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.
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.