Top 5 sources of renewable energy
Ryan Clancy | April 18, 2021It is (hopefully) a well-known fact in 2021 that humanity depends on fossil fuels far too much for its energy needs. Oil, coal and natural gas will eventually run out. These are finite materials and there is only so much that can be discovered around the globe.
There are hundreds of predictions and debates as to the specific date when fossil fuels will run out, but in time these non-renewable energy sources will either be too expensive to purchase, or they will be restricted/banned due to their harmful effect on the planet. Either way, alternative sources of energy need to be widely adopted - and fast.
Harmful carbon emissions from the burning of fossil fuels is adversely affecting the Earth’s atmosphere. Source: Ilia Petukhov/Adobe Stock
It would be difficult to name every kind of renewable energy source, as there are so many. It is even possible that there are some forms of renewable energy that do not yet exist, and might stand to make an impact in energy production in years to come. There are five options, however, that stand out both in terms of availability and sustainability: solar, wind, water/hydro, geothermal and biomass.
As always with different options, each of these sources has their own pros and cons.
1. Solar
The technology that harnesses the power of the sun is solar panel technology. It is currently the most studied and most popular (in terms of sales) renewable energy source in the world. There have been major developments to the solar energy infrastructure that have led to the technology becoming smaller, more powerful and also more cost efficient.
In India, Science Alert reports that solar energy is already down to the same price as energy produced from burning coal, which comes in at around 3 to 4 cents per kilowatt-hour (kWh). As with any of the choices on this list, the goal for solar energy is to be cheaper and more accessible than coal, and this is becoming more of a reality as it grows in popularity.
A couple of benefits of solar panels are that they require almost no maintenance once installed as they do not include any moving parts. Second, solar panels are completely silent once in operation.
Some downsides to solar panels are that they are completely dependent on the amount of sunlight they receive, and that the initial cost of installation can be quite high, with some installations costing up to $25,000 or more.
2. Wind
Wind is also another well-known and popular source of renewable energy. It is gaining ground on solar power as the most used renewable energy source, according to the Global Wind Energy Council (GWEC). Wind power does hold an advantage over solar power, as it harnesses constant wind that can blow 24/7. In contrast, solar panels cannot collect any power during cloudy weather conditions or at night. This makes wind power more desirable for industrial applications, which requires consistent and reliable sources of power. Still, wind has more advantages over the other options.
Wind turbines that generate power are taller than most other energy systems and consequently take up less ground space. Wind turbines are also more efficient than almost all other forms of renewable energy. That is to say, almost 100% of the energy that the wind generates, the customer receives.
On the other hand, wind turbines are known to be noisy, especially when spinning at maximum velocity. Although they can work 24/7, they need to be located in areas with high and consistent wind speed to work effectively.
Renewable sources of energy like solar and wind power are our best hope of deviating from fossil fuels. Source: Mike Mareen/Adobe Stock
3. Water
Continuing the list with another classical element, water holds the honor of being the oldest renewable energy source used by humans. The first hydroelectric plant was built in 1878 and water is still one of the most used and popular ways to generate electricity in most countries. National Geographic has stated that water energy produces almost 20% of the world’s electricity, and still holds the crown as the cheapest source of renewable energy.
It is one of the most consistent forms of renewable energy and is renewed constantly by snow and rain. Hydroelectricity is one of the few sources of renewable energy that can boast that it has absolutely no impact on the planet. It is 100% clean.
As you might imagine, building a dam is not cheap. There is a high initial cost to build a plant or dam, limiting this option to huge corporations and governments.
4. Geothermal
Geothermal may be the first option on this list that some may not have heard of at all. It creates electricity by harnessing the heat produced from the Earth’s core. This technology is growing consistently, and scientists have high hopes that the price of geothermal energy will continue to decrease as time passes.
Along with water energy, it is a very consistent source of energy as the Earth’s core will hopefully not be cooling down any time soon. That would be bad news for everybody. A geothermal pump is known to last for about 20 years, and once set up it is 25% to 50% more efficient than traditional heating and cooling systems.
This method also carries a high initial investment with it, as the apparatus needed can be very complicated and therefore expensive. The equipment also takes up a significant amount of space, which can also attribute to the higher cost for installation.
5. Biomass
Biomass is new technology that has had some big breakthroughs in recent years, leading to an overall increase in its popularity. It can be divided up into two sectors: biodiesel and biofuel. Biodiesels are made from vegetable oils or recycled grease, whereas biofuels are created from corn or sugar-based ethanol. The hope for biomass is to provide an alternative fuel for the automotive industry, among others. Transportation depends heavily on fossil fuels, and biofuels are expected to provide 25% or more of the fuel for transportation by 2050.
This type of fuel is the most like fossil fuels already used in transportation and will require little modification to the existing infrastructure to adapt to it. Other sources will require huge changes to be utilized, for instance water energy in a regular car.
There is a debate that biomass is not 100% carbon free. Carbon waste is produced when the biofuel is burned, and it also emits carbon emissions during use. Considering this, researchers believe that this method is probably around 50% to 60% more efficient than fossil fuels.
So, what do you think will be the renewable source of energy that will have the biggest impact on our fossil fuel dependency? Let Engineering360 know in the comments below!
Nuclear energy is the future...
I notice there was no mention of hydrogen being considered as a clean energy fuel for all sorts of combustion principals ...maybe nr 6 if were considered. Its a no-brainer that with sufficient solar available during the day, electrical energy produced can provide for electrolysis in breaking the water molecule into it's two constituent gases H2 and O.
Maybe this article was written prior to ' blue gas' being considered an alternative.
Solar panels sounds good. But what about the emissions released during their manufacture? When they quit producing, how are they disposed of? The ideal is to have renewable energy such as solar panels to make hydrogen and use the hydrogen to run fuel cell generators. The hydrogen could power fuel cells for transportation, home, and anywhere electrical power is needed.
Nuclear power would be nice if a way to get the waste to a radioactive level that doesn't require humans to safeguard it for 50000 years!
There is a false assumption in the topic--that we can simply change to renewable sources from current types of energy sources without implementing conservation and significant life-style or infrastructure changes, and addressing rampant population growth also.
In discussing solar, we are tempted to ignore solar thermal and only focus on solar electrical. In discussing hydroelectric, we are ignoring the environmental harms that come from damming streams as well as the environmental costs of the dam construction.
We want energy to be available 24/7 on demand. A balanced system has to look at storage of energy for times when the primary sources are limited. Such storage could be batteries (resource limited), pumped hydro storage (very effective in some locations), compressed air, hydrogen generation, and others.
More can be said about the 50+ year lead time needed to upgrade our infrastructure planning to more efficiently use efficient transportation modes, land use, and similar hidden factors.
--JMM
In my opinion, we will have to go with nuclear energy generation. I do NOT mean thermal nuclear which is most of what we have today, but fast nuclear (Generation IV technology) which utilizes fast neutrons and no moderator. It is better than thermal nuclear by a factor of about 100. Fast nuclear can consume for energy much of the "waste" that thermal nuclear produces. Yes, there is still waste, but much less volume that needs to be stored for much less time. In my opinion, renewable sources of energy will not be able to supply the needs of our society in the future; thus we need something else, and that is fast nuclear.