Posts Tagged Green Building

The ERoEI of Energy Efficiency

In previous articles, I’ve often claimed that the Energy Return on Energy Invested (ERoEI) for energy efficiency measures is much higher than the ERoEI for Renewable or fossil energy generation. This was based on the logic that a high ERoEI is needed to sustain the high financial returns from energy efficiency. Unfortunately, there are few studies of the energy return on energy efficiency, so most of my evidence was anecdotal.

No longer. I was just reading the 2009 Annual report for Green Building company PFB Corporation (PFBOF.PK.) PFB manufactures SIPS (Structural Insulated Panels) and ICFs (Insulated Concrete Forms) and in their sustainability report, they found that the energy saved by their insulation over 50 years would be approximately 130 times the energy used in its manufacture (see chart.)

Since ERoEI is a flawed measure, I also calculated the Energy Internal Rate of Return (EIRR), using both 25 year and 50 year lifespans… they worked out to be 262% and 264%, respectively. For comparison, the highest EIRR I’ve found for a energy generation technology is 205% for wood cofiring. The EIRR for a wind turbine is around 84%, and a combined cycle natural gas plant has an EIRR about 164%.

In otherwords, insulation is a slam-dunk when it comes to energy economics. That’s no surprise, but it’s nice to have some numbers, so we have a better idea of just how good a slam dunk it is.


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