Standard, Point of Use, and Extended Energy Return on Energy Invested (EROI) from Comprehensive Material Requirements of Present Global Wind, Solar, and Hydro Power Technologies

Abstract

Whether renewable energy sources (RES) will provide sufficient energy surplus to entirely power complex modern societies is under discussion. We contribute to this debate by estimating the current global average energy return on energy invested (EROI) for the five RES technologies with the highest potential of electricity generation from the comprehensive and internally consistent estimations of their material requirements at three distinct energy system boundaries: standard farm-gate (EROIst), final at consumer point-of-use (EROIfinal), and extended (including indirect investments, EROIext). EROIst levels found fall within the respective literature ranges. Expanding the boundaries closer to the system level, we find that only large hydroelectricity would currently have a high EROIext ~ 6.5:1, while the rest of variable RES would be below 3:1: onshore wind (2.9:1), offshore wind (2.3:1), solar Photovoltaic (PV) (1.8:1), and solar Concentrated Solar Power (CSP) (<1:1). These results indicate that, very likely, the global average EROIext levels of variable RES are currently below those of fossil fuel-fired electricity. It remains unknown if technological improvements will be able to compensate for factors, which will become increasingly important as the variable RES scale-up. Hence, without dynamically accounting for the evolution of the EROI of the system, the viability of sustainable energy systems cannot be ensured, especially for modern societies pursuing continuous economic growth.

1.5 °C degrowth scenarios suggest the need for new mitigation pathways

“…performance of the energy-economic system is the energy return on energy invested (EROI) 34 . The energy system's EROI is likely to shrink substantially during the transition to a renewable energy system 34 and to remain lower than the EROI of current fossil energy systems afterwards 35 . This is likely to have a limiting effect on GDP growth 23,34 .…”

“…This is likely to have a limiting effect on GDP growth 23,34 . However, there is a wide range of reported EROI values for individual renewable energy technologies, varying with geographic location and applied methodologies 35 . Moreover, in contrast to fossil fuels, the EROI of renewables is projected to increase over time 36 , but there also are counteracting effects, among others by diminishing returns to EROI at higher grid penetration 27,34,35 .…”

New Approaches for Ecological and Social Sustainability in a Post-Pandemic World

“…Some researchers have argued that a shift to non-carbon energy sources (renewable energy and/or nuclear) can largely solve the climate change problem e.g., [51,52]. Other researchers (including the present authors) are skeptical of this claim [53][54][55][56][57]. The critics have claimed that non-carbon energy sources are not really green [54,57,58], and that they could well merely replace one problem (CO 2 emissions) by another (rising energy and environmental costs of scarce materials needed for solar or wind capture devices) [59][60][61].…”

The Role of Hydrogen in Achieving Long Term Japanese Energy System Goals

“…As a result, our analysis and synthesis of these outcomes is optimistic toward the realization of such an energy system. It is important however to consider the overall feasibility of a renewables dominated energy system in Japan and other nations (in terms of critical materials required [61] and energy return on energy invested for certain renewable energy types [62]), and the compatibility of such an energy system with sustainable economic growth (cognizant of social, energy and environmental impacts [63] and the need to balance achieving environmental goals and economic growth [64]). This uncertainty is reflected in the present study in terms of economic feasibility aspects and energy system stability issues, however further consideration of these impacts on the timing and quantity of hydrogen introduced into the energy system as a result is required, along with empirical evidence of the feasibility of such a transition, yet to be demonstrated [65].…”