Coldham & Hartman Architects commit to renewables at home

On March 3rd, 2008, Philippe Rigolaud of Pioneer Valley PhotoVoltaics (PV Squared) officially threw the switch on the Coldham&Hartman Architects’ new solar electric array (both firms in photo adjacent). Utilizing the Mass Technology Collaborative’s generous business incentives, the 3.8kW system may provide up to 100% of the office’s electric needs, saving up to $700/year in electric costs and reducing the office carbon output significantly.

The results are in for the past year, and we have achieved net zero electrical production for September 2008 to 2009, with a positive balance of 190 kwh. The current total net is 604kwh, but this will be drawn down this winter. This comparison is only for site energy, not source values, and does not any include heating energy- which is primarily propane. Download the pdf of the monthly meter readings.

Not only did we install the renewable production, but we placed significant effort in reducing our loads, especially phantom loads.  We set up our printers on a power strip with an occupancy sensor so that they shut off over night, but automatically turn on when someone comes into the office. In the past years we've upgraded our computers so that we no longer have CRT monitors, but flat screens and laptops.  Andrew keeps us honest with notes on plug strips for backup drives to turn off... to avoid 2 watts!  If it can be plugged in, we've put a Kill-o-watt on it to see what it draws.  The beer fridge was being debated, but will remain on for now.  (AW: and that 2W powerstrip, left ON over the course of a year, would consume 17.5kwh.  Ten little items like that are the difference for us between Netting Zero Electric and NOT...)

Note, however, that this does not address our space heating at all, which is provided by a ductless gas unit at the wall.  While we're up by 190kwh for electric consumption, our propane usage was around 466 gallons for the same year.

Total Electric Consumption 6881kwh

Total Propane Consumption, 466 gallons x 91600 Btu/gallon x .000293 kwh/btu = 12553 kwh

Electric usage as percentage of total building energy consumption:  35%

 See our electric credit in perspective: