Renewable Energy in Perspective: The Carbon Gap
In the aftermath of yesterday’s announcement by EPA of its Affordable Clean Energy plan, which is proposed as a replacement for the Obama-era Clean Power Plan, it’s worth taking a look at the global carbon picture in order to maintain the appropriate perspective for global climate. The emphasis here being that it’s global climate, not just U.S. climate, and the deployment of renewable energy in the U.S. isn’t where our carbon-reduction focus should be confined. This brief analysis points to the need for large-scale deployments of nuclear power in order to offset the continued expansion of fossil fuel-fired power generation as renewable energy alone is not standing up to the challenge of carbon emissions at the global scale of billions of people and trillions of dollars in economic activity. The greatest impact the U.S. can have on reducing global carbon emissions is working with other countries in the deployment of nuclear power.
Renewable energy, particularly solar and wind, is often promoted as experiencing exponential growth. However, it’s important to put this exponential growth in context, particularly with respect to how renewables are growing relative to fossil fuels. This a brief analysis of the global carbon gap between non-hydro renewable energy and fossil fuels. That is, the difference between fossil fuel fired electricity and non-hydro renewable electricity. As renewable energy is integrated into the global energy portfolio, the climate objective is to offset fossil fuel consumption, thus reducing the gap between zero-carbon renewables and carbon-emitting fossil fuels—particularly coal.
In equation form:
Carbon Gap = Fossil Fuel Electricity – Non-Hydro Renewables Electricity
- When fossil fuel electricity is greater than non-hydro renewable electricity, the carbon gap is positive
- When fossil fuel electricity is equal to non-hydro renewable electricity, the carbon gap is zero
- When fossil fuel electricity is less than non-hydro renewable electricity, the carbon gap is negative
This analysis focuses on the U.S., China and India, dominant energy and economic drivers, with the energy consumption of all other countries lumped together as “Rest of the World”. Figures 1-5 illustrate the global trends in non-hydro renewable energy and fossil fuels for generating electricity. While the growth in renewables is encouraging, what’s most important is whether this growth is narrowing the carbon gap—that is, as renewables are integrated into the global energy portfolio are fossil fuels decreasing such that the carbon gap is smaller. It’s noted here that even if the carbon gap is zero, that only means renewables and fossil fuels are equivalent. It doesn’t mean fossil fuels are zeroed out or that carbon emissions are eliminated.
Figure 1. Non-hydro renewable energy is growing exponentially, which is certainly encouraging but not necessarily surprising since it is common for new technologies to experience exponential growth in the initial stages of deployment. However, it should be understood that solar and wind have grown exponentially in part due to the availability of traditional resources such as coal, natural gas and nuclear, all of which provide the baseload shoulders on which renewables can stand.
Figure 3. When placed in context with fossil fuels, the challenge for renewables comes into focus. A particular concern is the global carbon gap and how that gap between fossil fuels and renewables is trending.
Figure 4. The global carbon gap between fossil fuels and non-hydro renewables steadily increased until 2013 and has generally plateaued since then. It remains to be seen whether this trend will remain flat, decrease or increase.
Figure 5. A breakdown of the global carbon gap given in Figure 4 illustrates where the trend is increasing and decreasing. The carbon gap has been in decline in the U.S. since 2007 but is steadily increasing in India. In China, the gap plateaued for a couple of years from 2013-2015 but has begun to upturn over the past couple of years. The carbon gap for the rest of the world is currently flat. These three countries constitute 40.4% of world population and 42.5% of global GDP.
- Exponential growth in non-hydro renewables is a highly relative description. While growth is in fact exponential, it is dwarfed by fossil fuel consumption;
- The global carbon gap between fossil fuels and non-hydro renewables is not declining; moreover, global carbon emissions are increasing;
- India continues to increase its fossil fuel consumption and it remains to be seen whether India will be able to support its 1.3 billion people and grow its economy any differently than did China, which did so largely on coal;
- Since non-hydro renewable energy has grown exponentially due to the availability of baseload power (coal, natural gas and nuclear), it is unknown whether non-hydro renewables can reduce the global carbon gap; that is, can exponential growth of non-hydro renewables be sustained as baseload power declines?
- This continues pointing to the need to focus our global carbon reduction efforts on recently-developed economies (i.e., China), currently developing economies (i.e., India) and soon-to-be developing economies.
These trends support the call for large-scale deployment of nuclear power—the only energy resource with the proven capabilities of not only narrowing the global carbon gap, but shifting that gap to negative.