Turning poop into energy: mad science plan or viable solution?

Our energy needs are rising at breakneck speeds, driven by rapid population growth and higher standards of living. This has serious consequences, however, as we are all aware. The alarming increase in carbon emissions causes often irreparable environmental damage and leads to the exacerbation of climate change. Prompt abandonment of fossil fuels – which are among the worst polluters – could mitigate our carbon footprint. We should, instead, turn to more sustainable alternatives and explore new low-carbon power solutions. Besides solar and wind, there’s another promising renewable energy source – poop. Yes, you heard it right, this human and animal waste product could help us power our homes and fuel transportation. Some developed countries are already taking advantage of this alternative energy source. For instance, in the UK,uses manure to generate 50 per cent of its power. This could be a game-changer for the developing world as well. According to UN data, excretion-based waste could power up to 10 million homes. 

Prototype solution turns human waste into potable water and electricity 

Not very long ago, we published an article about a super-machine that turns faecal material into water and ash. Engineering company Janicki Industries has now taken this a step further by developing a prototype solution that turns this waste into potable water. Dubbed the Omni Processor, the prototype plant will be able to process up to 66 tons of biosolids per day to produce over 30,000 liters of water. And once the remaining fuel is burned, it produces enough electricity to power the plant, but also leaves enough surplus energy to store. Currently, the plant’s energy capacity could power up to 170 households. 

The pilot plant has been put to use in the city of Dakar, the capital of Senegal. CEO and co-founder of Janicki Industries, Peter Janicki, said that in the early stages of the pilot, the Omni Processor was able to achieve an ideal efficiency between 80 to 85 per cent of the time. But now, the unit achieves maximum performance at 95 to 100 per cent of the time. The pilot, however, didn’t assess the economic feasibility of the plant, which will be addressed in the second project, also taking place in Senegal. What makes these projects less viable in developing countries is the lack of infrastructural and technological capabilities, which is preventing potential investors from investing in these types of waste-to-energy innovations.

Pig manure is a cost-effective energy source and a high-nutrient fertilizer 

With its prototype, Janicki Industries has shown that human waste is a useful resource. But animal manure can be equally, if not more, beneficial. Animal manure could, for instance, be used to generate power and help farmers automate their crop and livestock production processes. And Chamraq Biogas Nigeria, a company that specializes in waste management solutions, makes this possible. 

The company develops biodigesters that convert animal waste into power. In fact, generating power from animal manure could be particularly beneficial for Western African countries where pig farming is on the rise. In those countries, energy is a scarce commodity, and often unaffordable for small farmers. Using pig manure as an energy source could, however, offer solutions to this problem. Due to a growing demand for pork products, farmers in West Africa are increasingly turning to pig farming. As a result, the amount of waste pig farms produce is also increasing. Some farmers utilize manure as a fertiliser, but this isn’t the safest solution as pig manure cancontain parasites, and it’s therefore not recommended for use in crop production. In addition to producing power, waste-to-energy solutions can also produce valuable byproducts. For instance, a byproduct released from pig manure is rich in nutrients and less damaging to crop production than traditional manure. This enables farmers to get cost-effective energy as well as fertilizer from the same source.

Sustainable fuel made from human waste helps Kenya tackle deforestation

Since people in Africa’s developing countries are still heavily dependent on traditional wood fuel, such as firewood and charcoal, this has created a major environmental issue. For example, it’s estimated that 90 per cent of people in East Africa use firewood and charcoal. Not only does this contribute to greenhouse gas emissions, it also leads to deforestation. To help reduce people’s reliance on firewood and charcoal, Kenya-based company Sanivation offers a better and more sustainable alternative to traditional wood fuel: human waste briquettes. The company collects human faeces from 650 specially designed toilets twice a week. At treatment plants, the waste is processed and turned into eco-friendly briquettes, which burn longer than charcoal and also produce less carbon emissions. So far, the company has sold 1,500 tonnes of human waste briquettes to households, schools and factories in Kenya. “For every tonne of briquettes that we sell, we save about 88 trees here in Kenya. People are actually purchasing our fuel because of the environmental impact,” says Sanivation’s co-founder, Emily Woods. The company claims this innovation even helped to reduce the risk of diarrheal conditions and improved sanitation for 20,000 people.  

The Manure Challenge 

As promising as manure-to-energy innovations sound, we still need to do much more research into these initiatives. To demonstrate that manure is a valuable resource, the Yield Lab Institute launched the Manure Challenge. The competition, which ended in June 2020, was designed to encourage agtech startups to come up with innovative and sustainable ways of using animal waste in farming. Out of 63 applicants, eight startups were given a chance to present their ideas to investors and receive mentorships. The winner of the Manure Challenge was Michigan-based Digested Organics, who won the grand prize of $50,000. Digested Organics’ idea is based on using a nutrient concentration and water reclamation (NCWR) system to convert manure into clean water, energy and fertiliser. To achieve this, the startup proposed two different methods. In the first method, known as the stainless steel ultrafiltration, manure is placed into porous tubes. These tubes hold the suspended solids, while water and dissolved solids pass through the tubes. According to Digested Organics’ CEO, Bobby Levine, the second method, called the two-step reverse osmosis, “involves patented forward osmosis technology to pull the water out of the permeate. This creates a different fertiliser product that is abundant in ammonia, nitrogen, and potassium. It also creates clean water for reuse later.”

Other finalists also proposed rather innovative ideas. For example, SoMax Bioenergy from Pennsylvania, suggested using a suite of technologies to break down organic materials into components, which can later be used to create various products. Phinite, based in North Carolina, came up with a cost-effective solution to dry out manure. The company’s sludge-drying wetlands use solar energy to dry out the waste, which reduces greenhouse gas emissions and odours by 70 per cent. And Connecticut-based startup CowPots designed manure-based biodegradable planting pots. Compared to other biodegradable pots on the market, CowPots decompose three times faster and provide the plant with important nutrients. Since a large percentage of US agricultural manure waste comes from the poultry industry, Alabama-based Chonex proposed a sustainable method to convert poultry manure into high-quality fertiliser. The method involves feeding manure to black soldier fly larvae. The digestive systems of these larvae then process the manure and release frass, which can be used as a fertiliser. Unlike raw manure, frass is a lot safer as it doesn’t contain any pathogens. 

Manure could be a viable source of renewable energy. As the world is looking for an alternative to fossil fuels, we’ll see more successful applications of waste-to-energy projects in the future. This could make a lot of difference in the farming industry. Converting animal faeces into a low-carbon energy solution and using processed manure-based fertiliser can help farmers improve profitability and productivity, while simultaneously reducing their environmental impact. There are so many possibilities, all we have to do is uncover them and put them to the test.