A growing global headcount and environmental awareness are driving a need/desire to treat our home (Earth) in a kinder manner. Thankfully, if we look closely enough, unlimited energy can be found all around us. Any object that is in motion, produces heat, or even light, is a potential source.
Identifying energy sources is the easy part. The difficult hurdle to clear is in harnessing such resources in a reliable, and consistent manner. Thankfully, advancements in material science have allowed for efficiencies undreamt of in the past.
Before we dive in to a few examples of clean energy, and the companies driving their utility, it is important to understand the distinction between sustainable and renewable sources.
Simply put, renewable energy comes from sources which naturally replenish their supply quicker than we use it. It does not necessarily mean that these sources provide clean energy though – only that the supply cannot be depleted with current demands.
Sustainable energy on the other hand, refers to sources which are not only self-replenishing, but over time will not have any negative effects on the Earth. These sources take future generations in to account, and look to bestow upon them a green Earth, rather than one continually ravaged by coal, petroleum, methane, and other dirty examples of energy.
It should be noted that although there is a distinction between sustainable and renewable sources, in most instances both labels apply. Naturally, those which manage to be both are the most intriguing.
Typically, sustainable energy must clear three hurdles to be deemed as such.
- Environmentally sustainable
- Financially sustainable
- Socially sustainable
A common example of a sustainable energy source is hydropower. Between the Moon creating tidal shifts, waves, and climate cycles, there will always be flowing water on Earth. Harnessing the kinetic energy within flowing water is not only a process that is naturally renewing, it is sustainable in that it will not negatively effect the Earth in years to come, while already being both economically and socially feasible.
A common example of a renewable energy source that is not typically viewed as sustainable is biomass. The most obvious implementation of this is burning wood as a source of heat. While the supply of biomass may be replenished quicker than we can use it, it is not sustainable due to the resulting greenhouse gases emitted through its use.
A common example of a non-renewable, non-sustainable energy source is fossil fuels. With the proliferation of the internal combustion engine, the end is already in sight for our supplies of fossil fuels. This source, which took literally millions of years to build up is essentially non-renewable, terrible for the environment, and simply not a sustainable source looking forward.
Now that we understand the distinction between renewable and sustainable energy sources, here are a few examples of those which boast the most promise. Each of these are already in use around the world, touting promising levels of adoption.
It is important to remember that one is not necessarily better than the next. The best energy source is the one readily available in the local environment.
Harnessing water as a power source is nothing new – we have been leveraging dams and watermills for centuries. In present day, Hydropower is the world's largest source of low-carbon electricity, accounting for over 15% of the total supply. Typical use cases rely on harnessing the kinetic energy of moving water to spin a turbine and create electricity.
|Renewable||Potential harm to ecosystems|
|Low carbon production||Can dramatically change landscapes|
|Reliable/Repeatable||Can negatively effect source feeds|
An example of an organization looking to forward our ability to harness tidal power, and our understanding of its effect on local ecosystems is the Fundy Ocean Research Centre for Energy (FORCE). This government-funded organization is based out of Nova Scotia, Canada, where the worlds largest tides can be found in the Bay of Fundy.
In the Bay of Fundy, over 160 billion tons of water flows in and out, twice a day, everyday – like clockwork. The force of this moving water is staggering, and offers the potential for equally staggering energy production that is as reliable as the Moon rising. This project is in the midst of a long-term study on the potential dangers that tidal turbines pose to marine plant and animal life.
Currently, Hydropower as a whole accounts for over 70% of global electricity to come from a sustainable source, with China and the United States leading the way. Moving forward, the wave and tidal market alone is expected to grow from $0.59B in 2021, to $4.41B in 2028.
Like Hydropower, electricity created through the power of wind is nothing new. Rather than tapping in to the kinetic energy in moving water to spin a turbine, the process is replicated by having wind spin fan blades connected to a turbine.
|Abundant||Potential harm to ecosystems|
|Low-carbon production||Large plots of land required|
|Renewable||Less reliable / consistent|
While wind can be harnessed to create electricity just about anywhere in the world, the practice does not come without its own set of challenges. Not only are large plots of land required to host these massive fields, wind is simply not as reliable as the tides. One day may be windy, and the next may be still.
Despite these challenges, Wind power continues to grow in popularity, representing over 7.6% of the worlds electricity production. Within the United States, Wind has already managed to become the largest source of renewable energy, representing roughly 10% of its own electricity production.
An example of a company pushing the adoption of wind power is Siemens AG (SIEGY). This conglomerate boasted a revenue of $71.98B in 2022, and at time of writing, shares in Siemens AG (SIEGY) are listed by various analysts as ‘over'. Having been around since 1847, this is a company that knows how to adapt to the times. With that in mind, Siemens has entire divisions dedicated towards developing technologies that will allow for us to transition from fossil fuels to sustainable sources.
