The net energy implications of the energy transition have so far been analysed at best at the final energy stage. Here we argue that expanding the analysis to the useful stage is crucial. We estimate fossil fuelsʼ useful-stage energy returns on investment (EROIs) over the period 1971–2020, globally and nationally, and disaggregate EROIs by end use. We find that fossil fuelsʼ useful-stage EROIs (~3.5:1) are considerably lower than at the final stage (~8.5:1), due to low final-to-useful efficiencies. Further, we estimate the final-stage EROI for which electricity-yielding renewable energy would deliver the same net useful energy as fossil fuels (EROI equivalent) to be approximately 4.6:1. The EROIs of electricity-yielding renewable energy systems, based on published estimations, are found to be higher than the determined EROI equivalent, even considering the effects of intermittency under a range of energy transition scenarios. Results suggest that the energy transition may happen without a decline in net useful energy, countering the view that renewable energy systems cannot replace fossil fuels without incurring a substantial energy penalty.

迄今为止，能源转型的净能源影响最多只能在最终能源阶段进行分析。在这里，我们认为将分析扩展到有用的阶段至关重要。我们估算了 1971 年至 2020 年期间全球和全国范围内化石燃料的有用阶段能源投资回报 (EROI)，并按最终用途对 EROI 进行了分类。我们发现，由于最终使用效率较低，化石燃料的有用阶段 EROI（约 3.5:1）远低于最终阶段（约 8.5:1）。此外，我们估计发电可再生能源将提供与化石燃料相同的净有用能源（EROI 相当）的最终阶段 EROI 约为 4.6:1。根据已发布的估计，即使考虑到一系列能源转型情景下的间歇性影响，发电可再生能源系统的 EROI 仍高于确定的 EROI 等值。结果表明，能源转型可能会在净有用能源不下降的情况下发生，这反驳了可再生能源系统无法在不造成重大能源损失的情况下取代化石燃料的观点。