This study estimates the fiscal, energy, and environmental tradeoffs involved in supplying California’s future energy needs. An integrated framework is developed whereby an econometric forecasting system of California energy demand is coupled with engineering-economic models of energy supply, and economic impacts are estimated using input-output models of the California economy. A baseline scenario in which California relies on imported electricity to meet future demand is then compared against various energy supply development scenarios over the forecast horizon (2012–2035). The results indicate that if California implements its renewable portfolio standard (RPS), there will be a substantial net cost in terms of value added, employment, and state tax revenues because the economic benefits of building capacity are outweighed by higher energy prices. Although carbon emissions fall, the cost per ton of avoided emissions is well above market prices. Building out natural gas fired generation capacity also leads to losses compared to the baseline, although the impacts are relatively minor. Meanwhile, a strategy of replacing imported crude oil and natural gas with domestic production using indigenous resources increases gross state product, employment, and tax revenues, with minimal impact on carbon emissions. This option could, therefore, help mitigate the costs of California meeting its RPS commitment.