Photovoltaic additions surpassing the net growth in coal: the birth of a new era of solar?

When I read the Bloomberg news article about solar capacity growing 50%, I was pretty disturbed. I was even more disturbed when I read its source: the IEA news article Solar PV grew faster than any other fuel in 2016, opening a new era for solar power.

I could understand that the Bloomberg journalist might have no clue what he was copying and pasting, but I expected much more from an organization like IEA.

The first sentence of the IEA news article sounds familiar for those who read previous two posts:

New solar PV capacity grew by 50% last year, with China accounting for almost half of the global expansion, according to the International Energy Agency’s latest renewables market analysis and forecast.

This was the subject of the last two posts, in which it is shown that the growth of installed capacity of photovoltaic is a meaningless metric for the growth of solar energy consumption. That 50% growth (which is in fact a 33% growth) translates to a 0.13 percentage point growth in solar energy consumption when compared to the total energy consumption worldwide.

This focus on the growth of installed capacity allowed the IEA to overstate the impact of solar energy. They even went a step further in the next paragraph(s) (my emphasis):

For the first time, solar PV additions rose faster than any other fuel, surpassing the net growth in coal.

Wait a moment. Do they really try to compare the capacity growth of solar energy with the capacity growth of coal?

Looking at a Global coal plant tracker, I find that a capacity of 61,895 MW was added in 2016. According to the BP data there was an additional 75,093 MW of solar energy in 2016. So sure enough, they compare the growth of the installed capacity of photovoltaics with that of coal. Do they really think this is somehow a meaningful comparison?

Although this is mathematical true (75,093 is no doubt larger than 61,895), it is still a comparison between two not comparable power sources. Solar energy is an intermittent energy sources with a capacity factor of on average 12% worldwide, while coal is a dispatchable energy source with a capacity factor somewhere between 40 en 70%. Both power sources will have a different impact on the production of electricity when we would compare the same installed capacity.

It didn’t stop there (my emphasis):

Boosted by a strong solar PV market, renewables accounted for almost two-thirds of net new power capacity around the world last year, with almost 165 gigawatts (GW) coming online, according to the new report, Renewables 2017. Renewables will continue to have a strong growth in coming years. By 2022, renewable electricity capacity should increase by 43%.

One has to pay attention here. Initially it is said that the PV market is strong, but the number they provide is not for solar, it is for all renewables. It is however not clear what their definition is of “renewables” is (solar, wind, probably also biomass and/or hydro?).

The capacity of 165 GW is impressive, but this is installed capacity and not necessarily representative for the electricity that will be generated by this installed capacity.

Also here, a 43% increase by 2022 seems impressive, but the question is how much was the capacity in the first place and what is the share in our energy consumption?

The article continues (my emphasis):

“We see renewables growing by about 1,000 GW by 2022, which equals about half of the current global capacity in coal power, which took 80 years to build,” said Dr Fatih Birol, the executive director of the IEA. “What we are witnessing is the birth of a new era in solar PV. We expect that solar PV capacity growth will be higher than any other renewable technology through 2022.”

Again that comparison with coal capacity. Looking at the Global coal plant tracker, the worldwide capacity of coal July 2017 (most recent data) is 1,965,368 MW or 1,965 GW. That is indeed almost twice the 1,000 GW growth. But again, this is a comparison of (mainly) intermittent energy sources with a dispatchable energy source and both have a different capacity factor. Coal is capable of generating 3-6 times the electricity of solar for the same installed capacity.

It might be true that solar is expected to have the highest growth of other renewable technologies but, also here, the impact could be rather different. Wind, biomass and hydro all have higher capacity factors than solar, so it might be a different story when we look at the actual electricity generation of that additional capacity.

The meaningless comparison continues:

This year’s renewable forecast is 12% higher than last year, thanks mostly to solar PV upward revisions in China and India. Three countries – China, India and the United States – will account for two-thirds of global renewable expansion by 2022. Total solar PV capacity by then would exceed the combined total power capacities of India and Japan today.

Not sure whether it makes much sense to compare the installed capacity of an intermittent energy source with that of two countries powered by mostly oil, coal and gas (all with higher capacity factors than solar).

Then at last, a comparison of the generation of electricity:

In power generation, renewable electricity is expected to grow by more than a third by 2022 to over 8,000 terawatt hours, which is equivalent to the total power consumption of China, India and Germany combined. By then, renewables will account for 30% of power generation, up from 24% in 2016. The growth in renewable generation will be twice as large as that of gas and coal combined. Though coal remains the largest source of electricity generation in 2022, renewables close the generation gap with coal by half in just five years.

Some caution here:

  • this is not only about solar, but all renewables together
  • it is also not the current situation, it is what will be expected in 2022
  • 8,000 TWh is not the growth that is expected by 2022, but the amount of electricity that is expected to be generated in 2022 (if I look at the graph that Bloomberg article showed, it was about 6,000 TWh in 2016)
  • this additional 2,000 TWh doesn’t close the gap with electricity generation of coal by then (only half of it) and coal still remains the largest source of electricity generation in 2022 (and probably for some time after that)
  • it is about the share of photovoltaics in electricity consumption, which is only one fifth of total energy consumption (so this growth will be less impressive when it is compared to the total energy consumption worldwide, see previous post).

The article goes on like this for the next seven paragraphs.

In the article, there are numerous mentions of the growth of intermittent energy sources (with no context or background whatsoever) and comparison with incomparable sources (also without any context or background). This could not be a coincidence anymore. At that point I start to wonder whether the author(s) of this article know the difference between installed capacity and actual electricity generation and also whether they realize that the actual impact of photovoltaics is much lower than what the installed capacity suggests? Especially since photovoltaic electricity generation is only 12% of installed capacity and electricity consumption is only 20% of total energy consumption.

So how does these incredible growth figures of photovoltaic capacity translates to actual consumption compared to coal? According to the BP Statistical Review of World Energy 2017 report, energy consumption of coal is 3,732.0 Mtoe in 2016. Compare this with the 75.4 Mtoe for solar consumption according to the BP Statistical Review of World Energy 2017 Renewable Energy report. This is 2% in 2016, coming from a 1.5% in 2015.


The trend from 2006 until 2016 looks like this:

Yeah right, just look at that incredible growth at the bottom right of the graph. We are definitely experiencing the birth of a new era of solar. 😉

1 thought on “Photovoltaic additions surpassing the net growth in coal: the birth of a new era of solar?

  1. poitsplace

    Oh, something else to consider, solar plants will need to be replaced about 2-3X as often as coal plants. So coal, a mature technology, has lots of coal plants already meeting demand as well as lots being retired. But in another 20 years, the solar farms of today will go into retirement phase and they’ll need to maintain these building levels just to hold it at the same rate. The same problem is found with wind…and frequently often being retired well before their advertised end of life, having consumed 5-10X the materials/labor for their installation, and then having to do it all over again, sometimes twice again before a coal or nuclear plant built at the same time finally dies.



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