15. Fuels and electricity in transport operation
Ever since the start of NTM the environmental effects of electricity generation have been scrutinized and heavily discussed. The core questions have been:
- System boundary definitions
- The link between consumption and production
The principal guideline for NTM is to include relevant and comparable system boundaries where data is sufficiently reliable. The consumer choice of a specified energy carrier based on production methods should be reflected in the environmental performance where the responsibility of data lies on the fuel or electric power producer. If a sold fraction of a specified energy carrier leads to a residual fraction with another performance this must be reflected in the specification of that fuel.These principals are easy to accept in general but when it comes to the details they commonly need further specifications and very detailed book keeping procedures.
For fluid fuels this very same debate is now emerging as biomass based fuels are entering the market. For these fuels the question is primarily concentrated on the relevant system boundary and which and how certain effects from production should be included or not. Connecting consumed fuels to what is specifically produced is in principle more straight forward than for electricity, but one could foresee similar challenges if the consumer buys a specified fraction of fuels defined by its impact on the environment but not always specifically consuming this blend of fuel and relying on the book keeping of the fuels supplier.
Originally the electricity debate only concerned electric rail operation, but as new electric and plug-in electric/combustion engines are now entering the market for cars, buses, trucks and even ships and aircraft (auxiliary engine) the issue now embraces the full transport sector.