Is the life-cycle energy required for renewable energy technologies comparable with their energy generation and will the construction of renewables always emit CO2?

Although most of the energy inputs to manufacturing wind turbines and solar panels are derived from fossil fuels in most of the world, this is changing rapidly. Picture: Shutterstock

Both are myths.

In its most extreme form, the energy myth claims that renewable energy requires more energy invested than it generates over its lifetime. A less extreme version is that renewable electricity has low net energy or low Energy Return on Energy Invested (EROEI) and so will compete excessively with the energy needs of other sectors of the economy.