The Past, Present, and Future of Solar Energy

Energy dictates everything from evolution to envelopes and from a universal scale to an atomic scale. The control of energy made us the apex predator of the Earth, with the ‘discovery’ of fire. Energy itself can be linked to every major change in the lifespan of modern history, with steam power turning into the First Industrial Revolution, the light bulb for the Second Industrial Revolution, and nuclear power dictating the 20th century. With our reliance on our control of energy, we have an issue in its sources. Most of our energy comes in the form of burning hydrocarbons, which end up releasing carbon dioxide and other carbon gases into the atmosphere. This release of greenhouse gases change the environment on a global scale, causing pH imbalances in the ocean, destruction of wildlife, and countless other ill effects. These hydrocarbons in oil, coal, and natural gas were created by a pressing of carbon rich organic matter, otherwise known as dead things. There are other energy sources other than these hydrocarbons with solar, hydropower, nuclear, and wind available at our fingertips. Out of these sources, solar energy has been the most widespread and efficient, with continuous innovation to continue to cut down on costs to the point where it is the cheapest source of energy known to humanity.

An Introduction to Solar Energy

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Solar energy may be the first form of energy we have harnessed. Magnifying glass has been used to create fire, and sadly to burn ants as well. Over the past 125 years, solar energy has turned sun rays and their heat into electricity. Solar panels are made of silicon, where photons from the sun agitate it where a current is formed. The current is then sent to an inverter to turn from direct current (DC) to alternating current (AC), where we can start to use it. Solar panels at this point in time are strong in certain areas, as they provide both an investment and a steady flow of current for those who choose to purchase them. That said, they haven’t been greatly efficient. In many areas, solar cells seem to be a never ending investment due to cleaning and repair, with little energy output. In many cases, direct solar energy from family to family may not be the most efficient use of resources. To counter that, there are multiple other forms of solar energy that can be used.

Solar Fuel

Solar fuels are simply fuels that use the energy of sunlight directly, most typically being hydrogen, water, and carbon dioxide. The main advantage of these fuels is storage; storing a tangible fuel is a lot easier than storing current. These fuels can be distributed to a fuel cell in order to create electricity.

For a fuel cell to work, electrons from hydrogen in the fuel flow through the system, creating a current.

One of the most promising solutions for fuel is hydrogen, but to store and liquify it takes a lot of energy. Hydrogen peroxide could solve that. Storage can happen in any dark plastic barrel, and the fuel cell doesn’t need a membrane, lowering the cost and resources needed to produce a cell. The production of hydrogen peroxide isn’t efficient right now, but that’s where solar energy comes in. A catalyst can be used with water and oxygen to utilize the sun’s energy and shine light on the combination, creating hydrogen peroxide. Hydrogen itself can be created through water electrolysis, which is running electricity through water. This can then either be turned into hydrogen peroxide or even function as part of an engine to get hydrogen fuel. If you want to learn more, check out this Ted talk!

Artifical Photosynthesis

Natural Photosynthesis turns CO2 and H2O into sugars, with the help of sunlight. This process can possibly be replicated, turning a greenhouse gas into a fuel. Plants utilize a chloroplast, which functions as a light absorber (turning light into energy) and a catalyst to break down CO2. Currently, the main method of artificial photosynthesis is utilizing electrolysis on CO2 and H2O to get CO and Hydrogen, and then turned into an alcohol with the help of bacteria, creating a fuel. These fuels have the potential to be very efficient, with a possible cost of $1 a gallon, creating a cheaper fuel than gasoline.

Energy Storage

One of the largest problems in energy is storage itself. An efficient, cheap, and space consistent solution is hard to come by. Here are the main problems with the current solutions:

  • The flywheel: Excess energy is transformed into rotational energy to move a flywheel, and the energy can then be used when needed, slowing down the wheel. It’s a fairly quick and safe system at nearly any size, but the size itself is the issue. Since the electrical energy transforms into rotational energy, more energy storage means a larger or faster wheel, putting stress on resources. It is also not an effective large scale energy storage option.
  • Batteries: Batteries function through an exchange of electrons. This flow of electrons creates a current, which can power any resistor. For rechargeable batteries, electricity from an outside source can reverse the process. The main problems with batteries has consistently been the environment; battery acid along with lithium mining isn’t an environmentally conscious option.
  • Compressed Air Storage: Air is compressed into a massive cavern, and when needed, the air can be expanded to push a turbine to get electrical energy. The main problem with this is the requirement of a cavern, or at least some hole large enough to store the air. This can work wonders for recycling old mining sites, but it still requires a large spatial capacity.
  • Pumped Storage: Two main reservoirs at different heights are utilized; when there is a large energy surplus, water is pumped up the reservoir, and when there is a energy demand, the water is pumped down, and the gravitational energy turns into kinetic energy that can be captured. The main issue is space once again; this only works if two reservoirs can be built/exist in a large space.

The sun could have a possible solution to energy storage, in the form of Seasonal Thermal Energy Storage, or STES. STES functions by heating up large vats of salt underground, melting it. The salt traps the heat, and the heat can be used in the winter months when it gets cold. Sand is also a good possible solution, where sand can be heated up, insulated, and can utilize the heat during colder times. The main problem is once again storage, but salt and sand are fairly cheap and efficient.

Blockers

The main problem with solar energy is consistency. Fossil fuels can be stored and burned whenever needed, going with demand, but solar energy has the perils of clouds, rain, and other physical blockers. Energy storage is key, but there are a plethora of problems with energy storage. Resources to create these solar farms are also a problem, both in land and in creation. Solar panels require arsenic, gallium, germanium, indium, and tellurium, all elements that require extensive mining. Placing these panels also takes up land, which is an ever scarce resource. The cost for a scale farm is around $1 for every watthour, which means that a plant that produces a GhW takes around 2.8 acres of land. Solar energy is by no means a perfect technology yet, but there is hope for improvement.

Solar Energy in 20 years

Solar energy is guaranteed to improve in the next 20 years. Designs that capture more heat, get more light, and require fewer resources will come to market. Two main methods are currently being tested out: One, adding on to existing solar technology, and two, creating new solar technologies. An issue with solar panels is that they don’t capture all possible energy as they are stationary, which could be solved with a device to rotate solar panels to the power of the sun. New solar technologies could involve thinner ‘sheets’ of solar panels producing better results, quantum dots, and possibly even solar panels in previously restricted regions.

Conclusion

Solar energy could provide the world with energy for the rest of humanity’s lifetime, but there are still major issues with energy consistency. It cannot hold every burden of energy right now, but it may be able to in the future.

I’m Aniket, and I’m interested in how we can make humans fundamentally better through better disease prevention and innovation.