English · Français
Forum Synergie

Linking sustainable practices throughout Europe

[EXP] Centre for Alternative Technology (CAT), Europe’s leading Eco-Centre

Researching, testing and demonstrating sustainable futures for over 30 years in Wales

Rural topic(s): Agroecology and agroforestry, Renewable energy and eco-housing

Type: Success story

Date of writing: July 1, 2011

Author(s) of this page: Delia Sambeteanu and Michael Dower

Organization(s): CAT (Centre for Alternative Technology)


The Center for Alternative Technology (CAT) is a charity that since the 70’s has been exploring and demonstrating alternative ways of living, trying to minimise their impact on the environment and communicating the options that can be employed to achieve positive change in people’s lifestyles.

In their visitor centre but also through training, they share their knowledge on a wide range of alternative practices in eco-building, renewable energy (solar, wind, etc) and organic farming (composting, seeds, green manure, gardening techniques).


Ethos and location

CAT’s ethos is explained in the following way : “The voices of scientists have been warning us for a long time that the effects of pollution and of using up the world’s resources result in rising sea levels, shifting climates and creating extreme weather systems. The majority of people have not paid attention to those warnings and continue their comfortable and unsustainable lifestyles. Others have started to promote alternative ways of living, trying to minimise their impact on the environment. CAT is a charity that for over three decades has been exploring and demonstrating a wide range of alternatives, communicating the options that can be employed to achieve positive change in people’s lifestyles”.

The Centre is located on the site of the disused Llwyngwern slate quarry near Machynlleth, in mid Wales, just outside Snowdonia National Park. It is approached by a quite narrow rural road, ending in a car park, with a small reception centre, behind which is the entry to a steep cliff railway, powered by gravity and water. This railway (itself an impressive example of alternative technology) takes the visitor up into the floor of the quarry, which is 3 hectares in extent and has been made into an attractive landscape of paths, trees and ponds, among which are set a rich succession of buildings and displays related to energy conservation, renewable energy, gardening, compost and all other aspects of CAT’s sustainability message. In the further part of the site is the fine modern building of the Wales Institute for Sustainable Education (WISE), opened in 2010 as the focus of CAT’s educational activity.

Stakeholders /Organisation

CAT was founded in 1973 by Gerard Morgan-Grenville as a project intended to show the nature of the problems caused by human impact on the environment and to exemplify ways of addressing these problems. It began as a community of volunteers living on or near the site and dedicated to greater self-sufficiency, eco-friendly principles and creation of a ‘test bed’ for new initiatives. The volunteers had difficult times in the beginning - no electricity, leaking roofs, long working hours, lack of funding. Over time, more volunteers arrived, bringing a wide range of skills and experience.

In 1974 came the idea of turning part of the site into a Visitor Centre, which opened to the public in 1975. Since then, CAT has grown to become one of Europe’s leading eco-centres. It is visited each year by about 55,000 visitors who come to learn about sustainable lifestyles. Over 100 people work there all year round and 60 more during the summer months, including many volunteers. 16 people actually live on the site.

In terms of organisation, CAT is a cooperative, that is a self-governing social enterprise owned and managed by its staff. Supporting it is a membership association, with 7,000 members worldwide.

CAT is a member of INFORSE-Europe, which is a non-profit network of 70 European environmental NGOs in 30 European countries who are committed to promoting sustainable energy development in order to protect the environment and to decrease poverty. It is part of the global INFORSE network, established in 1992 at the Global Forum, which was a parallel forum to the UNCED Conference ‘Earth Summit’. The activities of the global network include development of scenarios for a transition to a 100% renewables energy supply by 2050. Website www.inforse.org

Aspects of sustainable development

CAT addresses every aspect of the average lifestyle. Its key areas of work are communication about sustainability; energy conservation and environmental building; renewable energy; and sustainable land use.

Communication about sustainability

CAT’s central activity is to offer ideas to all who are interested in achieving positive change towards sustainable lifestyles. It searches, in very practical ways, for globally sustainable, whole and ecologically sound technologies and ways of life. The small community living at the Centre is experimenting with different ways of living, putting cooperative and environmental ideas into action. The aim is to show that living more sustainably is not only easy but can provide a better quality of life.

Drawing on this practical and idealistic work, CAT seeks to communicate its findings to all who are interested, in order to :

Inspire - instill the desire to change by practical example ·

Inform - feed the desire to change by providing the most appropriate information ·

Enable - provide effective and continuing support to put the change into practice.

This communication is done through :

  • all the displays on the Visitor Centre site, which is open seven days a week

  • a free information service, available five days a week, to answer enquiries on a wide variety of topics by phone, letter or email : about 55,000 enquiries are answered each year

  • a consultancy service to give advice to bigger projects

  • publication by CAT of books, and of educational booklets for pupils and teachers, on many ‘green’ topics, such as energy efficiency, alternative building, transport and travel, gardening, solar energy, wind power, water power and bio-fuels : many of these can be downloaded from the CAT Website

  • a shop and mail order service, selling these publications and many other eco-books and products.

