These days, it seems like actions by subnational governments to promote clean energy and address climate change are all the rage. Yet for all of the commendable measures from states, from emissions pledges to renewable energy or energy efficiency targets, actions at the local level are driving real, measurable change. More than 80% of the U.S. population lives in urban areas, and with fewer legal and logistical hoops to jump through, local governments can provide significant market pull for innovative clean tech.

Some recent examples illustrate cities' abilities to manufacture considerable demand for clean energy, especially when they band together. In August, a coalition of 20 U.S. cities—including Atlanta, Boston, Chicago, Houston, Los Angeles, and Phoenix—issued a Request for Information on how they could best purchase enough renewable energy to cover their aggregate municipal electricity demand of 5.7 terawatt-hours (enough to power about 500,000 average U.S. homes). The request acknowledges that most respondents are not in a position to meet 100 percent of the coalition's stated load, and is open to proposed projects that provide ancillary benefits, including local economic benefits and educational opportunities. This opens the door to a broad array of viable options, including demonstration-scale projects showcasing innovative technologies that can be used to inform residents and visitors of the cities' commitment to clean energy.

A similar effort is taking place with electric vehicles for municipal fleets across the country. After a successful Request for Information received 40 responses across all vehicle segments, Climate Mayors—a bipartisan network of over 400 mayors from nearly every state—launched an Electric Vehicle (EV) purchasing portal in September for municipal governments interested in greening their fleets. The portal is a one-stop, turnkey solution for mayors of some of the largest cities in the country; when viewed in conjunction with recent action at the federal level to boost DOE's Advanced Technology Vehicle Manufacturing Program, there is an unmistakable trend of increasing technology push and market pull in the EV space.

These are just two of the higher-profile opportunities that are being spearheaded at the local level, and highlight the collective influence cities can have. But smaller-scale opportunities present themselves every day, from a 200 megawatt Request for Proposals in Austin, TX, to a solicitation for a mere 10,000 kilowatt-hours per year in Caroline, NY (population: 3,481).

American cities are growing, and they represent a reliably constant source of demand for energy, and for clean energy in particular. There are opportunities out there for companies of every size to gain a foothold in this booming market.