Analysis
According to the U.S. Energy Information Administration (EIA), about 4.08 trillion kilowatt-hours (kWh) of electricity were generated at power plants in the United States in 2016. About 65% was derived from fossil fuels (coal, natural gas, petroleum, and other gases), about 20% from nuclear energy, and about 15% from clean or renewable energy sources.
More than 60 U.S. cities have committed to powering their communities with 100% clean energy, including large cities like San Diego (CA) and small towns like Abita Springs (LA). Several cities, such as Aspen (CO), Greensburg (KS), and Burlington (VT), have already achieved this goal using hydroelectric, solar, wind power, and biogas. Today they are powered entirely with renewable energy sources.
Other cities are working toward this goal by exploring clean sources of energy to power municipal buildings first. The City of Chicago (IL) has committed to having all government buildings powered with 100% renewable electricity by 2025. To meet its commitment, Chicago will use a combination of renewable energy certificates (RECs), utility-supplied renewable energy, and on-site generation, with initial purchases set to begin in 2018 and 2019. RECs, also known as Green tags, Renewable Energy Credits, Renewable Electricity Certificates, or Tradable Renewable Certificates are tradable, non-tangible energy commodities that certify 1 MWh of electricity was generated from an eligible renewable energy resource and was fed into the grid.
Similarly, the City of Atlanta (GA) recently adopted a resolution committing to have all city buildings run on clean energy by 2025 and the remainder of the community by 2035. The Atlanta’s Office of Sustainability will develop a plan for these targets to include interim milestones, budget estimates, equity metrics, estimated financial impacts, financing impacts, financing mechanisms, and the percentage of clean energy that shall be locally and distributively generated. Once the plan is completed, their office will be requesting funds as part of the city’s annual budgeting process for the implementation of this policy.
The City of Las Vegas (NV) began powering its municipal buildings and operations with 100 percent clean electricity in 2016. Approximately 120 buildings and over 50,000 streetlights, traffic signals, parks, and recreation centers run on renewable energy sources. The power flows from a mix of solar panels and hydroelectric turbines including the Hoover Dam. The use of renewables, plus other implemented energy efficiency measures, is estimated to save the city roughly $5 million per year.
On May 17, 2017, the Mayor and City Commission passed a resolution supporting the Sierra Club’s Ready for 100% Campaign, which challenges 100 cities across the United States to set a target of 100% clean energy, and urges the 2017 U.S. Conference of Mayors participants to commit to 100% renewable energy. That same day the Mayor and City Commission also discussed having Miami Beach commit to ensuring that all government buildings will be powered by 100% renewable electricity, resulting in a dual referral to the Sustainability and Resiliency Committee and the Finance and Citywide Projects Committee.
In 2015, the city consumed 1,741,770.5 megawatt-hours (MWhs) of electricity. Government operations consumed 54,556.5 MWhs of electricity, with 85% attributed to municipal buildings. Electricity was the main contributor of greenhouse gas (GHG) emissions in both the community-wide (69%) and government operations (77%) inventories for 2015.
In order to meet community-wide electricity needs with on-site generation, the city would need to install 3,583,890 (300 Watts) solar panels at an estimated cost of $250 to $450 per unit or 43,100 (50 kW) wind turbines. Powering only municipal building using solar would require about 95,420 (300 Watts) solar panels or 1,350 (50 kW) wind turbines. Alternately, the city can invest in RECs. For example, if the city opts for the Bonneville Environmental Foundation (BEF) REC, valued at $8/MWh, the city would need to invest about $370,984 to account for the electricity used by municipal buildings.
The city does not currently have utility-supplied renewable energy provided by FPL. In 2016, FPL’s main source of energy was derived from natural gas (70%), nuclear (23%), coal (4%), and purchased power (3%). Therefore, in order to offset current energy consumption off-the-grid, the city will need to use on-site generation and/or RECs.
Because of physical space constraints and high upfront investments related to solar and RECs, it is recommended the city begin by reducing municipal building energy consumption. The first step is to assess the inefficiencies in each building and determine which retrofits are best suited to improve energy efficiency and reduce consumption. The city should also track and monitor building utility bills to correlate cost and consumption information, ensuring energy performance.
The city is currently under a 13-year agreement with Ameresco, which is an energy service company (ESCO). ESCOs provide a broad range of energy solutions including design and implementation of energy savings projects, retrofits, energy conservation initiatives, energy outsourcing, power generation and supply, and risk management. The city's agreement with Ameresco was executed in 2010, and was focused on energy conservations measures with a total cost of $14 million and a payback term (not include the interest associated with the financing) estimated at 11.1 years. Other cities and counties, such as Miami-Dade County and City of Fort Lauderdale, have experienced greater benefit from having multiple ESCO agreements in place, rather than relying on only one ESCO.
The Environment & Sustainability (E&S) Department is working with several departments to compile government buildings energy consumption data in the Energy Star Portfolio Manager platform. The Energy Star Portfolio Manager is an online platform that measures and tracks energy and water consumption, as well as GHG emissions. This data can be used to benchmark the performance of one building or an entire portfolio of buildings.
The Property Management Division and E&S Department are also exploring utility bill management software to track and audit energy (or non-energy) commodity and bill detail. Miami-Dade County is currently correlating cost and consumption information using the EnergyCAP software, which provides granular and summary-level data that can be analyzed to yield actionable insights. EnergyCAP’s energy management software assists organizations with energy management challenges, such as utility bill processing, data integration, transparency, workflows, reporting, project prioritization, tracking and verification of savings. This software could assist the city to reduce energy consumption, lower emissions, and save money.
CONCLUSION
The following is presented to the members of the Sustainability and Resiliency Committee for discussion and further direction.