Energy Blog: Solar Momentum Can’t Be Stopped, Experts Report

Energy Blog: Solar Momentum Can’t Be Stopped, Experts Report

Twenty years ago, forecasts predicted solar power would be a marginal energy source for generations. A new report suggests solar domination of the energy market is now inevitable.
If you are of a certain age, you probably can recall the first time you saw a photovoltaic cell. It was part of a strip across the top of a pocket calculator, capable of providing just enough power to run the integrated circuit and liquid crystal display. That solar cell was something of a novelty, and not a terribly robust one, as it needed sunlight or strong lamplight to keep the numbers from fading.
 
Even decades later, experts treated photovoltaic (PV) cells as more of a toy than a serious power source. Around 2000, when the climate impact of carbon dioxide emissions started to be taken seriously, zero-emissions generating technology aside from nuclear power was considered something too far-off (and far-out) for planning purposes. 
 
A new study projects solar will grow to dominate the global electricity market over the next 15 year, but coal and gas will hold on to substantial slice of the market. Image: Nijsse et al/Nature Communications
For instance, the Annual Energy Outlook 2000 with Projections to 2020, published by the Energy Information Administration in December 1999, forecast coal power would actually increase its share of the electric power market between 1998 and 2020, while renewables, a catch-all category that included "conventional hydroelectric, geothermal, wood and wood waste, municipal solid waste, other biomass, petroleum coke, wind, photovoltaic and solar thermal sources,” would grow at less than a 1 percent rate per year. 
 
In fact, as wind and solar power started to grow—and more importantly, began to compete as the least expensive energy to be added to the grid—energy forecasters expected the growth to level off almost immediately while traditional sources kept their market share. But wind and solar growth continued to beat these forecasts and coal continued to lose it. (Coal’s decline itself is remarkable. Instead of climbing from 19 quadrillion btu (quads) to 24 quads, coal consumption in the U.S. has dropped to 8 quads.)

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On a global scale, solar power in particular has grown spectacularly. And a study published on October 17 in the journal Nature Communications suggests the factors leading to the rapid adoption of the energy source will continue unabated. The study, conducted by a team of economists and energy researchers based primarily in the United Kingdom, deployed data-driven technology and economic forecasting models to look at a number of different energy sources, to see if one of them was on the cusp of breaking out as dominant worldwide.
 
Anyone who has watched the international power sector over the past decade can make a fairly accurate guess of what the team, led by Femke J.M.M. Nijsse of the University of Exeter, found. 
 
“Between 2010 and 2020, the cost of solar PV fell by 15 percent each year,” they wrote. "At the same time, the installed capacity has risen by 25 percent per year, causing and partly caused by these cost reductions.” 
 
Wind was also growing fast, adding 12 percent of capacity per year and reducing costs in line with increasing deployment.
 
“If these rates of rapid coevolution are maintained, solar PV and wind power appear ready to irreversibly become the dominant electricity technologies within one to two decades,” the researchers reported, “as their costs and rate of growth far undercut all alternatives.”
 
What’s more, the researchers found, the rise of low-cost wind and solar would lead to a so-called tipping point, where the market position of fossil fuel power would be disrupted. “The policy and finance spheres should prepare for a rapid disruptive transition,” they concluded.
 
As of 2020, different technologies provided the lowest-cost electricity depending on local factors. In the next few years, however, solar will become the cheapest option everywhere, according to models published in Nature Communications. Image: Nijsse et al./Nature Communications
To be sure, that is a fairly large leap from the present capacity level of renewables, especially solar. Globally, solar power accounted for less than 5 percent of electric power generation in 2020, and wind power around another 8 percent. Instead of linear growth, which was the assumption used by a generation of energy forecasters, the model Nijsse and her coauthors developed forecasts 10 years of nearly exponential growth for solar followed by gradual slowing, with solar PV reaching 56 percent of worldwide energy production by 2050. 
 
Why is their model so different? 
 
“The historical failure of the modelling community to anticipate the rapid progress of solar power could stem from an overreliance on outdated data, the lack of use of learning curves, and the imposition of maximum deployment levels and floor costs,” the team wrote. "As the primary innovation in this paper, forecasting technology evolution and induced innovation can more effectively be achieved based on evolutionary simulations, using the most recent data available, that focus on the two-way positive feedback between induced innovation and diffusion.”
 
From a climate action perspective, however, Nijsse et al. is not altogether good news. While solar may wind up dominating the energy industry, if their models are accurate, fossil fuels retain a stubborn hold, keeping a 21 percent market share in 2050 and beyond. The team identified such factors as “grid stability issues, the availability of financial capital and critical minerals, and the willingness of decisionmakers to get onboard a rapid transition.”
 
It seems unstoppable momentum will take you only so far.
 
Jeffrey Winters is editor in chief of Mechanical Engineering magazine.
 
 

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