A year of kilowatt hours

A full year in the house brings a full year of energy data to pour through courtesy of Duke Energy®. Comparing the meter reading from June 26, 2015 with that of June 26, 2014 shows that we used 7211 kWh for the year, or 9.9 kWh per person per day on average. Yeah! We seem to have easily reached our goal of 13 kWh per day per person. Unfortunately, given losses from the methods used to generate electricity for the local grid, the site energy is about 1.8 times less than the source energy. That means it actually took about 17.8 kWh of energy per person per day to give us the 9.9 kWh we each actually could use. The good news then is that, with some careful planning and good building and living practices, getting down to the desired goal of energy usage at home that is more in line with global per capita norms is not that hard to accomplish, even with our harsh winters and hot, humid summers. We are still living in a rather large house with many modern conveniences and luxuries. The less good news is that we need more efficient methods to generate electricity to actually reach our goal.

So how do we lower that ratio of electricity generated at the source to electricity delivered to the site to something closer to 1? We can start generating energy on site or convince Duke Energy® to start producing and transmitting electricity by less wasteful means. Being surrounded by tall trees rules out wind energy on site. The house roof is angled for optimal solar panel placement and a channel was already built from the roof to the basement, where space is open for battery storage. With a year of energy data we can now see if investing in solar panels makes sense yet.

The average number of kWh used each day, divided by months, are plotted along with heating or cooling degree days (using 65 °F/18.3 °C as the baseline) for the area. Clearly, the majority of energy is needed to heat the house and colder incoming water during winter months.

The average number of kWh used each day, divided by months, are plotted along with heating or cooling degree days (using 65 °F/18.3 °C as the baseline) for the area. Clearly, the majority of energy is needed to heat the house and colder incoming water during winter months.

In looking at a map of solar energy that could be generated in this area, we definitely have enough south-facing roof area to generate around 7200 kWh each year with current technology. Unfortunately, looking at the energy analysis provided by Duke Energy®, the majority of the energy used is during the winter months when the skies are largely overcast. Most of the electricity we could generate with panels would be in the summer months. Without much better batteries for months-long (versus overnight) energy storage, only a grid-tied system would make sense. However, at this point, the fees charged for the connection and the price paid for home-generated electricity versus the price charged for grid electricity does not make solar panel installation attractive. A grid-tied system also still leaves the house powerless for many hours a year during storms. Clearly, lowering energy usage at home is just the first step needed to tackle the problem of living sustainably. At least that first step has turned out to be relatively painless in retrospect! A large bonus has been the joy of living in an air-tight house oriented toward the sun so that the spaces inside are comfortable, bright and cheery even on the grayest of Indiana days.

Blooming times

The heating season is completely over in our well insulated house and now many of the dozen Coral Sunset peonies planted last fall have put out their first blooms.

The heating season is completely over in our well insulated house and now many of the dozen Coral Sunset peonies planted last fall have put out their first blooms.

Daffodils bloom: The end of the heating season is near

The Ice Follies daffodil bulbs burst into bloom during the course of the day and have so far proven resistant to the local deer herd's nibbling.

The Ice Follies daffodil bulbs burst into bloom during the course of the day and have so far proven resistant to the local deer herd’s nibbling.

When I biked off to work this morning I had only an inkling of the flower display that would welcome me upon my return. Spring is really here! I turned off the minisplit heat pumps and ventilation system and opened a few windows for fresh air before heading to work. Although freezing temperatures are still in the forecast for the next week, the weather was picture perfect today. The house is insulated enough to comfortably survive the freezing nights without the heat pump when the sun shines and warms the outside air into the 60’s (°F) during the day.

The electric bill came again yesterday; 7470 kWh were needed to power our house and life in it (still including some construction work) for the last year. The water bill arrived shortly beforehand, too. We are averaging about 1000 gallons of treated water per month, or about 17 gallons per person per day. Soon the rain barrels can be set up again to collect water for the garden and indoor plants. I just planted some lettuce seeds in the rooftop garden planters on Monday and look forward to nurturing those seeds into salads. More rain should arrive here in Southern Indiana tonight to help. By contrast, the news from California is bleak today as the governor announced mandatory water use reductions for the first time in the state’s history. Fortunately, this house has so far taught me that small changes can reduce water usage significantly without reducing quality of life. Perhaps some agriculture will have to shift back to the Midwest from California, but my former home state should be okay given only current technology and some creative will. Designing our houses and lives for greater resiliency is clearly the future.