Goal: Net Zero - Companies Suggesting Widely Varying kW Systems

[Magius]

I am starting to build a spreadsheet for evaluation of proposals for my upcoming PV project in SoCal. If you are willing, I would like to see your Google Sheet, or is it so tightly tied to Florida PoCos that it couldn't easily be adapted to SCE?

My sheet is very specific to the central Florida area, as it contains a solar production model based on data extracted from PVWatts. In addition, the financial model is based on OUC's net metering policy, which is much friendlier than any other utility around. That second part doesn't really matter unless you're going to produce a lot more power than you consume, in which case it will significantly overestimate the financial benefits of doing so. The first part though, with the weather data, pretty much makes my sheet useless outside of central Florida.

Either way, I'm happy to share it, and I just remembered that this forum doesn't do PMs, so I guess I just have to drop the link here.

https://docs.google.com/spreadsheets/d/1m05RqDZ2hSzxSfd-1SmF7n4zKLZyPsq_kvOjNYs5MEI/edit?usp=sharing

It's shared read only, so just make a copy on your own Google Drive and see if there's anything of value you can borrow from it. If anyone else wants to give it a scan and give me any feedback I'd appreciate it. There are likely to be a couple bugs left, so if you find one please let me know. I created this to help a bunch of my neighbors who are interested in going solar. I had my own sheet in Excel that I used before buying my system, but it was complicated to use, required a ton of data entry and had zero instructions. I had to manually create a new version of it for each neighbor that I was helping. This one was built to be much more user friendly and require far less input, at the expense of a little accuracy. For modeling my own solar installation, the Google Sheet comes out to within 1% of the original Excel, so well worth the ease of use IMHO.

[brucet9]

Either way, I'm happy to share it, and I just remembered that this forum doesn't do PMs, so I guess I just have to drop the link here.

https://docs.google.com/spreadsheets/d/1m05RqDZ2hSzxSfd-1SmF7n4zKLZyPsq_kvOjNYs5MEI/edit?usp=sharing

Thank you for sharing. I assume that it is easy to set up a Google Drive?
Will I be able to see the formulas for the cells, so I can substitute SCE rate data and expected rate increases for your OUC values?

One thing that you might want to include in your ROI somehow, is the tax effect when comparing with other investments. 10% ROI earned as utility cost reductions is tax-free, therefor = 13.3% to 15% taxable investment return. It's an even bigger difference here in CA with the nation's 2nd highest state income tax rates and cap gains figured at ordinary income rates to boot.

[Magius]

If you have a Google/Gmail account you already have a Google Drive. Just click on my shared link and from the file menu choose copy to Google Drive, or something like that. Then you'll have your own copy that you can edit, and you can always get back to it at drive.google.com.

I appreciate your suggestion about building tax liability in to the financial returns, but I'm not a financial person and I'm not sure how to do that. This tool was intended as a quick sanity check for homeowners vs installer proposals, which typically claim a 16%+ rate of return and that you're doubling or more what an investment in the stock market would do.

Please let me know if you have other issues or suggestions for the tool.

[aleenoor]

Hi Nether, Congrats on your decision to go Solar. I am in Central FL as well and just finished up with my 11.6 kW install. Waiting for OC to do the inspection and Duke to swap out the meter. I have to say Magius was great help. Close to $2 / W is really good price. What kind of financing rates are you getting and whats the service warranty period ?