August 18, 2014
This infographic is an evolution of a significant amount research I did on the subject of comparative electricity generation approaches back in 2007. Today, the rising middle class around the world and their demands on electricity to fuel their new lifestyles has reignited the debate over the merits of various energy sources, particularly that of coal. So I recently updated my research and data, the latest of which is represented in the graphic that shows our world’s most prevalent energy sources pitted against one another through various stages of competition for the top spot. Only the strongest competitors move onto the next stage.
I use this data and the competition metaphor to argue in favor of coal. If you look at all the dimensions of energy generation, coal rates highly on most everything except carbon output. Coal is cheap to transport and store, requires less than an acre of land per megawatt of generate and requires no processing to make the fuel usable in a generation facility. We have hundreds of years of supply and as I continually say it is equally dispersed around the planet including most interestingly, in India and China, which matches the generation needs over the next several decades as defined by well-honed forecasts. Further, there is significantly more installed capacity than alternatives. It’s only negative is that it is the largest carbon emitter among the alternatives.
In comparison with oil (not represented in the graphic), you face almost as much carbon output and the risk of depleting the supply in the foreseeable future. The total efficiency of oil is the product of processing and generation efficiency, which in aggregate yields far less electricity per wrong unit of energy in coal. Nonetheless, it is easy to transport and store and can generate power at almost any level from the smallest gasoline-engine-driven generator to large facilities.
Gas also is more efficient and yields half as much carbon. Yet it is exorbitantly expensive to transport and its availability is highly concentrated, which exacerbates the geopolitical tensions it creates. Further, India and China lack natural gas.
Nuclear requires significant fuel processing and may face depletion challenges. Again, the natural resources that produce uranium are relatively concentrated in places like Australia and Africa.
Hydroelectric is relatively simple and much of the world’s opportunities are already developed. It will never be depleted and has no carbon footprint. But like wind, it cannot be transported and therefore is not a realistic solution for the energy needs of society in the future.
There are additional problems with wind. It takes an inordinate amount of land and cost, and is not transportable. Again, we have already developed many of the premium locations for wind on the earth, which greatly limits its expansion capability.
Solar exists everywhere on the earth and therefore doesn’t need to be transported. However, it is cumbersome to store and requires a relatively large footprint as well as significant efficiency losses in generation. I believe it will be the ultimate fuel hundreds of years from now but is impractical as a complete solution for the next century.
Although not represented in the graphic, biomass is a land-intensive approach with poor efficiency and significant transportation costs. This is based on the concept of ethanol made from corn and has largely been abandoned as an effective approach to renewable energy.
From this analysis you can see that coal has a lot of favorable characteristics except for the carbon footprint. Many consider transportation costs, the generation density and the readiness of the fuel when it comes out of the ground and start to realize its attractiveness. Factor in the significant reserves and its ubiquitous availability, and you further realize its attractiveness and the reason that it has the largest installed capacity.