Hello and welcome to Sustainable Thoughts.

Here we go, let’s first get familiar with the different technologies. Now, back to the question in the title of today’s blog… Is it the same as renewable energy? Or is it just anything that doesn’t have a negative effect on your health like fossil fuels? That would make it clean right?

Starting with the industrial revolution, where humans figured out how to mine ‘cheap’ sources of power through fossil fuels such as coal, crude oil, and fracked gas. Since then, society has had many positive gains, but recently the negative effects like pollution and water contamination have led to an urgent rush in developing renewable energy sources in an attempt to mitigate climate change. In 2015, 197 countries signed the Paris Agreement, which looks to limit the global temperature increase to under 2^oC between now and 2050 to minimise climate change effects. The European Union also signed a Green Deal to have net-zero greenhouse gas emissions and be carbon neutral by 2050.

Renewable sources are sources that are constantly replenished in a short period of time; the sun shines everyday and wind blows most of the time.The promise of a cleaner energy future is becoming more of a reality due to the less expensive harnessing methods of renewable energy sources.

Clean energy comes from sources that do not emit greenhouse gasses; nuclear energy is clean, but has a high safety risk, has waste-disposal issues, and can be weaponised. Hydropower is also a clean source, but has great negative environmental effects when production is over 40 megawatts of power due to the size of dam required. Clean sources mitigate climate change by reduing our reliance on dirty fossil fuels.

Renewable energy has many personal and national benefits over typical fosil fuels. De-centralizing your household’s energy supply gives you a more secure, and income generating energy supply. Having solar panels on your roof gives you the capability of selling your excess power to your national grid, thus allowing for competitive pricing in the energy markets. You also get a sense of electricity you actually use.

There is an uneven balance of fossil fuel reserves across the world, you don’t find crude oil, coal and natural gas in every place on earth. In contrast, renewables are everywhere. So the more renewable energy a country uses, the less reliance it has on fossil fuel-rich nations and thus electricity imports. Imagine paying so much money for power that pollutes the air and water and could be turned off at any moment over political disputes?

A study conducted by the National Renewable Energy Lab shows that the sun provides earth more energy in 1 hour than what everyone in the world uses in 1 year. This can be harvested in multiple ways, from your conventional rooftop solar, solar farms to the not so familiar concentrated solar power (CSP).

When you were younger, you might’ve tried to use a mirror or a magnifying glass to redirect sunlight to burn a piece of paper?

Concentrated solar power technology is a similar technique, it uses thousands of mirrors to reflect sunlight to a central receiver which converts light to heat. Thereafter undergoing a process to produce electricity or power a thermochemical reaction if required.

Over the years, the cost of wind energy has become the cheapest form of electricity today, with a levelized cost of electricity (LCOE) of under US$0.05/kWh (U.S Department of Energy). Wind capturing technology has been constantly improving resulting in it being cheaper than coal in recent years. Windmills were the first form back in the day, which were used to pump water and grind grain. They were inefficient and used more blades to catch more power. Today we have wind turbines, capable of being higher than skyscrapers, typically consisting of 3 blades to produce large amounts of clean and renewable power.

As expected, the largest worldwide renewable source is still hydropower. Large hydro dams cause major environmental damage, diverting river flows, flooding areas and forcing animals and humans to relocate. Yes, it produces clean power but the effect puts it as less renewable than solar and wind.

Similar to hydropower, biomass is often mistaken as clean and renewable. For some this might be obvious, cutting and burning trees has a negative effect on biodiversity. Geothermal energy is like a super deep well, bringing hot water from the earth’s core as a hydrothermal source of power, but is location dependent as they could trigger earthquakes in certain geological hotspots. Tidal and wave energy are also clean and renewable sources, harvesting energy from the movement of water in the ocean but possibly affecting aquatic life in the process. With careful design, this technology is promising while mitigating environmental effects.

At this point you might be thinking, what else is always available, clean, renewable and can produce electricity. The answer is (almost) hydrogen, the most abundant element in the world. As with everything in the world, it has its disadvantages.

Hydrogen is rarely ever found in its pure form, we produce it from reactions. The options are from fossil fuels (no, we don’t like fossil fuels anymore), nuclear (nope), biomass (50/50) or from renewable energies. If you remember your chemistry, we can use solar and wind energy to run an electric current through water and then split water into hydrogen and oxygen through electrolysis. The hydrogen we produce is then transported to a fuel cell where it splits into protons and electrons. The protons combine with hydroxide ions to create water and the electrons cause a flow of electricity.

In a perfect world, hydrogen is a good source of power, it has a 100% conversion efficiency but it is a highly flammable gas which is difficult to store in liquid form and transport.

Energy Efficiency

At the end of the day, sustainable living starts with us,we all need to be more energy efficient. That means we need to perform the same tasks by using less energy. That has many benefits that we may not physically see. To make this easier to understand, look at it thiis way… Before you buy a car, you will ask the dealer how fuel efficient is the vehicle? As you drive your car you are always aware of how much fuel your car uses over a given distance and how much fuel is left. You compare the fuel efficiency of your car to your peer’s car.

Now, lets imagine you used the same thought process for your household appliances, without compromising the quliaty of your desired product ofcourse. You would check; before you buy your TV, fridge, kettle, toaster, washing machine, how much energy it uses (Written in kilo-watts) compared to another brand that has the same specifications you want. If we all used the most energy efficient appliance availabe on the market we would :

1. Reduce the energy we use.
2. Reduce the energy wasted in the process of production.
3. Since we use less energy, we reduce greenhouse gas emissions.
4. Reduce our household energy demands.
5. Thus reducing the money we spend on electricity.
6. And we reduce the use of fossil fuels; keeping the price of energy low, because the more scarce a resource the higher its price becomes.

Another method is being more energy efficient is through our buildings, by using insulative material in our walls and upgrading to LED lighting. Using hybrid and fully-electric vehicles for personal use, as well as improving public transport systems and removing the stigma towards it will lead to a more efficient transport sector. Human behavior will need to globally change to truly live in a sustainable way, energy savings are lost due to cultural, social and economic fators.

So if you ever wonder; what is sustainable energy? An answer could be, it the use of clean and renewable energy sources while being holistically energy efficient in your day to day activities by being conscience of your appliance’s energy consumption.