Global available solar energy under physical and energy return on investment constraints

MEDEAS: a new modeling framework integrating global biophysical and socioeconomic constraints

“…In principle, we do expect technology improvements in the future, however we also foresee that there will be other relevant factors which in the medium term will tend to offset them as the RES progressively scale-up at large levels and gain substantial shares in the energy mix: (1) decreasing returns in the potential of renewables, i.e., after best places are occupied it is necessary to move to more uneconomical sites, [148][149][150] phenomena which may be worsened by eventual land availability constraints in some cases; (2) the increase in energy requirements due to ore grade decrease of minerals with cumulated extraction; [151][152][153] (3) thermodynamical limits to the continuous reduction of energy investments (e.g. related with limits to § § For more details on the methodology and assumptions for the estimation of materials in MEDEAS, see Capellán-Pérez et al 46 ¶ ¶ Note that dynamically accounting for energy magnitudes corresponds with power rather than to energy.…”

“…[220][221][222][223][224][225] All together, these factors tend to significantly reduce the techno-sustainable potential of RES. [33][34][35]37,52,64,110,149,150,217,226,227 In this work, the technosustainable potentials of RES for the generation of electricity, heat and biofuels, considering the aforementioned factors estimated in Capellán-Pérez et al, 52 are applied. Hence, there is a debate in the literature if energy resources could power the increasing demand of Humanity during the 21st Century.…”

Nanofluids in Solar Thermal Collectors: Review and Limitations

“…Coccia et al [186] conducted a numerical evaluation of the yearly yield of a low enthalpy parabolic trough collector operating with six water-based nanofluids. The nanoparticles used are Fe 2 O 3 (5,10,20 wt%), SiO 2 (1,5,25 wt%), TiO 2 (1,10,20,35 wt.%), ZnO (1,5,10 wt%), Al 2 O 3 (0.1, 1, 2 wt.%), Au (0.01 wt%). The effect of these nanoparticles on the thermal efficiency of the collector was investigated.…”

“…The efficient utilization of various forms of renewable energy has been an objective of many energy studies. Solar energy is currently the most consumed form of renewable energy [1]. Solar energy can be harnessed for heating and cooling buildings [2], domestic water heating [3], water desalination [4], and many industrial applications.…”

The potential land requirements and related land use change emissions of solar energy

“…For specific regions, these penetration levels can even range up to 90% 37 . Due to the potential relevance and relatively low power density of solar energy in a decarbonized future, and given that PV in urban areas will only be able to cover a share of the total demand 1 , 21 , this paper aims to quantify the potential land occupation of solar energy installed up to 2050, and the related direct and indirect impacts on carbon cycles, within a context of global climate action as proposed in the Paris Agreement. We concentrate on three regions with heterogeneous features where futures with a high solar energy penetration have been identified in the literature as likely to induce land competition: the European Union (EU), India and jointly Japan and South-Korea.…”