How can Singapore scale urban farming with the help of food waste

 

 

In Singapore, 763,000 tons of food waste was generated 2018. Focusing on households, each Singaporean household generates about 750g of food waste daily, (Ministry of the Environment and Water Resources, 2019) or around 1,000 tons for all households. (Department of Statistics Singapore, 2020) To make things worse, households throw away S$342 million worth of unconsumed food on an annual basis. (Low, 2019) However, many food waste initiatives are targeted at industrial food waste (hotels / restaurants / hawker centres etc.) and not at households. Thus, we decided it was time to act on this issue.

 

 

Tackling household food waste is difficult, even in a super-dense city like Singapore. There are two main reasons:

  1. Culture: Singaporeans do not have an established culture of waste separation, unlike in North Asia. Households generally throw everything away in a single bag. Recycling efforts have also been hampered by people throwing un-recyclable materials into recycling bins, which already do not require pre-sorting. This is further exacerbated by the substantial number of households that employ domestic helpers, who generally take care of the cooking and cleaning. These helpers have no incentive to sort household waste – it only serves to make their job more difficult.
  2. Space: Singapore’s extreme population density means that many stay in small apartments. Thus, many do not have gardens, negating the need for fertilizer. Additionally, there is no space for a compost bin, which is usually kept outdoors in other countries due the smell. The smell would be made worse by Singapore’s hot and humid climate, making a household compost bin difficult option for many.

As such, the Singapore government’s approach has been to tackle this from the industrial side of things, by building food waste processing units, where food waste is easily sorted due to existing processes. Businesses such as hotels and restaurants also have enough food waste volume and landscaping needs to make industrial food waste processing machines worth the money. (Tan, 2017)

What UN SDGs does this project help achieve?

Quite a few SDGs are covered by our initiative, should our business plan be fully realized:

Affordable and Clean Energy:

Food waste can be converted to biogas, which can be burnt for energy. The process is carbon neutral (Wilkie, 2019), unlike the natural gas that Singapore uses for power currently.

 

Sustainable Cities and Communities:

Our plans will help to make housing estates in Singapore more resource efficient. There is surprisingly high demand for fertilizer in Singapore due to how much urban greenery there is – in 2016, 16,900 tons of fertilizer was used in Singapore. (The World Bank, 2017) (The World Bank, 2017) Being able to produce some of this from waste that would otherwise have been incinerated, would be a great step towards sustainability. As it stands, most of Singapore’s waste is incinerated and buried in the Semakau landfill, which is estimated to run out of space by 2035 to 2040. This initiative would also help Singapore to conserve the Semakau landfill since none of the food waste will go to the incineration plants. Additionally, any surplus food waste can be converted to biogas.

Responsible Consumption and Production:

Making people more aware of the food waste they generate will help reduce its volume. Diverting food waste from incinerators into compost will also reduce the greenhouse gas emissions from the consumption of food. Finally, not having to ship fertilizer from foreign countries dramatically reduces the greenhouse gas emissions of producing food.

 

Climate Action:

Being able to shift more power production from natural gas to biogas would reduce Singapore’s carbon footprint. Again, not having to ship in fertilizer would cut down significantly on greenhouse gases emitted from the logistics of the shipping.

 

Why is this project relevant for the next 5 years?

By 2030, Singapore intends to produce 30% of its nutritional needs locally, compared to less than 10% as of 2019. (Mahmud, 2019) This is to ensure food security, especially important in light of supply-chain disruptions like Covid-19. This will require a significant increase in fertilizer use, particularly in urban and vertical farming. If the fertilizer can be produced in urban areas throughout the island, it would greatly reduce the amount of transport needed to grow the food. Currently, most fertilizer has to be imported.

Additionally, climate change has necessitated a shift away from carbon-positive fuels. The food waste can be used to generate biogas, which is carbon neutral.

