[…]until we develop a practical, cost-competitive alternative to fossil fuels, it is unlikely that renewable energy will ever make up more than 15-20% of global energy requirements.
[…]until we develop a practical, cost-competitive alternative to fossil fuels, it is unlikely that renewable energy will ever make up more than 15-20% of global energy requirements.
renewable energy:273
according to the international energy agency, biofuels have the potential to meet more than a quarter of world demand for transportation fuels by 2050.