Is Calculating Solar Payback REALLY That Simple?(Their Fancy Formulas vs. My Gut Feeling)

So, I've been diving deep into the world of solar ROI calculations (yes, my spreadsheets are a thing of beauty now, haha). But here's the thing: all those online calculators and formulas make it seem so straightforward! Like, plug in a few numbers, boom, instant savings prediction.

But something feels off... like they're not capturing the full picture.

Here's where my gut is clashing with the algorithms:

Most calculators assume constant energy prices. But haven't we learned ANYTHING from the past few years? Who knows what energy costs will do!

They rarely factor in maintenance or potential issues. What about inverter replacements, panel cleaning, unexpected repairs?

And what about the TIME value of money? Shouldn't we be discounting future savings somehow?

Am I overthinking this? Or are these calculators just glorified marketing tools? 🤔

Solar veterans, I need your real-world wisdom!

How closely did your actual solar payback match the initial estimates?

What factors did the calculators NOT account for?

Any tips for making a more realistic ROI assessment?

Let's cut through the marketing fluff and get real about solar payback! 💰

Leo Breydon wrote:So, I've been diving deep into the world of solar ROI calculations (yes, my spreadsheets are a thing of beauty now, haha). But here's the thing: all those online calculators and formulas make it seem so straightforward! Like, plug in a few numbers, boom, instant savings prediction.

But something feels off... like they're not capturing the full picture.

Here's where my gut is clashing with the algorithms:

Most calculators assume constant energy prices. But haven't we learned ANYTHING from the past few years? Who knows what energy costs will do!

They rarely factor in maintenance or potential issues. What about inverter replacements, panel cleaning, unexpected repairs?

And what about the TIME value of money? Shouldn't we be discounting future savings somehow?

Am I overthinking this? Or are these calculators just glorified marketing tools? 🤔

Solar veterans, I need your real-world wisdom!

How closely did your actual solar payback match the initial estimates?

What factors did the calculators NOT account for?

Any tips for making a more realistic ROI assessment?

Let's cut through the marketing fluff and get real about solar payback! 💰

Solar payback has to be seen as a starting point in a solar conversation not the only point. I do modelling when I propose a project but mostly it's about solar availability. I focus more on off grid and battery based grid tied than straight net metered; so economic modelling is not the main driver. At this point any economic model you create is based on all sorts of assumptions that nobody can tell right now. I would say utility companies are just waking up to the huge disruptive capabilities emerging in the solar world. Many of those companies are scared though leading to solar limits, reducing rates, connection delays and regulatory hurdles. If you can lock in a fixed price maybe you can economically predict your returns but what if your utility can change the rules mid stream? Personally I tell people to build in resilience to their grid connected systems. Choose equipment that might not be the cheapest but has increased range of uses. Say you use a sol ark central inverter instead of a battery less unit and only add a battery if say time of use rates get applied or your utility starts using peak use pricing. Enphase has micro inverters that can be retrofitted with a scalable battery as well. The next decade will be a struggle between those with the resources to deploy solar and those who wish to maintain the status quo of one direction power flow. To me the conversation has to be more than financial. How does the idea of producing power yourself feel? If you bought a vehicle larger than you absolutely needed or with more features than a spartan minimum would you apply the same ROI techniques? Why MUST solar make money when very few purchasing choices we make have to meet such a high bar?
Always love adding complexity....
Cheers, David Baillie

I’m am both a full time off grid dweller and also a professional solar electrician. Not a salesperson.

For me the payback would be about 10 years for my current system if the grid was present here. It’s not. It’s 6 miles away so it’s a moot point.

Your personal break even or ROI depends on many factors including shade, latitude, cost of system, utility buyback rate and cost per kWh etc.

Panel cleaning is a nonissue. Maintenance is rare. The components mostly just keep on ticking.

I second David’s opinion about SolArk and the ability to add batteries. That’s mostly the brand of inverter I’m installing these days. My home system is outdated. Midnite Classic charge controllers and a magnum 4448 inverter. Bulletproof but low tech compared to todays offerings.

Im obviously a solar advocate. For most people it makes sense and the tech especially batteries just keeps getting better and less fussy.