So after researching Solar, I ended up having "interesting" discussions with Solar vendors: SunRun, SunPower, and Tesla.
SunRun and SunPower (both "big boys" in the market) have a direct (commissioned) sales model ... so definitely motivated to close the deal ... and pretty wild how much you can negotiate a price reduction from the initial quotes. Even after that, Tesla is by far the cheapest as they came in (before 30% tax credit/subsidy) at $16,500 versus $23,500 for a 6.4kW system. Another reason for the lower price is Tesla uses cheaper String/Line inverter technology versus Micro-inverters. I won't go into the pro/cons of that, but here's a compelling video that the claim that "string inverters are 'bad'" is mostly marketing and not based on reality. Regardless, I don't have shade issues on my roof, so really isn't an issue for me.
The reps from SunRun/SunPower point another advantage of them is I have a knowledgeable person to talk to who ensures things get done "right" ... which at least for me didn't seem like that advantageous as they were mostly salespeople. Where as Tesla you get assigned a Project Advisor who's non-commissioned and not so motivated ... and as I've found out, not so smart (couldn't even tell me the dimensions of the Solar Panels) ... even though this person has been their 8 years! I suspect in both cases (and in most "projects"), you are best served by being an informed customer and taking some ownership of the process ... rather than just saying "whatever you think is best."
Regardless, I'm taking a look at Tesla ... so here's some financial numbers. Remember, they are a THIRD CHEAPER than the other vendors ... which one did admit that they can't compete on price against them.
One thing that works against me is I don't have any directly South facing roof area where I can put Solar panels - it's (basically) all East-West. This obviously affects your energy production ... so here are the numbers for a 7.2kW system (default parameters) using the handy PVWatts calculator:
| kWh Output | Orientation | |
|---|---|---|
| 6,923 | 0° - North | |
| 9,224 | 90° - West | |
| 9,531 | 100° - MY ROOF | |
| 10,754 | 180° - South | |
| 8,751 | 270° - East | |
| 8,419 | 280° - MY ROOF | |
| 8,797 | 2.4kW@100° and 4.8kW@280° | |
| 8,975 | 3.6kW@100° and 3.6kW@280° | |
| 9,117 | 3.2kW@100° and 0.8kW@110° and 3.2kW@280° - FINAL CONFIGURATION |
Given the reality of my roof layout, you might ask why not put all the solar panels on the East (100 degree) roof since it produces 13% more power
Battery Backup: The reason I'm not getting a battery backup system is they are expensive.
To add ONE Tesla Powerwall would cost me (after 30% tax credit and some other misc.) an additional $8,112!
That buys you 13.5kWh of energy. So yes, you could use a single 100 Watt light bulb for 135 hours ... but
my 4-Ton, 14 SEER Air Conditioner would only run less than 3 hours. BTW, the Powerwall warranty is for
10 years ... and energy rentention will be at least 70%.
Here's my utility bill
This spreadsheet, downloaded from the Internet, is a first WAG as analyzing the cost/benefit of Solar. About $23,000 total cost, but thanks to Inflation Reduction Act (cough, cough), American taxpayers will send me $7,000 back early next year ... so net cost is about $16,000.
Scroll down to the bottom and USING THOSE ASSUMPTIONS, the payback is at year 15. Obviously there's the expectation that when we sell the house, even after 15-25 years, there would be residual value in the Solar System such that you would realize a higher sale price.
On the spreadsheet, the $72/year is because in Colorado, we still HAVE to pay the $6/month Xcel connection fee and SunPower suggested that it would make sense to add the Solar panels to my Home Insurance Policy ... which is about $28/year. You don't see that "talked" about much - remove those and the payback is at year 13.
Second spreadsheet is misc. info about our house. Gas/Electricity really haven't moved that much. Water is the CRAZY one ... and it's going to be substantially higher this year. Yadda, Yadda, Yadda Climate Change, Drought, etc. But Lafayette water is going much faster IMHO ... they basically are using water to generate revenue for the city. One of these days, some local paper (HAH!) is going to look into it and realize that! ;-)
Annual Usage from spreadsheet
