Which fuel works best? RME, ethanol or gas – the choice is yours.
Scania has chosen to focus on three established alternative fuels with growing systems of secure supply.
RME (rapeseed methyl ester, also known as FAME or fatty acid methyl ester) is extracted from rapeseed oil, which is a renewable resource. RME can be easily blended with diesel. Scania permits a mix of 5 per cent RME in diesel fuel and our newest engines with unit injectors can handle 100 per cent RME.
Ethanol is typically extracted from sugar cane or sugar beets, but can also be derived from biological wastes including wood-processing bi-products. Ethanol provides less energy than diesel and petrol, so more fuel is required than with diesel for the same amount of work. However, its liquid form makes it easy to handle. Scania is the world’s only supplier of ethanol buses. Several hundreds have been delivered since the early 1990s – with amazing environmental gains.
Gas is another popular alternative. Sources can be either natural (CNG) which is a fossil fuel, or renewable biogas from waste aggregation. Gas-driven engines use the Otto principle and need more energy than a traditional diesel engine for a given task. Another consideration with gas is the need for heavy pressurised fuel tanks, which impact range, flexibility and passenger capacity. Since the 1990s, Scania has delivered some 1,000 vehicles worldwide.
Ultimately, all these solutions will find their markets. Scania is also working with hybrid solutions for heavy transport that have the potential to save 25 per cent in energy consumption. A standard bus engine is combined with robust electric motor/generators and an energy storage system; the fuel can be diesel, ethanol or gas.