Scofield Clarifies Facts Presented In Article

To the Editors:

In its last issue the Review published an article entitled “Environmental Studies Building Reexamined” by Scott Ewart. In that article Mr. Ewart describes data I presented in my April 10 seminar regarding energy performance for the Lewis Center. I accurately described these data in my talk and provided appropriate context, but I fear readers of Mr. Ewart’s article may inappropriately interpret the result. So I offer here clarification.
By my calculations the Lewis Center, since January 2000, has consumed between 419,000 — 431,000 kW-hr of energy, roughly 16 percent of this supplied by its rooftop PV array. The remaining 84 percent was purchased from Ohio’s mostly coal-fired power plants. These facts lead me to make the statement quoted in Mr. Ewart’s article, “So far this has been a coal-powered building.”
But this statement does not tell the entire story, nor did I intend for it to do so. In particular, it would not be a good indicator of future or even recent performance (i. e., the last 12 months). Indeed, the PV array was not installed until nearly 11 months into occupancy. In the 16+ months since its installation the PV array has provided 25-30 percent of the building’s energy.
In the last 12 months the PV array has produced yet a larger fraction of the building’s energy because, for a variety of reasons, the building energy consumption has decreased. In the last 12 months my measurement show that the building has consumed between 124,000 and 136,000 kW-hr, just under half of this (59,000 kW-hr) furnished by the PV array.
I do not believe there are major disagreements between the data I have presented and those obtained from logging system maintained by NREL and Environmental Studies Professor John Petersen. There are, to be sure, significant differences in the way that we interpret these data, and he and I are working on a pair of articles that will highlight some of these differences.
Irrespective of these differences I believe the building had great intentions and has been a worthwhile venture. There is no question that it has provided innumerable opportunities for educating us about our built environment and the ways in which we use energy. I am optimistic that, in time and with significant modifications to its HVAC systems, this building will approach its original target to generate, from renewable sources, all the energy it consumes. Professor Orr is to be credited for making this all possible.

–John Scofield
Professor of Physics