Clarifies Facts Presented In Article
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. Ewarts 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 Ohios mostly coal-fired power plants. These
facts lead me to make the statement quoted in Mr. Ewarts 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 buildings energy.
In the last 12 months the PV array has produced yet a larger fraction
of the buildings 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.
Professor of Physics