On a recent trip to Jamnya, CERES’ manager of Green Technology prepared an outline of potential strategies for green technology initiatives at Jamnya.
Fundamental to the reasoning is the aim to minimise the adverse impact on the environment, and by association, its impact on the quality of life & health of the inhabitants.
Sustainable materials features of the house include:
Compressed Earth Bricks: New sustainable brick making technologies are now emerging where bricks are made from the soil existing on, or around, the site where the building is to be constructed. The bricks have 5% cement, and are compressed rather than ‘fired’ resulting in significantly lower environmental impact.
Bamboo: Grown locally and sustainably in the Jamnya area, bamboo is used as the roofing structure for the new dwelling.
Recycled Tetra-pack Roofing: Made from recycled tetra-pack containers, which have been heated and moulded into roofing sheets with significantly better thermal properties compared to iron.
Active solar systems are being installed at the school:
Solar Photovoltaic Panels: There is an existing system at Jamnya consisting of an 8 panel array, orientated southwards and of low incline angle. Solar access is excellent and this is a reliable, proven and familiar technology.
Recent micro inverter technology can greatly improve efficiency of the an array of PV panels,
particularly if panels cannot be easily all orientated to southern direction, over shadowed at any time of the day, or if it is of benefit to get obtain more solar access in AM or PM, by facing panels to catch morning or afternoon sun, respectively. For recent building at Jamnya this would not be necessary but would recommend the installation Solar PV panels (suggest 1.5 to 2.5kW system) with battery backup to supplement intermittent mains supply.
Solar Lighting: Is also currently at Jamnya, but more is needed. These provide safety and security for the inhabitants. They are reliable, self-contained and easy to install. It was noted that some models such as the type currently installed have suffered from being tampered with and in larger villages the solar panels removed (stolen). The design shown on the right is an integrated solution that would prevent this type of problem.
Solar hot water: Evacuated tubes and storage tanks on stands are being installed to provide hot water for student bathrooms and for cooking
Cooking: The most common energy intensive activity is cooking. In most tribal village areas this appeared to be done by burning (locally obtained) timber. There are a number of problems from this; depletion of the surrounding wildlife sanctuary woodlands, time taken to collect and the health impact of creating fumes in poorly ventilated internal spaces.
Other forms of cooking were seen. Gas was much less common and the logistics of replacement cylinders is problematic because of the remote location (particularly in wet months) and also regulatory quotas that are imposed on the amount of gas that can be used by individual families.
Much of bottled gas is not a sustainable resource. The logical choice for cooking is an induction cooktop. This is a proven and simple and relatively available technology, already in use in domestic situations. It is quick to heat up and gives good control over cooking temperatures. There is some limit to type of cooking vessel (only ferrous material is suitable), but stainless steel are readily available and widely used.
Typical internal cooking facilities using wood Induction cooker available in India
There is an excellent opportunity to install a system to heat water from the sun. The technology is readily available. Evacuated tube systems offer the most efficient solution. Systems using storage tanks above the tubes (such as pictured) are simple, very reliable and low maintenance. The adequate sizing of the system can be achieved by combining a number of standard sized modules.
As hot water can be available early in the day (because of both the efficiency of the evacuated tubes and thermal inertia of water heated prior day and held in an insulated tank), solar heated water in Jamnya is a very attractive idea. It would mean significantly reduced need for using timber for fire in the mornings to heat water for breakfast and other morning activities.
Ventilation: Can be significantly improved for internal spaces with products such as the “Solar Whiz” (pictured).This consists of a low voltage fan used to extract air and powered by a solar panel that can be adjusted to maximise solar access. Its application would mitigate the issue of fumes created during cooking, (particularly if timber was used). The general movement of air in a building is beneficial to the performance of the building and the health and comfort of the inhabitants, even in the case where a wood fire is not used inside for cooking.
In Jamnya, I considered using wind turbines (small scale) to supplement solar PV, but this would bring complexity to the UPS / inverter need to takes charge from multiple sources. Placement of a wind turbine is also critical (not to be influenced by turbulence created by trees or buildings in the field). The difficulty of getting specialized maintenance – particularly in remote areas makes this an issue.
Water Harvesting: Much of Jamnya’s water needs appeared to be met by accessing the water table. It was also noted that the value of water was held in less regards than I am familiar with in Australia. It was very common to see continuously leaking taps or joints in water pipe work. It some of the larger villages in the area, Pal for example it was often seen that header tanks were being regularly over filled, wasting significant quantities of water. The effects of climate change and the potential contamination of ground water in the future will see greater placement of value on water. There is an opportunity at Jamnya to show an early take up of rainwater harvesting.
Installing suitable roofing material, guttering, filtering system and water tank would demonstrate the ease of collecting a significant amount of good quality water. Interlinking of the guttering system of multiple building roofs allows expansion of the water harvesting area. Annual rainfall figure are used to determine compatible harvest area and tank size.
John Burne – Green Technology Manager – CERES