Switchgrass vs. Photovoltaics

Świtchgrass vs. Photovoltaics There isn't enough water or land to sustain a prosperous world powered entirely by biofuels, but a similar world powered by solar energy is at least theoretically possible. Realistically, the future will have elements of both - ELECTRICITY SUPPLY I- LIQUID FUELS NATURAL GAS BIOFUELED WORLD INORGANIC WORLD Assumes that the world Assumes the world consumes consumes energy at current U.S. levels per capita. energy at current U.S. levels per capita. 4100% 9 100% REPLACED BY BIOFUEL MADE FROM SWITCHGRASS 100% 9 100% 0/% PHOTOVOLTAICS REPLACED BY PV-GENERATED ELECTRICITY SWITCHGRASS SWITCHGRASS PHOTOVOLTAICS 193% 173% 0.0 Billion 6% 12% 0.0 Billion LAND REQUIRED (ENTIRE EARTH) WATER REQUIRED (ANNUAL RAINFALL) CARBON EMISSIONS (METRIC TONS OF CARBON PER YEAR) LAND REQUIRED (ENTIRE ÈARTH) WATER REQUIRED (ANNUAL RAINFALL) CARBON EMISSIONS (METRIC TONS OF CARBON PER YEAR) BALANCED PORTFOLIO TRANSITIONAL Assumes the world (except the United States and Africa) consumes energy at Europe's current level per capita. The United States reduces its energy use to 75 percent of its cur- rent level, and Africa increases its to a quarter of the U.S. level. Assumes the world consumes energy at Europe's current level per capita, which is 44 percent of the U.S. level. ןוי11 ןויוו 4 10% 10% 10% 10% 20% | 20% 20% 4 10% 10% 10% 10% | 20%| 20% 20% CLEAN COAL COAL PHOTOVOLTAICS HYDROPOWER WIND NATURAL GAS NUCLEAR CLEAN COAL COAL PHOTOVOLTAICS HYDROPOWER WIND NATURAL GAS NUCLEAR 25%| 25% 25% 25%O STAYS AT CURRENT LEVEL (OTHER THAN THAT USED FOR ELECTRICITY GENERATION) 5% 35% 20% 40% STAYS AT CURRENT LEVEL (OTHER THAN THAT USED FOR ELECTRICITY GENERATION) ALGAE SWITCHGRASS NATURAL GAS OIL ALGAE SWITCHGRASS NATURAL GAS OIL 14% 13% 7.5 Billion 25% 26% 134 Billion LAND REQUIRED (ENTIRE EARTH) WATER REQUIRED (ANNUAL RAINFALL) CARBON EMISSIONS (METRIC TONS OF CARBON PER YEAR) LAND REQUIRED (ENTIRE ÈARTH) WATER REQUIRED (ANNUAL RAINFALL) CARBON EMISSIONS (METRIC TONS OF CARBON PER YEAR) OUTPUTS INPUTS OUTPUTS INPUTS ILLUSTRATIONS: MCKIBILLO.COM OUTPUTS INPUTS OUTPUTS INPUTS