Hi there,
This is a note on our experiences and lessons learned from doing a home solar installation, with the ‘GoLive’ date in March 2020.
Lesson #1 – long time-line
We decided to go ahead with the installation in Sep 2019, and the system was finally productive -meaning turned on and grid connected on March 3rd 2020, about six months later. The timeline roughly went like this:
Sep 2019 : We signed up with Energy Sage as they had good educational resources and they had several providers available in our area.
We receive three proposals and we end up selecting Unicity Solar. The main factors we liked about Unicity were their price was quite competitive (more about that later), they offer good warranties for everything (panels, system output, workmanship etc). We signed contracts by mid-Sep, and Unicity submits the permit application to Oldsmar city building department.
October 2019: Permit application stalls. I initially check in with Unicity, get responses that essentially are saying “yes we are checking”, but nothing progresses. I contact the building department directly.
November 2019: Permit application winds itself through the bureaucracy, physical paper applications (!! 2020 !!) and back and forth emails.
December 2019: Finally Dec 4th the application is approved, it is sent by snail mail to Unicity so they receive it on Dec 12th. This is un-fn believable in this day and age.
December 24th – Installation day.
The Unicity team arrive, install the panels and are done by the end of the day. Yay! (you would think..)
January 2020: Unicity has provided the information to our utility company Teco, Teco needs to come inspect the installation so that they can confirm the interconnection to the electrical grid. Inspection happens on January 13th, and we sign the interconnection agreement.
February 2020: Waiting for final paperwork to arrive.. This is getting frustrating..
March 4th 2020: We get the final go-ahead to turn-on the system… We are just more relieved than happy at this point.
Lesson #2 – good economics
One of the keys for us to go with the Unicity Solar offering was that their offer made sense from a financial perspective. Here’s how the numbers worked out:
We bought a 8.1 kw system, made up of 27 Silfab 300 watt panels, 27 Enphase inverters and these associated warranties. It included also an Intelliflo pool pump that reduces our electricity consumption.
- The total cost of the system was $19,158, which after the 30% tax credit works out to be $13,410.
- The cost per watt is $1.66 ($13410 / 8100 watt). This is really good considering this is cheap even for Florida (source).
- Our electricity bill used to be around $150 / month ($1700 / year) and that has now been cut to $17 / month.
- Assuming savings of $133 per month the payback period is 8 years.
- Knowing that after 8 years we will have ‘free’ energy for at least another 17 years, and that we are not producing carbon emissions from the house is feeling pretty good.
Lesson # 3- Solid production numbers
The overview of the production per year (the initial grey zone in Feb was as we were not connected to the grid yet) :
The system has been producing over 1000 kwh per month and around 37 kwh per day, here a 6 month sample that I have full data for:
From a carbon footprint reduction perspective this looks good as we’ve cut our carbon emissions from about 17000 lbs / year to effectively zero (source).
Previous emissions:
Revised emissions:
That vehicle number could be cut, hmm… Anyway this looks great right? Not so fast 🙁
Lesson #4 – Production numbers ≠ what the utility company receives
Note that for Sep 2020 our system produced 988 kwh according to our inverter (Enphase):
Now this is the Sep 2020 electricity bill:
So apparently what’s going on here (according to Unicity) is that the system also funnels electricity to the house, so whatever the utility company received is after our consumption has been removed.
Summary
Overall we’re happy with the results as we’ve replaced almost 100% of our consumption, the system is performing well, it’s fun to monitor it, and there’s a small positive feeling of doing something for the environment.
As usual when doing more long-lasting changes – if it’s worth it it will take you three times longer to get there than you initially imagined, but the positive effects can carry for a long time – when you remind yourself of them.