We reached the point in our Chicago deep-energy-retrofit where we get to work on the renewable energy component: a solar electric system in our case. Needless to say that we are super excited.
The topic of renewable energy generally creates a lot of excitement and buzz. So let me throw in a word of caution:
If you are on a path to make your home more energy efficient, the renewable energy component should be at the very end of your list. First take steps to reduce the overall energy demand of your home, because this is where you get the biggest return on your investment.
A general rule of thumb that I have come across says: every $1 spent to improve the efficiency of a structure saves $3 to $5 on the cost of a renewable energy system. That said, I did not find any research that backs up this claim.
Nevertheless, it rings probable: I did an initial performance analysis back in 2012 and 2016. I took energy data of a building comparable to ours prior to any energy improvements and compared it to our energy usage. I converted both data sets to a square foot basis to get an apples to apples comparison.
By 2016 we had reduced our heating load by 80%, while our electrical consumption decreased by 57%. And keep in mind that we were still working on the building, meaning that there still were lingering inefficiencies.
The bottom line is a renewable energy system for our house would be 1/2 to 1/4 the size of what it would have been prior to any energy improvements. This translates into major cost savings.
And then there are spatial limitations to keep in mind.
Take a solar energy system, i.e. photovoltaic panels in an urban setting. The panels are typically mounted on the roof. But any given residential roof can only accommodate so many photovoltaic panels.
The lower the energy use of a home, the more likely that the panels on the roof cover the majority, if not all of the energy needs, which again translates into major cost savings.
How do you improve the energy efficiency of your home? I provided some guidelines in the previous post. But there is plenty of more information in this blog. Just search the blog for keywords like “building shell”, “insulation”, “air sealing”, “windows”, “heating”, “space conditioning”, “moisture management”, and “ventilation” and you will find plenty of reading material on energy efficiency strategies.
Ok, the “word of caution” turned into several paragraphs. In the next posts, I will get into the basics of solar PV and our journey to the system installed, including all preparations. Stay tuned!