In the 21st century, those who wish to live sustainably must take a proactive approach to the demands of energy. Without sustainable power sources, our world would be doomed to environmental devastation and human suffering.
This article explores the meaning of sustainable energy, and how this differs from renewable energy.
It also introduces the various types of sustainable power sources and how they might be implemented, as well as the benefits and drawbacks of each.
Sustainable energy is defined as coming from sources that do not have any adverse effect on future generations.
Most sustainable energy sources (such as hydro, wind, and solar) are also renewable. But the opposite is not necessarily true (as you will see below).
In order to be classed as a sustainable energy source, it must be possible for the energy to be collected, stored, and distributed in an effective and efficient manner.
Renewable energy is produced from resources that are replenishable over time.
In order to be considered renewable, the energy source must be replenished at a rate that can sustain our current energy usage.
This contrasts with non-renewable or fossil fuels, which are mined or extracted from the Earth and cannot be replenished on a human time scale.
Many people believe that renewable energy and sustainable energy are synonyms, and use the terms interchangeably. However, this isn't actually the case - there are subtle differences between the two.
Renewable energy is produced from resources that can be replenished over time, such as solar, wind, tidal, hydroelectric, biomass, and geothermal heat.
But not all renewable energy sources are sustainable.
Biomass, for example, is renewable. However, it does release greenhouse gases when burned, which will certainly impact future generations, meaning it cannot be described as sustainable.
For too long the world's energy has come primarily from burning fossil fuels such as coal, oil, and natural gas.
These fossil fuels are not sustainable. If we continue to burn them at the rate we have been, they will eventually run out.
Furthermore, fossil fuels emit greenhouse gases when burned, which are a major contributor to climate change.
We can of course make every effort to save energy, but energy conservation cannot win this fight alone.
To reduce greenhouse gas emissions, prevent further global warming and provide energy security for both current and future generations, we need to switch to using sustainable energy resources.
The use of renewable power is becoming more and more popular with the public and (as a result) with governments around the world.
The world is waking up to the fact that using renewable power can help to prevent global warming and solve the energy crisis.
Sustainable energy is also good for the economy. There are thousands of new green jobs being created as the world transitions from fossil fuels to clean energy sources. Energy sector professionals are often paid more than the average salary for comparable positions in other industries.
There are several sustainable energy sources in use today.
These are both sustainable and renewable sources of energy, which can potentially fulfill our energy needs now and in the future.
Each of these alternative energy sources has its own pros and cons, as we will now see.
Geothermal energy is any energy derived from ground heat. It is reliable, sustainable energy that is non-polluting and has no by-products.
However, geothermal power plants cannot be used everywhere. Large plants require geothermal reservoirs of 100°C and above. These are generally only found near the boundaries of tectonic plates or other areas where the earth's crust is thin.
The construction and setup cost is usually very high compared to other clean energy technologies, although the ongoing costs are low.
There are currently 61 geothermal power plants in the US, spread across 7 western states. The vast majority are in California and Nevada.
Geothermal energy is used for heating purposes as well as electricity production. It's also often combined with other sustainable sources of energy such as solar or wind, to provide a constant supply of clean energy.
Hydroelectric power converts moving water into electricity. Most hydropower is generated via dams on major rivers. The water flow is diverted through a pipe and spins large turbines, which in turn generate power.
This form of sustainable energy has been used in the US since 1880 and remains the largest source of renewable electricity to this day.
However, its share of the total output is reducing as other sustainable and renewable energy sources such as wind and solar become more widely used.
Of course, you need a suitably large and powerful river to produce energy in this way. Hydroelectric power stations have a high upfront cost. They are also vulnerable to changing weather conditions, especially drought. There are also some environmental considerations when disrupting the natural flow of a river.
Wind power is used to generate electricity by converting wind into mechanical energy.
The advantages of wind energy are that it is a renewable source of power that does not harm the environment in any way, and it can be used as a secondary source of energy for homes and offices which have already been powered by sustainable sources such as solar panels or geothermal heat.
