For emergency power systems with fuel stocks of less than 1,000 to 2,000 liters, a meaningful fuel check is not recommended for economic reasons. In these cases, it is more advantageous to replace the fuel in good time so that it can still be recycled/used elsewhere if necessary.
In order to maximize the usability of fuel stocks as far as possible, a switch to paraffinic fuels could be suitable, depending on the application. These are somewhat more expensive to purchase but are characterized with greater storage stability.