“Electricity is but yet a new agent for the arts and manufactures, and, doubtless, generations unborn will regard with interest this century, in which it has been first applied to the wants of mankind.” – Alfred Smee
Just as our generation has looked back at the last century’s transformation through the production of electricity with fossil fuels, so will future generations look back at this century’s adoption of new renewable resources.
The future is predicted to be one in which we derive energy from sources that are completely renewable. That will lead to a cleaner, less wasteful human reality. Here we explore 5 of the most promising renewable energies of the future.
1. Space-based Solar Farms
The gist of it:
- Can deliver energy anywhere on Earth
- Circumvents current drawbacks of traditional solar energy production
- May be commercially viable within the next 30 years
This technology was first proposed by an aerospace engineer by the name of Peter Glaser in 1968. People also consider him to be the “the father of the solar-powered satellite.”
Since then, the idea of creating space-based solar energy farms has been a topic of interest in the scientific community. However, they have never fully realized it.
This model of harnessing energy is based upon the fact that sunlight in space is largely uninterrupted. Current solar technology is at the mercy of weather conditions. It can only produce energy during daylight hours.
Space-based solar farms overcome these obstacles by eliminating nighttime blackouts and inclement weather. Additionally, sunlight found outside Earth’s atmosphere is 30% more intense than the sunlight we receive on Earth’s surface.
In order to create a functioning solar farm, companies would send inflatable modules into space to form a bell-like structure that contains mirrors which direct and concentrate sunlight onto solar panels. They could then send this energy down to Earth.
However, the difficulties associated with space-based operation may be holding back the development of this future technology.
The biggest challenge is getting the harnessed energy back down to Earth. The energy these solar farms produce can be sent down in the form of microwaves or with a powerful laser. The issue with this is that the cost of the entire process currently outweighs the benefit of the increased power production it provides.
The transferring of energy also has the potential to be harmful through weaponization or mishap. Despite these concerns, the possibilities for this technology are great. It will be able to deliver energy to remote locations anywhere on Earth, which is of tremendous value.
With the rise of private space companies, some have predicted that this technology could be commercially viable within 30 years. China currently has plans to construct a space-based solar farm. They claim to already be testing the technology and aim to have a functioning space-based solar farm before 2050.
2. Human Energy
The gist of it:
- Viable for busy urban areas
- Can convert heat and kinetic energy that humans have produced into electrical energy
- Harnesses energy that would otherwise go to waste
Humans gather calories through the consumption of food, which our bodies then convert into usable energy. In many ways, our bodies are similar to a machine, just like any other that uses energy to perform work. We use this energy for vital functions, such as keeping our hearts beating or powering our brains.
However, much of the energy our bodies produce is also used in the forms of heat and kinetic energy through movement. Much of this is goes to waste and remains unclaimed by humans.
That may seem like a lost opportunity given the number of humans on Earth and the amount of land that is in use to feed the vast population.
In fact, for most of human history, human power has been the most important form of mechanical energy available to us. Human or animal energy has created and utilized all our structures, homes, farmlands and tools.
The energy converted by human bodies was used to push the shovel into the ground when digging a dam and when the hammer was swung by a mason carving stone. It is only relatively recently that we humans have started using other forms of energy, namely fossil fuels.
At rest, the average person’s body produces around 100 watts of power. Production is much higher when performing vigorous activities.
For example, cycling can generate 400 watts of power per hour. However, top-performing cyclists have been recorded generating up to 1800 watts. That was during short bursts of exertion.
If you consider the average amount heat and kinetic energy being produced by humans in a single city (energy that is not being harnessed) you can begin to see why scientists are taking notice of this promising renewable energy source.
So, with all this energy going to waste, we must ask ourselves the question: how can we harness this energy? There are two big issues with the harnessing of human energy.
The first is that current energy harvesting strategies are not very efficient. However, this is set to change in the future. Scientists are developing technologies that harness this energy at enhanced efficiencies and at a lower cost.
The second problem holding back human power as a viable renewable energy source is that of modern battery technology. The battery systems currently available to us are too large, heavy and bulky to make this sort of technology viable. However, recent breakthroughs in energy-storing technology may soon be on the horizon.
Scientists envision cities that can harness enough human power to run entire buildings through our daily actions alone. In fact, a street in London has been converted with materials that harness kinetic energy as people walk along it.
In the Human Power Plant project, the University of Utrecht based in the Netherlands plans to create a dormitory. It is fully powered by the students who live within it.
These 750 students will power the 22-story building with human mechanical energy alone. That includes lighting and heating, without the use of any fossil fuels.
3. Core Geothermal Energy
The gist of it:
- Is accessible anywhere on Earth
- Provides a limitless supply of pollution-free energy
- Could produce energy equivalent to that of nuclear power plants
While we already possess technology to harness geothermal energy in certain locations that have volcanic activity close to the Earth’s surface, it is by no means readily available in most parts of the world.
However, deep below the surface of the Earth is its molten core, containing enough energy to provide for the needs of humanity in limitless supply. If we could drill down to the core, we would be able to access incredible amounts of clean, pollution-free energy that people anywhere on Earth could tap into.
