Leading the Clean Energy Transition
This article was prepared by our Director of Office of Energy and Resource Recovery Programs, Jane Gajwani
As New York City faces down climate change, our role as a part of City government is to lead on the clean energy transition. The de Blasio administration set a target for us to achieve energy and carbon neutrality by 2050. This may seem a long time in the future, but we think about and plan projects on decades-long timeframes. Infrastructure that we design and construct today may still be operational in 2100, let alone 2050! Over the past year, the Office of Energy and Resource Recovery Programs has worked to identify the investments needed for our energy- and carbon-neutral future. Daunting though the transition seems, our path forward is summarized by a few guiding principles: electrify where possible, use energy wisely, and leverage resources unique to our operations.
Based on economy-wide studies conducted at the State level, electrification, or converting loads that currently use fossil fuels to electricity, will be the foundation of a clean energy future. Currently, the energy that our facilities and vehicles use comes in forms as varied as marine diesel for our sludge barges, to jet fuel for our helicopters, to electricity, natural gas, and fuel oil used at our wastewater resource recovery and water treatment facilities. Unlike the consumption of fossil fuels, using electricity results in no emissions — it’s the generation of electricity that traditionally creates emissions. However, as the grid decarbonizes and more renewables like solar and wind brought online, electricity generation can be zero-carbon as well. New York City and State are building new transmission lines to bring renewable hydropower from upstate and beyond and planning major investments in off-shore wind. The shift in our planning is already underway — we are evaluating our Coney Island Wastewater Resource Recovery Facility (WRRF) as the first of our WRRFs to electrify its heating system when its existing boilers reach the end of their useful lives.
The efficient use of electricity is a vital component of our plans to electrify. As more of New York State turns to electricity for heating needs, electric demand is expected to double, and the highest demands will shift from summertime to peaking in the wintertime. Every energy consumer will have to manage their own consumption to ensure that electric utilities can meet the forecasted increased demand without compromising reliability or cost. To make sure that we maximizes opportunities for energy conservation, each of our largest capital projects undergoes a rigorous evaluation during design to identify conservation measures. Those can range from LED lighting upgrades and controls to altogether changing the technology used for our treatment processes. Our office is working on projects that will oxygenate wastewater more efficiently and on sludge thickening upgrades that will reduce the amount of energy needed to heat our digesters.
To achieve energy and carbon neutrality, we will have to use our assets creatively and find new ways to extract energy from our infrastructure, such as by recovering thermal energy from the sewers and plant effluent. In New York City, 1.3 billion gallons of wastewater flow through 7,500 miles of sewers daily, a resource that can be used as a heat sink or source. In the future, the city might rely on heat pumps tied to the sewer system or centered around our WRRFs to heat or cool large district systems. Co-digestion of food scraps is another example of creative asset usage. Our digesters can also accept pre-processed food waste including fats, oils, and grease, which cannot be composted. When properly managed, co-digestion keeps waste out of landfills and results in greater yields of renewable digester gas that can be used as a replacement for natural gas. Even the open spaces of our facilities are assets that we need to use; we’re planning to install nearly 15 megawatts of solar power in the space above WRRF process tanks at Wards Island WRRF and on the open land at Pine Hill and Margaretville WRRFs. Our water supply system, too, already has more than 50 MW of hydropower generating capacity, with several more sites already in design.
Leadership on climate change requires that we harness the latent energy in our infrastructure. Water has always been critical to energy production, from the first watermills to nuclear power-plants. Our vision is to transform the system that delivers clean water and treats wastewater from one that consumes energy into an energetically self-sustaining system that will serve New York City for decades to come! Project by project, we are turning that vision into the future.