While turbines are pivotal in the creation of electricity when utilizing sources like hydro or wind, they are no longer needed when we leverage photovoltaics. The photovoltaic effect, which is made possible by allowing for photons to place a substrate in an excited state, is the underlying technology behind Solar power. The Sun is possibly the most abundant source of energy in our solar system – why not utilize all it has to offer.
|Low-carbon production||Requires huge surface areas for large energy production|
Solar is unique in its ability to be used in applications as small as a personal battery bank, or as large as powering cities. Like all energy sources, it does have limitations. While modern technologies have greatly increased the efficiency and affordability of solar panels, the practice still remains best suited for regions that have lots of sunlight. Travel close enough to the poles, and there are areas of the Earth which are deprived of a sunrise for months at a time.
As it stands, recent advancements in solar technologies have allowed for 4.8% and rising of global electricity production to come from this sustainable source. While the United States may be ahead of the trend in energy production derived from wind, it falls behind slightly in solar, with roughly 3% coming from harnessing the suns rays.
One of the most prominent companies and innovators in the field of solar technology is none other than electric vehicle (EV) manufacturer, Tesla (TSLA). For years now, the company has been developing and installing its solar roofs, which allow for home owners to do away with traditional solar panels, and use photovoltaic roof tiles in their place. Over the course of 2022, Tesla boasted a revenue of $81.46B, and at time of writing is listed by various financial analysts as ‘over'.
It is believed that ages ago, the Earth was comprised entirely of molten material, covered in oceans of magma. Billions of years later, and it has since cooled off, with the surface becoming habitable to humankind. The core however, is still raging, continuing to heat the various layers surrounding it. It is this energy, found below the surface of the Earth, that we are now tapping into, referring to it as geothermal.
Geothermal typically functions by harnessing thermal energy from the Earth to heat a liquid medium boasting a high heat-capacity, which is then used to power turbines that create electricity. In recent years, geothermal has become increasingly popular, as it is no longer only feasible in large scale applications, but also for residential installations as a form of heating.
|Reliable / Consistent||Geographically dependant|
Although geothermal energy can be harness anywhere if you dig deep enough, there are natural hotspots found around the world that make the process much easier – namely volcanoes. Nations like El Salvador have recognized this, and are making concerted efforts to harness this clean energy source, as it is also abundant and reliable.
Currently, despite its promise, geothermal energy is believed to account for roughly 0.4% of the worlds electricity supply – a number in line with production in the United States as well. Beyond volcanoes, geothermal is particularly accessible near tectonic plates and fault lines. As a result, Coastal California is a prime region for accessing this clean power.
For investors looking to gain exposure to the geothermal energy industry, one of the companies leading the way is Ormat Technologies (ORA). The company currently owns over 150 geothermal power plants, and employs over 1,300 individuals. Over the past 5-years, Ormat Technologies has consistently produced yearly revenues in excess of $650M, and should be well positioned to capitalize as geothermal grows in popularity.
Looking to the Future
While the power sources listed above boast massive potential for facilitating a greener future, there are another pair of options which one day may day dwarf them all.
Once a part of science fiction, Nuclear fusion may one day be a reality as scientists continue to make promising breakthroughs towards harnessing what is the ‘holy grail' of energy production. In fact, progress has come such a long way, that governments are now planning to build working prototype plants before 2040.
For those unfamiliar, Nuclear Fusion – the same process which powers our sun ‘Sol' – should not be confused with Nuclear Fission (the current process used in modern-day Nuclear plants). Each process releases massive amounts of energy, however the former does so by creating conditions to combine nuclei, while the latter splits heavy elements like Uranium.
Fusion not only releases more power than fission, it is a significantly cleaner process. The issue at hand, which scientist are working on solving, is developing the right conditions to both facilitate and safely harness the process.
We recently took a look at Piezoelectricity, and how it is one of the most commonly used, yet unknown power sources. Piezoelectricity is the ability of a material, man made or naturally occurring, to create an electric discharge when subjected to external pressure.
Already in use for decades in mundane items like microphones, lighters, and more, modern material science continues advancing towards a day in which we can harness enough electricity through this effect for large scale applications.
Like Nuclear Fusion, the potential of widespread use of piezoelectric materials used to feel like science fiction. Although many years away, it may one day lead to a world in which sizeable batteries are largely obsolete, as piezoelectric materials allow for self-powering devices.
Although the world may still be hooked on energy sources like petroleum products, coal, and natural gas, it is abundantly clear that they are not the future. Thankfully, energy is everywhere around us, and modern science is increasingly giving us the opportunity to tap into a growing list of clean sources.
While the future may one day see Earth reliant on nuclear fusion and self-powering devices, it will be the continued adoption of hydro, wind, solar, and geothermal that allows us to get there.