What size propane tank do i need to run a 16kw generator for 5 days?

You will use just over 38 gallons of propane in a 24 hour period at half load. So over a 5 day time frame at half load you will use around 190 gallons. Given that, a 250 gallon water capacity propane tank, when filled to 80% capacity liquid propane would give you 200 gallons of liquid propane. So your answer is a 250 gallon propane tank is the size you need. Just keep in mind that ASME propane storage vessels are sized by water capacity in gallons of water. To get actual propane gallons, you need to factor 80% of the water capacity. This is simply the maximum fill capacity for propane allowing room in the tank for expansion of the product due to temperature fluctuations. If you have the room for it you may want to consider a 500 gallon tank doubling your capacity to 400 gallons of liquid propane. You may even want to consider the benefits of an underground tank. I’ve done quite a few of these installations over the years and it’s just been my personal opinion that if your investing ...  more