Knowledge Problem

The “First Feel-good Sustainability Story of 2012,” So Long As You Ignore the Costs

Michael Giberson

Consider the claim in the headline, “How One Man’s Roof Paid for His Car.” Here’s the introduction:

It’s the first feel-good sustainability story of 2012. A man in Orlando, Florida installed solar panels on the roof of his home, sold the excess power back to the grid, and then used that money to make a down payment on a new Chevy Volt, the plug-in car that gets 60 miles to the gallon.

Now those solar panels are charging his new car.

The nut of the story is that over the last two years the Orlando homeowner netted $5,600 in power sales to his local utility due to the oversized solar power system installed on his roof and in his backyard, and he recently made a similarly-sized down payment on a Chevy Volt.

If we were to assume that the solar panels fell like manna from the skies and were installed by angels refusing payment for their services, it still just isn’t the case that the solar system paid for the car. One indication: it took two years to accumulate $5,600, an average of about $117 per month, and actual monthly car payments for a Volt are likely north of $400. Maybe the homeowner is (reasonably) figuring in foregone electric power bills, but that value is not reported.

The story appearing at StateImpact Texas was based on a newspaper article appearing in the Orlando Sentinel under the more modest headline of “Sun Powers Orlando Man’s Electric Car.” The Sentinel article describes the homeowner’s own investment in the solar power system as “hundreds of thousands of dollars” and mentions “tax breaks and rebates” provided by taxpayers and ratepayers without quantifying them.

Let’s look at it this way: If I poured hundreds of thousands of dollars into the ocean and caused other taxpayers and ratepayers to pour tens of thousands of dollars into the ocean, and then the waves washed a few hundred dollars back each month, the claim that “the ocean paid for my car” would seem a little silly.

The Sentinel reported the owner’s own estimate of the payback period at an astounding “50 years or more.” (Astounding because, as the NPR story discussed yesterday indicates, the projected lifespan of the system is much closer to 20 or 25 years.)