Using sewage as a resource to generate clean transportation
The development of two biogas plans in the outskirts of Stockholm shows the potential in using sewage as a resource to produce heat as well as vehicle gas without adding any net CO2 emissions to the process. The project “Stockholm Vatten Biogas initiative” was developed with partial support (SEK 23m) in 1998 (completed in 2002) from the LIP Local Investment programme.
Biogas is a good alternative to fossil fuels. The sewage treatment plans make use of waste materials and have become net suppliers of energy. As a result, emissions from vehicles as well as from heating have reduced drastically. This successful partnership was implemented by Stockholm Vatten (The Stockholm Water Company) in cooperation with the company AGA (a major distributor of gas). One of the key clients for the biogas is SL (the local public transportation company in Stockholm) which in turn has developed buses that run on biogas instead of diesel or petrol.
Overall the project was regarded a success. Administrative components worked well including support from the Swedish EPA (LIP office).
However, the project also encountered some barriers along the way. The introduction of a new business and a new technology contributed to a long start up phase of the project. The time planning was initially unrealistic and the internal resources at were at first not sufficient to effectively manage the project (Stockholm Vatten AB, 2002). These issues were improved during the project implementation process.
Another important lesson learned was the cost of the project. The project became more expensive (30%) than initially planned because:
- It was difficult to estimate the costs for the new technology.
- An unexpected bankruptcy of one of the suppliers caused a significant increase of costs and a delay of the project.
- The construction costs increased significantly in Stockholm during the construction phase.
These lessons learned serves as valuable insights for the effective planning, management and execution of other innovative Eco-Innovation projects.
- Overall reduced energy use (5 GWh/year)
- Increased gas production due to input of organic material (ca 800.000 Nm3 equivalent to 5 GWh/year)
- Reduced use of petrol and diesel (6 million litres/year)
- Reduced CO2 emissions (14,000 tonnes CO2 /year) as a result of the increased use of biogas replacing the use of petrol and diesel fuel.
- Lower emissions of particulates and nitrogen oxides
The two biogas plans have a low operating costs and the project has contributed to a development of a new technology with an 10-20% improved energy efficiency of biogas compared to petrol.