Archive for the ‘Sectors’ Category
Efficient Shower
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Since Chennai was plagued by water shortages, technologies to minimize water use were worked on at the Shri AMM Murugappa Chettiar Research Centre(MCRC). We worked towards a one litre bath. Can a technology be built that men and women (long hair included) can use to take a complete wash within one litre of water?
When you take a bath or shower the main idea is to wet the skin surface before the application of soap. In all the conventional ways this is done, the water is used very inefficiently. Stand in a shower and most of the water bounces of you. If you use a bath tub it is the most colossal waste of water. The typical mug and bucket system also is a waste us only a very small fraction wets the body and the rest falls to the ground without touching the body.
People who are bedridden are given a sponge bath. This is method uses just enough water to wet the body and after application of a suitable disinfectant (or soap) the rinsing is done again with a sponge. A wet cloth could just as well be used instead of a sponge.
At MCRC we designed and built a mist bath. We had an air compressor push compressed air through a custom built nozzle. Water was pushed through the centre of the nozzle and air from the compressor would hit it from all sides and make a fine mist. The nozzle was attaché to flexible hose and could be moved to different parts of the body. This shower was tested by men and women staff members. The men could shower in 1 litre of water comfortably and the women used about 1.5 litres.
The mist would be cooler than the surrounding air and ideal for a hot summer day in Chennai. Imagine how water consumption in the city would be reduced if everybody used just 1 litre of water for their daily bath. There is a design challenge in building this shower.
The simplest version of this would be to take the hand sprayer that is used to water plants, spray perfume or cleaning solution and fill with water. Washing this way, or with a sponge/cloth, takes less time compared to throwing water with a mug on to the body and conserves water as well.
Water Technology – 3. Reverse Osmosis
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Since distillation is considered energy intensive, reverse osmosis as a process was developed and found to be more economical as it works at low temperatures but higher pressures. “Reverse osmosis is highly effective in removing several impurities from water such as total dissolved solids (TDS), turbidity, asbestos, lead and other toxic heavy metals, radium, and many dissolved organics. The process will also remove chlorinated pesticides and most heavier-weight volatile organic compounds”.
http://www.freedrinkingwater.com/water-education/quality-water-filtration-method.htm
The basic principle is difficult to explain but let me give it a try. Suppose we have two chambers separated by a membrane. On one side we have salt water and on the other side fresh drinking water. We know over a period of time the fresh water will move into the salt water and thus try to reduce the concentration on that side. This is what is called osmosis. Reverse osmosis means we want to squeeze the salt and make the fresh water go back (reverse). So essentially we need a suitable membrane (technical name semi-permeable membrane) that can withstand very high pressure and only allows water to flow to the fresh water side. If my explanation is not satisfactory see http://science.howstuffworks.com/reverse-osmosis.htm
This technology was used at the village level by many civil society organisations including the Byrraju Foundation, Nandi Foundation and many others to provide potable water to rural communities. Providing safe drinking water is seen as a good entry point for many social entrepreneurs in the villages of rural India.
Organic Honey
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Once upon a time honey was considered to be one of the most natural and healthy food products. As modern, chemical intensive agriculture started dominating farm practices, doubts were cast whether pesticide residues would be found in honey. Sure enough, when the research and analysis was done, many different pesticides and even antibiotics were found in the honey. See http://articles.timesofindia.indiatimes.com/2010-09-16/india/28225876_1_honey-brands-antibiotics-honey-samples
Introduction of foreign species of bees to improve honey production meant that commercial beekeepers had to resort to use of antibiotics to prevent the bees from succumbing to infection. Bee keeping also requires that when honey is not available substitute feed sources have to be used. So the honey has the potential to be contaminated from several sources.
The standards for organic production of honey specify the following:
- General principles
- Conversion period
- Origin of the bees
- Siting of the apiaries
- Feed
- Disease prevention and veterinary treatments
- Husbandry management practices and identification
- Characteristics of hives and materials used in beekeeping
The details of the European standard can be seen at
http://www.beekeeping.com/databases/eu_organic_honey_standard.htm
Social enterprises have found that production and sale of organic honey and the byproducts can be highly beneficial as additional income to small and marginal farmers.
Water Technology – 2 Distillation
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The most perfect way to treat and purify water is through distillation. In this process water is boiled and converted to its vapour phase. When this happens all dissolved ions and other particles get left behind. The vapour is taken to a cool surface and it condenses back as liquid droplets. Distillation happens to be one of the most energy intensive techniques for treating and purifying water but it is also the best.
