Achieving high-tech quality results with low-tech solutions

How the interdisciplinary integrated approach of aggregating effective solutions works in practice

There are countless examples of low-tech solutions applied domestically and commercially. It is easier to build, apply and repair such creations often made with recyclable parts and materials available everywhere. This extends the life span of the sum total of materials used by another 50-100 years before final scrapping.  Low-tech integrated systems that I discuss here replace too expensive or unavailable high-tech alternatives. They are a perfect offspring of a collaborative approach that brings together different disciplines to enable the innovation and installers work in synergy. Moreover, a sheer simplicity, beauty and quirkiness of such designs can awaken latent sparks of imagination, especially in young people and inspire a new generation of eco inventors on all continents.  One of the most redeeming features of these designs is not only high performance; it is the ingenuity of the thinking processes that are set into motion and then accelerated by viewing ‘old’ answers through a lens of new possibilities and needs.

In this article I focus on three solutions that to my mind are absolute stars in terms of what they achieve and how they transform the lives of individuals and communities alike. These eco solutions are examples of a highly effective approach to addressing socio-environmental and economic problems in communities all at once, if implemented strategically, as shown in application examples here.  When it comes to Europe, the low-tech is largely underfunded and almost invisible at a household level. As a result, immense educational and entrepreneurial opportunities are missed by our more materially well-off societies to accelerate a shift of scaling up and down all green innovation across different sectors. The councils could be promoting these as a sound option for house retrofits while interested craftspeople, the unemployed and generally anyone with technical skills and interest to develop them could be making these and gain an additional income.

The intermediate technology is one of springboards for a new approach that I have been promoting and presenting at COP conferences, art festivals and wherever possible to date– an integrated multi-disciplinary approach to tackling diverse problems by building an ecosystem of solutions shared globally within a framework of an open source philosophy. We called this a global immune system of solutions – a sort of constantly updated inventory of all solutions for tackling global warming.  We argued that it was no longer enough to just wait for everyone to change their behaviour, change lightbulbs or retrofit old houses; what was needed was a big plan that would aggregate the most effective solutions into all of our activities and all sectors. We proposed a framework where new forms of sharing of green solutions globally could be put forward at national levels so that interdisciplinary teams of specialists and generalists can tackle the issues effectively within today’s timeframes. This process would also need to interact with the public as creative solutions are innovated outside of academic circles everywhere.  Together with community instigated and managed lifestyle centres and newly defined SDGs, this would offer each country a highly effective tool helping them align their economies and social reforms with a robust climate change strategy that complies with Paris Accord agreement. More on this approach can be found on of my blog.  

Star solution 1:  Solar powered kitchens inside our homes

“We are star stuff harvesting sunlight.”  ― Carl Sagan

Have you thought about cooking ecologically with sun: to boil water for endless cups of tea or coffee or prepare a main meal of the day? A range of solar cookers including parabolic cookers, solar box ovens and other folded solar cookers that can be found on the market today have made this possible. They are easy and fun to use and can be incorporated in to a busy schedule. They make a perfect promotional tool when used at a local event promoting eco, locally sourced food made by a chef cooking with sun.

Solar cooking is often demonstrated at festivals and I set-up and ran a solar café with parabolic and other solar cookers at a Brighton festival. We boiled water for drinks and cooked light meals for amazed customers. Even on a slightly cloudy day, there was sufficient light that enabled our demo of the sun potential to provide us with free energy to meet our basic needs.  Without doubt, solar cookers are a great magnet for festival goers of all ages and crowd pleaser because of a sense of wonder they evoke. There is nothing better than seeing smiley surprised faces at the sound of kettle whistling in a field kitchen that doesn’t have any visible cables connecting it to the electricity. The whistle going off is like something switching on in the observer’s mind, a realisation that low-tech works and that intermediate technologies are a solid part of complex answers to our existential problems, which are increasingly framed and controlled by the climate change events. Solar cookers discussed here are The Sheffler Reflector units originally designed by Wolfgang Scheffler who built the first such device in 1986 at a mission-station in North-Kenya where it is still in use today. Nowadays, these novel solar kitchens are widely distributed by a German company Solare Brücke and their international partners. Their prolific work has resulted in a few thousand of the Scheffler Reflectors installed worldwide. The idea behind this innovation is that the sun energy is the only source powering our kitchens and we switch away from gas or electricity to these ecological units that can be partly fitted in our homes and partly outside. They help us run our kitchens more efficiently whilst reducing our household’s carbon footprint. For people living in the southern developing countries these solar kitchens power daily activities in absence of utilities and are therefore a much bigger deal as they save firewood and fuel – the two diminishing key resources consumed in vast quantities causing deforestation and global warming. So these solar kitchens are a win-win solution that can be deployed anywhere in the world allowing to build new green infrastructures that high-tech alone cannot bridge whilst accelerating the awareness of the need to act.

