Alternative fuels for waste collection : Alternative fuels, different views

The Working Group on Collection and Transportation Technology (WGCTT) of the International Solid Waste Association (ISWA) addresses the storage, collection, transfer and transport of solid waste. The group is looking to the future with the increased sustainability of the propulsion of operational fleets and the use of data and ICT to optimise route efficiency of collection.

During the latter part of 2021 and earlier this year, the WGCTT was busy working on a report to explore the adoption of alternative (non-fossil fuel) and low-emission fuels for waste collection in middle- and upper-income countries. The work involved a combination of a widely circulated survey and in-depth interviews with municipalities, vehicle manufacturers and waste management contractors. The report presents a snapshot of the situation in some countries. It is by no means an exhaustive market study, nor are the findings intended to be representative of the global position. The report is a showcase of practical examples, benefits, challenges and lessons learned, aimed to assist others in their decisions towards decarbonising their waste collection fleet.

The report was commissioned by NVRD and CIWM, and overseen and distributed by the International Solid Waste Association and its Working Group on Collection and Transportation Technologys. The report is due to be published in early July, and will be available at www.iswa.org

In the first stage of the project, an online survey was circulated to municipalities around the world by WGCTT members and via ISWA’s National Member network, with the aim of gaining an understanding of the motivations for municipalities adopting – or not adopting – low-emission and alternative vehicle fuels for waste collection. While not intending to be fully representative of the global picture, the survey yielded useful insights. Figures 1 and 2 show what perhaps many waste managers already know – environmental concerns are the key motivation for those municipalities considering using alternative vehicles, to address the current carbon and air-quality negative impacts, while cost is the primary reason for not introducing them, with concerns also held around supporting infrastructure for fuelling and the availability/performance of the current technologies.

For a more detailed assessment of the use and barriers encountered with alternative fuels in practice, a structured set of interviews took place. A total of 26 organisations contributed to the discussion. These included municipalities, waste management companies, vehicle manufacturers and other relevant organisations, covering electric vehicles, hydrogen-electric, hydrogen-diesel hybrid combustion, hydrotreated vegetable oil (HVO) and natural gas.

The key points for each fuel type from the experiences reported during this study are summarised as follows:

Battery electric vehicles

• Charged by mains or stored power; charging process can be lengthy – overnight or short top-up charge; sufficient power supply is needed – substation infrastructure, charging points
• Zero tailpipe emissions at the point of use; full life cycle depends on how power is generated; environmental impacts relating to battery
• High vehicle capital costs, but lower operating costs, reduced maintenance and longer vehicle life
• Battery range (distance) may require route changes or more vehicles
• Clean, quiet and smooth operation gives improved driving conditions
• High torque creates good start/stop efficiency, improving overall collection time

Hydrogen fuel cell vehicles

• Electrochemical reaction from hydrogen fuel and oxygen within the air produces electrical energy to power the vehicle motor; zero tailpipe emissions at the point of use – water vapour only, no NOx, SOx
• Hydrogen is produced by different methods, some more sustainable than others; electrolysis of water using renewable electricity produces “green” hydrogen, other methods less sustainable
• Deliver extended range (distance) compared to battery electric vehicles
• Much development around hydrogen fuel cell vehicles; vehicle supply chain is developing but few suppliers, long lead times and high capital cost
• Reliable and sustainable hydrogen supply is needed; demand is developing around “hydrogen clusters”
• Clean, quiet and smooth operation gives improved driving conditions and extended vehicle life

Hydrogen-diesel hybrid combustion vehicles

• Conversion of existing or new diesel vehicles to dual fuel hydrogen-diesel; vehicles can run on either full diesel or blend of hydrogen and diesel
• Requires sustainable hydrogen supply to achieve environmental benefits, but vehicles can run solely on diesel
• Emissions reductions limited to diesel substitution rate – diesel displacement rates are around 30-40% for refuse collection vehicles
• Moderate cost for vehicle conversions, not necessarily limited to vehicle replacement schedules
• Ease of use – driving experience is the same as diesel

Hydrotreated/hydrogenated vegetable oil (HVO)

• Renewable, non-fossil biofuel typically produced from fuel crops and waste vegetable oils
• Ease of use, used as a “drop-in fuel”, direct replacement for diesel
• Cleaner burning fuel than diesel, lower emissions – c. 90% carbon dioxide reduction, lower NOx and particulates
• Supply of HVO – concerns over sustainability and ethics of production
• Cost of HVO can be 10-15% higher than diesel, with some potential loss of performance efficiency

Natural gas

• Fossil energy source (methane) extracted from the ground or seabed; established use for heating, cooking, industrial and transportation
• Compressed natural gas in vehicles is similar to diesel, combusted with air; similar driving experience
• Cleaner burn than diesel, reduced emissions at tailpipe; fugitive emissions from methane extraction, processing and transportation
• Further decarbonisation of waste management process through closing the loop by recovering methane from waste treatment as renewable natural gas – requires biogas cleaning and processing infrastructure
• Vehicle capital cost slightly higher than diesel, but pump price of gas is lower for similar performance

Key benefits of alternative fuels include reduced emissions, lower operating cost and longer vehicle life. There are several themes in the key challenges: in particular, the high capital cost of alternative fuel vehicles, supply-chain issues and developing appropriate infrastructure for fuelling or charging.

