Can 100% Renewable Energy Power the World?
Pretty sure you’ve thought about this.
Statistics show that every year, the world uses at least 35 billion barrels of oil, a massive scale of fossil fuel dependence which pollutes the earth, causing climate change. Sensing the impending catastrophe on our planet resulting from this dependence, the United Nations enacted the Paris Agreement, an agreement signed by 195 countries and later approved by 168, with a major purpose — to curb this bane. Varying solutions were identified, the most efficient being the switch from non-renewable to renewable energy sources. By the way, if you think we have an infinite supply of oil and coal, you’re mistaken, as scientists and geologists predict that we’d have run out of oil in 50 years’ time, and coal in a century. On the flipside, we have abundant water, sun, and wind which are renewable energy sources, meaning that we won’t use them up over time. However, renewable energy still provides only about 13% of the world’s energy needs. So why don’t we exchange our fossil fuel dependence for an existence based solely on renewables?
The concept of renewable energy was first revealed to me (in a vision! Laughs) when I was 10, and for years I wondered and pondered (like Brain in “Pinky and the Brain”) on this question. For some time, I felt like I was the only one in the world thinking about this, but the (bitter) truth hit me when I learnt that many scientists, engineers and even economists had been working on it for decades. Yes, economists, because reaching 100% requires renewable energy that is economically feasible. Even if we ignore the politics involved and focus solely on science and engineering, this still presents a big challenge.
A good place to start would be to understand how the world uses energy. Global energy use is a diverse and complex system, and different elements require their own solutions. Electricity powers computers, elevators, entire buildings, blast furnaces, block chain systems and all manners of things in homes, businesses and manufacturing. The great news is that we have technology already advanced enough to capture all that energy from an ample supply, the Sun. This celestial body continually radiates about 173 quadrillion Watts of solar energy at the earth. That’s 173 with fifteen zeros following it. (How did NASA measure this please? Lol.) This is almost 10,000 times our present energy needs. It’s been estimated that a surface of solar panels that spans several hundred thousand square kilometers would be needed to provide power at our present usage levels. So why don’t we just build that?
Efficiency and energy transportation.
Here’s the conundrum. To maximize efficiency, solar plants must be located in areas with lots of sunshine year-round, like deserts. But those are far away from densely populated regions, where the energy demand is high. In principle, a connected electrical energy network with power lines criss-crossing the globe would enable us to transport power from where it’s generated to where it’s needed. But building a system on this scale places an astronomical price tag. We could lower the cost by developing advanced technologies to capture energy more efficiently (or probably buying alien tech from The Vulture in Marvel’s Spiderman: Homecoming. By the way, if you haven’t seen this movie, you don’t know what you’re missing!). Our energy transport infrastructure would also have to change drastically, as present-day power lines lose about six to eight percent of the energy they carry because of the dissipation of energy by the wire material through resistance, and thus longer power lines mean more energy loss. (That’s basic physics.) Superconductors, materials that can transport electricity without dissipation, could be one solution. Unfortunately, they only work if cooled to low temperatures, which requires energy and thus defeats the purpose. To benefit from this tech, we need to discover new superconducting materials that operate at room temperature.
There are other forms of renewable energy we could draw from: hydroelectric energy, geothermal energy, and biomass. But these also have limits based on availability and location. So, what about liquid fuels? You know, electrolysis and stuff. What about them? The scientific challenge is to store renewable energy in an easily transportable form. Recently, we’ve gotten better at producing lithium-ion batteries which are lightweight and have high energy density. However, even the best of these store about 2.5 mega joules per kilogram, which is about 20 times less than the energy in one kilogram of gasoline. To be truly competitive, car batteries would have to store much more energy without adding cost. The challenges only increase for bigger vessels like ships and planes. To power a Cross-Atlantic flight for an airplane, we need a battery weighing about 1 million kilograms. This, too, demands a technological leap towards new materials, higher energy density and better storage. One promising solution would be to convert solar energy into chemical energy, which is already happening in laboratories, but the efficiency is still too low for the tech to hit the market.
To find novel solutions, the world needs lots of creativity, innovation, and powerful incentives. The transition to 100% renewable energy is a complex problem involving technology, economics and politics. There is ample reason, however, to be optimistic that we’ll get there, as top scientific minds around the world are working on these problems and making breakthroughs all the time, and many governments and businesses are investing in technologies that harness the energy all around us.
So, spoiler alert for those of you who still think that everything that needs to be invented has been invented. There’s so much more that needs to be done! In fact, the technology presently in existence and in use is but a minuscule fraction of technology that’s capable of changing our world. And while (aspiring) engineers like me might rant about being at the forefront of this quest, the truth remains that there exist no rear ranks. Who knows, the solutions we seek may be inspired by the shape of the next meat pie you eat, or by the next cadaver that’s cut in the theater, or perhaps by the way your crush will curve you the next time you attempt to shoot your shot! So, get to work. The world needs you. The world needs me. The world needs us.