CAT has made a significant contribution to sustainability research and policy at national level, starting in 1977 by publishing a “Low Energy Strategy for the UK”. In 2010 CAT produced the “zerocarbonbritain2030 (ZCB2030)” report, which builds on the analysis in the first Zero Carbon Britain report in 2007 and describes in detail how the UK could make the transition to a zero carbon society as early as 2030. It sets out an integrated approach involving “powering-down” (minimising energy wastage) and “powering-up” (deploying renewable energies), combined with changes in lifestyle and land use. CAT believes that this report should be essential reading for politicians, policymakers, researchers and all who wish to address the challenges of climate change and energy security.


CAT is also heavily involved in education, from primary school to post-graduate level. The range includes :

  • school trips, tied in with the National Curriculum : over 10,000 children each year came to CAT on these trips

  • residential visits by children in the school holidays, when the children live in two eco-homes on the site and take part in a wide range of educational programmes

  • residential courses for adults, on which they can learn about energy conservation, renewable energy, composting and many other specialist subjects - hosting of volunteers, who may stay for six months or more on the CAT site, learning practical skills which will help them to get future employment

  • training sessions and conferences – held in the Wales Institute for Sustainable Education (WISE) building – for organisations and businesses which are keen to find out how they can improve their green credentials by being more sustainable.

  • A range of postgraduate courses offered by the Graduate School of the Environment at WISE, including : Professional Diploma in Advanced Environmental and Energy Studies ; MSc courses in Architecture, in Renewable Energy and the Built Environment, and in Environmental Change and Practice ; Doctorate in Ecological Building Practices; Distance Learning Masters course in Sustainable Built Environment.

Energy Conservation and Environmental building

The CAT website offers abundant advice on minimising energy consumption. CAT shows that there is huge potential to reduce energy demand in homes and other buildings without decreasing comfort or convenience. Much domestic energy is wasted. Simple conservation measures - such as good insulation, draught-proofing and adequate ventilation - can greatly reduce the use of energy and the emission of carbon. A low-energy house can meet half its heating needs by ‘passive solar’ design, e.g. making full use of available sunlight by careful orientation of windows and doors.

Eco-building is one of CAT’s key areas of work. Many building materials and techniques are displayed and explained in the visitor centre, in CAT publications and during residential courses. The ‘Whole House Book’ is a complete reference guide for self-builders and architects, showing how to choose materials and to design a healthy, efficient, and low-impact home. CAT advises that builders should use only sustainable building materials such as wood, straw or rammed earth; and should aim to minimise the ‘embodied energy’ of a building, which includes the energy used to extract, manufacture and transport all the materials used.

Renewable energy

CAT demonstrates various renewable energy options at the Centre. For the first 17 years of its existence, it depended wholly on its own supply of renewable energy from wind turbines, hydro-electricity and wood-burning. Since 1991, it has drawn part of its energy from the national electricity grid, including a period during which it helped to create (and drew power from) a 75KW wind turbine owned by the local community. More recently, it has built within the Centre a combined heat and power plant, powered by wood chips, from which hot water is pumped throughout the Centre’s site and which (when fully operating) will provide 97% of CAT’s energy needs.

For its visitors, CAT provides a wealth of information on renewables such as wind power, hydro-electricity, solar water heating, photovoltaic panels, heat pumps, and biomass heating. Thorough information on each renewable technology is available for different levels of understanding and interest : one can have a basic overview, have questions answered, acquire more in-depth knowledge (from a manual) or benefit from the short courses available. Every technology is presented in an objective manner, with its benefits and drawbacks, and with reference to other technologies that might produce energy or save carbon emissions more cost-effectively in a particular situation. With this help, enquirers can make an informed choice.

CAT’s advice on different options may be summarised thus :

  • Wind power may seem a good option because the UK is very windy, but for domestic locations people should be sure the site really is windy in order for the system to be cost-effective. A domestic-scale wind turbine may involve a big up-front cost. CAT also gives advice on community-scale wind turbines.

  • Hydro-electricity is one of the cheapest methods of providing renewable electricity either on or off grid. Turbines produce 240 volts AC and can be turned on just when needed, without the need to use batteries or an inverter (to step from DC to AC voltage). However, it is very site-specific, depending on a suitable flow of water.

  • Solar water heating systems use the sun’s energy to produce domestic hot water. A household in the UK can easily produce from solar energy about half the hot water it needs over the course of a year, thus reducing energy consumption.

  • Photovoltaic (PV) panels, which convert sunlight directly into electricity, can be used to reduce domestic carbon emissions : they can also feed surplus electricity into the main electric grid, yielding income for the household. This unobtrusive technology can be integrated into buildings, requires little maintenance, makes no noise or pollution, and can generate clean energy for a very long time. It requires a high up-front cost, but with the feed-in tariff incentive scheme can be a very attractive long-term investment.

  • Heat pumps are not a completely renewable heat source. Only if they operate very efficiently can they offer a better option than gas- or oil-fired heating. CAT provides advice on how to evaluate the efficiency of a heat pump, how the different types work, and what the costs are likely to be.

