It is often believed that the overarching goal of our energy future is the 100 per cent transition to renewable energy generation. But what is the possibility of a fully renewable energy powered world?
Renewable energy has come a long way, from being a part-time energy source to one that is quite dependable. The renewable share of the global energy mix grew by about 10 per cent over the last decade alone and now constitutes 26 per cent of the global generation. While this capacity largely consists of hydropower sources, there has been tremendous growth in solar photovoltaic and wind energy adoption in recent years, with more development expected as their prices fall.
In light of these, it is not far-fetched to believe that renewable energy sources would one day be 100 per cent responsible for the entirety of our power generation. In some places, this is already happening. In Scandinavian countries, renewable energy provides a substantial amount of the total electricity generated. In Norway, it makes up about 98 per cent of the total energy mix (albeit from hydro sources); for Iceland, this value is closer to 100 per cent as the combination of geothermal heat and hydropower constitutes the country’s energy mix.
In Portugal, during some spring and summer months, renewable energy can account for 100 per cent of the country’s energy needs. In March 2018, the average renewable energy generated was 103 per cent of consumption. However, due to the variable nature of wind and solar generation, the grid still needed conventional power plants for stability.
Our Hope for the Future
With the advent of cheaper batteries with higher energy density and efficiency, we would increasingly see more wind and solar power capacity added globally. We have already seen batteries begin to replace peaker fossil fuel plants (plants needed during peak periods to provide more power) in Australia and the United States. Cheaper battery storage systems are increasingly becoming more economical than gas peaker plants that only operate for a few hours in a year.
Hydropower is essential in the renewable energy transition; as such, the proliferation of small hydropower plants would be essential in eliminating diesel generators in areas with good hydro potential.
An increased amount of electricity trade between countries would go a long way towards ensuring grid stability. In the Nordic countries, high interconnectivity and energy trade ensures that during periods of overgeneration or peak demand, renewable energy can be exported or imported to stabilise the grid.
As countries increase their renewable energy capacity, provisions should be made to enable trade and supply to low capacity countries, ensuring a global spread in adoption. Imagine if solar power from the Iberian Peninsula can compensate during periods of lower wind generation in Scotland, or if solar energy from Ethiopia can compensate for the low wind supply from the Kenyan shores.
So how soon would we see a 100 per cent renewable future? Renewables are predicted to make up half of the world’s mix by 2050. Still, suppose more countries adopt ambitious policies like Germany’s Energiewende that aims to increase the share of renewable energy in the country’s energy mix to 65% by 2030. In that case, I’d reckon we are not far off.