The Earth’s core is incredibly hot, around the mark of 6,000 degrees Celsius, which is as hot as the surface of the sun. This heat is a combination of remaining heat from Earth’s formation, heat from the decay of radioactive materials, and the heat generated from friction when dense core material sinks to Earth’s center.
So, with this incredible amount of energy lying beneath our feat, why haven’t we been tapping more of it? In order to access this energy, we would need to drill down to a depth of 10,000 kilometers or more in order to access deep geothermal heat. The heat found at these depths is comparable to the energy produced by a nuclear reactor.
However, this incredible depth complicates the drilling process because of extreme temperatures. Another crippling issue is getting this energy back up to the surface with the materials available to us. Copper melts at these temperatures, along with most other viable materials.
Scientists may have found the answer through a recent development in graphite technology. That is the discovery of graphene.
Graphene is an amazing material, one that is 200 times stronger than steel, and is an excellent thermal and electrical conductor. This material is 100 times more conductive than copper and only begins to melt at a temperature of around 4,000 degrees Celsius.
Using graphene rods that drop down to regions close to the Earth’s core could yield us limitless energy that is 100% pollution-free, no doubt transforming the energy industry.
4. Quantum Dot Solar Cells
The gist of it:
- Will revolutionize current solar technology through solar windows
- Converts considerably more solar energy
- The technology can be applied to numerous materials
Not only will the future contain new ways of harnessing renewable energy, it will also contain greatly advanced versions of the technologies that we currently use today. We have been successfully harnessing solar energy for quite some time and this technology has been continuously advancing.
More recently, scientist have created quantum dot solar cell technology.
Quantum dots are nanocrystals constructed with semi-conductive materials. A thin coating of these cells can be applied to a solar cell. The quantum dots absorb sunlight to excite the nanocrystal particles.
The band gap of these quantum dots corresponds to the frequency of the sunlight they are receiving, allowing them to convert more than 65% of the sunlight into energy.
This is far, far more than any solar technology available to us today, with the average solar cell in use today reaching around a 15% efficiency rating.
This, coupled with the fact that quantum dot solar cells are much lighter, versatile and durable than our current solar cells, means that this technology has the potential to transform numerous material surfaces.
A promising application for this technology is solar windows. These windows would be able to generate electricity while providing insulation and shading at the same time. Windows are incredibly efficient because the front layer absorbs blue light while the second layer absorbs the rest of the spectrum.
Quantum dots in the second layer of a solar window re-emit photons at a longer wavelength, allowing the solar cells integrated in the window frame to convert the energy into electricity. This technology would be relatively cheap and has the potential to significantly lower the price of solar technology.
5. Nuclear Fusion
The gist of it:
- Has the most potential to change the face of energy production
- Nuclear fusion energy is 100% clean, as compared to current nuclear fission energy
- Small production facilities would be portable
People sometimes view nuclear technology as a “dirty” way of producing energy since the current method of nuclear fission produces significant amounts of radioactive waste.
However, people should make a clear distinction between nuclear fission and nuclear fusion. Nuclear fission splits a large atom into two smaller ones, releasing energy and neutrons which causes further atoms to be split. This results in a possible chain reaction.
Nuclear fusion, on the other hand, occurs when two atoms slam together to create a heavier atom which releases energy, but exponentially more than that of fission. Fusion does not produce long-lived radioactive waste products like fission does, making it a clean energy source.
Fusion can also be carried out with materials that are largely inexhaustible and widely available. In fact, solar energy is a type of fusion energy because the sun produces energy through a fusion process within its core.
With nuclear fusion’s ability to produce approximately four million times more energy than that of coal burning, we would need only a fraction of the number of power plants on Earth today to be able to supply the human population’s energy needs. The amount of energy produced by fusion is so large that one could consider it virtually limitless.
Even though fusion is an incredibly promising energy source, it is not without its flaws. The process is incredibly difficult to achieve. That is due to the fact the reaction can only to take place under extreme conditions. Fusion requires extreme amounts of heat (100 million kelvin) and massive amounts of pressure.
These requirements mean that achieving nuclear fusion on Earth often requires more energy than it produces. However, as technology advances and scientists conduct further research, we grow closer to creating a viable fusion reactor.
The International Thermonuclear Experimental Reactor (ITER) in France is a collaboration of 35 countries. It has been seeking a way to harness this potential energy source.
Some predict that the ITER could provide nuclear fusion energy to the grid as early as 2045. That is leading the way in clean, limitless energy.
Private companies have also undertaken the pursuit to harness the full potential of nuclear fusion. Those include Lockheed Martin and Tokamak, a company in the UK.
Lockheed Martin claims that they could potentially produce a fusion reactor small enough to fit on a truck trailer that would have the capability of powering 100,000 homes. Tokamak could be producing nuclear fusion energy as soon as 2030.
Our Next Steps
Human technology has been advancing at exponential rates, and the energy sector is no different. Scientists almost unanimously agree that we will transition into a world that solely relies on renewable energy within the lifetime of someone born in the last 20 years.
This transition is an absolute necessity given the threat that climate change poses to us as a species. Although people may not always view the future with optimism, when considering the future of energy production, it is definitely a brighter, cleaner forecast.