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1. Techno-Economic Analysis of Atmospheric Water Harvesting Across Climates

   https://doi.org/10.1021/acsestengg.4c00098  

   Gayoso, Natalie; Moylan, Emily; Noha, Wenny; Wang, Jingjing; Mulchandani, Anjali (July 2024, ACS ES&T Engineering)

   Drinking water scarcity is a global challenge as groundwater and surface water availability diminishes. The atmosphere is an alternative freshwater reservoir that has universal availability and could be harvested as drinking water. In order to effectively perform atmospheric water harvesting (AWH), we need to (1) understand how different climate regions (e.g., arid, temperate, and tropical) drive the amount of water that can be harvested and (2) determine the cost to purchase, operate, and power AWH. This research pairs thermodynamics with techno-economic analysis to calculate the water productivity and cost breakdown of a representative condensation-based AWH unit with water treatment. We calculate the monthly and annual levelized cost of water from AWH as a function of climate and power source (grid electricity vs renewable energy from solar photovoltaics (PV)). In our modeled unit, AWH can provide 1744–2710 L/month in a tropical climate, 394–1983 L/month in a temperate climate, and 37–1470 L/month in an arid climate. The levelized cost of water of AWH powered by the electrical grid is $0.06/L in a tropical climate, $0.09/L in a temperate climate, and $0.17/L in an arid climate. If off-grid solar PV was purchased at the time of purchasing the AWH unit to power the AWH, the costs increase to $0.40/L in an arid climate, $0.17/L in a temperate climate, and $0.10/L in a tropical climate. However, if using existing solar PV there are potential cost reductions of 4.25–5-fold between purchasing and using existing solar PV, and 2–3-fold between using the electrical grid and existing solar PV, with the highest cost reductions occurring in the tropical climate. Using existing solar PV, the levelized cost of AWH is $0.09/L in an arid climate, $0.04/L in a temperate climate, and $0.02/L in a tropical climate. 

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2. Evaluating the Environmental Benefit of Residential Photovoltaic Modules Early Retirement in California

   https://doi.org/10.1109/PVSC48317.2022.9938865  

   Kothari, Mallika; Anctil, Annick (January 2022, 2022 IEEE 49th Photovoltaics Specialists Conference (PVSC))

   The state of California is the foremost leader in solar photovoltaics (PV) installations in the United States. With 1,390,240 installations and 24.76% of the state's energy coming from solar, the demand for PV modules is steadily increasing. Most PV modules have an expected lifetime of 25-30 years. However, due to repowering or early module failure, module lifetime can often be shorter than anticipated. Current studies calculate the environmental impact of PV systems based on ideal installation conditions and a full 25-year module lifetime. This study considers the impact on the life cycle of PV systems from early PV module retirement and actual system installation in California. Using the life cycle cumulative energy demand, electricity data from the Energy Information Administration (EIA), and greenhouse gases, carbon payback time (CPBT) was evaluated. Data from various PV module rooftop residential installations in 2019 were collected from the California NEM database. Information on the system design (tilt, azimuth, module model) and module specification sheets were used to calculate the cumulative electricity generated in kilowatt-hours (kWh) over the system' lifetime. The calculated average CPBT was 2.8 years, shorter than most of the system lifetimes, and the mean number of zero carbon years experienced by earlier retired systems was about 5 years. Although the rapid movement towards solar energy is promising and essential as reliance on greener energy increases, attention must be paid to the diverse lifespans of PV modules, system design, and performance to substantiate or reject the assumption that PV always have a positive impact on the environment. 

