What hydro changes about the question
Much of southeast Alaska is supplied by hydroelectric generation rather than by diesel or gas, which is unusual within the state.
That means the electricity you already buy is largely renewable, so displacing it with rooftop solar does not reduce emissions the way it would in a community running on imported diesel.
It also tends to mean a lower retail rate than parts of Alaska where fuel has to be shipped or flown in, and a lower rate means smaller savings per displaced kilowatt hour.
None of that makes solar pointless here. It does mean the honest case rests on the economics at your actual rate rather than on an environmental argument that applies more strongly elsewhere in the state.
And the climate is the other constraint
Southeast Alaska is among the cloudiest and wettest parts of the country, with heavy overcast for much of the year in addition to the high-latitude winter.
That compounds the seasonal problem: not only are winter days short, but a large share of the daylight that does occur is heavily diffused.
Ask what data source the production estimate used and whether it applies location-specific irradiance for your address, since a model built on a state or regional figure will not capture southeast conditions.
Ask for the estimate month by month rather than as an annual total, and ask what the model assumed about cloud cover specifically.
Reaching an honest conclusion
Ask your utility whether it offers net metering at all, since Alaska has no statewide mandate, and get the terms in writing before going further.
Ask for the payback calculated from your actual rate rather than a state average, since a hydro-supplied southeast rate is likely below the Alaska figure.
Ask for the projection with production based on location-specific irradiance including cloud cover, month by month.
And be willing to conclude that it does not work. An installer who says so about a genuinely poor site is more useful than one who finds a way to make every roof pencil.
Costing it out when your utility sets the terms
The 30 percent federal Residential Clean Energy Credit under Section 25D expired for property placed in service after December 31, 2025, so a cash or loan purchase in Juneau receives no federal tax credit, and Alaska has no state solar credit.
Section 48E survives at 30 percent for third-party owners under leases and power purchase agreements, so ask what a provider claims and what reaches you in the rate.
What exists is whatever your utility voluntarily offers, plus the retail value of electricity you consume as it is generated at your own rate.
Ask for that rate from a recent bill, a location-specific production estimate month by month, and an honest view on whether the site supports a project at all.