We have just returned from Aberystwyth (in west Wales), near to where is the Centre for Alternative Technology (CAT). There is a web-site www.cat.org.uk and a link to it on the left of this blog. The setting is an abandoned slate-quarry, which was bought-up about thirty years ago by a group of people with the vision to live sustainably. I am not suggesting that wider society will change overnight to a means for living at the laudably low-energy levels that the CAT pioneers have achieved, but they have provided a wonderful example and from which many important lessons can be learned. My comments here are purely my own opinions and reflect my immediate impressions following my visit there yesterday.
The main sense I am left with is one of both the necessity and possibility for energy efficiency. As I have laboured in these postings, the energy requirements of modern society are gargantuan and completely unsustainable. Running cars and planes takes almost 30% of the total energy used in the U.K., and heating buildings probably the same again. If we are to try and maintain these levels, we are going to need a lot of coal and nuclear power for all kinds of purposes including making synthetic fuel as the world's oil production inevitably falls. Sustainable energy provision, e.g. from renewables only makes sense if the demands that we place on such technologies, e.g. wind, wave and so on are reduced to a manageable extent. At CAT they have manged that, and for example their base-load electricity is provided by two hydroelectric turbines, which combined generate 7 kilowatts of energy. On top of this, they have arrays of solar-panels and wind turbines that produce much more power (when the sun shines and the wind blows), and they can export this onto the National Grid - or draw some of it back for necessary operations (e.g. arc-welding) if they need to. Thus, while they are self-sustaining to a large extent they are not totally free-standing, and it is unlikely and probably undesirable too, that we should ever become isolated communities with no common goals or bonds.
The water to run the hydroelectric power is supplied from a reservoir which is at height, and gravity then allows it to fall to drive the turbines. This same source even provides the means to run a water-powered cliff-railway consisting of two carriages, counter-weighted against one another. Water is run into a tank on the upper carriage until it is heavier than the lower one, and gravity does the rest! Water for washing and all purposes (I believe that around 15 people actually live full-time on the site) is also supplied from the reservoir (which collects rain water) after passing it though sand filters, and potable water after exposing it to light from a U.V. source (which causes small particles including bacteria to clump together so they can be more readily filtered out). Sanitation is taken care of using earth-toilets, some of which can help to generate compost for growing food, most of which is done on site, and there is a vegetarian restaurant which visitors can sample the delights of. The food is very good, and the important point is made, that most of agricultural land is used to grow food to feed to animals which are then killed to feed humans. If we lived on a completely vegetarian diet, we could cut the area of land we need to grow our food down to about one sixth, possibly allowing production of biofuels on some of the acreage that is thereby left clear. There is no doubt that we are going to have to live differently, and adopting a (more) vegetarian diet might afford far greater security of food production and indeed supply of fuel that is not dependent on imported oil. Don't get me wrong, we are still going to have to cut car and plane use, and I mean by considerable amounts, before too long.
There are many things to see - for instance, one gets a close-up of the hub (where the blades are attached) from a 72 meter rotor, wind turbine. There are displays of building using timber frames and with walls packed with straw and even sheep's wool as an insulating material. In one full-scale building "warm" air is drawn through underground pipes, thus reducing the amount of heat needed to keep its interior at a comfortable temperature for living in. There as also a theatre made from straw bales which fill-in the walls based around a timber frame.
There is a battery-store for essential stand-alone applications, e.g. running computers, where the power supply needs to be constant. The point is made that there is not enough nickel in the Earth to use in batteries to store electricity at the level we use it in the form of stand-alone power systems, though for isolated communities this would be ideal. Otherwise we can import and export electricity according to demand via a National storage-grid. Combined heating and power (CHP) is used to generate electricity too, from burning wood-chips, but most of the heat (two-thirds of it!), which is usually wasted from conventional power stations, is recovered and used to provide hot water for the restaurant.
There is so much here: based around energy efficiency, recycling of all kinds of waste, growing food on the local level, using the power of water and the Sun, and maximising the use of sustainable fuels (e.g. wood) and also the most efficient means for extracting the energy from whatever fuels are needed to be burned. I think it is fair to say that CAT have made a success out of a dream, and the world may turn to heed the message they have been espousing in a very practical and elegant way for over three decades.