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.

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.

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.

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