  • Wood is a renewable fuel that can be produced locally, and can be counted as sustainable if a new tree is planted for every tree that is cut down. Batch log boilers and pellet boilers offer more convenient and efficient ways to heat with wood than do traditional stoves.

CAT also provides information on the Government’s grant schemes which encourage the use of renewable technologies, such as the Feed-in Tariff scheme to support small-scale generation of electricity from renewable sources, and the Renewable Heat Incentive scheme to support generation of heat from renewable sources.

Sustainable Land Use

The Sustainable Land Use Initiative at CAT provides a formula for the adoption of appropriate practices and a catalyst for change. The main elements are described below.

  • Soil and growing techniques. CAT has experimented for over 30 years with various methods of enriching the soil without use of artificial chemicals. CAT’s gardens, including a vegetable field, demonstrate the benefits of organic growing and the techniques used in producing healthy vegetables and flowers. Advice is available on using different compost mixes and on nutrient recovery from human excreta and green manures.

  • Composting. CAT demonstrates many different kinds of compost - for example high fibre; leaf mould; grass clippings and paper towels; woody waste Food waste is composted hot in a machine that turns it and aerates it. The waste from earth toilets is composted in a chamber below the toilet pedestal. Solids from the sewage of the entire site are separated in a reed-bed system and then composted in a process that takes about 2 years before they are used to fertilise ornamental gardens.

  • Green manures are fertility-building crops such as clover and field beans, which are grown to collect nutrients in their biomass. When mulched into the soil, they increase fertility and improve structure. This helps to reduce the use of nitrogen fertilisers and thus cuts down on carbon emissions.

  • Pest control is done using natural methods. Predatory species are encouraged by providing them with habitats and nectar sources. The vegetable crops are inter-planted with flowers and green manures.

  • CAT is researching the effects of biochar in improving soil quality. Biochar is a means of storing carbon dioxide from the atmosphere in the form of charcoal, which can then be permanently stored in the soil in a stable form.

  • CAT it is also known as a seed saver. It preserves rare vegetables by saving their seeds from year to year and by trying to bring certain varieties back from the brink. Some of the seed is sent to the national Heritage Seed Library at Kew Gardens in London.

  • Water and sewage systems. Water from upland catchments is collected in a reservoir on the CAT site, where it is used for producing electricity or for domestic use. Only part of the domestic water is treated to drinking standards, and this is done without the use of chemicals by using an ultraviolet filter. The water for flushing toilets and for watering the garden comes directly from the reservoir and from the rainwater collected off roofs. CAT uses a variety of sewage treatments, without electricity or chemicals, in order to demonstrate sustainable alternatives.

  • Habitat restoration. Coed Gwern (Alder Wood) is a 6-hectare woodland acquired by CAT only recently. It is a former coniferous plantation that was clear-felled 16 years ago but retains healthy regeneration and some mature oaks. The woodland was drained in the past for forest activities. CAT intends to restore the wet woodland that existed prior to the planting of conifers, and will include alder trees in order to fix nitrogen.

Challenges / Perspectives

The Centre for Alternative Technology is sited in a beautiful but relatively remote region in Wales, which (however) can be reached in just over 2 hours by train from Birmingham in the centre of England. Its diversified educational activity, and varied means of communication, enable it to serve a wide public. Success in the campaign that CAT and other organisations in many parts of Europe are pursuing, to avoid serious climate chaos and to deliver energy security, depend on political leadership and for social change. The technology is there : the challenge is social and political. That is why CAT places such emphasis on broad public education, and why it has published a Zero Carbon Britain scenario, which explores what would need to be done to remove fossil fuel dependency in 2 decades. This report can be downloaded free of charge from the CAT website - www.cat.org.uk



The Centre for Alternative Technology is a very pleasant place to visit, easy to wander round, and very thought-provoking. It offers information in simple bites, and in a provocative way, with hands-on opportunities for children and adults. It is run by enthusiasts, and is clearly expert, which encourages confidence in the ideas that it offers. Its range of information and educational activity enable it to connect with people of all ages and all degrees of interest in sustainability. The opening in 2010 of the WISE building and Institute has greatly strengthened its ability to raise levels of awareness of sustainability issues and solutions among organisations of all kinds in Wales; and its outreach of information services and publications allows it to reach people much further afield. This offsets the disadvantage of its rather remote location. The search for sustainability in Europe would be enormously assisted if every European country had a Centre for Alternative Technology like this one in Wales.


Source: CAT’s website www.cat.org.uk

Visit to the Centre : Paul Allen, External Affairs Director, CAT


Centre for Alternative Technology (CAT),

info (a ) cat.org.uk


See also publications.cat.org.uk




Scale of intervention : Local

Keywords: eco-business, renewable energy, collective approach, organic farming, Information / Education for sustainable development, solar energy, wind energy, energy saving, eco-housing, organic building material, seeds saving, natural habitats preservation, composting, reed-bed sewage, waste water treatment, green manure, improving soil quality, gardening

Places: United-Kingdom

Actors: self-governing social enterprise (cooperative), training and visitor centre

Methods: voluntary work, non formal learning, training workshop, training/capacity-building, research and training, consulting/expertise, ouvrage