August 28, 2012
Bagley Energy and Metering Summary
Over the past few months, I completed a detailed review of the metering system for the Bagley
Classroom. The goal of this review was to determine if the building systems are operating
properly and if metering data from our system and from Minnesota Power is accurate. I also
took readings from the solar arrays at Malosky and Bagley throughout the summer to compare
performance. The results are listed below.
Building Systems
All building systems appear to be operating properly with the exception of the water heater for
the men’s bathroom. I tested all of the lighting and ventilation features and the composting
toilets and found no problems.
Metering System
There is a problem with the building metering hardware that causes some of the panel circuits
to be reported with the wrong circuit tags. I tested all of the circuits locally and verified that the
data is accurate, but some of the circuit ID numbers are reversed when stored in the archives.
Also, the total energy usage for the panel is reported as a calculated number and the calculation
is wrong. The good news is that we have accurate energy usage for the building since the
archive was activated in 2011. The bad news is that it takes some manipulation of the data to
figure out where the energy is being consumed and I don’t know the start date for data
collection. I am estimating that data collection goes back to early 2011. The technician from
Schneider Electric will be here in September to correct the archive issues.
I also tested Minnesota Power’s utility meter using our building system and portable meters.
The utility meter is accurate for both energy delivered and energy received.
Bagley Metering Data since early 2011:
Total Building Consumption:
Total Solar Production:
Deficit from Net Zero:
Top Consumers (95%):
1. Boiler
2. Women’s Biolet
3. Men’s Biolet
4. Fire Panel
5. All Lights
6. HRV Unit
7. Network Panel
15417 kWh
11353 kWh
4064 kWh (26%)
7919 kWh
2336 kWh
970 kWh
960 kWh
929 kWh
846 kWh
726 kWh
August 28, 2012
Solar Comparison
I took weekly readings for both systems throughout the summer. The readings show that the
Malosky system produced almost 20% more electricity than Bagley over this period. The hours
of operation are similar for both systems. The Bagley system often has a slightly higher daily
output until late afternoon, but drops off dramatically after 2-3pm. It appears that the Malosky
system performs much better late in the day and that difference is enough to create the gap. It
will be interesting to see how they compare in the winter months.
Solar Data since June 1, 2012:
Bagley Total Production:
Malosky Total Production:
2084 kWh
2571 kWh
** Bagley had a slightly higher daily energy output until late afternoon on 8 of the 12 days that I
took readings (3-4pm).**