Dual Fuel Hot Water Boiler
It turns out that this is actually a dual fuel boiler. The primary clue is that it has both fuel oil and gas piped to it. You can get a sense of that when you look at it in the picture that shows the entire boiler from the front because of the large pipe with a valve in it coming in from the left and the smaller lines with flexible connections coming into it from the right. In the field you can take a closer look and if you do that, you will discover that there are in fact pipes labeled "Natural Gas" and "Fuel Oil Supply" and "Fuel Oil Return" connected to the boiler and its burner.
Mission critical facilities like Fred Hutch frequently have multiple energy sources for their prime movers to ensure that they can continue to provide service if the loose a utility due to a disaster like an earthquake. But the dual fuel capabilities can also provide a cost benefit by allowing the facility to use a curtailment based rate.
In other words, because Fred Hutch can fire their boilers with oil or gas, they can elect a rate plan with the local gas utility that allows the utility to notify Fred Hutch that they need to go off of gas with-in a certain time frame (usually an hour or two) when the utility is experiencing a demand peak. If Fred Hutch is able to switch their boilers to fuel oil and drop off of the gas system for a while, that provides capacity for the utility to use to serve other customers with out that flexibility. In return for being flexible, the utility sells gas to Fred Hutch under non-peak conditions at a lower cost.
But if something happens and for some reason, Fred Hutch is not able to switch over to fuel oil, the utility does not cut them off. However, they will charge a much higher rate for the gas Fred Hutch consumes during the peak due to what it will cost the utility to provide the service under those conditions.
Mission critical facilities like Fred Hutch frequently have multiple energy sources for their prime movers to ensure that they can continue to provide service if the loose a utility due to a disaster like an earthquake. But the dual fuel capabilities can also provide a cost benefit by allowing the facility to use a curtailment based rate.
In other words, because Fred Hutch can fire their boilers with oil or gas, they can elect a rate plan with the local gas utility that allows the utility to notify Fred Hutch that they need to go off of gas with-in a certain time frame (usually an hour or two) when the utility is experiencing a demand peak. If Fred Hutch is able to switch their boilers to fuel oil and drop off of the gas system for a while, that provides capacity for the utility to use to serve other customers with out that flexibility. In return for being flexible, the utility sells gas to Fred Hutch under non-peak conditions at a lower cost.
But if something happens and for some reason, Fred Hutch is not able to switch over to fuel oil, the utility does not cut them off. However, they will charge a much higher rate for the gas Fred Hutch consumes during the peak due to what it will cost the utility to provide the service under those conditions.
