Never Dark Carolinas

What size propane tank do I need?

One of the questions we get when we are doing our site visits is what size Liquid Propane tank will I need to run my generator. When someone already has service it can be a little tricky as it may mean a bigger tank. And what about the existing natural gas meter? Is that sufficient?
Like with a lot of things, there isn’t a one size fits all. Each circumstance is a little different. But for the most part we can provide some guidelines that will help determine what you might need or need to consider when installing a whole home standby power unit.
One of the factors to determining the size tank you will need is how much of a load you will use when the power goes out. If your whole home is electric and you have the generator running at full load, you are going to go through a lot of LP. That existing tank is no longer just running the fireplace. It now is powering the whole home.
Another factor is how quickly your gas company will commit to filling your tank. If your service provider typically requires 5-7 days lead time, then you will want to have a tank that is big enough to be used during an extensive black out. Most gas companies consider those with generators as “will call” and not necessarily an emergency. They will handle emergency tanks before those with whole home standby power units. Be sure to let your gas company know if your standby power unit is for a medical condition such as for oxygen. They will note that on your account and consider you a priority.
So how much LP gas does a typical standby power unit use? Here is a breakdown:

LP Gas (Gal/Hr) 50% Load Efficiency 100% Load Efficiency
16 KW 1.99 0.25gal/ kw 3.57 0.22kw

20 KW 2.08 0.21gal/ kw 3.85 0.19kw

22 KW 2.16 0.20gal/kw 3.67 0.17kw


With those numbers in mind, you can see that with the generator running wide open, if you have a 250 gallon tank, you would have roughly 3 days of run time before the tank is empty.
This of course is if the unit is running full load that whole time. You would need to consider scheduling a refill within the first 24 hours and even then it might not be soon enough. That is why we often recommend at least a 500 gallon tank if you are installing a standby power unit and plan to run the whole home. For those with medical needs and who work from home, perhaps a bigger tank is in order.
When doing your cost analysis of a unit and installation, you will need to account for the gas service and installation or if need be the cost to upgrade your tank to a bigger size. Additionally, if you live under an HOA, don’t forget to consider if you need to bury your tank or camouflage it in landscaping. That could add to the final cost.
With Natural Gas, you will more than likely need to upgrade the meter to account for the generator. Most companies will upgrade the meter for free. That doesn’t mean there won’t be additional costs if you use natural gas. Depending on where you will need to install the unit, there might be the need for additional pipe to be plumbed or moving of the gas line. We work with the gas companies as best as we can to determine what additional work if any needs to be done. And pricing will vary depending on the gas company.
There are a lot of things to consider when looking into installing a home standby unit. One customer told us there are things he didn’t know that you can’t find out even on the Generac site or Lowes where he bought his unit. That’s why using a Dealer/Service Provider that specializes in automatic home standby power and turn-key installs is so important. They have the knowledge and experience to help guide you through the experience. You don’t know what you don’t know. But Never Dark Power Solutions does. Don’t be in the dark! We will keep you informed.