The energy intensive nature of this process is due to the physical properties of water. If we take I gram of water (1gm =1 ml) it will take 1 calorie of energy to raise its temperature by 1 degree centigrade. So typically it takes 70 calories to take the temperature of water from 30 degrees centigrade to 100 degrees centigrade. However when we want the water to change phase from liquid to vapour each gram of water requires 550 calories of energy. This is a very large amount of energy that is again released by the vapour when it condenses back to liquid.
Engineers have designed systems that capture the energy when the liquid condenses and use that energy to evaporate more water. This is called multiple effect distillation. Countries in the Middle East typically combine their electricity power plants with Multiple Effect Distillation plants to desalinate sea water to meet their drinking water needs. See http://people.uwec.edu/piercech/desalination/MED.htm
http://www.h2ome.net/en/tag/multiple-effect-distillation-med/
Many inventors play with building multiple effect distillation units with solar power as the thermal input. So far these have remained as laboratory prototypes and have not shown technical or commercial viability. It remains a challenge.
Wind Energy
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Many times I hear people talk about renewable energy and mention wind energy as their solution to the problem. It is a romantic notion that wind energy can be used to become independent of the electric grid. Wind is unstable as it varies in speed and direction. The device built to harness energy from the wind has to withstand both these stresses and has to be light weight. The energy that is harnessed from the wind has to be stored. Currently energy storage is done in batteries, which add to the initial cost and have a replacement cost that can be very high.
Wind velocities are better at a height than near the ground. Because of this the wind energy conversion device has to be placed on top of a tower. This again adds to the initial cost and makes repairs difficult.
Wind energy conversion devices have traditionally been used to do mechanical work, like pumping water (think of the Netherlands) or grinding flour. Nowadays they are thought of only for electricity generation. Twenty years ago there doubts about the Energy Return on Investment (EROI) for wind energy as well. Today the view is that their EROI is very good. See http://www.theoildrum.com/node/1863
Organic Cotton
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It may seem like Organic Cotton is a fashion statement being made for and by the elite of society but it is actually a dire need for cotton farmers in India and for the environment. India has the largest area under cotton cultivation amongst all countries in the world and provides a livelihood to around 7 million people. Cotton cultivation also uses more than half the total pesticides used in Indian agriculture as a whole. In terms of the cultivable land in India cotton takes up 5% and when you consider more than 50% of total pesticides is used for concentration it can be understood what an effect it would have on the environment and the cultivators.
Organic or eco-friendly cotton cultivation can address the issues of human health, environmental pollution, soil health, ecology of the surrounding areas and mainly the profitability of cotton farming. For a more detailed understanding of these issues see http://www.indiaagronet.com/indiaagronet/seeds/organiccottonarticle-seeds.htm
“Mikaal Fibres” was a company that was a pioneer in the field of organic cotton farming. It brought together more than 1500 small and marginal farmers and proved that organic cotton farming can significantly improve the livelihoods of small farmers. A detailed report on the project and the productivity of the farmers in comparison to conventional farmers is given in http://www.fibl.org/en/switzerland/development/services-projects/production-systems/organic-cotton.html.
Zameen Organics has part shareholding with cotton farmers and is providing organic cotton products at different process points such as cotton lint, cotton seed, yarn, fabrics, garments and home wear. There is a good video here.
http://www.youtube.com/watch?v=yYLNuve1Z48.
The introduction of Bt Cotton was supposed to improve the livelihood of conventional cotton farmers. But independent researchers are claiming that organic farming is better for farmers than Bt Cotton. http://www.i-sis.org.uk/OCBBCI.php
Managing Rainwater
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Kerala and Tamil Nadu have opposite priorities when it comes to rain. Kerala (3000mm) receives almost 3 times the annual rainfall of Tamil Nadu (1000mm). In Kerala civil engineering designs concentrate on quickly draining the rainfall to the nearest river without eroding the land. Tamil Nadu civil engineering designs have strived to tap the rain in many different ways and prevent its run off to the sea.
The boundary between houses in the heavy rainfall areas of Kerala consisted of deep channels that would flood during the rains and connect to other channels that eventually led to the rivers. Tamil Nadu built dykes on the surface that would have spill overs and channels leading to recharge structures like tanks. All across Tamil Nadu these man made structures arrest the flow of water and allow people in that region to use the water as a common facility. A very dramatic image of these structures can be seen at http://wikimapia.org/#lat=10.0188914&lon=79.0706635&z=11&l=0&m=t
Harvesting rain water and storing can be done in many different ways and the wikipedia entry on these describes the techniques very well.
