The More You Spend, The More You Save

3 11 2009

Talk about an oxymoron.  Years ago this was a favorite saying of my roommate and I as we lambasted dopey ads on TV, on paper, or over the airwaves.

Fewer years ago, once I got into this energy efficiency profession, I was speaking with a utility energy-efficiency program guy who frequently interacts with regulators.  This was during a stakeholder meeting for quantifying energy saving potential by sector and by technology.  (technology = lighting, furnaces, chillers, etc.)  Knowing buildings systems rarely work as they are supposed to, I asked, “Have you considered retrocommissioning (RCx) as an energy efficiency program?”  His answer in effect was, that would be great, but it would be double dipping since customers have already been incentivized for energy efficiency.  I didn’t have a response for that.  I do now.

Incentives are based on building systems working as they should.  Unfortunately, this is rarely the case.  Buildings almost always use more energy than they do on paper (or computer).  See the recent Illinois LEED performance report, Figure 14.   Buildings underperform badly compared to design models.  I would venture to guess that the majority of this discrepancy is lousy controls.

Therefore, my response to the “buildings have already been incentivized and therefore, RCx is double dipping” is twofold:

  • Incentives for efficient equipment and systems are many times actually too low.  The building’s systems and controls are performing so poorly that the boiler actually has to make more hot water and the chiller has to make more chilled water than planned.  The lights are saving more because they are on longer than they should be.  If you’re going to waste energy, you may as well do it efficiently (oxymoron alert).  The more you spend, the more you save!  Other measures probably under-predict savings but these are typically control measures and control measures make up a small fraction of incentives and associated savings that programs take credit for – a thesis based on my experience – a thesis I am very confident with.
  • Savings from RCx IS NOT double dipping.  When I poll our own recent RCx projects, I find that 75% of the savings are derived from measures that either (1) fix control issues that wouldn’t even be eligible for incentives in the first place or (2) implement measures that are required by energy code.  Some buildings aren’t built to comply with prescriptive energy code requirements – imagine that! and (3) implementing new measures that exceed code requirements.

Conclusions:

  • Incentives in many cases are too low because systems perform poorly (the more you spend, the more you save)
  • Incentives in other cases are too high because they are controls-based and the control sequences are wasting energy
  • Reducing over-use and fixing things that aren’t even incentive-eligible almost certainly outweigh fixing control issues on measures that were already incentivized.  Therefore, the net of RCx measures is all new unrealized savings.

By the way, the utility mentioned above has an RCx program now.

written by Jeffrey L. Ihnen, P.E., LEED AP

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