The report, published in the Environmental Science & Technology journal hoped to establish how efficient each of the power sources were by comparing how energy crops are converted into electricity, how corn and other crops are converted to ethanol, and how photovoltaics convert direct sunlight into fuel. The results indicated that the clear winner here were the photovoltaics.
Norway’s University of Science and Technology experts James Kallao and David Stoms, led by UC Santa Barbara’s Roland Geyer conducted the study by considering three factors: how photovoltaics and biofuels affect direct land use, the amount of greenhouse gases emitted and the specific greenhouse gas’ lifecycle.
Photovoltaics were the standout leaders in all three scenarios, emphasized by the author of the report stating that even with the most efficient biomass-based process, nearly 30 times more land is required for biofuel generation than for photovoltaic systems. According to the author, photovoltaics also require the lowest input of fossil fuels and have the lowest greenhouse gas emissions during their lifespan.
Evidently, the cause of this increased efficiency for photovoltaics is that photosynthesis in plants only converts sunlight into electricity at 1% efficiency, whereas the efficiency for photovoltaics is about 10%. Thus, experts believe that with reducing prices for solar technology, electric vehicles would become a more beneficial option.
This means that investment in subsidies for biofuels is essentially a step in the wrong direction, as in time, the accelerated growth of solar technology will further increase the gap between that and biofuel technology, which, though would see some growth, would still not be enough to compete. The stage is therefore set for solar to be the future of vehicular transport since corn ethanol continues to be further disadvantaged by negligible reduction in carbon emissions while putting food supplies and ecosystems at risk.