(http://en.wikipedia.org/wiki/Rainwater_harvesting)
Since water is so crucial for human survival and has become a serious problem in many different parts of India, there are public and private efforts to address the issue. The Tamil Nadu government was the first to mandate by law the use of water harvesting structures in buildings. Many other governments are expected to follow suit. There are some civil society efforts like the Rain Water Concepts run by Ayappa Masagi, http://www.rainwaterconcepts.co.in/, Narieta Services Private Ltd, run by Biplab K Paul in Gujarat, Sekhar Raghavan and the Rain centre in Chennai (http://www.rainwaterharvesting.org/network/raincentre.htm) and Varsha Jal run by Vijay Kedia http://www.varshajal.com/jalmitra_kedia.htm
For those interested in building water harvesting structures this is a good start (http://www.saiplatform.org/uploads/Modules/Library/SAI%20Technical%20Brief%202%20Rain%20Water%20Harvesting%20and%20Artificial%20Recharge-2.pdf)
Biodynamic Association of India
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The Biodynamic Association of India is currently being run from Kodaikanal by David Hogg (dhoggn@yahoo.com). In previous blog entries I have written about my experiences with preparations, chromatograms and the calendar. For those of you who found that interesting please note that there is a Biodynamic Association of India and their work statement is below along with the link to the website.
Bio-dynamic agriculture is an advanced form of organic farming, with techniques to ‘farm the air’ as well as farm the soil, and is the oldest organic farming movement practiced in over 20 countries in the world. It includes the normal organic farming practices, such as the use of compost, green manures, and crop rotation. In addition, Bio-dynamic agriculture uses a series of Preparations numbered from 500 to 508 which are based on various mineral, plant, and animal substances. These enhance all the bacterial, fungal and mineral processes that are found in the organic farming system. Placing great importance on the auspicious positions of the moon, sun and planets, a Planting Calendar is used for applying the biodynamic preparations, sowing seeds, planting plants, applying liquid manures, spraying fruit trees and crops, and other farming activities. Experience has shown that use of the Bio-dynamic techniques can make all organic farming processes work more quickly and better. http://www.biodynamics.in/
Water Technology 1- Filteration
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There will be short pieces on water and water treatment technologies from time to time in this blog. The world is going to experience many different types of problems with respect to fresh water. The availability of fresh water is one issue. The more important one is around what the quality of the water will be like. The quality will decide what treatment needs to be done. With the rise of air pollution around the world even rain water cannot be considered safe, as small particles will form part of the rain drop.
The simplest, cheapest and oldest technology for treating water is filtration. Filtration is a process by which water flows through a membrane like cloth. It is one of the oldest water treatment technologies. It is almost always used as a first step before more complex processes are implemented. Filtration removes macro level contaminants like dust and is very versatile as very large filtration systems can be built at relatively low cost. Filtration systems need regular maintenance otherwise they can end up contaminating the water they are meant to treat. Important design consideration for a water filtration system therefore is how quickly and cheaply can the maintenance be done.
The biggest drawback for a conventional filtration system is that it cannot get rid of chemicals dissolved in the water (like salt). More recent technologies can do this too but then the cost would be higher and the quantity of water the system can treat would be limited and maintenance would be costlier. The following link gives more technical update. http://www.allaboutwater.org/filtration.html
Renewable Energy for India
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I wrote this piece for Wake Up India – It was printed in the July- September 2011 edition and that has not come online as of yet.
(http://www.ts-adyar.org/content/magazines#Wake_Up_India)
Renewable Energy. Can it work for India?
Most people will confuse energy with electricity. This confusion has spread throughout media and can even be found in government planning. This may have to do with the way electricity is delivered to us through a hole in the wall. Electricity does not have an origin in plain sight as with any other fuel and yet we will equate it to primary energy.
The requirement for energy and electricity depends on where you live in India. We all know that there is an availability problem for electricity in rural areas and that urban area become paralysed without electricity. The primary fuels (energy sources) that are used to create electricity in India are coal, natural gas and oil. These fuels are commonly called ‘fossil fuels’ since they are mined from the earth and represent dead plant life from millennia before and us and are finite in availability.
Fossil fuels are also responsible for the phenomenon known as global warming since it is believed that the carbon dioxide they produce after combustion cannot be absorbed by the plant life of the earth at the same rate that they enter the atmosphere. This build up of carbon dioxide and other combustion products create a green house effect since they absorb and retain heat that should otherwise be rejected to outer space. This is how global warming happens and the end result is violent and unpredictable changes in rainfall, hurricanes and prolonged heating of certain parts of the world.
