Monday, July 1, 2013

LEED Operations

We have been in the house for a little over a year now, and I thought I would give a little update on the performance.  

The vegetation on the site has filled in nicely.  The wildflowers we have planted are slowly beginning to assert their place in the prairie, and we have a profusion of color with purple, white, and a sprinkling of yellow flowers.  It is still early in the season for all of the flowering plants to bloom, but we are expecting a spectacular display.  

The fireflies hatched about two weeks late this year.  The vast majority of the time they illuminate only when their flight is in an upward path which I call "lighting up" (I swear I never inhaled).  Early in the evening they light up close to the ground, but eventually work their way up to the treetops.  

We have several sightings of an Indigo Blue Bunting.  This morning as I left the house, I flushed four of them from the driveway.  We assumed that they had a nest nearby, and this appeared to be several of the juveniles.  They are a striking iridescent blue.

The floor plan has worked perfectly for us, doing everything we had hoped for during the design process.  We have adapted to the one design element that was somewhat questionable, and that was the placement of the laundry room at the center of the bedroom wing.  We struggled during the design process with wanting the convenience of the proximity to the laundry facilities, and the noise that would be generated.  We have scheduled most of our laundry during the day, and we seem to have tuned out any noise that encroaches on our sleeping time.   

The solar panels were installed last October.  We were generating roughly 50 - 75 kilowatt hours of electricity per month through the winter, far less than our demand of around 750 kWh.  The blue line in the graph on the right shows the power demand from the utility company, and the green line shows what we produce and put back into the grid.  

The demand peak in August aligns with the cooling load attributed to the hottest summer on record, and the peak in January aligns with entertaining the family at Christmas time.  Other than those two anomalies, we have consistently used about 750 kWh per month.  We have had a very cool spring, and have been able to have the windows open for the last two months, helping to keep our loads to a minimum.  We have had another addition to the household in the last month that has an impact on our total energy use.  My daughter moved back from California and is staying with us while she looks for work.  It is good to have her back home.

We did not have the production agreement finalized with Consumers Energy until December last year; hence the late start on the contribution to the grid.  You can see the production climbing steadily as we move into the summer months.  Winter production was substantially below expected output, and summer production is slightly above expected output.  I found historical data for average days of sunshine per month, but nothing current to compare with actual sunshine over the last year.  We do still produce some electricity on cloudy days.

You may be interested to know that even the supermoon we had the other night was not enough to start up the solar array.  I can't remember enough of my college physics to recall if the properties of reflected light are the same as direct sunlight.  Proper wavelengths notwithstanding, the added illuminance from the close proximity to the moon was not enough to excite the "lunar" array on the roof.  We checked a couple of times during the night to no avail.  You can cross that off your list for any contributions to energy production.

The only major energy expense we should have right now is our electric hot water.  Since this is derived from the heat pump and an electric coil, I have started looking at the cost of installing the solar hot water array.  We already have the storage tank and the piping in place, we need only install the rooftop array, and some controls.  Hopefully this will reduce our energy requirements to the 550 kWh/ month levels we projected in the design process. 

Thanks to our decision to install smooth concrete floors as our finish floor, cleaning has been a breeze.  We have resisted installing floor coverings, having only two rugs in the house; one in the living area and one in my office to protect the floor.  We also have walk-off mats at the entrances.  With a dust mop, we can clean the floors in about 5 minutes, vacuum the rugs in about another five minutes, and mop the kitchen and bath in another 10 minutes as needed.  This is a vast improvement over the last house which took at least a half a day to clean.  

We have not installed the data logging equipment to record how we use energy.  Though I was looking forward to a more detailed look into how we use energy, we will have to hold off until we can squeeze it into a future budget. 

In the meantime, our new home provides us with everything we had hoped for in comfort and quality of life.  I will keep posting periodically as there is anything to report.  Have a great summer.



Monday, January 28, 2013


We received word from the US Green Building Council that our home has been certified at the LEED Platinum level.  The long delay was due primarily to waiting for the installation of the solar panels.  We achieved all of the points we intended to achieve, though we had inadvertently double counted a few.  The executive summary of the points we attained is listed in the adjacent table.  The first number is the total received contrasted with the total achievable.  We needed a minimum of 90 out of a possible 136 points to achieve the Platinum rating.

We have also received the signed agreement from Consumers Energy, officially making us a supplier to the utility company.  From the data we have gathered so far, our average use is 742 kWh (kilowatt hours) per month against a budget of 562 kWh of consumption which is the number we estimated to design the system.  Keep in mind that this includes all energy use including heating, cooling, and cooking, as we opted not to install any gas.  June and July were the first two full months of electrical consumption data.  Both of those months came in below our energy budget when we were able to have the windows open most of the time. 

Then came one of the hottest summers on record, and we delighted in testing out our new radiant floor cooling system.  After installing cedar shake shingles all day in 95 degree weather it was a great relief to come in to a cool home.  We also spent a considerable amount of energy dehumidifying the house, with two dehumidifiers operating full time from August to mid December.  The amount of water in the concrete, drywall, and insulation will take a long time to extract, and the energy cost of performing that function was not considered.  Hopefully dehumidification will not be as much of a factor this next year. 

Around 3:00 am this morning I heard a thumping noise that sounded like a neighbor either chopping wood or kicking his door in.  It was a deep somewhat rhythmic noise that occasionally became staccato.  I got up and looked out the windows but could not see anything out of place.  The noise continued for another hour before tapering off.  I mentioned it to Judy in the morning, and she identified the sound as snow falling off the roof.  We had a mild thaw last night with about three inches of snow on the roof.  I felt like an idiot for not figuring it out myself. 

In the critter department; three small does walked through the front yard yesterday morning, and later in the afternoon a herd of thirteen more walked through.  A parasite related to the drought we had last year that has decimated the deer population in Michigan, so we are relived to see signs of more activity.  Our neighbor gave us a corn feeder which we put out for the deer.  So far it has served only to attract five fat squirrels, half a dozen blue jays, innumerable sparrows, and a few cardinals.   Last week a flock of 17 turkeys ambled nervously through the backyard.  They make their appearance about once a month and are very alert for the slightest motion.  They certainly do look prehistoric. 

May you all have a great New Year!