Powering the Entire World in Six Solar Arrays: Is It Possible?
A Natural Question
For as long as humans have been using energy and electricity, we've continued striving to attempt to perfect our methods of production. Combine this with our instinct to provide for the world and the rest of our species, & it's no wonder the urge to power the Earth compels us as humans. Although the idea of generating enough shared power for the many divided nations of the world may seem impossible right now, for political, practical, and financial reasons, it doesn't stop the many great minds of our society from theorycrafting possible methods to make it happen in the future. There are a few common problems with the idea of using large solar arrays to power the world, namely, the transportation. One single giga-array is out of the question, as the inefficiency of transporting all of that energy around the world would simply render this method not worth using. The second best option would be to evenly spread out several mega-arrays to different places on Earth.
This is exactly what affiliate of University of California, Berkeley, Matthias Loster, set out to do. Although not much information is available online about the man behind the theory, what he's proposed has since been a semi-famous reference point to this conversation since 2010. In a single image, Loster managed to accurately propose the areas of Earth that would be perfect candidates for super arrays, powering the entire world in a mere six utilized locations, without losing too much production to transportation.
To Map The Sun
If humans were theoretically capable of capturing every tiny ray of sunlight that hit the Earth and converted it into power, we would produce more total energy in two days with solar than all oil available on the planet ever could. Of course, it will never be possible to reach output like that, but it gives you a scope of what solar power is capable of, and how little of it we're truly utilizing. Above you can see Loster's proposal for six systems scattered across the continents, capturing enough sunlight to produce 18 Terawatts of energy, enough to power the entire world. If these arrays were built, they would need to be roughly 140,000 to 180,000 square kilometers each, or the size of one and a half Mojave Deserts. Altogether, the systems would equal 910,019 square kilometers spread across six locations, rivaling the Kalahari desert of Southern Africa in total area.
These numbers may seem intimidating at first, until you realize the locations of these proposed arrays. In order of smallest to largest, they are:
- Atacama Desert, South America
- Takla Makan Desert, China
- Great Sandy Desert, Australia
- Great Basin, U.S.A
- Arabian Desert, Middle-East
- Sahara Desert, Africa
As you may have noticed, all of these are deserts. Low-population, low-usage areas that are mostly made up of unused land. They're also generally sunny year-round, and although solar units do not need constant sunlight, it certainly helps keep production consistently high. Why, then, are we not trying to use this method of production instead of rooftop or more local versions of solar?
A Mortal Foil
This strategy faces the same problem as many, many other grand ideas. The immense cost. A presentation by Jeffrey C. Grossman of the Department of Materials Science and Engineering (DMSE) MIT from 2012 goes into detail on this, stating that the cost of units to supply such a gargantuan project would be approximately $50 trillion, not even taking into account transportation and labor fees.
Another potential issue with this style of production is, as was mentioned earlier, the loss of efficiency through transport of energy. When energy is transported across long distances, around six to eight percent of it is lost at a minimum. Although spreading these systems across the globe helps with this issue, it doesn't fix it. Loster himself mentioned in his publication, "..it is better, in many cases, to generate energy closer to where it is needed. Roof tops of buildings and small solar farms are such places, saving transmission costs and, by interconnection, balancing periods of less sunshine."
Of course, a huge-scale project like this would also require global cooperation from the nations of the world, something that would likely be near-impossible to achieve politically.
All things considered, I don't think it surprises anyone that this project is pretty much impossible, and only serves to function as a hypothetical. Why, then, is it important? What does this tell us? Take another look at the total surface area of the project: 910,000 square kilometers of solar units to power the entire world. Consider that the United States alone covers 9.8 million square kilometers. With land, water, and soon even space to work with, it's not too difficult to see that we can achieve amazing things with solar energy while only taking up a relatively small footprint.
Although we likely won't be putting these proposed mega-arrays into action, that doesn't mean we can't use the idea. In fact, several countries such as India and China have already been singling out large masses of land for use with solar energy, creating giant solar farms to produce huge swaths of power all from one location. These areas are close enough to the cities that actually need the power to be practical, while also being small enough in scale that, while expensive, they're able to be tackled eventually if taken in strides.
We also don't need to just leave the proposed deserts unused, either. Although we probably can't practically spread that energy out around the world, the areas closest to those deserts certainly can benefit from units placed there. For example, the U.S. has already built several solar arrays in the Mojave Desert, which supply power to Nevada and its surrounding areas. It's true that deserts are fantastic places for solar, and we're slowly taking advantage of them as we progress.
The idea of creating super-systems to provide the world with energy is an enticing one indeed, but unfortunately, not only is it unrealistic, it also turns out to be impractical. Despite this, however, it's still a useful exercise in realizing how important localized solar is, and why solar has to be spread out evenly around the country. Rooftops and small ground-mounted arrays are perfect for this. Even though a single array covers only a small area, this means we can seamlessly integrate solar power into our residential homes, covering that large span of area without dedicating a huge landmass to it. Rooftop arrays also couldn't be closer to the people that need the power, ensuring we'll lose as little of it as possible through transportation.
Overall, slow and steady will win the race. The more homes that install solar on their roofs, the closer we will gradually come to covering our total energy production with solar (and other renewable forms of) energy, and the closer we can come to kicking coal and oil to the curb.