier to shape. If you want to develop this area of your business, a workshop can prove invaluable. Many sustainable woodland businesses use foot operated lathes to turn furniture legs and tool handles.

“The gentle interaction between the woodland and the woodsman, between wood and craftsman, is something to be cherished. The natural environment is our life support system and through understanding it we can step closer to making our communities more sustainable.” – Adam Thorogood, woodland management officer at CAT (you can read more here)

The warmer months also provide a fantastic opportunity to monitor the biodiversity in your forests. Ideally, we’d recommend that you record the different flora and fauna throughout the year but this can prove tough after the leaves have fallen. Trees become harder to identify and the forest floor can be masked by rotting leaves and snow or mud.

Managing a native woodland offers a great opportunity to promote biodiversity. Without active management, levels of life-promoting sunlight become reduced. The woodland understorey can become overgrown with brambles and high levels of nutrient run-off from agriculture can encourage prolific growth of plants like nettles instead of more diverse flora.

So as the local wildlife becomes more prominent over the next few months, you can witness firsthand how your sustainable management has affected biodiversity.

Many woodland owners may not realise that with a more considered approach to management they could get a wealth of rewards. More active management can help them make a bigger contribution to the economy, to carbon storage, whilst at the same time protecting and enhancing the environment and our heritage.

“Community woodlands are delivering a huge range of public and community benefits, including recreation facilities, biodiversity conservation, rural development and jobs, renewable energy through wood fuel, locally produced woodland products, social inclusion, and outdoors education.” – Coed Lleol Website

By hanging up our felling axes and focusing on biodiversity and green wood products until the nights draw in again, we can create truly sustainable woodlands.

CAT have approximately 30 acres of woodland under management, including a mix of species and ages. Our woodland experts teach on a series of short courses throughout the year. Find out more here.











































Recommended Weekend Viewing

The web is choc-a-bloc with videos vying for your attention on a cold evening indoors.  There are some great nuggets of green information and environmental news online.

Here’s a selection of CAT’s top videos and our favourites from the rest.

ZCB’s artist in residence, Joanna Wright, shared this inspiring video on zerocarbonarchive. The film by Lucas Oleniuk and Randy Risling documents a windmill builder in Africa:


Germany is leading the way with renewable energy and the Energiewende. This great little video from The Heinrich Böll Foundation explains what’s going on over there:


This video created by Lightgeist Media and the London College of Communication highlights the positive message of CAT:


Bob Shaw teaches on our woodland and greenwood crafts short courses. Here he demonstrates how best to fell a tree sustainably:


CAT has some fantastic organic gardens at the visitor centre. Our experienced gardener, Roger, talks briefly about his techniques:


Community energy schemes are a great way to cut costs and emissions! This short film by Cornelia Reetz shows how the Scottish town of Fintry is using renewable energy to benefit the community:


This short film from Josh Fox, Oscar-nominated director of GASLAND, looks at the techniques used in fracking for shale gas. (Warning: this contains strong language)


You can find all our videos on CAT’s youtube channel.

And let’s not forget why being sustainable is so important in the first place. Last year, Sir David Attenborough spoke to the Guardian about climate change from his perspective. Watch it here.

Confessions of a Wannabe Woodsman

I’ve been living in deepest, darkest Wales for nearly half a year now, surrounded by trees and forestry. However, I know next to nothing about these magical places. So earlier this month I decided to rectify this and take part in CAT’s sustainable woodland management course.

I have always been captivated by being outdoors. Not gardening though. Secateurs aren’t really my thing. But the idea of managing a wild wood is a different prospect altogether. There’s something magical about woodlands. These places have captured my imagination more than farmlands or the coast or even mountains ever could – and I love meandering up mountains. No, secretly, I’ve always wanted my own wood and to chop my own timber.

The course was run by Bob Shaw and Adam Thorogood. Shaw has been working in woodlands for over forty years and is an expect in sustainable forestry, whilst Thorogood is responsible for managing CAT’s woodlands. They both begun with a tour of the woods at CAT. What was immediately apparent was Shaw’s deep knowledge and passion for the landscape around him. He seemed to have an eye-opening answer for any question the course participants threw his way.

