I Signed up to Install a Home Solar System

My interest in home solar power systems began when I was a undergraduate student at Colorado State University in the early 1970's. At that time I recall that I was waiting in a nearly one mile long line to get gas for my car during the 1973 oil embargo. The reason for the long line was that word had quickly spread that someone saw a tanker truck at the local Texaco station. After a 3 hour wait, I was able to get my 5 gallons of rationed gas and was happy. This meant that I would be able to use my car to bring groceries home for the week rather than having to walk a couple of miles every morning to carry enough food home for the day in a single grocery bag. This was the catalyst for my career choice. I wanted energy independence for the US as well as myself.

I started seriously thinking about installing a home solar power system in 2018 when Rose (my spouse) and I purchased our current home. The roof has a wonderful southern exposure as well as excellent east and west exposures. The east exposure is free of shadows and would provide excellent morning electricity production while the west exposure would provide wonderful afternoon electricity production during peak loads. When we purchased our electric car in May of 2023, I thought that this would be a good time to begin the process of purchasing a home solar power system. I was particularly interested in being able to charge our electric vehicle at home with the sun.

Rose and I made the decision to go with Green Leaf Solar. The installation will incorporate 34 x 400 watt panels capable of producing 19,052 kWh per year and the system will be grid connected. The city of Columbia allows one to one net metering. This is an outstanding benefit because for every excess kWh of solar energy produced during the day, the city will give an equal amount of grid energy use credit to you. Plus the city has a rebate program of up to $600 per kW installed and a very attractive solar loan program. Our home solar system will basically produce all of the electricity that we will need when combined with the one to one net metering. Our electric bill will only reflect a connection charge of $22. The timing couldn't be better. Columbia will raise its electricity rates 7% in the fall and the federal government currently has a 30% tax credit. The installation of the solar system essentially freezes our electricity cost in time. This is important because rates will only go up in the future. The components in the solar system have a 25 year warranty. Even though you typically use a 25 year system lifetime in solar power system calculations (the panels are guaranteed to retain at least 84.3% of the initial power output over 25 years), they actually last longer. The system will payback the investment in 6.9 years.

A New Book on the Holocaust in Serbia

I was excited to learn that Amsterdam Publishers will publish a new book by Julie Brill about her Serbian family's experience during the Holocaust. This is one of a handful of books on the topic. You can follow Julie on her website juliebrill.com.

Exploring solar for my home

I began exploring solar power generation for my home after convincing myself it was time to jump in and purchase an electric vehicle. My view on the carbon footprint of power generation has evolved over my academic career in teaching and research. The fact is that there is a carbon cost for everything in our lives and we consciously or unconsciously choose to pay it. One of my favorite examples which I shared with my students in my lectures is that in the production of a 9 Oz cup of coffee, about 3 Oz of oil is used. A rough estimate is that 3 Oz of oil is about a half pound of carbon dioxide equivalent. The simple truth is that food production uses oil. Modern farming technology requires tractors, combines, harvesters, pesticides, dryers, fertilizers etc., all of which consume fossil fuels. To put it in another way, you would be hard pressed to find something we own, touch or use that doesn't use oil or has a carbon footprint. This reasoning also holds for power generation technologies. There is, what I will call, "a carbon investment" that is required to bring a power generation technology into service.

In a previous blog I introduced the concept of an energy multiplier for power generating technologies, which I called the energy "Q" value. In a nutshell it is the expected energy production over the lifetime of the power source divided by the energy investment required to bring that power source into operation (such as mining materials, transportation, processing, construction etc.). Currently, most of this energy investment uses fossil fuels so there is an associated "carbon investment" (or footprint if you like) to build a power plant and make it operational. When Tushar Ghosh and I wrote the Energy Resources and Systems books, listed on my website, over 15 years ago, solar photovoltaics had a Q value of less than one, wind power was about 2, and natural gas fired power plants, coal fired power plants as well as nuclear power were about 5. As photovoltaic cell technology improved over the years its Q value increased. I last looked into photovoltaic cells 6 years ago and its Q value improved to about 1.03 for commercially viable systems.

I explained in a previous blog why I chose to purchase an EV at this time. To summarize, the city of Columbia has a very good strategic plan for implementing renewable energy. That means that even though most of the electricity on Columbia's grid is still generated with fossil fuels, a larger percentage year after year will come from renewable sources and some will be purchased off the grid where a fraction will be generated by Ameren's nuclear power plant. Yes, a "nuclear power plant"! Remember, I am a nuclear engineer who chose to go into the field 50 years ago because I am an environmentalist who believed it was critical to develop non-carbon based energy sources. Nuclear energy is one of the best ways to limit carbon production.

As previously stated, everything we own has a carbon cost. An electric vehicle still has a "carbon investment" which is no better than the "carbon investment" made in producing a gas powered automobile. However, I look at it this way, if you consider that anything that uses energy will have a "lifetime carbon multiplication factor". This means that you will produce carbon no matter what fuels the car and you use carbon when you maintain it. The question then becomes, what type of vehicle will have the lowest carbon impact over a lifetime. My reasoning for choosing an EV is that it will use less carbon over its lifetime.

Why am I now considering a home solar power system? I am still looking at the "carbon investment". If the present state of technology hasn't changed in the past six years since I last looked at the "Q" value for solar plants, it would still be 1.03. This is still a 3% savings. This "Q" value assumes a lifetime of 25 years. However, it appears that 25 years may be too conservative. It is probably higher. Anything beyond 25 years is very good. An additional consideration is that higher temperatures during the summer will put a strain on the electrical grid. Since I believe that climate change is real, this is a consequence that will only get worse. Regular brownouts and blackouts are a real possibility in the future. Anything that will reduce the strain on the electrical grid is good. A further consideration is the cost savings. Right now the payback on a home solar system is between 7 to 10 years. If you take out a loan to pay for the system, you can mostly pay off the loan from the reduction in monthly electric bills. Plus, electricity rates will only rise in the future. For example, this fall Columbia will impose a 7% increase in its electricity rate. If I find that I can put in a solar system, and I am able to get a fixed rate loan, then my payment will be fixed. So, I will not have to worry about future electricity rate increases. Right now I think the benefits for looking into solar are worth it. Plus, when I charge my electric vehicle, I know where the energy comes from. I can live with that.

A resource for calculating greenhouse gas equivalencies- https://www.epa.gov/energy/greenhouse-gas-equivalencies-calculator