Are they better than high-tech? They are because they better suit the needs of people who utilise them at present.  It can be argued they are not perfect solutions as they function at 70-80 % efficiency when perhaps compared to highly technical and expensive solar systems produced today by high-tech companies. However, they are addressing the energy needs as you read this. When it comes to climate change scales, anything that works less than 100% now is better than something that works 100% tomorrow.  The idea with low-tech is to take some of that lost control back in our daily lives by empowering our energy consumption choices and this is true wherever you live.  On a community level low-tech solar removes the inertia caused by a lack of affordable answers and kick-starts new projects and businesses.  Everyone stops just hoping for things to improve, they are benefiting from such improvements in a way that promotes sustainable existence of man and nature. The use of simple techniques and tools, and local materials make the task possible and immediate. There is also a pool of data collected that enables us to extrapolate positive gains to help others to transition to a more equitable, eco-oriented economy, faster.

This point is emphatically driven home by the example of a Solar Kitchen installation at The Brahma Kumaris Yoga centre in Rajasthan, India. In 1999 – a giant solar-steam cooking system, based on 84 Scheffler dishes (9,5 m²) was built for 35,000 meals a day. The solar kitchen, which was installed by the centre itself, feeds around 18,000 visitors that pass through it at any given time and saves it 400 litres of diesel per day.

More on how they are built, various configurations of systems and other interesting background information can be found directly on the maker’s website:  They offer detailed construction manuals, which can be downloaded for free from their company website.   

Star solution 2:  Biochar water filtration system

“When the well’s dry, we know the worth of water.” – Benjamin Franklin

“2 billion people without sufficient access to water leading to 343 conflicts worldwide.”(Pacific Institute, 2018 Report).

“1 in 3 people globally still do not have access to safe drinking water.” (WHO’s 2019 figures)

“90% of the global economy and 78% of jobs worldwide depend on access to enough water of the right quality.” (Water Europe Water Vision 2030 and UNESCO)

“On average, Europeans consume 128 litres per person daily.” (EurEau survey, 2017)

“60% of sludge (wastewater) is reused.” (EurEau survey, 2017)

Annually, European water services invest approximately €45 billion in water infrastructure, suggesting that €93.5 is invested per inhabitant, per year according to EurEau’s (European Federation of National Associations of Drinking Water Suppliers and Wastewater Services).  These are phenomenal costs given that only just over half of wastewater is treated sufficiently to be used again.  A deeper look into the costs of drinking water investment in different countries across Europe reveals that they are not recovered and many countries fall behind the European regulations whilst the rising prices of water are the norm.  The feeling all around is that we need a re-think of about every process of water cycle; how water is used, managed and recycled.

Why is the drinking water, treated at high cost to us and the environment, still used for bathing and showers or doing laundry? Significant savings could be achieved if households switched to biochar filtrations systems for drinking water.  Rain water or surface water from streams could be treated using this method. For example, many houses in arid areas of southern Spain as droughts are commonplace and saving water is key to survival of man and livestock. These systems work in similar ways and are based on a roof capture where water is stored in an underground tank and filtered inside a house.  

Gravity-fed biochar systems are a proposed low-tech alternative to the conventional systems, particularly in regions where no or very little water is treated. They are made of four tanks-barrels filled with four types of filtration media, differing in diameter from large stones to gravel to sand and small size biochar pieces. The tank system is connected by pipes allowing the water to be fed through the system to be finally deposited in the fourth, clean water tank ready for use by a household.  The barrels are just food-grade plastic and can be assembled together into a system without power tools. They sit on the roof and filter the water. 

Biochar-based systems work in similar ways to the activated carbon systems and achieve comparable if not better rates of filtration at zero energy inputs as generally no pumps are required. Although the electricity might be necessary if the water needs to be brought to the site from a stream or other source. Two greatest advantages are; systems can be built in a few hours and do not require any mechanical parts that can break.  This repair-free system offers an ideal solution for resource-poor communities.

The maintenance which involves replacing biochar is said to fall in ranges of 4, 6 or 12 months after constructing a system depending on the breakdown rates of the pollutants in the treated water. Decentralised bio-filtration systems developed by Aqueous Solutions are estimated to produce 300L and 2000L of drinking water. Although they are too large for a small household’s drinking water needs, the designs can be adapted at the house level. 

