SRP calculator for determining solar savings and comparing basic, TOU, and EZ-3 rates

All,

In trying to figure out how much money I was actually saving with my PV array I created this program. All you have to do is fill in your production numbers from the SRP statement and the calculator crunches everything for you based off of today's rates. It took me a few hours to create this and I feel like it's a great tool for anyone who has an SRP grid-tie system.

Calculates actual numbers:
1. Your return on investment or ROI.
2. The number of years the system will take to pay for itself.
3. The amount of money you would save on EZ-3 VS. Basic or TOU VS. Basic
4. The monthly savings in your electric bill from solar.
5. The total amount of electricity that you’re paying for.
6. The monthly percent of energy that comes from solar.

My entire article is here - http://www.jeremywhittaker.com/2014/01/08/determine-much-youre-saving-srp-bill-solar-panels-pv-calculator/

Download link - Link to download

Comments

  • JburgessJburgess Solar Expert Posts: 130 ✭✭✭
    Re: SRP calculator for determining solar savings and comparing basic, TOU, and EZ-3 rate

    Jeremy,

    Thanks for posting the spreadsheet.

    Looking at the data you entered I think you short changed yourself on savings by solar. You also saved sales tax on the solar you produced, so your solar is worth about 8% more than you show. That would reduce your years to pay for itself to about 6-1/2.

    JBurgess
  • WhittakerJWhittakerJ Solar Expert Posts: 67 ✭✭
    Re: SRP calculator for determining solar savings and comparing basic, TOU, and EZ-3 rate
    Jburgess wrote: »
    Jeremy,

    Thanks for posting the spreadsheet.

    Looking at the data you entered I think you short changed yourself on savings by solar. You also saved sales tax on the solar you produced, so your solar is worth about 8% more than you show. That would reduce your years to pay for itself to about 6-1/2.

    JBurgess

    Jburgess,

    Excellent catch. I have updated the spreadsheet!

    There is also an income tax savings here as well if you consider the savings from solar as income. I'm just not sure if I should calculate that into the equation or not.
  • WhittakerJWhittakerJ Solar Expert Posts: 67 ✭✭
    Re: SRP calculator for determining solar savings and comparing basic, TOU, and EZ-3 rate
    Jburgess wrote: »
    Jeremy,

    Thanks for posting the spreadsheet.

    Looking at the data you entered I think you short changed yourself on savings by solar. You also saved sales tax on the solar you produced, so your solar is worth about 8% more than you show. That would reduce your years to pay for itself to about 6-1/2.

    JBurgess

    Same link to download the new version which reflects taxes. http://www.jeremywhittaker.com/2014/01/08/determine-much-youre-saving-srp-bill-solar-panels-pv-calculator/

    With the tax updates for my first PV system(5kw) it increased my ROI to 15.35% and the years to pay for itself to 6.51.
    For my second system(10kw) it is now estimated to have a 20.35% ROI and 4.91 years to pay for itself.
  • aravinthraravinthr Registered Users Posts: 3
    Does anyone have the spreadsheet that Jeremy created?
  • WhittakerJWhittakerJ Solar Expert Posts: 67 ✭✭
    I noticed some flaws and I created this when rates were older.  Also, remember I'm grandfathered in.  Anyways, here it is to use or modify. https://dl.dropboxusercontent.com/u/13721177/Cost analysis after 1 year of use.xlsx
  • aravinthraravinthr Registered Users Posts: 3
    Thanks Jeremy. Yes. I need to plug demand charges into the mix. When I am done, I will post here.
  • aravinthraravinthr Registered Users Posts: 3
    I have the spreadsheet if anyone wants it to calculate savings on new SRP E27 price plan. The data I have are after three months being on the solar plan.
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