The use of biofuel in cold temperatures can be problematic for two reasons. Firstly, biodiesel blends become unusable at temperatures that are, relative to standard diesel, very close to their cloud points. Secondly, biodiesels derived from different sources (e.g. soybean oil, corn oil, animal fat) have different freezing points, so it difficult to determine the temperature at which biodiesel will congeal enough to plug an engine filter if the feedstock is unknown.
For operators of standby generators, it is important to know both the percentage of biodiesel in their fuel and the feedstock from which their biodiesel is derived. With the use of biodiesel that has a high freezing temperature; heaters can be affixed to fuel tank to prevent waxing. There are also additives available that decrease the cloud point temperature.