Activated carbon filters are the most common type of filters that give us clean drinking water in our homes today. They rid water of chlorine, bad odours and tastes through adsorption, by locking pollutants in a carbon substrate. Their effectiveness is limited as they leave behind salts and some inorganic pollutants such as heavy metals from mining, agriculture and pharmaceuticals.  In biochar systems, the purification process works the same, i.e. pollutants are stored within highly porous biochar particles. The key difference between these systems is water flow speeds, which impacts their effectiveness.  More detailed system specifications can be found on the developer’s website. Biochar systems work independently of the water mains, therefore the flow can be regulated unlike with on-grid filtrations systems where water comes in at high pressure and flows through the system too fast to allow enough time for the activated carbon to do its job well. The advocates of biochar systems argue that they are superior to the standard carbon filtering due to these better adsorption rates for certain contaminants.   

Another drawback of carbon filtering is waste creation:  tons of plastic cartridges that encase the carbon need to be replaced and recycled every year.  And on this point biochar system scores higher because owners of these systems can make their own biochar or purchase it from the community thus supporting green jobs locally. So combining these improved systems with the existing ones makes a good economic sense in terms of green jobs’ creation.

Biochar – an ancient carbon sequester

It is possible to sequester historic carbon emissions as carbon in biochar remains stable for millennia. Scientists have found charcoal particles as old as 400 million years in sediment layers from wildfires, at the onset of a life on earth. The indigenous people used biochar to fertilise the rainforest soils of the gardens that they planted in the forest.

Biochar can be made simply by charring (the pyrolysis) anything organic, i.e. dry wood, hay, bones, timber by-products such as chips and sawdust in a two-drum, vacuum sealed charcoal ‘retort’, using high heat. ‘Retorting’ is a process, originally developed by NASA to preserve the natural flavour and nutrition in the freshest ingredients in which already cooked meals are sterilised in multi-layer tubs at high heat. Organic matter is ‘cooked’ by heat and gasses in low oxygen environment into a BIOCHAR ‘meal’ for plants or bio-filtration.

Benefits of ACTIVE CARBON in biochar:

  • increases crop yields
  • improves nutrient absorption by promoting soil microbes particularly mycorrhizal fungi
  • retains moisture, helping plants during drought and helping you save water
  • making biochar makes biofuels
  • reduces soil & water pollution by reducing leaching of fertilisers from the land

Biochar making is a rewarding activity although it requires some practice. There are videos that teach how to make your own. All that is needed is a couple of old metal drums, cutting tools and organic waste to burn. 

Star solution 3:  Swamp coolers

Also known as evaporative coolers – swamp ‘air-cons’ are the item to have when living in semi-arid or dessert environments. They are used as the name has it to cool the ambient air and increase humidity. Not only do they beat the air-conditioning units in terms of cost if not efficiency, they do not heat up the planet while cooling our living space. Swamp coolers are manifold today and they show the advances in ecological engineering that re-designs solutions so that they serve people and planet far more sustainably.  

How do swamp coolers or wet air coolers cool the air?

A larger commercial swamp cooler

Through a very simple gaseous exchange of molecules in the hot air as it passes through the unit and interacts with cooler water particles, which draw the heat from the hotter air entering the unit, cooling it down. This form of cooling by evaporation has been prevalent in many cultures for millennia until it got replaced in modern times with standard AC units, which require refrigerants to perform this exact task.  In North Africa and Andalusia that has similar hot and dry climate, the oldest effective method of passive cooling during summer was to hang wetted cloth in doorways and windows and allowing the hot air to cool as it passed through the openings while humidifying the environment. This is a highly desirable feature of swamp coolers when used in dry climates making breathing more comfortable. In colder climates, two-stage evaporative coolers are more suitable as they produce less humidity.

The biggest differences between the two types of air coolers are the cost of building and running the units and their environmental impact. Conventional conditioners produce chemical waste in the form of Freon, a chlorofluorocarbon (CFC) that has been linked to ozone depletion and needs to be disposed of accordingly which is costly. CFCs have been used in the manufacture of fridges, freezers and ACs although newer models use safer refrigerants due to improved regulation of phasing out ozone-depleting chemicals in the landmark agreement –The Montreal Protocol – signed in 1987. So if you still have an AC unit installed in your home that is a model made before 2003, it is certain to contain Freon gas. Swamp coolers are also considered a healthier cooling option than conventional units because the AC units run as closed systems; they re-circulate the same air over and over and can trap bacteria whilst outputting dryer air into our rooms.

A DIY swamp cooler

Swam coolers have been a real hit in the American southwest and Australia where demand for this type of cooling has been so great it has precipitated the trend and produced hundreds of variations of swamp cooler designs, ranging from simple DIY portable coolers made from food cooler boxes and fans to large, more complex commercial units. As the global temperatures are rising, they are likely to become cooling option of choice also in Europe.


Main banner peddle-powered blender image from:

DIY swamp cooler image from:

Large swamp cooler image from:

Biochar stove image from:

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