Science teacher’s innovation that uses compost heat to boil water takes pressure off forests

A science teacher is trialing an innovation that produces high value compost and heating water for domestic use taking pressure off forests.

Robert Sabimana’s innovation is as a result of the passion he has long held for environmental conservation and offering unique cheap solutions to his fellow village mates. “I have always aimed at utilizing my knowledge to better the society. In order to add value to the world and the society, we have to champion the adoption of meaningful development activities that also ensures that the future generations will find resources to use. This therefore is always my mantra when it comes to innovations,” explained Robert.

Robert has even showcased his innovation to Ugandan President Yoweri Museveni. The innovation involves use of domestic wastes like animal wastes chicken droppings, cow dung, weeds, city garbage especially from the vegetable markets among others.  One set up of the structure requires about USh200,000 ($57) to set up. One will require the piping materials for plumbing and connection from the drum to other water outlet points, 100 litre metallic drum.

In order to get the best results that include good heat and best organic fertilizer, one has to ensure that the wastes are piled up in layers of varied types. For instance at the base there can be the chicken manure then followed by the weeds, dry grass, domestic garbage like potato and banana peelings and so forth.  “The different layers helps in balancing carbon and nitrogen ratio because more carbon may mean that some minerals may lack in the final organic fertilizer and similarly more nitrogen may hinder plants from fruiting well,” explained Robert.

The wastes are piled around the drum and eventually cover it. It is from this tank that cold is pumped in with pipes connection for outlets.  In order to speed up the rate of organic matter fermentation, Robert introduces natural micro organisms that get through culturing and in a solution to the heap of wastes. The natural micro organisms include fungi and lactic acid bacteria.

The compost heap is then covered tightly with a tarpaulin to allow the fermentation process to set off uninterrupted by Oxygen supply.  Due to the high microbial population and varied wastes, the compost heap that is covering the drum produces a lot of heat. The composting material heat then heats the water in the drum which can be used for other domestic uses at home and saving families and enterprises millions from power bills.  The heat curve according to Robert rises gradually and then reaches a peak point from where it starts falling. “As the number of days increases, the temperature from the compost also rises and reaching a peak of over 70 degrees centigrade. This may take about one and half month, meaning that families or organizations that have set up the structure will enjoy a hot shower for over one month,” added Robert.

After about 30 days, the fungi would have colonized the compost which is an indication that the organic fertilizer is ready for use. At this period, for farmers or organizations that are keen to establish this technology, should have set up another similar structure to ensure continuous supply of the hot shower and timely supply of the organic fertilizer. It’s also advisable for farmers to harvest the fertilizer after this process and cover it well if they have no plans of using it immediately.

Currently there are over 35 farmers from Kabale who have adopted the innovation for the supply of hot water and quality organic fertilizer for their farms. The technology has also been adopted by Entusi Resort in Kabale which it uses to help supply hot water to their clients.

The innovation according to Robert is a classic example to how local wastes can be turned into wealth and in the process save the society and the environment from the shocks of carbon emissions.  One set up of compost shower according to Robert reduces greenhouse emissions greatly as it translates to saving six trees in 21 days. The concept according to Robert helps safe guard the environment from global warming. “Heat from the earth is trapped in the atmosphere due to high levels of carbon dioxide and other heat-trapping gases that prohibit it from releasing the heat into space. This creates a phenomenon known today as the “greenhouse effect.” Therefore, trees help by removing CO2 from the atmosphere during photosynthesis to form carbohydrates that are used in plant structure and return oxygen back into the atmosphere as a byproduct,” explained Robert. It is estimated that half of the greenhouse effect is caused by CO2. Therefore, trees act as carbon sinks, alleviating the greenhouse effect hence given that the technology generates heat for boiling water, cuts on the chances of cutting down trees for the same function.

On the other hand Robert enlightens the farmers and enterprises adopting the technology to earn carbon credits. On average, one acre of new forest can sequester about 2.5 tons of carbon annually. Young trees absorb CO2 at a rate of 13 pounds per tree each year. Trees reach their most productive stage of carbon storage at about 10 years at which point they are estimated to absorb 48 pounds of CO2 per year. At that rate, they release enough oxygen back into the atmosphere to support two human beings. 

“The technology helps safeguard about 6-10 trees per month. With the international market rate of one carbon credit amounting to six dollars, Robert estimates that with just 1000 farmers continuously operating compost heater can earn the country about Ush180 million.”

The resultant organic fertilizer is ideal for all farm use. In Robert’s farm he uses the organic fertilizer to grow sugarcane, spinach, avocado trees, leeks, kale, sweet potatoes and more.  “I want to see how rich and diverse we can be in our food supply,” he said. “I want us to move toward growing food forests instead of depleting our soils with chemicals.” The farmers around Kabale who are adopting the compost heater technology are counting increased yields in their farms as well as reduced expenditure on purchasing inputs like chemical fertilizers. “90 percent of the farmers in this area have been priced out of the reach for these chemical fertilizers. Since I the introduction of the of this technology in early 2014, farmers in the area thanking me for offering them an alternatively superior but cheap innovation. I receive inquiries even from farmers from Kampala environs for the structure set up.

The permaculture expert is now hoping that stakeholders from local governments can adopt the idea for helping solve the waste disposal menace in urban areas. “The technology has now been tried and tested by farmers as well as a business in the hotel industry and found to be very practical. They can turn the wastes into wealth and sell off the organic fertilizers to farmers if they do not have immediate use. The government too can adopt the technology and scale it up to the whole country, a move that will see the forests safeguarded as well as help the economy earn from carbon credit trade,” noted Robert.