 

Our Product

WasteNot’s mission is to turn food waste from waste into something of value. Our plan is to install portable food waste collectors in high-density residential areas in Singapore, starting with HDB estates (public housing that 80% of the population lives in). The collectors are designed to convert food waste into compost for fertilizer use. To encourage residents to separate their food waste from other garbage, we intend to use a mobile app to track and reward residents’ contributions of food waste (with cash / vouchers etc). Compared to incineration, WasteNot’s process can reduce CO2 emission by up to 35%.

 

The goals of WasteNot are:

  1. Divert food waste away from incinerators and into biogas production. Using food waste to generate biogas is carbon-neutral, thus allowing for clean power generation while simultaneously reducing carbon emissions from incineration.
  2. Improve the efficiency, productivity and sustainability of urban farming and agriculture. We estimate that the fertilizer produced from the food waste can reduce the fertilizer costs for urban farmers by up to 50%.
  3. Raise public awareness around food waste, sustainable consumption and sustainable food production. Having food waste collectors installed in housing estates, as well as tracking food waste, helps to prompt residents to reduce unnecessary food waste and conduct proper waste categorization.

The inputs (food waste) of WasteNot will be continually measured and compared against normal garbage national statistics – if there is a downward trend, we have succeeded. The outputs (renewable energy and fertilizer) can be monetized through the circular economy. This will not only recover the invested capital, but also be an additional measure of food waste.

The UN SDG Global Indicator Framework mentions the following target on food waste: “12.3: By 2030, halve per capita global food waste at the retail and consumer levels and reduce food losses along production and supply chains, including post-harvest losses” .

WasteNot focuses on household food waste, which accounts for the largest portion (80%) of discarded food. With its financially sustainable business model, user-friendly technology, and aligned incentives with various stakeholders, WasteNot aims to deploy 2000 – 2500 food waste collectors in the residential areas of Singapore within the next five years. This means that half of the unrecycled food waste from homes in Singapore will be converted into greener energy and organic fertilizer. This not only reduces CO2 emissions but also creates value for urban farmers. Government grants (Iau, 2020) can be used as the initial capital to run a pilot. Based on the financial and operational forecast, WasteNot will generate annual revenue of 8.4m dollars. The total profit for the first five years will be 26m dollars.

 

Our Business Model

  • Deploy: Portable food waste collectors will be installed in residential areas, such as HDBs. The collectors are connected to the internet and power grid. The collector consists of three parts, namely: waste collector, fermentation compartment and liquid fertilizer storage.
  • Collect: Residents bring their food waste in a biodegradable bag to a WasteNot collector. The collector scans the food waste for any metal or glass. It then dries it out and compresses it, before it passes the food waste to the fermentation compartment. Residents then scan the one-time QR code generated on the screen of the collector to claim rewards in the mobile app. Anonymized user data will also be collected via the mobile app. Valuable information could be generated by analyzing the data for government, businesses and NGOs to use.
  • Process: The food waste will be fermented for 3-4 weeks. The outputs are biogas and liquid fertilizer. The conversion rate of food waste into fertilizer is around 9 to 1. One collector can process 250kg food waste daily, which will produce 28kg of liquid fertilizer.
  • Monetize: The liquid fertilizer will be collected and sent to a central facility for packaging. The liquid fertilizer can be sold at 50¢ per litre (1.2kg). The final products will be sold to urban farms for half of the price of other commercial fertilizer. Hence, one collector can generate at least S$350 per month in revenue.
  • Share: There is a one-time installation cost of S$4000. The monthly maintenance fee and other costs will be around S$100 per month. Hence, we can recoup the investment of one collector within 1.5 years. If the lifespan of a collector is 10 years, it can, on the average, generate a profit of S$2500 annually. In order to promote waste categorization among the residents, 30% of the profit will be given back to the residents through the mobile app.

 

The sustainability and financial goals are aligned in the business model of WasteNot. A portion of the net profit will be invested in purchasing and deploying more food waste collectors in broader locations besides residential areas, such as hawker centers, restaurants and hotels. The expansion means more food waste being recycled and hence a larger environmental impact. Vice-versa, if more people actively participate in recycling their food waste, more revenue will be generated for further investment in expansion.

