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Abstract: An energy efficiency and control analysis is given for application of a transparent electric curtain for dust mitigation on a solar panel. The electric curtain technique has been proposed by NASA as an effective active method for dust removal from solar panels in planetary and lunar exploration, and this method also has potential for mitigation of dust build-up on terrestrial solar panels in dry environments. Since energy expenditure rate required for electric curtain operation can be significantly higher than the energy capture rate from a solar panel, a control scheme for activation and deactivation of the electric curtain is necessary to achieve optimal net energy capture. The control method examined in the current paper is one in which the electric curtain is activated when the panel output voltage decreases to a fraction of the clean panel output voltage and deactived when the output voltage exceeds a second output voltage fraction . A combination of theoretical and computational approaches is used to determine how the energy efficiency changes with change in the threshold voltage ratios. A scaling analysis is developed that identifies a single key dimensionless parameter that influences the efficiency results. Optimal values of turn-on and turn-off voltage ratio are determined in terms of this parameter, and it is demonstrated that the efficiency decreases rapidly as the turn-off voltage ratio is raised above the optimal value. All of the efficiency predictions for a given mitigation velocity profile are collapsed onto a single curve with appropriate choice of the scaling parameters, which is then used to develop an optimal control criterion. [Copyright &y& Elsevier]

• We examine the emissions impact of battery storage across sensitivities and regions. • Existing studies focus on dispatch; we show how investment effects drive emissions. • Emissions impacts of storage vary based on policy and market assumptions. • Storage emissions reductions are more likely when wind and solar are lower cost. Battery storage technologies have attracted attention from policymakers for their potential to reduce electric sector emissions by enabling greater wind and solar penetration. Yet existing studies indicate that adding energy storage actually increases emissions. The difference may be explained by the absence in the previous literature of "investment effects" – changes in deployment of other generation technologies after storage is deployed. Our paper tests this hypothesis by evaluating battery-storage-induced emissions changes using a model that accounts for both long-run investment and dispatch effects simultaneously across regions in the United States, which can be used to separate the relative magnitudes of these two effects. Model results indicate that the investment effect dominates the dispatch effect under a range of sensitivities. We find that emissions may increase or decrease with battery storage, depending on policy and market assumptions, with reductions more likely in environments where wind and solar are more economically competitive relative to natural-gas-fired generation. These results suggest that existing studies that only account for operational impacts likely underestimate potential emissions changes from battery storage deployment. [ABSTRACT FROM AUTHOR]