free solar financial software analysis

[khanh dam]

OpenSolar Orientation Video - YouTube

www.Opensolar.com

Other companies charge $50 a month for similar functionality of Open Solar.
There is also

https://www.pvcalc.org

solar estimator used to be a good site, but it's nothing more than a scammy sales lead generator now.

Any other good solar software out there that doesn't have expensive monthly fees for calculating ROI on a grid tie or battery system?

[Mike90250]

> Any other good solar software out there that doesn't have expensive monthly fees for calculating ROI on a grid tie or battery system?

Sadly, I suspect anyone who needs a website to perform basic math for them (even if it involves 15 years in the calculation) is going to be so gullible, the first scam artist that says "green" and "solar power" is going to pocket their money.

[J.P.M.]

OpenSolar Orientation Video - YouTube

www.Opensolar.com

Other companies charge $50 a month for similar functionality of Open Solar.
There is also

https://www.pvcalc.org

solar estimator used to be a good site, but it's nothing more than a scammy sales lead generator now.

Any other good solar software out there that doesn't have expensive monthly fees for calculating ROI on a grid tie or battery system?

SAM from NREL has some pretty fair financial analysis in one of the modules.

Not for the feint of heart and a user will need to input an entire case for the financial analysis to make any sense, but the included references provided are a tour de force of financial analysis methods as they may pertain to solar, and for that matter just about any alternate energy financial analysis.

Pros:
- Good methods with lots of backup.
- Very flexible once you know what you're doing.
- Free.

Cons:
- Lots of input required.
- Learning curve for SAM is rather lengthy and twisted.
- If you don't know the basics of what you're doing and why, you're wasting your time with SAM.

GIGO applies here, at least with respect to required effort.

[khanh dam]

>I suspect anyone who needs a website to perform basic math for them (even if it involves 15 years in the calculation) is going to be so gullible, the first scam artist that says "green" and "solar power" is going to pocket their money.

I used to think like that, but with some of these Net metering contracts you have to be a freaking accountant to figgure out the ROI.
Residential Service (georgiapower.com)
Above link is a simple example.
winter rate is almost half the summer time rate!
And then there are escalation charges if you go over a certain kwh/month.
but if you switch to net metering the basic service charge increases.

when is excess energy refunded? is it rolled over every month, every year? what happens to excess production at end of year, etc.

its' far from simple math.

I got all A's in high school math up to calc , and I've been studying researching this for a couple days.
todays issue is what is the formula to determine what your electricity bill will be 15 years from now with a 3% increase every year?
Using pvcalcs bottom input field :

Energy Price Inflation (%/year)

Even when I put in a ridiculous number like 100% increase on year it does not affect the payback period.

But if one puts in a higher number for feed in tarrif price Price (per kWh) ROI is decreased rapidly.

looked at every single solar forum out there and have not found answers yet.
if you have a simpler way then please let me knwo.

[Mike90250]

I'd forgot about the TOU rates. But still, with a bit of spreadsheet skilz .... But my focus is off grid, and I've forgotten all the billing subtleties .

[khanh dam]

several people told me spreadsheet on other forums, but when I ask for formulas, dont' hear any response. easier said then done I guess.

[khanh dam]

how does this solar sale work for example? whopping $5.50 cost per watt, but numbers show $80 saved the first year
5% annual increase in electricity. Quote also assumes inverter will always be replaced for free under warranty.


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