A short tea-break gave me a chance to find out more about the other participants. This group of eager beavers ranged from forestry staff to landowners to people that just wanted to know more about their countryside. Blue, a budding attendee with a background in media, was keen to start managing his own forestry. Like me, he had been interested in woodlands all his life. Unlike me, he was already deeply involved in woodland management and had volunteered previously. He wanted to learn as much as he could. You have him to thank for the great photos by the way!

The fantastic thing about managing woodlands is that there’s so many people that want to get involved and there are so many possibilities for co-operatives or social enterprises.

The short course was only three and half days long but the schedule offered us the chance to visit a number of different woodland types. We visited Escair Timber, Shaw’s own woodland nearby and a co-operative of which Thorogood is a member. Comparing the three was a great demonstration of how varied this woodland malarkey is. There’s coppicing, plantations and ancient woodland sites all need to be taken into account. It’s not just about growing a few trees and then chopping them down… well it is, but there’s so many different ways of approaching it. One thing did keep nagging at the back of my mind though: when are we going to cut down one of these trees?

I mean, there isn’t a shortage of them. Surely there’s a tree somewhere that no-one will miss? I was probably missing the point.

Coed Gwern is CAT’s very own sustainable wood. It’s an idyllic spot overlooking the Dyfi valley. The blossom has yet to burst. The canopy is a web of silvery purple birch, winter wonderland pine and the odd crunchy orange oak leaf.

It was here that we finally got the chance to practice the skills that we had learnt so far. The group spent a morning assessing a small patch of the wood for problem areas that needed attention. Maintaining light levels is key to encouraging growth. It is vital that you identify the important trees. By pruning the lower priority trees nearby, you stop them from crowding the more important timber and can stimulate growth. It was apparent that some hardcore pruning was needed. This called for… secateurs!?

Coed Gwern also has a delightful workshop complete with lathes and saw-horses. Shaw and Thorogood used this wonderful spot to demonstrate what greenwood craft products can be produced sustainably from wooded areas. Everyone in the team got involved and by the end of the day we had a new gate to show for our hard efforts.

The evenings were spent watching engaging films about sustainable forestry or scouring CAT’s extensive library of practical text books. Both were fantastic tools for completing our workbooks in order for accreditation from the Open College Network.

CAT’s course did a great job at displaying how we can all record the abundance of wildlife around us. Biodiversity is a bit like the back of your hand – you know it’s there, but despite the saying, you very rarely stop to look at it closely. As our weather patterns continue to change, monitoring biodiversity is becoming an ever more important aspect of wood management. CAT has a monitoring scheme in place at Coed Gwern. Volunteers take responsibility for one of many monitoring posts in the forest. Tree types and coverage are recorded every month as well as moss and wildlife. This helps build up a clearer picture of how the woodlands are changing.

But they did not seem to be changing that much to me. We still hadn’t felled a single tree!

The final morning was spent learning horse-logging with Barbara Haddrill. I was admiring the majestic shire horses when Shaw said those magic words, “I think we need to fell that tree.” Finally the moment had come, we were going to chop something down! Of course first we had to do some messing around with health and safety equipment.

The tree was a Douglas Fir that had no potential for timber and was blocking sunlight for a nearby Oak. We were soon ready to go but discussion turned to alternatives for felling the conifer. Was it really necessary to chop it down. Eventually, Thorogood and Shaw decided it wasn’t.

It suddenly became all to clear to me, knowing when not to fell a tree is even more important than knowing when you should. This Douglas Fir was never going to produce quality timber. It was never going to capture the heart and imagination that an ancient oak might but that was no reason to chop it down. It did not pose a threat to any other trees, wildlife or passers-by. All that had to be done was to prune the fir’s lower branches. Now where was those secateurs?

My inner axe-wielding maniac had been sated… at least for the time-being.

The short course proved a fantastic entry point for anyone looking to try their hand at managing a woodland. The tutors are not only experienced but also great at communicating the essentials. You’re sure to learn something new about sustainability even if you’ve spent years in forestry management already. All you need is a sturdy pair of boots, good waterproofs and an open mind. Everything else is provided, even secateurs!