Wind turbines can be used to produce power on a small scale, for example by using them in wind farms. Alternatively, they can be used at a commercial level to make electricity which can be fed into the national grid.
However, wind turbines can only be used in certain areas - it's not possible to create wind farms anywhere you like, such as in urban areas or wildlife reserves. The turbines can be noisy and are certainly unsightly, so they need additional infrastructure to transmit the power to where it is needed.
The amount of energy each turbine can produce is also very low, so to generate enough electricity to power a large number of homes or offices requires many turbines to be used.
Wind turbines are unpredictable. Needless to say, they need the wind! Wind speeds above 6mph for them to function properly, so it is difficult to predict how much electricity a turbine can generate over a period of time, and you can't guarantee they will be able to meet peak demand.
Also, turbines can sometimes cause problems with local wildlife (for example birds might fly into the blades).
Solar power is produced using photovoltaic cells, which convert sunlight directly into electricity, without any harmful by-products being released into the environment.
This makes solar energy a great option for powering homes and offices because it does not contribute to air pollution or global warming in any way.
Statistics show that solar panels are very popular with homeowners who want to make the most of their solar power. They can be used domestically on rooftops or in gardens, or on a commercial scale in large solar farms
Once installed, the energy generated by solar panels is free. This can dramatically lower your energy bill and you can even make money selling energy back to the grid.
However, the initial installation cost of solar means they need to be treated as a long-term investment to be worth it economically.
You will also need to find a competent local solar installer to set up a home solar system.
Once set up though, this is a truly sustainable energy solution that can improve the value of your home, save you money and fulfill your current and future energy needs.
Compared with other sustainable energy sources, tidal power has never been widely used because it's not as cost-effective.
The US currently has no tidal plants. South Korea, France, the United Kingdom, and Canada operate the largest plants in the world.
Generating tidal energy is only feasible in certain areas, where there are strong tides and large volumes of water close enough to the shore.
Additionally, tides only move at certain times of the day, so this is not a constant energy source. To ensure coverage at other times, you need to have the infrastructure to store the energy created.
However, tidal power is sustainable, permanent, and energy-efficient. Once set up, maintenance is cheap due to it having relatively few moving parts.
As we discussed earlier, the sources of sustainable energy listed above are also renewable.
Biofuel is made by directly converting biomass (such as plants and trees) into fuel, rather than using the sun, wind, oceans, or ground for this process.
This biofuel is burned, which does release carbon dioxide just like burning fossil fuels. For this reason, they are not considered to be sustainable energy.
Only limited biomass can be grown on a small area of land to produce enough fuel to meet demand. It is also a relatively inefficient process, using more energy in the growing and harvesting process than is generated when the fuel is used.
The higher the biomass density (how much volume per surface area), the better it is for the environment.
Biofuels are not always considered renewable because it depends on how they are grown. For example, some biofuels can cause deforestation if fast-growing crops like sugarcane and palm oil are used.
So what is energy sustainability? It's the ability to use renewable resources to provide a continuous flow of clean, sustainable energy that can meet the needs of today, without compromising future generations.
What makes sustainable energy so important is that it doesn't produce any harmful emissions or pollutants like coal, oil, and natural gas do.
This means that we can continue to use them without harming the environment. There are lots of different types of sustainable energy, each with its own advantages and disadvantages.
Sustainable energy provides jobs, has numerous environmental benefits, and will never run out. It can be expensive to set up in the first place, but the long-term benefits are huge and obvious.
Show your support for energy sustainability by lobbying congress, and/or by choosing an energy supplier that generates all or most of its power from sustainable energy sources.
You can also harness sustainable energy in your own home by investing in domestic wind and solar power systems, depending on your budget, location, and the type of building you live in.
What matters most is finding the right sustainable energy system for your needs, and using it in conjunction with other forms of sustainable energy to create a reliable and consistent supply of clean power.