When will renewables overtake coal in generated electricity?
“Renewable power generation capacity now exceeds that of coal” (IEA) - True, but it will take a decade or so before this is the case for electricity generated.
IEA, the International Energy Agency, recently stated that renewables overtook coal in terms of cumulative installed capacity in the world, and it’s true.
After record additions in 2015 of 156 GW, led by onshore wind (+63 GW), solar PV (+49 GW), and hydropower (+31 GW), the world’s total renewable electricity capacity ended the year at a formidable 1,968 GW.
According to IEA, the total capacity of coal-fired power plants by end of 2015 was 1,951 GW. With the help of CoalSwarm and its Global Coal Plant Tracker database, we learned this was after an increase of 71 GW over the year. So renewable capacity overtook that of coal at a high speed, and is set to blast further ahead in coming years.
But does this mean that more electricity was produced from renewables than from coal? Not yet!
This is because the average capacity factor of coal-fired power plants is higher than that of renewables, and especially of the rapidly growing wind and solar power plants. Capacity is what a power plant can produce when it’s operating at its maximum rate. For coal-fired power plants, this is determined by demand and economics: at a given demand, the power plants with the lowest marginal costs get to run. Wind and solar always have very low marginal cost, but their actual capacity is determined by wind speed, or solar irradiation respectively. The capacity factor is the average fraction of total capacity that is achieved over the year: typically around 0.6 for coal, 0.4 for hydro, 0.3 for wind and 0.1-0.2 for solar.
The resulting share of renewables in 2015 global electricity production was 23%, according to IEA. For coal this was around 40%. IEA expects the share of renewables to grow at almost 1 percentage point per year, to 28% by 2021, and IEA has a track record of being on the conservative side here. Due to falling costs of wind and solar, and more ambitious policies following the Paris Agreement on climate action, I expect this trend to accelerate.
Given the dominance of coal in the remainder, its share will probably drop by roughly 0.5 percentage point for every percentage point that renewables gain.
In conclusion, I would expect the share of renewable energy in global energy production to overtake that of coal around 2025, with a share of 35% for both. And in view of the climate, we would actually need to get there even quicker.
One reaction on 'When will renewables overtake coal in generated electricity?'
19-12-2016 at 01:55
Coal adding 71 GW in 2015 is 71 GW too much.
The good news is that 157.6 GW of new coal in the pipeline were cancelled. The bad news is that there are still 350 under construction and even 932 proposed. All via the CoalSwarm Global Coal Plant Tracker page (I don't know if I am allowed to link to individual pages here).