Transition to 100 percent renewable energy is cost efficient
Global warming, air pollution and social instability are all challenges that the new roadmaps to a renewable energy system address. A new report from Stanford university1 presents different scenarios in which 143 countries transition to 100 percent renewable energy by 2050.
Such a transition would reduce energy demand by 57 percent and decrease social costs by 91 percent compared to a business-as-usual scenario (BAU). The 143 nations included represent more than 99.7 percent of the world’s fossil fuel emissions. This transition would make it possible to stay below 1.5 degree of global warming and reduce the air pollution that causes approximately 7 million premature deaths every year.
The calculations conclude that such a development would cost $6.8 trillion/year compared to $17.7 trillion/year for business-as-usual energy systems. These figures account for electricity, heating, cooling, hydrogen generation and storage, and transmission and distribution using annual private market costs. Thus, the transition costs 61 percent less than the BAU energy scenario.
However, the aggregate social cost (private together with health and climate expenses) of BAU energy is $76.1 trillion/year. The net present value of the capital costs of transitioning to renewable energy worldwide is $72.8 trillion for the entire transition period, from now until 2050.
These expenses will be covered by electricity sales and increased job opportunities. The presented Wind-Water-Solar scenario (WWS) creates 28.6 million more full-time jobs than the BAU scenario.
Besides the argument of expense, others argue that the material resources it will take to produce the WWS energy equipment could be a liability in their own right. However, the calculations show that the equipment will only consume 1 percent of the world’s annually produced steel and 0.4 percent of the concrete. The net carbon dioxide emissions from producing the materials needed would be approximately 0.014 percent of the annual current carbon dioxide emissions.
The technology that is needed for a 100 percent renewable energy transition already exist. According to the authors, the transition would be economically and technically feasible by 20302. However due to political, institutional and cultural obstacles 2050 is a more realistic target.
The calculations for how to reach 100 percent renewables by 2050 are made based on the US democratic party’s proposal, The Green New Deal. This plan calls for a launch of a “10-year mobilization” to reduce carbon emissions, by sourcing 100 percent of the country’s electricity from renewable and zero-emissions power, upgrading to more energy-efficient buildings, investing in electric vehicles and high-speed rails etc.
The first step in the study was to project 2016 end-use BAU energy in multiple energy sectors in 143 countries to 2050. The end-use energy of BAU 2050 was then electrified using renewable energy sources. When the 143 countries move from BAU to WWS energy, the 2050 annual average demand for end-use power decreases by 57.1 percent. This reduction is due to: efficiency gains from using WWS electricity over combustion (38.3 percent), eliminating energy in the mining, transporting and refining of fossil fuels (12.1 percent), and improvements in end-use energy efficiency and reduced energy use beyond those in the BAU case (6.6 percent).
Compared to previous studies on strategies and scenarios this study adds important factors and new perspectives. The main differences are the following:
First, socioeconomic costs include external costs not accounted for in market costs or prices. In this case the social costs can be air pollution mortality, morbidity and global warming damage. When it comes to political applicability a social cost analysis is of greater value than a private cost analysis alone as it presents a comprehensive view of the impacts of policies.
Second, other studies use the cost per unit energy rather than the aggregate energy cost per year. This has an important effect as a renewable energy system uses much less end-use energy than a business-as-usual system.
Two main issues that are often brought up in technical discussions on the transition to 100 percent renewable energy are storage and transmission. Regarding energy storage the report finds that the problems have already been solved. As a result of the decrease in energy demand by switching to renewable energy sources (see Figure 1) and developing the technologies already in play, storage will not be a limiting factor.
When it comes to grid congestion and new transmission, the study concludes that both the risk of congestion and the need for additional transmission are lower than previously thought. Even when the most conservative WWS scenario model is used together with the highest costs, the BAU scenario still has the highest expense. However, continent-scale grids will not be a solution for isolated nations such as Japan and South Korea. The study found that even when sticking to grid isolation, the costs of a renewable grid are lower than BAU.
Comprehensive road maps of this type naturally involve some uncertainties and sensitivities. Assuming perfect energy transmission, inconsistencies between load and resource datasets and projecting future energy use are some examples of the uncertainties. By modelling several scenarios with different levels of costs and climate damage several of the uncertainties are addressed. When it comes to accounting for extreme weather events the model includes these by measuring the variability of weather worldwide at a 30-second time resolution.
One of the authors explains3 that the aim of the study is to illustrate that there is no downside to making this transition, and to allay some of the fears that the transition would be too expensive. The evidence shows that the technology, resources and knowledge needed for the 100 percent renewable transition already exist.
Additionally, the study shows that the transition is by far the cheapest option. The risk is rather that these types of transitions will not be implemented quickly enough. They should inspire policymakers, according to the one of the authors, Marc Jacobson: “I hope people will take these plans to their policymakers in their country to help solve these problems.”
The article is based on the report:
“Impacts of Green New Deal Energy Plans on Grid Stability, Costs, Jobs, Health, and Climate in 143 Countries” is available at:
1. Jacobson, M.Z., and Delucchi, M.A. (2009). A path to sustainable energy by 2030. Scientific American, November 2009 https://www. scientificamerican.com/article/a-path-to-s ustainable-energy-by-2030/
Figure 1. Timeline for 143 countries, representing more than 99.7 percent of world fossil-fuel CO₂ emissions, to transition from conventional fuels (BAU) to 100 percent wind-water-solar (WWS) in all energy sectors. Also shown are the annually averaged end-use power demand reductions that occur along the way.