Photo: Building the new green roof display

Thanks to a generous grant by People’s Postcode Trust, CAT has been able to build a new green roof for the visitor centre. This photo gallery shows the steps that CAT’s Buildings and Maintenance Officer, Carwyn Jones, has used in the building process…

1. The old food-store is one of the oldest buildings at CAT. But it was in dire need of a new roof, so Alex and Carwyn got rid of the old one first. They managed to re-use the membrane though.

2. A frame was built for the new roof. The original timber was reused where possible but as you can see, we needed a lot of new wood. The new timber was sourced from local forestry.

3. Here you can see how Carwyn re-used the old membrane. He also installed a new skylight to increase the light levels in the food-store.

4. This special membrane has pockets in it that collect water to allow for slower drainage. Bigger grades of stone were used on the edge of the roof to border the frame.

5. Almost finished! A layer of slate chippings went onto the roof (notice the extra batons that Carwyn put in place to stop the slate sliding down the roof). Soon the roof will be planted with sedums, which will need less soil and be easier to maintain than turf.

Watch this space for more photos of the new roof. Why not come and see it for yourself over Easter? CAT has a full schedule of Easter activities over the holidays!

Sustainable Architecture Blog: Ramming home the benefits of earth buildings

Building with earth is an incredibly ancient construction method but that doesn’t stop it from being fantastic for modern building design. Rammed earth has excellent construction properties being flexible in design and application. It also embodies low-tech building methods.

Rammed earth is formed from loose subsoil, which is moist and compacted in layers. This presses the material to about half it’s original depth and forces the clay in the earth to bond with the aggregate. Because this process is physical, no chemicals are needed. You do however, need a high enough clay content (around 15-30%).

Due to it’s simplicity, this ancient building technique has been popular all across the globe. Cob, adobe and rammed earth were all used historically and these traditional building methods are now being re-discovered by sustainable developers and architects.

Rammed earth, in particular, is becoming ever more prevalent in modern architecture with the growing popularity for sustainable buildings.

There are many environmental advantages to earth buildings. In most instances, construction with earth requires low energy outputs and emits virtually no pollution. This means that rammed earth has very low embodied energy. The embodied energy of brick is six times that of rammed earth!

The thick walls of compressed earth buildings are also extremely fire-resistant; there are no flammable components and everything is so tightly packed there is little chance of combustion. At the other end of the scale, the addition of a stabiliser makes rammed earth resistant to most moisture but continued exposure to water at the top and bottom of earth walls must be prevented.

Earth has benefits for heating as well. It is a dense material that provides high levels of thermal mass, especially when compressed. However, the thermal resistance of rammed earth is very poor so it’s use in external walls is limited.

Rammed Earth: Design and construction guidelines suggests that “to meet thermal performance levels expected of modern energy efficient buildings… external rammed earth walls must either be very thick (over 70cm) or use additional insulation.”

Rowland Keable, co-writer of the book, began building earth structures nearly thirty years ago and now teaches on many natural building courses. He has extensive experience of working with earth, having published Rammed Earth Structures: A Code of Practice. He also established Ram Cast CIC and is a founder member of Ebuk. Clients of Keable’s have included the Eden Project, Big Brother and Bath University.

Building with earth is a great method for construction, especially when other buildings materials are limited. The Whole House Book states that “earth is the most immediate and locally available material it is possible to build with. It is also one of the cheapest and lowest impact construction methods.

Building with Earth is a three day short course at CAT that gives a thorough grounding in the building method. Designed for anyone that is interested in natural building methods, Keable’s course is very hands on and participants can expect to get muddy!

Photo: Biomass training at CAT

CAT’s new HETAS accredited Biomass facility is used for our Installers Short Course as well as allowing our postgraduate students to learn about the possibilities of biofuel heating. Check here for more information about Biomass.

Postgraduate study at CAT includes REBE and AEES courses, both of which teach students about sustainable heating.

The new short courses at CAT also include Building Regulations for Biomass Installers. This course is intended for heating engineers wishing to attend the Biomass for Installers course but have not undertaken the HETAS H003 and H004 courses.