Increasing investment in renewable resources is raising important questions about how to equitably share the costs and benefits of such investments. It is essential for utilities and communities to evaluate how their renewables investments impact customers, including energy cost changes and grid adequacy support. For shared solar investments, this work develops an equity index that incorporates energy cost increases and resulting grid support during scarcity scenarios. A solar investment is modeled for two Midwestern manufacturing towns at different income levels. Using the developed metric, it is determined that energy cost increases from a solar investment may inequitably impact lower-income households, but that the investment results in improved grid support. © 2024 IEEE.