Many people consider ‘fire’ to be the most important thing man discovered, and some others hold on to the steam engine as the single most powerful thing that determined the future of human civilization. Well, add them together and you get the disaster we currently face together in form of global warming.
To be fair, both fire and the steam engine did improve the shape of our lives by miles, and led to economic boom. But machines and combustion are now doing enough harm to push us into question if they really mean good for our planet and us. Well maybe it’s the humans behind the machines or the sources of energy that power them.
But we need energy. In 2016, the primary energy consumption of the world was 13.3 billion toe (‘toe’ means ‘ton of oil equivalent’); that’s like 56 kilowatt hour of energy for everyone on Earth per day. Energy serves many purposes for us that it is impossible to take it out of our lives—from transportation to electricity, communication, farming, and heating our homes.
And this is not a bad thing. However, in the U.S, 81% of the total energy demands are met using coal, oil, and natural gas—which are fossil fuels. That is the bad thing. We have become over dependent on the single energy source that is causing the planet to heat up—the source of our climatic woes.
Fossil fuels come from the decayed remains of ancient lifeforms and plants; when burnt they produce gases that leaks into the atmosphere, lets heat pass through from the sun but prevents heat from escaping. The over all effect is that the Earth gradually heats up; and this has been happening as the average surface temperature of the planet has gradually risen over the years—and sharply in some regions.
In fact, according to a current temperature investigation carried out by experts at NASA’s Goddard Institute of Space Studies (GISS), the mean temperature of the Earth’s surface has grown by roughly 0.8 degrees Celsius since 1880.
Another thing about the 1800s was that the world’s population was barely 2 billion; today it has almost quadrupled. And same thing can be said about the amount of CO2 emissions—they have increased by almost 26%. Carbon dioxide is one of the harmful gases emerging from getting energy from fossil fuels.
So we are in a dilemma; the most productive energy source (fossil fuel) seem to be creating the most climatic harm (carbon emissions of ~1000g CO2 eq/kilowatt hour). The question now is: how do we cut down on carbon emission and solve the Energy-Climate conundrum? Could we try alternative energy sources? Let us look at some possible ones.
Alternative Energy Sources and Their Carbon Footprints
This form of energy is drawn from organic matter. It could be done directly from energy crops such as short-rotation coppice willow and grasses like miscanthus and straw, or extracted indirectly from by-products of agricultural and industrial activities like wood-chips. Biomass has very low carbon footprint (~45g CO2 eq/kilowatt hour), in fact it is categorized as a “carbon neutral” energy source.
This is because the small CO2 it emits is just absorbed by plants that need it for metabolism. Their energy supply is however much lower than what is obtainable from fossil fuel; so large amounts of biomass is required to harvest significant energy, making this energy source suitable for small-sized generation facilities.
There had been plants that combined fossil fuels and biomass in a ratio that optimized energy generation and cut down a huge fraction of CO2 emission.
This energy source has about the lowest carbon footprints. The manufacture and construction stages of the wind turbines actually constitute 98% of the carbon emission we are referring to here. The rest come from lubrication and transportation during maintenance. While onshore wind turbines can be reached using vehicles, offshore turbines are accessed with helicopters and boats. Wind energy is almost 100% clean as all the energy is drawn from the mechanical motion of the wind, which in turn sets the propellers in motion.
Like wind energy, nuclear energy involves very low carbon emission (approx. 5g CO2 eq/kilowatt hour), and does not depend on combustion. 35% of the carbon is released when uranium is being mined and enriched.; and another 40% is emitted during uranium extraction. There has been concerns that with more dependence on this energy source, higher grade ores would be depleted so quickly that we would have to look at lower grade ores for energy, thereby facing the same energy—climate conundrum we had avoided. Many developed countries, like the U.S and Russia, are currently generating nuclear energy to meet some of their needs.
Photovoltaics are constructed with crystalline silicon—a semiconductor that helps it trap sunlight ad convert it into electricity. The semiconductor used in the development of solar cells comes from quartz sand, and this process of extraction is where most of its production energy is expended. The emission of the solar cells is put around ~58g CO2 eq/kilowatt hour. However with advances being made in nanotechnology and thin films, tinier layers of silicon would cut down this already low carbon footprint.
Solar energy is leading the adoption levels compared to the other renewable energy sources. In 2017, the operating solar power generated globally was 405 Gigawatts, and 89% of users installed their cells within the last 7 years. One of main reasons for its slow adoption until recently was the cost of installing it, but with advances being made, the price is 57% cheaper than it used to be about 20 years ago and would even get cheaper.
Research is currently ongoing on how to made this energy source more efficient, as only 37% of the sunlight received gets converted to useful energy.
Just like wind energy, hydro works by converting mechanical energy of propellers connected to a turbine into electrical energy. There is no combustion plus low carbon emissions (~10—30g CO2 eq/kilowatt). Hydro-electric power sources have about the least carbon emissions among all electricity-generating technologies.
Addressing the Climate—Energy Conundrum
Admittedly we cannot turn the hands of the clock and undo all our carbon emissions, but the beauty of time is in that it gives you control over the future. We can take steps to correct our mistakes and repair our planet; from speaking out for greener global practices to learning not to be energy gluttons. Consider the following recommendations:
- Invest more funds in researches investigating the efficiency of energy sources like solar and biomass; raising investments to $500 billion by 2035
- Cutting down on the usage of low-efficient coal plants
- Governments should completely eliminate or reduce subsidies on fossil fuel
- Methods should be looked into that reduce the amount of methane emitted during the production of oil and gas