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3. Recent Advances in Cyberattack Detection and Mitigation Techniques for Renewable Photovoltaic Distributed Energy CPS

   Jessica Whitaker and Danda B. Rawat (June 2023, Computing Conference)

   Cyberattacks targeted to the energy cyber-physical system (ECPS), also known as the smart grid, could interrupt the electricity supply with major ramifications. Attackers identify and exploit any vulnerable portion of the energy power grid, including the inverters with solar-powered photovoltaic (PV) panels. PV presents unique challenges as electricity consumers have also become providers of solar energy for utilities. As mandates require increased PV penetration across the world for positive environmental impacts, increased cyberattacks targeted at PV systems impact reliability and efficiency within the ECPS. The new technologies continuously being introduced to manage the ECPS and ensure bi-directional communications and energy flow between components also lead to more attack surfaces, system vulnerabilities, and heightened malicious attacks. Data integrity attacks are increasing within PV systems. In this paper, we present a survey of different methods that are proposed and explored for identifying and preventing cyberattacks targeted at PV systems. The attack detection methods include voltage control, data diodes, and voltage measurement algorithms. Furthermore, we present blockchain, cyber switching, and other attack mitigation techniques for PV systems. 

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4. Three-Dimensional Solar Harvesting with Transparent Spectral Selective Photovoltaics in Agrivoltaics

   https://doi.org/10.3390/en18071788  

   Shi, Donglu (April 2025, Energies)

   Although photovoltaic (PV) solar cells have been widely used for a variety of applications, several critical issues are yet to be addressed, including further enhanced power conversion efficiency (PCE) and their 2D solar harvesting with limited land availability. It has been reported that traditional PV installations require approximately 22,000 square miles to power the entire United States—posing a significant barrier, particularly in urban and agricultural settings. A unique dual modality of PV system has been proposed and implemented for both power generation and crop photosynthesis, namely, agrivoltaics. This system installs PV panels over the crops while harvesting solar for PV electricity generation and, at the same time, integrates with crop cultivation, which is a promising solution to optimize land utilization. However, for opaque PV panels, sunlight is often obstructed, potentially impacting plant growth and yield. To address this critical issue, a 3D solar harvesting concept has been proposed and experimentally investigated. By placing multiple layers of transparent PV panels parallel, sunlight can penetrate multiple layers and generate electricity on each PV, significantly enhancing the solar harvesting surface area. Most importantly, sunlight can also be collected by the crops underneath for effective photosynthesis. Among various PV materials, dye-sensitized solar cells (DSSCs) using porphyrin-based dyes have demonstrated potential for spectral modulation, optimizing both electricity generation and crop illumination. This review focuses on a novel approach to a 3D solar harvesting system via a multi-layered PV architecture for agrivoltaics. Also discussed are the current challenges in agrivoltaics, spectral selective mechanisms, and 3D solar harvesting architecture that show promise for sustainable energy production and land-efficient solar power deployment. 

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5. Development of a Tool for Optimizing Solar and Battery Storage for Container Farming in a Remote Arctic Microgrid

   https://doi.org/10.3390/en13195143  

   Sambor, Daniel; Wilber, Michelle; Whitney, Erin; Jacobson, Mark (October 2020, Energies)

   null (Ed.)

   High transportation costs make energy and food expensive in remote communities worldwide, especially in high-latitude Arctic climates. Past attempts to grow food indoors in these remote areas have proven uneconomical due to the need for expensive imported diesel for heating and electricity. This study aims to determine whether solar photovoltaic (PV) electricity can be used affordably to power container farms integrated with a remote Arctic community microgrid. A mixed-integer linear optimization model (FEWMORE: Food–Energy–Water Microgrid Optimization with Renewable Energy) has been developed to minimize the capital and maintenance costs of installing solar photovoltaics (PV) plus electricity storage and the operational costs of purchasing electricity from the community microgrid to power a container farm. FEWMORE expands upon previous models by simulating demand-side management of container farm loads. Its results are compared with those of another model (HOMER) for a test case. FEWMORE determined that 17 kW of solar PV was optimal to power the farm loads, resulting in a total annual cost decline of ~14% compared with a container farm currently operating in the Yukon. Managing specific loads appropriately can reduce total costs by ~18%. Thus, even in an Arctic climate, where the solar PV system supplies only ~7% of total load during the winter and ~25% of the load during the entire year, investing in solar PV reduces costs. 

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