Additionally, data on food waste recycled, user behavior as well as sales of biogas and fertilizer, will be collected and analyzed via the WasteNot mobile app. The data would be valuable to government, NGOs, urban farmers and businesses. As the business scales up and more data is collected, more insights on food waste reduction and recycling could be generated. This would also be one of the income streams for WasteNot.

There are quite a few pieces of information that will have to be determined before we can conclude that our business model is viable. These can roughly be broken down into a few categories:

  • Production quantity: How much fertilizer can be produced from the food waste we gather? Due to the varied composition of people’s diets, it could change significantly from one part of the country to another. Additionally, this would determine how much excess we could sell for biogas rather than be used as fertilizer.
  • Demand quantity: How much urban farming will be required to achieve Singapore’s 30% goal? What sort of plants will be grown? How will they be grown? This would determine the fertilizer requirements. A substantial proportion of Singapore’s fertilizer use is in urban greenery, making it even more difficult to project future demand.
  • Pollution avoided: Given how much logistics is involved in getting the fertilizer from source to the various parts of the island it is used in, calculating the amount of greenhouse gases / carbon removed from the system would be exceedingly difficult. If we are able to determine a number, it would significantly help our push our use case with the government. It would also help in bringing users on board, as it would be easier to market with a pollution figure.
  • Incentive plan: What type and amount of rebate or cash reward would sufficiently incentivize households to sort and take their waste to the collector? Which household income segment should be targeted to ensure sufficient uptake? Surveys would need to be conducted.

 

Incentives need to be aligned with residents, farmers and the Singapore government. A small amount of cash will be set as an incentive for residents who recycle their food waste into WasteNot collectors. Other monetary incentives such as shopping coupons would also be applied occasionally to promote more food waste recycling actions among households. These cash rewards or rebates could be obtained through partnerships with government bodies and / or large corporates who have an interest in pursuing CSR initiatives.

Moreover, through the WasteNot mobile app, each user is able to track how much food waste has been recycled and converted into biogas and fertilizer. Thus, they will be able to track how much CO2 emissions they have prevented. The quantitative and qualitative environmental impact made by each WasteNot user will be highlighted in the user account on the app, to motivate people to continue recycling food waste via WasteNot. This would ultimately help change people’s behavior and make food waste recycling a habit.

Additionally, this would cultivate the habit of waste separation. This might encourage households to take further steps in sorting other types of waste, which would greatly improve the efficiency and effectiveness of recycling initiatives.

To incentivize urban farmers to join our system, the price of WasteNot fertilizer will be 50% lower than the market price. As for the Singapore government, since they intend to push urban farming, reducing farmers’ costs while reducing the reliance on imported fertilizer would be an incentive for government to support the project.

In order to succeed, the project needs to interface with:

  • Individual households to supply the food waste
  • Manufacturers of the food waste collectors for supply and maintenance
  • Regulatory authorities for approvals
  • Governmental organizations for grant support
  • Urban farmers to purchase fertilizer
  • Companies that process food waste to biogas (eg Anaergia)
  • Corporates for provision of rewards / rebates
  • NGOs / associations such as social enterprise association for partnership to promote food waste separation and recycling.

Incentives could be offset by the government’s support and promotion of making Singapore a zero-waste country, the financial benefits for urban farmers from WasteNot’s business model and more revenue for the suppliers of food waste processing machines.

There are a few downsides, mainly regarding the conditions requiring it to be viable. The business model is reliant on the generosity and charity of large corporations and governmental organizations to provide the incentives for households to recycle their food waste. If this support is cut, then the business model may no longer be viable.

The collector will need to be compliant with all health and safety regulations, which may be onerous due to the decomposing food waste. The biodegradable bags utilized to contain the food waste will need to be capable of degrading within a reasonable time – if possible, during the time taken for the food waste to ferment. If not, this may require that food waste is thrown directly into the collector.

Lastly, an alternate environmentally friendly fertilizer packaging needs to be procured. Transporting the fertilizer to other parts of Singapore (or if also exported overseas) would also result in some level of pollution that needs to be ascertained.

