What is renewable energy?
Renewable energy is a term that all of us will be well aware of by now. It has managed to find a spot in our vocabulary with many of us still having no idea what it actually is. Many could ramble through an explanation, maybe hitting a few buzzwords along the way – but there is no genuine understanding there. If you were to ask a hundred people to explain the difference between renewable and non-renewable energy, you would likely receive a hundred entirely different answers.
So, what is the difference between renewable energy and… energy? Both traditional fuel sources and renewable energy finish at the same finish-line, they just run very different races.
The main difference is the original source of the energy. Traditionally there has been a reliance on finite fossil-fuel sources – burning things like coal to release and utilise the energy stored within. The problem with these fuel-types is that they are both incredibly dirty, and will run out eventually. There is a limited amount of coal held within the earth, and it is not replaced after extraction.
Renewable energy comes from clean, naturally replenishing sources. It does not matter how much energy we harvest from the tide, as it will keep rising and falling the following day for us to harvest all over again. Renewable energy implies that we will be able to continue exploiting the source indefinitely. There are some small exceptions to this, as we will soon discover.
The seven sources of renewable energy
There are seven main sources of renewable energy that are exploited globally. All are at varying stages of development with pros and cons for each. Some have been commonplace for years, while others are facing massive barriers.
The seven sources of renewable energy are as follows:
- Solar (heat)
It may be slightly confusing to see solar energy on the list twice – but this is due to two completely unique methods of electricity production. The solar energy we are all most comfortable with and see daily in the form of solar panels relies on a process called the ‘photovoltaic effect’.
The other type of solar energy sourced from the sun relies on the heat from the sun, rather than photons from sunlight. This type of solar energy is far newer, and is nowhere near as commonplace. By installing huge fields of solar panels in direct beating sunlight, it allows production sites to focus the heat from the sun onto a heat-carrying medium with the aim of turning it into steam, to drive turbines and generate electricity. This type of production site is referred to as a CSP plant (concentrating solar panel). Source: You Matter
5 characteristics of successful renewable energy
- Clean, non-polluting
- Low greenhouse gas emissions and toxic waste
- Reliable in the long-term
The dirty truth behind clean solar energy
With renewable energy sources – we are often led to believe that there is no downside. That we do not need to feel guilty from this type of exploitation. But should we maybe be feeling just a little bit of guilt?
The truth is that solar energy is not completely morally perfect – and have negative environmental consequences too. Photovoltaic panels are made with minerals like silicon (often in the form of quartz), copper, nickel, and cadmium. These minerals are not quite as easily accessible as the other factors of production needed for solar energy production – and will require a bit of digging to extract them.
I’ll rephrase that last sentence – they will require a lotof digging to extract them.
All of these minerals are trapped deep within the earth and the energy needed to extract them is astronomical. It takes fifteen seconds to type in a quick google image search for these mines, it does not take an environmental genius to figure out that the mines needed for solar panel production are not sustainable.
Massive excavators tearing into the earth, vehicles guzzling petrol, machines billowing smoke, horrible working conditions – and for the most part, this is all happening in underdeveloped nations where cheap labour can be exploited. Huge volumes of water are used throughout the entire process, the terrain is left utterly destroyed, habitats of endangered species are completely wiped, silicosis is rampant in workers from exposure to silica dust. As can be seen all to often from developed nations – they do not solve problems, simply outsource them to underdeveloped nations.
There is also scope for further problems along the production process – even after extracting raw materials. Once silicon has been extracted, it needs to be turned into high quality silicon. The process for creating this polysilicon produces incredibly harmful fumes (silicon tetrachloride) and contributes to soil acidification.
Following the creation and shaping of polysilicon, chemicals are used to maximise light intake. Chemicals such as hydrofluoric acid are used, but if this isn’t disposed of correctly there is scope for huge environmental damage. Even the name ‘hydrofluoric acid’ sounds toxic.
Should I tear the solar panels off my roof?
No, not just yet.
It is true that there are damaging aspects from the production process of solar panels. But the fact remains that these pale in comparison to the negative aspects of the fossil fuel industry. The production of solar panels does need further improvements that is true, but on the whole they are still incredible pieces of technology.
There are processes that have recently been developed that takes the toxic silicon tetrachloride and converts it back into polysilicon, increasing yield and lowering negative side effects. Further to this, researchers at the National Renewable Energy Laboratory in the United States have begun to investigate how to develop polysilicon without creating any silicon tetrachloride as a by-product.
There are also manufacturers who have listened to the calls for concern surrounding their toxic chemical use. There is a slow switch towards using safer alternatives like sodium hydroxide and zinc sulfide, and further research into other potential replacements.
This is one key area in which the renewable sector will always differ from fossil fuel extraction. Although solar panels are not quite at the stage where they are 100% ethical and renewable – they are certainly heading in that direction. There is such a wide focus on developing good practice further and improving every single stage of production.
Just because solar panels aren’t completely ethical, does not mean they are not the most ethical.