|Number of Lights Committed||Electricity Savings kWh/yr)||Value of Electricity Saved ($/yr)||Carbon Dioxide Emissions Reductions (metric tonnes/yr)|
In 2013, the Tennessee Department of Environment and Conservation’s Office of Energy Programs (TDEC OEP) received an award under the U.S. DOE’s State Energy Program Competitive Funding Opportunity Announcement, to stimulate energy investment in local jurisdictions, K-12 public schools, and public housing authorities. As part of this award, TDEC OEP and subrecipient Clean Energy Solutions, Inc. stimulated demand for light-emitting diode (LED) streetlight conversion projects by providing education, outreach, and no-cost technical assistance to local governments. To facilitate conversions, the State developed replicable ownership, tariff, and maintenance structures that produce beneficial economic outcomes for both local governments and local utilities.
TDEC OEP provides support and technical assistance to State agencies, public higher education institutions, and local jurisdictions throughout the entire State of Tennessee.
- At the time of the project, tariffs imposed by municipal utilities did not acknowledge or capture the cost reduction benefits of LED technology, and often, complex ownership arrangements made it difficult for local governments to predict the financial impacts of an LED street light conversion.
- The project team found that one of the most effective ways to support local governments was to assist with pulling together an initial lighting inventory and financial analysis, based on a typical use estimate for each wattage type at the utility per kWh rate. The result of the financial analysis provided a preliminary estimate of energy and cost savings (based on reduced kWh use and reduced maintenance charges) and project cost, based on a 1-to-1 replacement of existing lights with LED equivalents. Any available rebates or other incentives are included within the calculations to determine a simple payback, which can be used by the local government’s representative in discussions with other decision-makers.
- Examples of financing selected by local governments include: Montgomery County’s streetlight retrofit is part of a larger ESPC project, the City of Clarksville has utilized Qualified Energy Conservation Bonds (QECBs) to finance its streetlight conversion, and the City of Knoxville identified self-finance as likely the best option.
- The project team also found that incorporating insight from experienced local governments in Tennessee that had already gone through the streetlight retrofit process was invaluable in demonstrating to other local governments the feasibility of such a conversion as well as incorporating into the dialogue a very fact-based consideration of localized challenges and potential solutions, as well as lessons learned.
- Price quotes in individual locations were wide ranging, initially resulting in estimated paybacks from less than 2 years to 7 years. At least four variables explain these differences:
- Timing of the quotes - Costs dropped for LED streetlights, as much as 40-50% in three years
- Differences in scopes of work - Some quotes factored in maintenance and replacement costs in their bids, while others did not; some reflect material costs only and not installation;
- Differences in configuration of lights by wattage distribution - The 100-150 wattage fixtures in 2016 cost about $200, while the 300+ wattage replacements could be as high as $600.
- Quantity of fixtures / economies of scale - A large city like Knoxville has about 7 times the number of poles as does a city like Lebanon.