They are also unreliable (we still have no idea what to do when the wind is not blowing). Even with optimistic assumptions, the International Energy Agency estimates that, by 2035, we will produce just 2.4% of our energy from wind and 0.8% from solar.
今天，太阳能和风能仅能满足我们一小部分能源需求——风能仅占总需求的0.7%，而太阳能仅占0.1%。这两项技术目前都成本过高。而且相关技术也并不可靠（不刮风的时候怎么办我们还不知道）。即便应用乐观的假设，国际能源机构预计到2035年风能将占能源总量的2.4%，而太阳能仅占0.8%。