Solar-city plans with large-scale energy storage: Metrics to assess the ability to replace fossil-fuel based power

It's important to have objective metrics for assessing the value of solar-city plans in terms of their ability to avoid fossil-fuel based generation. The need is further augmented by the prospect of integration of large-scale energy storage options with the solar-city plans. This paper addresses this need by defining a novel metric, energy-credit, along with the established metric, peak capacity-credit, and its slightly modified variant, the 90th percentile of peak capacity-credit (90PCC). The methodology has been illustrated by application to a solar-city plan for Mumbai city in India, along with two custom energy storage scenarios, ES20 and ES40. The ES20 scenario corresponds to shifting 20% of the solar-city generation during the slot 12:00 hrs - 15:00 hrs to the slot 18:00 hrs - 21:00 hrs; for the ES40 scenario, the corresponding value is 40%. The results show an energy-credit of 29.7% and 21.2% for P50 and P5 levels of solar-city generation, respectively. The metric 90PCC is found to vary from 12.78% for base case to 15.05% for ES20 to 15.45% for ES40, for P5 level of solar-city generation. The corresponding values of 90PCC for P50 level of solar-city generation are 13.72%, 18.82% and 22.60%, respectively.

Automated summary

This paper introduces the novel metric of energy-credit along with peak capacity-credit and its modified variant as objective metrics for assessing the value of solar-city plans. The methodology is illustrated through a case study in Mumbai, India, with custom energy storage scenarios, showcasing the impact of different scenarios on solar-city generation levels.