The scalability of the project depends on the level of incentives that need to be provided for people to sort and take down their food waste, and organizations’ willingness to provide those incentives. This will also depend on household income and other peculiarities of each residential area. Residual profits generated (ie those not going towards rewards for residents) will be used for expanding WasteNot to more residential areas.

Barriers for scaling will also include cost of maintaining and procuring collectors. Although a portion of the profit will be invested in purchasing and deploying more collectors, it is unclear if this can be done as quickly as desired. This is because the return per collector is estimated to be S$350 per month (see above), and there may be other costs that need to be incurred. These include developing the mobile app as well as its maintenance, the cost of transporting fertilizer to the urban farms and provision of biodegradable bags (if applicable), among others.

A pilot could be conducted with a collector installed at a selected HDB, with rebates provided by a local supermarket chain known as NTUC Fairprice Cooperative and fertilizer supplied to existing urban farmers such as Bollywood Veggies and Sky Greens. Additionally, grants could potentially be obtained from the government for the pilot. If the results are favourable (i.e. the uptake by households and urban farms is significant), we can expand the project to a larger scale on an incremental basis to enable excess food waste to be used to make biogas and provide power rebates.

Next Steps

The immediate next steps include finding suitable machines and technology, such as the food waste collectors, designing and developing the WasteNot mobile app, and conducting pilot tests.  The resources needed would be manufacturers and suppliers of food waste processing machines, a digital agency for mobile app development, and funds for initial investment.

References

Ministry of the Environment and Water Resources. (2019). Food Waste. Retrieved from Towards Zero Waste: https://www.towardszerowaste.sg/foodwaste/

Tan, S.-A. (2017, September 16). Hotel recycles 500kg of food waste into fertiliser within 24 hours using food-waste digester. Retrieved from The Straits Times: https://www.straitstimes.com/singapore/hotel-recycles-500kg-of-food-waste-into-fertiliser-within-24-hours-using-food-waste

Wilkie, D. A. (2019, December 16). Biogas A Renewable Biofuel. Retrieved from University of Florida: https://biogas.ifas.ufl.edu/FAQ.asp#:~:text=While%20combustion%20of%20biogas%2C%20like,add%20to%20greenhouse%20gas%20emissions.

The World Bank. (2017). Fertilizer consumption (kilograms per hectare of arable land). Retrieved from The World Bank: https://data.worldbank.org/indicator/AG.CON.FERT.ZS

The World Bank. (2017). Arable land (hectares) – Singapore. Retrieved from The World Bank: https://data.worldbank.org/indicator/AG.LND.ARBL.HA?locations=SG

Department of Statistics Singapore. (2020). Households. Retrieved from Department of Statistics Singapore: https://www.singstat.gov.sg/find-data/search-by-theme/households/households/latest-data

Low, Y. (2019, August 30). Every Singaporean household throws away an average S$258 worth of food a year: Study. Retrieved from Today: https://www.todayonline.com/singapore/every-singaporean-household-throws-away-average-s258-worth-food-year-study

Koh, F. (2020, April 6). Parliament: Encourage growth of urban farming to secure Singapore’s food supplies, says Ang Wei Neng. Retrieved from The Straits Times: https://www.straitstimes.com/singapore/parliament-encourage-growth-of-urban-farming-here-to-secure-singapores-food-supplies

Singapore Food Agency. (2019). Food Farming. Retrieved from Singapore Food Agency.

Mahmud, A. H. (2019, March 07). Singapore aims to produce 30% of its nutritional needs by 2030, up from less than 10%. Retrieved from Channel News Asia: https://www.channelnewsasia.com/news/singapore/singapore-produce-30-own-food-up-from-10-nutritional-needs-11320426

Iau, J. (2020, May 8). NEA’s $1.76m fund to help minimise food wastage. Retrieved from The Straits Times: https://www.straitstimes.com/singapore/neas-176m-fund-to-help-minimise-food-wastage

 

 

 

Authored by Jenna Law, Lea Li, Yinghui Tan, Chao Wang

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