Solar panel investment calculator

Mattias:

Before we go further, it might be helpful (for me at least) to describe how much you know about solar energy and its applications, what your goals are for both your plans to add solar energy to your dwelling as well as what and to who this application is aimed at.

I'm not trying to rain on your parade, but have you looked into what types of information already exists that may do what you seem to want to do with this application and much more ?

If you do, I believe you'll find you may be reinventing the wheel - and that there are a lot of bigger, more versatile tools already in existence.

Welcome to the neighborhood and the forum of few(er) illusions.

Hi J.P.M

Thank you for the welcome! I am a beginner at Solar energy and my goals are to ease the burden on my wallet by adding panels to my house. Ultimately, I also would like to have a battery, but as I understand it, they aren't good enough yet (to, for instance, charge the car at night).

As for the app I made, I mostly wanted to spread awareness of this way of creating calculators/apps. As I described, the solar sales guy used pen and paper when he outlined the deal for me, and I felt that I didn't really see my benefit straight away that way, and also, his scribblings were not a good way for me to keep on playing with the numbers once he was gone.

As I am a beginner at solar energy, I thought that this might inspire someone of higher expertise to try out Molnify and create a better solar calculator. The cool thing about Molnify is that all apps are made in Excel, using just regular Excel functions and formulas. Also, having an app made using Excel means that you can also update the app using Excel. This makes app development very quick and the only skills you need are Excel skills.

I am sure there are other calculators out there, but the salesperson at my house certainly didn't know about them

Best regards Mattias

I used a solar panel output calculator on the California state website but this one works as well in terms of panel angle. With my house I had the panel angles such that I would get maximum output for the calendar year and not to maximize output for any one period of the year.



This calculator also considers the panel model and the inverter and other factors.


I wanted to put as much in the way of panel production on my roof as possible and conform to the fire codes. I found a dealer that did both commercial and residential solar installations and so could buy and resale higher output commercial panels on my house. I only had space on the roof for 11 panels and so wanted as much from this size array as possible. In 2012 that was the SunPower 327 Watt panel which provided 40% more power than the residential ones available at the time. Ten years later they are providing 99% of their rated output so it was a good investment.

I recommend considering a dual MPPT inverter if have multiple strings or sets of panels or a situation where some provide a different output voltage due to their location on the roof, as at a valley of a roof.

I did the design work as I would never rely on a salesperson to do this properly. There is too much money at stake to have it done incorrectly and need to live with it for the next 20 plus years. Had I relied on a salesperson I would have fewer panels and a less efficient inverter (and not a dual string one).

Costly to remove panels to re-roof a house so this should be considered before installing panels on the existiing roof.