Today is the fifth anniversary of something many drivers stuck in Seattle traffic have become familiar with: the PEMCO solar panel reader board. According to PEMCO, "Thanks to the efforts of a not-for-profit called Solar Pie, PEMCO’s sign shows the amount of electricity being generated – as well as 'carbon offsets' – by the solar panels." They also have a web page that updates the cumulative amount of energy produced during the past five years.

Since November 21, 2008, PEMCO's solar panels have produced 36982.46 kilowatt hours, reducing the amount of CO2 emitted during that time by 31.25 metric tons. What do all those numbers mean?

In California's cap-and-trade system, the current price of a ton of carbon is $11.10. Put simply, that is the amount it costs companies in California to reduce a ton of carbon, either in the form of a permit or an investment that reduces carbon in their facility.

Ultimately, PEMCO's 31.25 tonnes of CO2 amount to $346.87, or $69.37 per year.

It is unclear whether PEMCO or Solar Pie receive any of the many subsidies from taxpayers that would actually pay them to produce these tiny environmental benefits. If PEMCO wants to spend its own money to buy solar panels, that is their choice.

Taxpayers and those who care about reducing carbon emissions, however, should not subsidize such a paltry and expensive effort at reducing emissions.