With enormous tax breaks and the ability to actually “recharge” the grid with electricity, home solar panels are gaining wide acceptance as a thoughtful long-term investment.

However, according to the Arizona Department of Revenue: those solar panels are subject to property taxes if they’re leased.

SolarCity Corp. and Sunrun Inc. filed a lawsuit Monday challenging the state Department of Revenue’s 2013 decision that leased panels don’t qualify for property-tax exemptions that apply to panels that are owned by homeowners and businesses and used primarily for on-site consumption.

Due to the high cost ($10k+) of paying for solar panels all at once, leasing is a much more reasonable alternative (and usually marketed as being less than the power bill you would be paying for without the panels).

These taxes are not insignificant either:

Based on the department’s figures, a $34,000 solar-panel array leased by a homeowner would cost approximately $150 in property taxes in the first year, decreasing annually year as the system depreciates.

Obviously, the company is suing—either they would have to absorb the cost or pass it on to consumers, and neither of those options can end positively.

The whole point of leasing solar panels is to save money—instead of providing $15-50k right off the spot, pay it off like a car payment at the same rate as a power bill then never pay a power bill again.

With many states giving tax incentives and discounts to those purchasing solar panels, this is a strange move by the state of Arizona, which should be encouraging the use of solar panels given the proliferation of their largest energy resource—the sun.

Do they have a case? Possibly, considering the Arizona’s DoR decision to apply property taxes as recently as 2013. No word if that decision is retroactive either—the last thing a homeowner wants is an added expense on something with a fixed cost.