I've got a consultant coming over on tuesday to take measurements and give a more solid quote for installation.

We'll see. But I have an outbuilding with a large two plane roof and the south facing plane has no penetrations and is pretty much unshaded. Our utility rates have pretty much doubled over the last three years, and there's another ~30% increase scheduled over the next three years. Said roof is coming up on the end of its expected life, so it may be a good time to put on a new roof and put on solar at the same time.

Could someone get better ROI doing a larger solar project somewhere else? Probably. But if it maths for me, I'm going to do the project on my roof, because I don't have anywhere else to do it (well I could do a ground install, but I'd lose aesthetically)

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xnx an hour ago | parent [-]

Good plan. Sounds like you're going into it with the right approach. Many homeowners accept the ROI calculation from the salesperson and don't account for opportunity cost and other factors.

	▲	toast0 an hour ago \| parent [-]
		I did my NPV calculation with probably the wrong interest rate, but I'm also looking at the 10 year NPV of 80% of our kWh charges as my guide (including the published rate increases). If it maths with that, great. If not, but it's close, we'll look again when we need to do the roof. Utility prices are rising, panel prices are dropping, it'll probably make sense eventually... Installer costs are going up too though.