Eight case studies have been compiled on the experiences of the municipalities interviewed:

• Aberdeen City Council, UK – hydrogen fuel cell
• City of Groningen Council, Netherlands – hydrogen fuel cell
• Municipality of Kampen, Netherlands – HVO
• Department of Sanitation New York, USA – battery electric
• Rotterdam City Council, Netherlands – battery electric
• City of Toronto Council, Canada – renewable natural gas
• Westminster City Council, UK – battery electric

These case studies are available as an appendix to the main report, with the intention to provide useful practical context for those seeking to adopt a similar approach.

If you want to read more about waste management services jumping on the e-train, read our article here!

The experience and adoption of alternative fuels is a rapidly changing landscape. Each municipality has a different energy and fuel supply situation, which is often connected to the regional or national energy strategy. Each municipality also has its own terrain, collection service requirements and supporting infrastructure. As such, there is no universal single solution; the optimum fuel will depend on the particular situation. In implementing a collection system using alternative fuels, consideration has to be given to route planning and vehicle range, fuelling/charging infrastructure, driving experience and total overall costs (including vehicle life, maintenance, etc.). The total overall costs of some alternative fuels are reported to be lower than for the diesel equivalent; however, the initial capital cost can be significantly more, currently at least two to three times that of a conventional diesel alternative. Few operators have experienced a full life cycle of these alternative vehicles to be able to validate the actual cost relationship.

Supporting infrastructure is a key issue for many fuel types. Even fuels involving “simple” changes, such as replacing diesel with HVO, require a reliable source of fuel, which has proved problematic for some, with broader environmental/sustainability concerns of supply. Substantial changes, such as electric and hydrogen or investing in renewable natural gas generation, require supply and fuelling infrastructure to be developed locally, at significant cost. The suitability of the local grid capacity to accommodate widespread charging of electric vehicles needs early assessment prior to committing to the technology, with the capital cost of substations taken into account in the business case for change. The hydrogen market is developing in many countries in regional clusters or hubs; it may be some way from widespread commercial viability for many applications that are not located in these hubs.

Vehicle technology is constantly developing, particularly in terms of hydrogen and electric vehicles. Early adoption means that environmental benefits are realised sooner. There is a risk, however, that investing now may lead to early obsolescence, particularly with regard to electric vehicle battery capacity. Furthermore, the cost and disruption of developing supporting infrastructure for the move to an alternative fuel is likely to lock many municipalities in to longer-term arrangements. Many municipalities have been trialling different vehicles for this purpose, prior to committing, or using a transition fuel, such as HVO or a hybrid arrangement.

Many of the current alternative vehicle developments described are comparatively small scale, resulting in a high unit cost. It is suggested that strategic policy direction towards a particular fuelling solution at a national or regional level would aid and accelerate the transition process, particularly with regard to further research and development, strengthening supply chains and reducing manufacturing/purchasing costs.

This article has been produced in association with the International Solid Waste Association and its Working Group on Collection and Transportation Technology.

Situation

Location: South of Guangdong Province (coastal, adjacent to Hong Kong); major sub-provincial city, known as China’s Silicon Valley – 4th largest city in China

Area: Approximately 1,990 sq km

Population: 17.56 million in total (2020) (contract covers a population of two million people, 10% of the total city area)

Waste generation: 1,800 t/day

Facilities: Public charging points located near to secure company parking facilities

Collection: Food, kitchen and mixed general waste

Influencing policies:

• China’s first Special Economic Zone developed as an eco-city
• China’s first climate commitment and sustainable transport policies
• China’s first carbon trading pilot programme

Fleet

Waste collection is outsourced to INFORE Environment, whose fleet for the collection of approximately two million people comprises 197 vehicles:

• 64 refuse collection vehicles (31 t) – diesel
• 133 smaller vehicles (7 t) – electric

The electric vehicles are used for food and kitchen waste and for mixed general waste collection. The electric vehicles are manufactured by Changsha Zoomlion Environmental Industry Co., Ltd.

Our Journey

Two years ago, Shenzhen outsourced its waste collection and street cleaning contract to Changsha Zoomlion Environmental Industry Co., Ltd, a wholly owned subsidiary of INFORE Environment. This public-private partnership (PPP) contract is for 10% of the city area, approximately two million people.

The smaller (7 t) vehicles are two years old and all electric to meet national/local policies and carbon targets. The vehicles are charged overnight at social (public) charging points, and parked in nearby company car parks. Quick top-up charges are also undertaken around the city during the day by the drivers, using power from the national grid.

The electric vehicles operate for six hours, plus two hours travel time to the start of the round. The fleet operates on single or double shifts – the second shift will start with the vehicle being charged.

Through the contract, it is planned to convert the entire waste collection fleet to electric over the next three to five years. The challenge is that the range of the larger vehicles is only 200 km before charging is required, and 130 km for the smaller vehicles.

Key Considerations

Electric vehicles require fire-risk and charging awareness but no special driver training

Battery life/range of electric vehicles

Costs and Budget

The annual waste collection service cost for the contract is RMB 520 million ($81 million).

The contract duration is 15 years, and the electric vehicles were introduced early in the contract.

The PPP contractor manufactures and supplies the vehicles. Shenzhen is also unique in its internal infrastructure and its concentration of high-tech companies, which have helped to facilitate its network of public charging points for electric vehicles that the smaller vehicles utilise.

The service costs of the electric vehicles are about 25% of the diesel equivalent and if driven well there are no additional maintenance costs.