When you live in rural India your biggest energy consumption is for cooking and then for lighting. Cooking uses biomass in various forms like firewood, agriculture residue, twigs, and dung cake. This biomass for cooking is a sizable chunk (more than 2/3rd ) of rural energy consumption. However very rarely will this very important source of energy find its way into any planning document. The focus is always on electricity
If you live in urban India and depending whether you are poor or rich your energy consumption will be different. The rich will use electricity and Liquefied Petroleum Gas (LPG) and in some cases kerosene, primarily for cooking. If you are poor in urban India there are good chances of using firewood as the primary cooking fuel. This will explain the numerous firewood depots that can be found near the slums of any metropolis. Firewood is also the fuel of choice for rural eateries.
Most planning documents prepared by governmental or international agencies will talk about electricity and developing means to increase power generation. Though biomass is one of the biggest contributors to the energy consumption of the majority of our population, attempts made for the sustainable supply of biomass is limited.
When we talk about renewable energy what pops into the mind are windmills, solar devices, hydropower and for some strange reason nuclear power. Rarely does the renewable energy sector talk about biomass. Again this is due to the concentration on providing electricity rather than energy. India is also very rich in electricity generated by hydro power which as mentioned is a renewable resource.
The way to understand renewable energy is to think about it as the result of what is available in nature right now, rather than as a finite remnant from a distant past. Thus if we can convert or capture all the sunlight that falls on the world on a daily basis there would be sufficient energy available for everybody’s needs across the globe.
To quote from wikipedia: (http://en.wikipedia.org/wiki/Solar_energy)
“The total solar energy absorbed by Earth’s atmosphere, oceans and land masses is approximately 3,850,000 exajoules (EJ) per year.” (The solar energy that falls on the world in one hour is equivalent to the world energy consumption in 2002).
“Photosynthesis captures approximately 3,000 EJ per year in biomass. The amount of solar energy reaching the surface of the planet is so vast that in one year it is about twice as much as will ever be obtained from all of the Earth’s non-renewable resources of coal, oil, natural gas, and mined uranium combined.”
There are various problems associated with renewable energy that have prevented its widespread use. One of the biggest challenges is to create technologies that will allow the energy captured to be stored for use at a later time. The other challenges are with the variable nature of the input.
Take for instance wind energy, all of us know that wind speeds are highly variable and can change both speed and direction minute to minute. This gives designers of windmills many challenges. They have to account for the wide variation in speeds and the changes in direction. If you drive past any wind farm where there are multiple windmills installed, there are good chances that you will see rotor blades broken and therefore windmills not working. These catastrophic failures are an indication of how difficult it is to design across a highly variable speed and direction regime. Extremely modern designs make use of advances in material technology that help them build lighter and stronger wind mills that overcome the earlier flaws and perform better.
In the case of solar energy too there are variations in the input due to cloud cover or overcast days where the amount of sunlight reaching the earth is not sufficient for meaningful use. Sunlight can be captured and used for heating or otherwise through photovoltaic cells converted to electricity. However the storage problem is there for both conversions. Some of these conversion devices also tend to be very expensive and have poor efficiencies. Much of the research work around converting sunlight to electricity is around making high efficiency low cost photo voltaic cells. If you think about it all plants are using sunlight and fixing carbon dioxide thus increasing their mass (referred to as biomass). So a plant by its photosynthetic process overcomes the problem of conversion of sunlight, build up of carbon dioxide and storage of energy.
The answer to the question posed in the title is that Renewable Energy is already working in a big way for India. Biomass energy is providing a very large part of the energy requirement of the rural population and for the poor in urban areas. Hydro power provides around 14% of the electricity produced in the country according to the International Energy Agency1 and 25% according to Asian Development Bank2. The potential identified and not exploited could contribute over 60% of electricity requirement but the investment requirements will keep this sector contributing between 20 to 30% of current requirement. In a report by the Global Energy Network Institute3 states “the technical potential of these renewables exceeds the present installed generation capacity.”
The potential of biomass has again been missed in many of these reports. The cooking energy requirement if met by anaerobic digestion of all household waste can free biomass that can potentially create small power generating units of 25kW to 50 kW in each village of India. This means that these villages after meeting their internal requirements could sell power to the national grid.
Mistaking electricity for energy has led to this situation whereby planners have missed on how simple biogas technology at a household level can free up sufficient biomass to create as much energy as the country needs for current and future demand. In simpler terms renewable energy can work for India.
Ref 1. (http://www.iea.org/textbase/nppdf/free/2010/key_stats_2010.pdf pg21)
Ref 2. (http://www.adb.org/Documents/Reports/Hydropower-Devt-India/Hydropower-Devt-India.pdf pg 15)