Is a country installing renewables fast enough to meet climate goals?
Researchers and policy analysts have checked and rechecked future climate scenarios. We know how much carbon dioxide we can emit while keeping the world from warming by more than 2 ° C, and we can use that number to determine how quickly we need to move away from fossil fuels. We have several routes to get there, most of which involve replacing fossil fuels with the cheapest renewable energy sources: wind and solar. From there, it’s just a matter of figuring out how quickly wind and solar energy use needs to increase to get us there.
Wind and solar have become the cheapest new sources of electricity in most countries, and we now have massive economies of scale for their generation and installation. We also have decades of experience in managing them effectively. There is little reason to believe that these renewables are not ready for explosive growth.
And yet, a new study in the history of renewable energy shows that only a handful of countries have experienced this kind of growth. And even when these countries achieved their goals, they only did so for a short time.
A new article in Nature Energy says most technologies have a predictable pattern of adoption. They start with a minimal growth period, when the technology is expensive, poorly understood, and cannot be manufactured on a large scale. Once a critical point is reached, adoption accelerates to a period of rapid acceleration, with higher growth rates each year. Over time, however, this increase slows down and the curve flattens out for an extended period of steady growth.
This is generally referred to as an S curve because if you plot the growth over time you end up with something that looks like a flattened S. There is a curve to the period of the fastest increase, followed by a curve back to the observed constant increase. in mature technology.
What does this have to do with climate goals? To achieve these goals, countries need to bring renewable energy sources into peak growth period as quickly as possible. But achieving maximum growth is not enough on its own: countries should stay in the peak growth phase for as long as possible to reach a higher plateau when they enter a period of stable growth. If we can’t manage this, we’ll have to look for other ways to meet our emissions targets.
At present, enough countries have experienced growth and stabilization that researchers think they can determine whether sufficient increases are occurring and, if so, what conditions allow them. They looked at data from 60 countries that collectively account for more than 95 percent of global electricity production.
For starters, the researchers identified when countries entered the wind or solar growth phase, and they found that achieving a growth rate of 1% was a good marker. Many of these countries could be followed into a period of peak growth, and a number then saw growth slow down again, producing the full S-curve.
As expected, the exact results varied by country and technology. The price of wind first came down, so most countries saw this technology take off about a decade earlier than solar. But solar has become cheaper faster, easier to manufacture on a large scale, and requires less infrastructure to install. Its growth therefore accelerated more quickly.
Local conditions also mattered. Several countries, mainly in Northern Europe, have seen wind take off but have not experienced similar growth in solar. Others have only seen solar experience a period of rapid growth.
According to the most recent data (2018), there were 11 countries where growth was accelerating, and another 21 experienced three consecutive years of reduced growth, indicating that they had completed the S-curve. started the acceleration phase later do not appear to achieve faster growth rates, suggesting that maturing technology and the experience gained by early adopters do not make it easier for countries adopting later technology. wind and solar.
The researchers’ analysis estimated that the median growth rate after the acceleration period was around 0.8 percent of the country’s electricity supply for wind and 0.6 percent for solar. The highest growth rate was 1.8 percent of electricity supply per year, and the largest countries rarely saw rates exceeding 1 percent.
In a few cases, growth plateaued and restarted, but there were only three examples of this.
Is it fast enough?
The answer is a fairly clear “no”. If we work backwards from climate stabilization scenarios, we would need the wind to roughly double its current rate, from 0.6% to 1.2%. In the experience of several large countries, this would amount to reaching and staying at their maximum growth rate. Solar is expected to see its current global tariff triple, with capacity additions equivalent to 1% of electricity supply each year. And both of these examples are based on the numbers to limit climate change to 2 ° C, when countries agreed that 1.5 ° C is a preferable target.
As the authors of the article say, current scenarios that meet our climate goals require decades of renewables growing at rates above those seen during peak growth periods in most countries.
That’s not to say that it’s impossible to increase growth rates to get things on the right track. Many countries have experienced renewable energy growth despite uncertain or effectively absent policies. But if countries are not improving their political situation, they must either start looking for alternatives (like efficiency and carbon capture) or recognize that they do not really intend to change. ” meet their commitments.
Nature Energy, 2021. DOI: 10.1038 / s41560-021-00863-0 (About DOIs).