@article{jain_kumar ch_sonti_keskar_johnson_ghosh_patel_2023, title={High-Performance Hybrid MPPT Algorithm Based Single-Stage Solar PV Fed Induction Motor Drive for Standalone Pump Application}, volume={59}, ISSN={["1939-9367"]}, url={https://doi.org/10.1109/TIA.2023.3310490}, DOI={10.1109/TIA.2023.3310490}, abstractNote={The article presents a high-performance hybrid sample-based perturb and observe (P&O) maximum power point tracking (MPPT) algorithm for a single-stage solar photovoltaic (SPV) fed open-end winding induction motor (OEWIM) driven standalone pumping system. Traditionally, the P&O algorithm utilizes slow sample-based computation for MPPT to avoid high oscillations near MPP. The slow sample-based algorithm has the drawback of poor tracking speed and loss of MPPT for the environmental change corresponding to the decrement in the PV power (i.e., step decrement in irradiance). Conversely, the algorithm designed for a faster sample rate faces the drawback of poor MPPT performance due to high oscillations near MPP. The proposed algorithm integrates the advantages of both fast and slow sample-based P&O MPPT algorithms. It switches to the fast sample-based MPPT when the PV operating point is away from MPP or there is a change in environmental conditions. It switches back to slow sample-based MPPT algorithms when the operating point reaches near MPP. The complete details of the proposed hybrid sample-based MPPT algorithm for the SPV pump application system are given in the article. Further, a comparative analysis of the proposed algorithm performance with both fast and slow sample-based algorithms is also carried out using MATLAB/Simulink simulation environment. The simulation results demonstrate the superior performance of the proposed algorithm in terms of MPPT speed and accuracy. The enhanced MPP accuracy further improves the pump performance by minimizing torque and speed ripple. The robustness of the proposed strategy is also elucidated experimentally.}, number={6}, journal={IEEE TRANSACTIONS ON INDUSTRY APPLICATIONS}, author={Jain, Sachin and Kumar Ch, S. V. S. Phani and Sonti, Venu and Keskar, Aditya and Johnson, Jeremiah X. and Ghosh, Subhojit and Patel, R. N.}, year={2023}, month={Nov}, pages={7103–7115} }
 @article{chalendar_keskar_johnson_mathieu_2024, title={Living laboratories can and should play a greater role to unlock flexibility in United States commercial buildings}, volume={8}, ISSN={["2542-4351"]}, DOI={10.1016/j.joule.2023.11.009}, abstractNote={<h2>Summary</h2> Energy demand flexibility from commercial buildings can play a critical role in the ongoing energy transition. There is an urgent need to redirect more research and deployment efforts toward real-world experimentation. Buildings-sector roadmaps overwhelmingly rely on simulations that imperfectly capture reality. We draw lessons from a review of two decades of literature on real-world flexibility and demand response experiments and from our "Living Laboratory" experiences at three major academic institutions in the United States. While the prevailing method is "model first, experiment second," there is also strong value in "experiment first, model second" and in improving our understanding of a system through experimentation while modeling it. Commercial building clusters on university and corporate campuses offer valuable and often untapped potential. They are both ideal test beds for research on energy flexibility and a significant source of flexibility. Our research agenda provides practical recommendations for conducting and scaling experimentation in these test beds and leveraging experimental findings to improve modeling.}, number={1}, journal={JOULE}, author={Chalendar, Jacques A. de and Keskar, Aditya and Johnson, Jeremiah X. and Mathieu, Johanna L.}, year={2024}, month={Jan}, pages={13–28} }
 @article{keskar_soni_shukla_jain_ghosh_patel_johnson_2023, title={Tapping the Unused Energy Potential of Solar Water Pumps in India}, volume={57}, ISSN={["1520-5851"]}, url={https://doi.org/10.1021/acs.est.3c02378}, DOI={10.1021/acs.est.3c02378}, abstractNote={India seeks to deploy millions of solar water pumps to farmers who often lack access to electricity or face an unreliable power supply. Improving the use of this technology can bolster sustainable agriculture and expand clean energy services. We investigate farm-level impacts and opportunities with primary survey data (n = 292 farmers) and a large real-time pump operational data set (n = 1106 pumps). By modeling the potential solar generation of off-grid solar water pumps, we estimate 300-400 kWh/month of unutilized solar energy per pumping system, representing up to 95% of potential generation. While farmers report increased revenues and ease of pump operation, unsolved challenges concerning the lack of panel cleaning and tracking remain. Pump operational data show pump usage in the summer and monsoon seasons and an expansion of irrigation to grow crops in the winter. Relative to emissions associated with the use of diesel pumps, solar pumps that are highly utilized reduced life cycle CO2-eq emissions by 93% on average, while the pumping systems with the lowest use result in a net increase of 26% relative to the diesel alternatives. Based on observed usage rates, approximately 70% of pumps had positive environmental benefits. The high share of unutilized solar energy provides a significant opportunity to use the energy for nonpumping purposes.}, number={38}, journal={ENVIRONMENTAL SCIENCE & TECHNOLOGY}, author={Keskar, Aditya and Soni, Vivek and Shukla, Jaya and Jain, Sachin and Ghosh, Subhojit and Patel, Ramnarayan and Johnson, Jeremiah X.}, year={2023}, month={Sep}, pages={14173–14181} }
 @article{keskar_galik_johnson_2023, title={Planning for winter peaking power systems in the United States}, volume={173}, ISSN={0301-4215}, url={http://dx.doi.org/10.1016/j.enpol.2022.113376}, DOI={10.1016/j.enpol.2022.113376}, abstractNote={Most regions in the United States experience peak electricity demand during the summer months. Several regions, however, are dual peaking with distinct summer and winter peaks of roughly equal magnitude. Deep decarbonization of our energy system could lead to greater instances of dual or winter peaking power systems across the country. This seasonal shift has important implications for grid operations. Furthermore, the compounding impacts of decarbonization strategies and climate change could introduce new challenges in ensuring sufficient generator availability during peak demand. This paper provides policy recommendations to plan for a shift to dual or winter peaking power systems. We first analyze the seasonal peak demand trends between 2016 and 2021 at the regional and subregional levels. We provide key examples of how regulators and system operators plan for winter resource adequacy, focusing on the measures undertaken by different stakeholders, post-Winter Storm Uri. We then detail challenges posed by the multilevel regulation framework in planning for winter peaking power systems for both extreme cold events and a gradual shift due to electrification. Finally, we provide our policy recommendations for utilities and regulators on how they can robustly meet the challenges of winter peaking systems.}, journal={Energy Policy}, publisher={Elsevier BV}, author={Keskar, Aditya and Galik, Christopher and Johnson, Jeremiah X.}, year={2023}, month={Feb}, pages={113376} }