Our process of purchasing and installing solar panels began in October of 2023. As I write this on March 9, 2024, I have just received permission to operate the system. The process has been lengthy and has presented various challenges. Below is a summary of what I have learned.
First things first
I would recommend a home energy audit as the first thing anyone does when considering solar panels or even if one is just looking to improve efficiency. The other side of the equation from energy supply is energy demand. Reducing demand can mean as much as increasing supply so understanding all your options can be a very important part of the process. The organization Rewiring America is very helpful and can provide coaching. I came late to this revelation and have not done the audit myself yet. My house is a Cape Cod style with our bedroom in the attic. Over the years I have heavily insulated the bedroom, so my conditions are a bit different than what others may experience. Nonetheless, it makes sense to do the audit as friends who have done it have all learned things about their house they didn’t know.
Saying goodbye to a tree
It’s never nice to have to remove a tree. However, in this case the tree needed to be removed as it blocked the southern sun and it was dying. The tree was next to the house and the parking lot. So not only were some dying branches over the cars, they were over our heads as we came and went. Ironically, the lack of shade will increase the energy demand in summer. If you need to remove a tree the cost can be negotiated with the company. In our case we ended up roughly splitting the cost. Tree removal is an expensive proposition. The company took several bids but in the end we ended up going with a company they had used before. When removing a large tree next to your house, it is a good idea to use someone with a proven record. Watching a guy dangling from the top of a tree with a chainsaw in one hand is itself an intimidating experience when it is taking place on your property.
Dude, please be careful!
And then there is the roof
I signed the contract that said something to the effect that, if we have to remove and replace the panels for roof repair, the cost would depend upon various conditions related to the steepness of the roof, etc.. Once the contract was signed the language was much less wishy washy—$2,500! Given that our roof was going on 18 years, and hadn’t been the best roofing job to begin with, we decided that before the panels went up we’d replace the roof. This, of course, added to the time to complete the project. My advice is to get the cost of panel remove/replace in writing before you sign a contract. It is likely negotiable. In my case I ended up with a nice new roof at a reasonable cost, but it was all paid by me. There are systems available that are not mounted on your roof. I understand that they tend to cost more as they require underground cabling and an appropriate land area not easily found in suburban or urban yards.
Panels for Christmas
Even though the process began in October, because of the need to remove the tree and then replace the roof, it wasn’t until the week between Christmas and New Year that the panels were put in place. Given that the tree removal, roof replacement, and panel placement are all weather dependent, it was a good thing that we had a mild winter. The panels themselves were installed in a day and the final electrical connections were made the next day.
A new roof and new solar panels.
Inspection and then wait
The inspection took place on January 12th. It was conducted online, which at first seemed very confusing because I thought I would be conducting it on my end. However, an electrician showed up and the county inspector took him through all the steps. After some additional grounding it passed. So, we were ready to roll. Alas, the power company was not. It was four days shy of two months when we got the word that we had permission to operate. I’d imagine that some of the wait is technically motivated. However, some of the wait must be motivated by the bottom line.
Happy Pi Day
Now that the wait is over the fun part begins. The first couple of days were lackluster as they were very cloudy and rainy. The next day was sunny, but the output was still under-performing. However, Thursday, March 14 (Pi Day) was a very sunny day and there was an almost 10-fold jump in generation from the day before. In retrospect I believe that the software was not fully functioning until March 14. The values in the picture below are based on total operation to date, the vast majority of which came from March 14th at the time. The CO2 savings below is greater than I would have estimated.
The CO2 savings is greater than I estimated
When I first estimated the CO2 savings per kilowatthour of electricity, I used the U.S. Energy Information Administration’s electricity carbon factor for Virginia of .649 pounds per kWh (1). The CO2 reduction estimated by using that value and the generation below would be 21.9 pounds. The CO2 reduction value of 54.1 pounds implies a factor of 1.6 pounds CO2 per kWh. While I’m happy to use this higher value, I am perplexed by it. Given that the U.S. Environmental Protection Agency is given as the source, I’ll need to contact my old friends there and see if they can shed light on this.
Source: Enphase Energy Systems software.
Some panels perform better than others
If you look at the picture of the house above, you will notice that the chimney is in the position to shade two to three panels. When the panels were being installed, I wondered about the effect that would have. I have my answer now. There is a 5-percent decline in the third from the top right panel, a 20-percent decline in the second from top right panel, and a 34-percent decline in the panel most directly affected by the chimney shadow when compared to the best performing panels. There is clearly other space on the roof for panels that are not in the shadow of the chimney. There may be additional constraints that I’m not aware of, but this may be a topic of future negotiation.
Source: Enphase Energy Systems software, electricity production for March 14, 2024.
Here’s what a beautiful sunny day looks like
The impressive thing about the peak production on March 14 is that the Alternating Current power rating for the system is 3.1 kW and despite several under-performing panels it was consistently producing at 3.2 kW.
Here’s what a cloudy day looks like
Beware the Ides of March
As nice as Pi Day was, March 15th, or the Ides of March, was a stab in the back to solar generation. The thin line above is the generation on March 14th, while the bars represent March 15th. I thought that a cloudy day would still generate at least 60% of the output that a sunny day produces. It was a sobering revelation to see that it is only about 25% of a sunny day.
Summary
In the category of do as I say and not as I do, here are some recommendations if you go down this path.
Get the energy audit done first. I’ll do mine before the air-conditioning season.
You should pay around $3/watt of capacity. There are regional differences.
Read the contract thoroughly. There were several things that I let slip through that should have been negotiated, such as the cost for panel removal and replacement. Get everything in writing.
Think about the other related costs such as tree removal and roof replacement if needed.
Check all the warranties. The panels themselves have 25-year warranties, but some of the components have 5-year warranties.
Think about the costs and benefits of paying over time versus paying up front. I decided to pay up front as it saved several thousand dollars. Also, I realized that if I paid over time I wouldn’t really ever own it given my age.
I have never really liked cloudy days and I have always loved the bright sunshine. This has been amplified at least 10-fold. My wife fears that she’ll never hear the end of it.