In this guide, we look at the different types of renewable energy and outline why they may or may not be sustainable.
What Is Renewable Energy?
Essentially, renewable energy sources generally come from natural sources and/or natural processes, replenish quickly (immediately or within the course of a human lifetime), and won’t deplete when used.
Why The Different Energy Sources Are Renewable
What Is Non Renewable Energy?
Essentially, renewable energy sources generally require processing, take hundreds of thousands or millions of years to replenish, and may deplete in the future as we continue to use them.
What Are The Different Types Of Renewable Energy?
What Does Sustainable Mean?
There’s many different definitions of sustainability. Sustainability can refer to environmental, economic and other types of sustainability.
But, a general definition of environmental sustainability might be:
- the ability to to be maintained constantly, especially over the long term
- … without depleting natural resources, degrading the environment, ecosystems or biodiversity
Renewable vs Non Renewable Energy Sources, & Sustainability
Based on the above definitions of renewable energy and non renewable energy, we can already see that non renewable energy sources like fossil fuels and nuclear/uranium may deplete over time the more we mine them and use them.
So, this alone brings their sustainability into question.
But, apart from depletion, we must also look at environmental impact, and any waste produced.
Fossil fuels has some pretty significant negative environmental consequences like greenhouse gas emissions leading to climate change, air pollution from air contaminants, water pollution, land degradation from mining, and so on.
Nuclear also has to deal with mining and nuclear waste.
Renewable energy sources on the other hand do have some environmental consequences, but, they are thought to be nowhere near as large and significant as that of fossil fuels. For example, most renewables have no greenhouse gas emissions or air pollution while in operation.
Sustainable energy tends to be renewable, but not all renewable energy is sustainable.
And, there are different types of renewable energy. Let’s look at them each individually …
Is Solar Energy Sustainable?
Solar uses the sun’s energy and tends to be relatively sustainable as there are no emissions, no air pollution, and no waste products.
There is also no human processing of sunlight before it can be converted by solar panels or used for heat.
Solar energy does use a lot of land resources though with the big utility solar farms.
Is Wind Energy Sustainable?
Wind energy uses the energy from wind gusts and tends to be relatively sustainable as there are no emissions, no air pollution, and no waste products.
There is also no human processing of wind before it can be converted by wind turbines.
Wind turbines use a lot of land onshore though.
And they can disrupt sea beds and marine life or aquatic life offshore.
Is Hydro Energy Sustainable?
Run of river hydro tends to be quite sustainably. There’s no emissions or air pollution.
Hydro electric dams can have some environmental impact such as impacting aquatic life when water is discharged. There’s no emissions or air pollution.
Pumped storage hydro though can use fossil fuels to pump water uphill – so it will need to use solar and wind energy for this application in the future.
Is Geothermal Energy Sustainable?
Generally quite clean and sustainable compared to fossil fuels.
But, can release waste steam and gas, can cause hydraulic fracturing, and can cause air and water pollution, amongst other issues.
Are Wave & Tidal Energy Sustainable?
Generally quite clean in operation with no emissions or air pollution.
But, can dislodge and have a negative impact on seabeds, and marine life.
Are Bioenergy, Biomass & Biofuels Sustainable?
Some can be, whilst others may not be as much.
Some may produce waste after operation, as well as emissions or pollutants like methane, because it requires the combustion or break down of organic matter.
Some types of bioenergy also require human processing, or biocrops may require resources like water, land, fertilizers, pesticides and so on … bringing into question their overall sustainability
Other General Sustainability Problems With Renewable Energy Sources
It’s also worth noting that over the lifecycle of renewable energy, it does have some environmental impact, such as the water and carbon used and emitted to make solar panels, wind turbines, construct hydro dams etc. Materials do also have to be recycled or dumped once a solar panel gets to the end of it’s lifetime as well for example.
There could also be sustainability issues in the future in certain areas like the mining of, and potential scarcity of precious metal like lithium for example, that are used in renewable energy technology like energy storage batteries for power, and for electric vehicles.