Anticipate Collateral Benefits

This is the fourth in a series of guest posts by Ted Borer, PE, the energy plant manager for Princeton University. He is actively involved in campus and community energy efficiency and carbon emissions reduction efforts. He has over 25 years of experience in the energy industry, is a registered professional engineer, and holds both undergraduate and graduate degrees in Mechanical Engineering as well as the CEM, CEP, and LEEDAP Certifications. He has published numerous magazine articles, technical papers, and a book chapter on topics relating to energy and cogeneration. 

We are all familiar with the concept of collateral damage, i.e., when one system fails, something downstream is also damaged. When a nail punctures your tire, the tire goes flat, but you’re also forced to drive slowly and are late to get somewhere, then if you drive on the rim to get home, both tire and rim need repairs.

I’d like to suggest that the reverse is also true, and our efforts to save energy will often yield delightful and unanticipated “collateral benefits.”  Here are a few examples:


We replaced an old oil-fired furnace with a new electric heat pump. The upgrade was justified on life-cycle savings alone. I.e., the cost of new equipment (less rebates and incentives) plus the cost of several years of operation was actually less than the cost of operating the old, dirty, inefficient equipment for several more years. Saving money was just the anticipated benefit. We also knew that by using a highly-efficient heat pump instead of burning home heating oil we would substantially reduce our family carbon footprint. But what we hadn’t anticipated were a few other nice benefits:


  • We eliminated the liability of having 270 gallons of diesel fuel stored in our basement. 
  • By replacing a combustion process with electric equipment we were able to move the air handler from the middle to the corner of the basement, allowing more recreational space.
  • By eliminating the oil tank, we freed-up even more recreational space.
  • We eliminated fuel oil deliveries.
  • We moved ourselves farther from foreign fuel.

In another project, we did air sealing and added extra insulation in the house. We measured the “infiltration” (air leaks through all the tiny cracks and gaps in the house) before and after this work and anticipated about 19% reduction in energy use. In fact, that turned out to be a very accurate prediction of our energy savings. What we hadn’t anticipated was that the house would be quieter and more comfortable. With less leakage, the heating and cooling equipment didn’t have to run as often. With less leakage, the house was less drafty and more comfortable.  With less warm air exhausted through leaks, less cool air was pulled in through the basement. This resulted in such a dramatic decrease in measured radon levels that we were able to shut off the 100 watt radon exhaust fan – further reducing our energy use continuously all year!  (100 watts) x ($0.18/kilowatt-hour) x (1 kilowatt-hour/1000 watt-hours) x (8760 hours per year) = $157.68 savings per year! A nice added benefit!

Just a slight caution: think before you act. It is possible to make energy-saving changes that aren’t entirely satisfactory. For instance, do consider all the qualities you’d like in a new light bulb. That energy efficient LED light may be ideal. But think first about whether it’s got the right shape for your fixture and the right light color, and can dim if you want it to. Does it make noise? Will you use it enough hours to justify the cost? 

But go ahead and dive in! Start making thoughtful energy-saving changes. Think. Plan. Act. Then, expect to be delighted with unanticipated collateral benefits from your work!