Sustainable LA Grand Challenge

Like many cities around the world, Los Angeles is already experiencing the impacts of climate change first hand. In order to align with state and regional climate goals, the city of Los Angeles is taking steps to help residents adapt and become more resilient in the face of these changes, while simultaneously mitigating greenhouse gas (GHG) emissions through targeted policies, such as building decarbonization.

Los Angeles County contains 215 community water systems that are disconnected and fragmented. These water systems vary greatly in their local water resources including access to groundwater storage, stormwater capture, water re-use, infrastructure and potential for conservation. For instance, some systems contain more water resources than they need to meet their local demand. Other systems have limited resources and depend on a single source of imported water or groundwater aquifer. As a result, households face unequal access to affordable drinking water that is mainly determined by their geographical location. A feasible strategy to integrate these fragmented water systems is needed to address the inequities in pricing and ensure Los Angeles County can achieve 100% local water. 

Solar energy is the world's most abundant clean source of energy. The research objective of this project is to develop a tandem device capable of providing both energy generation and storage by combining the functions of a photovoltaic and rechargeable battery. Although both systems individually have been studied in-depth and developed, a tandem device that both generates and stores electricity had yet to be explored. The Sustainable LA Grand Challenge provided a unique opportunity to create an interdisciplinary research and design team to exploit this resource and significantly enhance energy self-sufficiency in Los Angeles and beyond. 

Los Angeles County is a biodiversity hotspot that harbors over 4,000 species of plants and animals. The most populous county in the nation, L.A. County offers a unique environment where more than 10 million people coexist with wildlife. The biodiversity of L.A. County provides many benefits to people, including air and water purification, food security and mental/physical well-being. But land development and climate change threaten the county’s species, their habitats, and the region's ecosystem. With 1 million animal and plant species globally facing extinction due to human activity, efforts to better understand the factors that shape biodiversity in Los Angeles could help shape global conservation efforts. 

Direct Potable Reuse (DPR) is a water recycling technique that uses treated wastewater as a source of drinking water. The State Water Resources Control Board (SWRCB) of California is currently tasked with developing regulations for DPR by the end of 2023. In this project, UCLA researchers focus on ways to clear the legal path toward the adoption of DPR in Los Angeles County and California. The ultimate goal of this project is to facilitate the adoption of DPR in a manner that is timely, secure and protective of public health. 

For Los Angeles County to achieve a 100% renewable energy future, developing highly efficient and innovative systems that take advantage of its abundant natural resource—solar energy—is critical. So far, two well-developed technologies, photovoltaics (PV) and concentrating solar power (CSP), have advanced solar energy conversion in different directions. While PV is cheaper and relatively more efficient, CSP is dispatchable (can be turned on or off by operators) and can be used on-demand. Thus, efforts have been made to develop hybrid solar and thermal systems to increase PV "dispatchability." However, these hybrid systems suffer from the elevated temperature of the PV cell, which decreases overall efficiency. Realizing such a technology gap, the UCLA research team aims to develop a novel technology that is both a highly efficient and dispatchable form of solar energy conversion and storage to help the county achieve its sustainable goals.

Nearly 60% of Los Angeles County’s water demand is fulfilled by imported water from hundreds of miles away. Securing a sustainable local water supply via recycled wastewater can help save the enormous amounts of energy required to transport water and make the region more resilient to climatic change. Over the years, the use of bioreactors (a type of membrane filtration) combined with wastewater treatment has significantly contributed to ensuring local water supplies.   However, it has also raised concern for biofouling, which is a phenomenon that occurs when microorganisms in the wastewater adhere to the surface of the membranes and restrict water flow. Membrane surfaces must be cleaned periodically by discontinuing the bioreactor operation, which limits the economic advantages of using this approach. Thus, for the use of bioreactors in wastewater treatment to become widely adopted as a fully sustainable and economical technology across Los Angeles County – the membrane biofouling issue must first be resolved. 

Southern California experienced a significant drought from 2012 to 2016, which was exacerbated by warming due to climate change. Defined by unprecedented high temperatures and low annual precipitation, it was the driest four-year span in the last 1,200 years.  As a result, overall vegetation health and cover has most likely been affected (e.g. decline in greenness, high vegetation mortality in chaparral-dominated communities). Changes in vegetation health and cover create favorable conditions for wildfires and landslides. These changes threaten both the stability of the natural environment and the structures that depend on it, such as built electricity generation plants, power lines and pipelines. Because these types of infrastructure are often located on or run through wildland areas, changes in vegetation, wildfires and landslides can impact the region’s energy supplies. To better understand these impacts and assess Los Angeles County’s energy supply vulnerabilities, researchers analyzed the impacts of the 2012-2016 drought on vegetation health and cover using satellite and geospatial environmental data. 

There are a variety of local, state and federal policies in place designed to promote the adoption of photovoltaic or solar power systems in the United States. Examples include the federal Residential Renewable Energy Tax Credit, the California Solar Initiative rebates and the Los Angeles Department of Water and Power (LADWP) Net Metering program. These policies operate by reducing the economic barriers to solar power adoption, while other potential strategies like public outreach focus on educating the general public on the economic and social benefits of solar adoption. like public outreach focus on educating the general public on the economic and social benefits of solar adoption.   Ultimately, the adoption of solar power in residential settings depends on many factors, including finance and homeowners’ perceptions and social influences, as well as regulatory and technological factors. These confounding factors influencing residential solar power adoption rates are far too complex to be fully analyzed using traditional economic models. Thus, a new method is needed to better understand what policies are most effective at increasing solar power adoption in residential areas. 

Los Angeles is located in a semi-arid region with finite supplies of local water. The region relies on imported water sources from snowmelt that account for over 85% of the City of L.A. water supply. With climate change leading to declining snowpack and more severe droughts, L.A. County has become more susceptible to water shortage conditions. Thus, to enhance water supply resilience and sustainability across the county, a full characterization of the water budget is necessary. Accurately characterizing the water budget will in turn improve local water resource management and will aid L.A. County to achieve 100% locally sourced water supply by 2050.