Renewable Energy Solutions to the Water-Energy-Climate Nexus

Via Connect4Climate, an article on the potential for renewable solutions to reduce the watergy crisis:

The water sector is energy-hungry, with energy consumption by the sector equivalent to all the energy used by Australia. In 2014, around 4% of global electricity consumption was used to extract, distribute, and treat water and wastewater as well as 50 million tons of oil equivalent of thermal energy.

By 2040, the amount of energy used in the water sector is likely to double due to trends including increased desalination, large-scale water transfers, and increasing demand for wastewater treatment, as well as higher levels of treatment.

The energy used to supply water and clean used water is responsible for around 3–8% of global greenhouse gas emissions. With global demand for water projected to increase by 55% by 2050, a business-as-usual scenario will see emissions increasing by 50% in the same timeframe.

Decoupling Emissions from GDP Growth

As part of the San Diego’s Climate Action Plan, which calls for clean and renewable energy to be generated via a combination of on-site and large-scale renewables, San Diego’s Public Utilities Department has a forward-thinking renewable energy program that generates more renewable energy from water and wastewater than any other San Diego Gas & Electric customer. In addition to reducing water-energy-climate nexus challenges, the program has contributed towards the city’s 21% reduction in greenhouse gas emissions compared to the 2010 baseline (at the same time GDP growth has increased by 35%).

Utilizing Methane

One of the by-products of the wastewater treatment process at Point Loma Wastewater Treatment Plant is methane gas. The gas is used to fuel two continuously running generators that can each produce up to 2,235 kilowatts of electricity. A diesel-powered generator can also burn methane and produce an additional 1,220 kilowatts as a peaking generator. By utilizing the methane gas, it means the site is energy self-sufficient, with excess power generated sold back to the grid.

At the Metropolitan Biosolids Center, which produces dewatered biosolids that are around 30% solids and 70% water, methane produced by the digesters and from the adjacent Miramar Landfill is converted to electricity, which is used to run the facility. Thermal energy produced by the generators is used to heat the plant, as well as for air conditioning of the center.

The Sun’s Power

At three Public Utilities Facilities, solar photovoltaic systems have been installed:

  • Alvarado Wastewater Treatment Plant has installed a 1.1-megawatt system, producing 1.4 million kilowatt-hours annually
  • Metropolitan Operations Center III has installed a 30 kilowatt (AC) rooftop solar system that produces 45,000 kilowatt-hours annually
  • Otay Water Treatment Plant has an 804 kilowatt (AC) system that produces 1.5 million kilowatt-hours annually​

The Takeaway

Water utilities have multiple renewable energy options available to reduce water-energy-climate nexus pressures.

This entry was posted on Monday, November 4th, 2019 at 8:16 pm and is filed under Uncategorized.  You can follow any responses to this entry through the RSS 2.0 feed.  You can leave a response, or trackback from your own site. 

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About This Blog And Its Author
As the scarcity of water and energy continues to grow, the linkage between these two critical resources will become more defined and even more acute in the months ahead.  This blog is committed to analyzing and referencing articles, reports, and interviews that can help unlock the nascent, complex and expanding linkages between water and energy -- The Watergy Nexus -- and will endeavor to provide a central clearinghouse for insightful articles and comments for all to consider.

Educated at Yale University (Bachelor of Arts - History) and Harvard (Master in Public Policy - International Development), Monty Simus has held a lifelong interest in environmental and conservation issues, primarily as they relate to freshwater scarcity, renewable energy, and national park policy.  Working from a water-scarce base in Las Vegas with his wife and son, he is the founder of Water Politics, an organization dedicated to the identification and analysis of geopolitical water issues arising from the world’s growing and vast water deficits, and is also a co-founder of SmartMarkets, an eco-preneurial venture that applies web 2.0 technology and online social networking innovations to motivate energy & water conservation.  He previously worked for an independent power producer in Central Asia; co-authored an article appearing in the Summer 2010 issue of the Tulane Environmental Law Journal, titled: “The Water Ethic: The Inexorable Birth Of A Certain Alienable Right”; and authored an article appearing in the inaugural issue of Johns Hopkins University's Global Water Magazine in July 2010 titled: “H2Own: The Water Ethic and an Equitable Market for the Exchange of Individual Water Efficiency Credits.”