>So for most home owners it’s easily worth it.

Can you elaborate on how you arrived at that conclusion? At least where I live, the math didn’t work out. It seemed like smarter conservation was a much better alternative. A couple portable/window A/C units that pay for themselves within a year or two made a heck of a lot more sense than $30k of solar on a roof already at half it’s life. Maybe when it’s time to replace my roof I’ll reconsider, but the payback didn’t seem there. (FWIW, I probably average < $100/mo in electricity.) I know conservation can go against human nature, but it sure seems like the better option for me.

I got there by just looking at how far north people go before it becomes questionable and then realizing most of the world’s population is closer to the equator. The other approach is to look country by country and solar generally works in China, India, US etc.

For your specific situation, you can reuse panels, inverters, and most wiring etc between roofs or depending on things like a HOA install them elsewhere for less. A solar gazebo or car port for example can directly use the panels as a roofing material. Some people are even using them as fences.

The actual calculations get involved including things like permits and your weather etc. But don’t assume your only option is spending 15+k for some contractor to show up and slap a bunch of panels on your roof.

PS: 30k is overkill for your usage, and you don’t need a battery unless you are particularly worried about power outages.

I am waiting more for the longevity of the roof than the panels. I’m not too keen on putting a lot of penetrations on an aging roof. The $30k number was based on a 10kW system (we’re limited based on a multiple of actual usage). But what you said makes sense and I should ask around for other quotes. But even at half that cost, I’m still looking at a 12-15 year simple payback. On a 20-25 year system, that puts the IRR at ~5%. My thinking is I’d rather have the liquidity of putting that money in the stock market.

Good luck. Also, at least in the US you’re looking at 30% federal and possibly state incentives plus again savings being tax free.

And don’t forget about inflation when doing your ROI and invest returns calculation. US electricity prices averaged 16.04c/kWh March 2023 to March 2024, but 15.50c/kWh March 2022 to March 2023. https://www.eia.gov/electricity/monthly/epm_table_grapher.ph...

As to liquidity, the stock market may be a better long term investment but it’s quite risky even over surprisingly long periods.

In my place (NZ) finance is only available for 3 years, power is cheap and install is expensive. No subsidies either. I’m looking at anywhere from 15-25 year payback (assuming same power prices and interest rates I pay for house (7.5% atm)).

I’m still keen to at least DIY a shed, but even then it’s like 5 years to pay back.

To compare with my parents place in LT (or even Australia) - power is 3x more, install 2x less and subsidies are available. You are basically looking at 6x quicker payback.