The required fuel tank size depends on a number of factors including the size of the generator and how long the generator needs to run for. There's also environmental factors which need to be considered for each specific site. We would always advise you to speak to whoever has carried out the site survey to give the best advice.
The runtime requirement is an important aspect of back-up power. It may also be worth considering how long the generator will run for without refuelling. In emergency situations it may not be possible to refuel. Most generators are manufactured with a minimum of an 8 hour run time base tank but this is worth checking. GFE Power Products offer both Bunded and Non-Bunded fuel tank options and as standard these are 8 hour fuel tanks which is usually enough for most back-up generators.
If longer run times are required then it may be worth fitting a 3-way valve to your generator to allow for manual transition between the base tank and a larger external tank. It ultimately comes down to the level of protection you need for power outage emergencies bearing in mind your refuelling options.
If you are unable to install a large enough tank within your facility, it is possible to join multiple smaller tanks together. Therefore providing the fuel capacity you need without having to tackle any logistical issues.
How Much Fuel Does A Diesel Generator Burn Per Hour?
All good generator manufacturers should have a datasheet available which will state the fuel consumption of the generator. You can also check this table to give you an indication of the fuel level required to fulfil your emergency power needs.