In November 2006, citizens of Boulder, Colorado, voted to approve Ballot Issue No. 202, authorizing the city council to levy and collect an excise tax from residential, commercial and industrial electricity customers for the purpose of funding a [http://www.bouldercolorado.gov/files/Environmental%20Affairs/climate%20a... climate action plan] to reduce greenhouse gas emissions. The plan outlines programs to increase energy efficiency, increase renewable energy use, reduce emissions from motor vehicles, and take other steps toward the goal of meeting the Kyoto Protocol.
Beginning April 1, 2007, and expiring March 31, 2013, the initial tax rate was set at $0.0022/kWh for residential customers, $0.0004/kWh for commercial customers, and $0.0002/kWh for industrial customers. The city council was given the authority to increase the tax after the first year up to a maximum permitted tax rates of $0.0049/kWh for residential customers; $0.0009/kWh for commercial customers; and $0.0003/kWh for industrial customers. In July 2009 the city council voted to increase the tax up to those caps. Voluntary purchases of utility-provided wind power are exempt from the tax.
Boulder citizens voted in favor of the Climate Action Plan Tax again in 2012, extending the expiration of the tax to March 31, 2018. Click [http://www.bouldercolorado.gov/index.php?option=com_content&view=article... here] for more information.