Recommended Fuel Tank Size For Gensets


During a power failure, generators provide the backup electric power shortfall caused by the main electricity provider. Generators generate power by converting the mechanical energy into electrical energy. If there is no fuel during the power failure of the generator then the generator will fail. For this reason, it is important to store enough fuel into the fuel tank. A number of factors have to be considered while choosing a fuel tank.


Fuel Tank Capacity

The amount of diesel which can be stored by a generator’s built in fuel tank is usually fixed. Therefore in situations where prolonged use of the generator is required, you would need an external tank. Determine the following first:

Emergency Stock: What is the required amount of fuel as a buffer in the event the re-supply comes late?

Lead-Time for Supply: What is this required lead time to buy fuel from the supplier?

Lead-Time Stock: What is the amount of fuel needed to run the generator during the lead time awaiting re-stocking?

According to all the three variables, the minimum storage capacity can be determined by the equation-
Minimum storage capacity = Lead-time Stock + Emergency Stock 


Storage capacity

When it comes to electrical power blackouts, a smaller tank would be needed to ensure you have enough amount of fuel. You will need to buy fuel regularly to fill up the storage tank if storage space is not sufficient. Since you incur minimum capital costs for setting up the storage tank and minimum repair costs, the delivery cost will be higher. Prior to finalizing the storage requirement/capacity, it is necessary for you to finalize the commitment with the supplier. The supplier’s capacity to deliver the required amount of fuel needs to be assessed.


Types of Fuel Tanks

The fuel tanks can be divided into three types-

Sub Base Tanks

The sub base tanks are usually used to store less than one thousand gallons of fuel. They are developed to fit under the base and above the ground. Their cross section is rectangular in shape and it allows preventing the consumption of fuel due to leakage. The filling system of the tank needs to be designed such a way that no spillage occurs during filling.

Underground Storage Tanks 

These tanks are usually used to store more than one thousand gallons of fuel. These kinds of tanks are more expensive to run, but have a great strength since they are protected from environment. Fiberglass-reinforced plastic is used to make underground storage tanks and sometimes they are fabricated from steel. They use an ideal cathodic safety against deterioration of ground water.

However, any leakage of the underground storage tank is very hard to rectify. For this reason, this tank must have spill prevention tools and procedures. 

Above Ground Storage Tanks

From its name, we can easily think these type of tanks to be set up above the ground. They have a construction similar to underground storage tanks but, their installation processes are not same. This kind of installation is easier but requires space above the ground and it is not aesthetically pleasing too.