Keep up with UCAN.org by following us on Twitter!

Thanks for visiting UCAN.org! Please remember our services are available because of grassroots donations from people like you. Please help us continue our work with a donation of any amountClick here to visit our secure donation page.

Solar Cost Calculator - Coming Soon!

   With little more than your electric bill, you can estimate the pv system size that's right for you (note: you need to have Microsoft Excel to open this file). 

Under current SDG&E rates, installing too many solar panels could mean that you will give away free electricity to SDG&E.  With this calculator, you determine how much photo-voltaic capacity you need to hit the "sweet spot" in SDG&E's complicated rates.

All you need is your electric bills for the last 12 months (they're online if you don't have them) to determine what size system is right for you. 

Filed Under

Comment viewing options

Select your preferred way to display the comments and click "Save settings" to activate your changes.

Considerations when mapping out the size of your system

This comment may only apply to SDG&E customers so you may need to check with your local utility company......

SDG&E has a little fee that many of you may not be aware of. It's called a minimum charge. This will be applied whenever your average usage falls below $.17 a day. I know, not a lot. But if you are targeting your system to essentially zero your bill, be aware that will never happen. I unfortunately over generated this last year by a couple of kilowatts. Because of that I ended up with a "True-up" bill for about $63 ($.17 x 369 days). So not only did I give a little bit of electricity back to SDG&E, I paid more for the privilege. Ideally then, you will want to scale your system so that you are not at a zero sum for yearly usage but actually a few hundred kilowatts above (my estimate given todays rates). Oh, for those who don't know the "True-up" statement is the yearly bill you receive when you are net-metered. Perhaps if there was an actuate calculator in place, I may have been aware of this from the early stages of conception. However for the future, I'm looking forward to getting rid of the fluorescent bulbs and maybe putting in air conditioning!

As one person told me, "SDG&E has NO vested interest in you doing this (installing solar), so don't expect them to make it easy...." I'm finding this statement to be quite true.

Solar output

For the record I have a 2200 watt Solar system, installed 5/03, 2 Blocks from the beach. Our output to date is 20519 kwh. I couldn't find any data on beach weather solar output when designing my system, and hope this helps others. Of course we have no electric use except minor and refrigerators during the day so our net output generally exceeds the house requirements during the summer. Am an engineer and if I can be service be glad.

live online spreadsheets via GoogleDocs

I know Google has a bunch of online applications and one is a spreadsheet application which can be shared to anyone with an email account. You don't have to be a gmail user so anyones email account works. What I don't know is how one would create such a spreadsheet and let many users input their own unique values. Possibly using the Forms mechanism.

If that works, it would be cool to have such a spreadsheet where as people enter in their specific data to size a system, those data points remain for everyone to see the results. ie, a history of many different sizes such that after a short period, many could just look for values close to theirs and see the size immediately.

Just a thought since there is an online spreadsheet program instead of requiring everyone purchase and load up one on their own computer. Web 2.0 stuff is pretty cool for these kinds of things.

if this sounds interesting let me know and I can dig into this further.

UCAN PV Solver Red file

This file seems to be corrupted. Please check it out.

PV Solver

Your Excel program is corrupted alright.

Heck-and I was about to calculate how much it would cost to be installed on my home.

Oh well.

Maybe you cd let me know when it starts working?

Thanks--Rik Keller

Corrupted XL file

Rik, we are working on the problem now. I apologize for the delay, but I promise, it is worth the wait.

Charles Langley
Gasoline Analyst & Publisher, UCAN Watchdog

Post new comment

The content of this field is kept private and will not be shown publicly.
  • Allowed HTML tags: <em> <p> <strong> <cite> <code> <ul> <ol> <li> <dl> <dt> <dd> <!--break-->
  • Lines and paragraphs break automatically.

More information about formatting options




Like what you see? Go ahead and show your support! UCAN is a truly independent non-profit watchdog organization, dependent on grassroots donations like yours!

Utility Consumers' Action Network

(619) 696-6966 or file a complaint about a company online.

Terms & Conditions

UCAN.org is made available by the Utility Consumers' Action Network to assist you in becoming what you always knew you could be, a consumer ROCK STAR! We take no corporate money, and are beholden only to you, the consumer. As such, the site is here for educational, advocacy, and empowerment purposes, as well to to give you general information and a general understanding of the law. Just remember this site is NOT here to provide specific legal advice. By using this web site you of course understand that there is no attorney client relationship between you and the Web Site publisher, UCAN. The Web Site should not be used as a substitute for competent legal advice from a licensed professional attorney in your state.

That said, get to digging on the site, inform yourself, speak your mind, and earn Watchdog Bones! This is YOUR site, and we mean it. So comment on any of the content, discuss the latest issues in the forums, file a complaint on a company with the fraud squad, and generally cut loose.

See our Terms of Use, Privacy, and Copyright complaint policies as well as our Content Reuse Policy, Some Rights Reserved.