A rate that is revisited every year
The export credit rate under Idaho Power net billing is updated annually. That was the first such annual update following the Commission decision allowing real-time net billing in Case IPC-E-23-14.
The scale of the proposed change in that filing is the point worth noting: from an average annual rate of around 6.2 cents per kWh to just under 2.5 cents.
A reduction of that size in one filing tells you how much these figures can move, and it is a caution against treating any published rate as a durable input.
Ask which rates the projection used and from which filing year, then confirm the current published figures with Idaho Power directly.
How a projection should handle that
Ask what the model assumed about export rates across its term. A model holding today figures flat for twenty-five years is assuming roughly twenty-five annual updates leave them where they are.
Ask for the projection with export rates reduced, by a quarter and by half, so you can see how much of the case depends on figures nobody has promised you.
Ask what proportion of the projected savings comes from self-consumption rather than from exports. That portion is unaffected by any annual update.
That last question converts an abstract worry about rate risk into something you can act on by changing the design.
Designing to reduce the exposure
Sizing is the main lever. A system matched to what your household uses during daylight exports less, so less of its value rides on a rate revised every year.
Load shifting is the free lever. Every kilowatt hour moved from export into self-consumption is moved from an exposed category into a protected one.
Storage does the same at scale and adds the ability to target the summer on-peak export window, though the value of that window is itself subject to the annual update.
So the most robust Idaho design is one weighted heavily toward self-consumption, with export treated as a bonus rather than as the foundation of the case.
Rebuilding the estimate from what is confirmed
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 Caldwell receives no federal tax credit.
The Idaho Residential Alternative Energy Tax Deduction remains as a deduction rather than a credit, worth the deducted amount multiplied by your marginal state rate.
What exists on the utility side is retail-rate offsetting for self-consumption and an export credit that varies by season and time and is updated annually.
Ask for the projection stress-tested with export rates reduced, and with the self-consumption portion identified separately as the part that does not move.