Friday, August 31, 2012

Information Can Change Behavior - An Energy Use Story

I keep the information tracking system in my Volkswagen TDI set to average MPG. When I get a little heavy on the accelerator (which happens from time to time), my mileage reflects my driving. When it drops below 40 MPG, I change my behavior because that threshold (for some reason) is important to me.

We recently started the install of our energy monitoring system for our office building at 502 Rigsbee. As of today, we can track the total energy generated by the PV system and the building’s total energy use. Our plan is to have full circuit-by-circuit monitoring in place in the coming weeks. The energy geek in all of us can check it out at:

I’ve been on a rampage about how and when we use energy ever since we started to see this information. Why is our building using so much power at night when we have moderate and comfortable evenings with outside temperatures lower than the settings on our thermostats? What else is using power besides our HVAC system? Look at that spike in energy use during our grand opening party! A few hundred people really heat up the place. Why is that computer monitor on when not in use? Are our motion sensors working correctly and shutting off our lights when we forget to turn them off? How much power does our UV rainwater filter use? Yes, I can drive myself a little crazy with this stuff, but the information allows us to take care of three major items. One, we can assure the systems we have installed are functioning properly as designed and installed. Two, we can address those items and see direct results. Three, we can modify behavior to assure we are using the facility to assure the greatest efficiency.

When you have data, all these things come to the forefront. When our building is using more energy at night than I think it should, I use the information and investigate. If you know where the waste is, you can change the right things. Without the information, energy guzzlers just keep quietly guzzling often with little real benefit.

Although we are not yet showing the power generated by the wind turbines and we are not yet seeing individual circuit use, we have enough information to start changing behavior and tweaking systems. With the monitoring system fully functional, we can continue to tune our habits and systems for maximum benefit and minimal energy use.

Information changes behavior for the better.

Making Our Home a Home Sweet Home - Part 11: ENERGY STAR washer

Unfortunately, I did not think far enough ahead to take pictures of our old washer and dryer, but suffice it to say that they were old, loud, and inconsistent.  They were used when they were given to us when we moved to Durham (10 years ago). The free price tag, which thrilled our graduate student and first-time schoolteacher budget, was a deceptive value that failed us for too many years.  While they were free, the water use and higher wattage motors meant we were paying for it with each use.  The stackable washer and dryer we bought this year are the lower end Samsung front loaders that still have vibration reduction technology (VRT™), which allows faster spin speeds and dryer clothes after washing.  They aren't as quiet as they claim (I think it's because of the stacking), but their performance trumps that for me.  ENERGY STAR’s website tells us that an ENERGY STAR washer uses 14 gallons of water per load versus 27 gallons for standard machines. Our 10 year old machine may have used up to 35 gallons per load. According to Whirlpool, a machine from 1994-2003 uses about 904 kWh per year versus 192 kWh annual use for a new ENERGY STAR washer. A washing machine using 30% less energy and 50% less water can translate to annual savings of $100-$150 and more depending on the size of your family and machine use.
New stackable VRT washer and dryer

Thursday, August 30, 2012

Making our Home a Home Sweet Home - Part 10: Why pay to heat and cool your home when you’re not even there?

If you’re looking for a really low hanging fruit to save some money on utility bills, simply head out and buy a programmable thermostat at your local home improvement store.  They are relatively easy to install, with a couple standard tools, if you follow the instructions (which is of course pretty important).
Sometimes I wish I would have made all of the improvements I’ve mentioned in this series in sequence with enough space in between the phases to see what kind of impact each one had on savings, but in this case my impatience outweighed my need for science.  Once you learn something about building science, the things in your own home begin to glare at you.  I just want to make those things go away.
While I don’t have clear numbers for you on what the programmable thermostat saved us at my home, the EPA publishes some industry averages.  They say folks save an average of $180 a year by replacing a conventional thermostat with a programmable one.  It is certainly part of the story that resulted in our receiving a letter from PSNC that our equal pay gas bill would be $13 per month instead of $43.  Some of that is attributed to better insulation and air-sealing, but the thermostat ensures that our HVAC system can relax during times we are either not in the house, or when we are asleep.  Those are the largest proportions of time in the life of a house, and big opportunities for savings.
There is a range of programmable thermostats, from ones that have standard times and periods of day predetermined without customizability, to ones that can link up with your wifi network so you can control them with your smart phone when you’re out of town, across the street.  The one you see here cost me about $70.  But, as you can see from the EPA information above, it pays for itself, on average, in less than half a year.  That’s both smart and puts money back in your pocket.
What are you waiting for?  I was proud of my accomplishment.  You will be, too!

Remove old thermostat
Wire and mount new thermostat
Program and Save!!!