This is the first entry in a 3-part series called, “Solving the World’s Energy Problem.”
The world has an energy problem. This energy problem began developing the moment that man invented fire. At first it developed very slowly, imperceptibly, when there were very few people in the world and humans were relatively uncivilized. At that time, much of the energy expended by humans was energy spent on activities for survival.
Times changed, and humans grew in numbers and in technological prowess. Eventually, mankind learned how to burn fossil fuels – coal, natural gas, and petroleum – to produce energy in ever-increasing amounts. These fossil fuels were plentiful and could be extracted from the ground cheaply. To this day, civilization on earth runs largely on the burning of fossil fuels.
It is useful to put into perspective how these fossil fuels came about. Coal, gas, and petroleum are all the result of long-dead plants and animals that were converted during millennia into the deposits of fossil fuels that remained buried under the ground until mankind discovered them.
So here is the all-important question. What was the source of the energy that produced these fossil fuels?
It was the sun.
All plants and animals, dead or alive, derive their energy ultimately from the sun. It is the energy in sunlight that powers the build-up of plant mass, and some those plants were consumed by animals and converted into animal mass. Thus, coal, gas, and petroleum can be thought of as fossilized energy from sunlight. And it is worth noting that fossilized sunlight energy is concentrated. The energy content of fossil fuels is astonishingly high. That is why a gallon of gasoline can power your car for 25 miles, but the sunlight continuously bombarding a solar panel on your car cannot move it 25 inches.
Similarly, a biofuel is also concentrated energy derived from sunlight. But rather than being fossilized, a biofuel is energy from the sun created very recently.
Viewed in this way, we can understand our looming energy problem more clearly. Fossil fuels are finite, and they are not quickly regenerated. Millions of years were required to produce the coal and oil that the world is consuming, and at some point all that fossilized sunlight energy will have been exhausted.
Biofuels are different from fossil fuels only in the time it takes to convert the energy from the sun into concentrated sunlight that we can use. It only takes a few months to grow sugar cane or corn or any other plant that can be converted into a biofuel. Biofuels are thus completely renewable, creating a sustainable source of concentrated sunlight energy year after year. Thus, biofuels could potentially be a solution to the energy problem.
But they are not, at least not by themselves. Biofuels are an important part of the solution to the energy problem, but only a part.
Why? The main problem is supply. The world simply cannot produce a sufficient quantity of biofuels to completely replace all the fossil fuels that the world is now consuming. In fact, the total amount of biofuels the world can produce will never even come close to matching the current consumption of fossil fuels.
So how can this energy shortfall (one could also call it a shortfall in renewable concentrated sunlight) be solved? I think the answer is to develop alternative ways to capture the energy in sunlight rapidly and either use it or store it.
Earth receives plenty of solar energy – more energy in 1 hour than the world uses in 1 year – but a vanishingly small fraction of that energy is captured and used today. Developing new technologies that can covert more of the energy in sunlight into energy we can use in real time is the key to solving the looming energy problem. Investing now in alternative energy technologies – and particularly in technologies that can create more usable energy from sunlight in real time – will be the most important part of our replacement of fossil fuels in the future.