An Illustrated Guide to Clean Energy
Words by Maddison Brake, Melina Bunting and Chantelle Gourlay
Illustrations by Carla McRae
This story was originally published in Issue 4 and is brought to you by our impact partner, Deakin University.
To prevent catastrophic climate change, we need to halve global carbon emissions by 2030. To keep global warming below 1.5 degrees, emissions need to reach zero by 2050. Intimidated?
Currently fossil fuels contribute approximately 89 percent of the globe’s emissions. A statistic that we need to change. Fortunately, sustainable energy is more accessible than we once thought.
Wind Power
Wind turbines are incredibly powerful and can produce energy at extraordinary rates. A single wind turbine can produce up to 6 million kilowatt hours (kWh) per year – enough to power 1,500 homes. Already, wind farms are responsible for approximately 600 gigawatts of global renewable energy. That’s enough power for 430 million households! In regional Victoria, the Hepburn Community Wind Farm – Australia’s first community-owned wind farm – produces enough energy to power 2,300 households. That’s nearly the entirety of the Hepburn Springs and neighbouring Daylesford populations combined.
Twenty percent of Denmark’s energy comes from wind turbines, most of which are offshore. The popularity of offshore wind farms has also spread to Canada, the Netherlands, the United Kingdom and the United States. Wind turbines in the US contribute to approximately 273 billion kWh of renewable energy for the country per year. This may sound like a lot, but it’s actually only 6.5 percent of the country’s power.
Tidal Power
Another clean energy alternative is tidal power. Taken from the idea of a ‘tide mill’, which dates back to medieval times, tidal power transforms the energy of moving water into mechanical power. The world’s first tidal power station, the Rance Tidal Power Station, opened in France in 1966. It was overtaken as the largest tidal power station in the world by South Korea’s Sihwa Lake Tidal Power Station, which opened in 2011. Sihwa Lake station uses sea wall defence barriers and 10 turbines to generate 254 megawatts of energy per year. Maybe those waves you surfed on the weekend will power your hairdryer one day!
Solar Power
In drier places like the Sahara desert, where there is consistent sunlight and lots of unused space, solar panels have the potential to supply energy throughout the world. A single square kilometre of the Sahara has the potential to produce 2,000 to 3,000 kWh of solar energy per year. One study argues that, if all the desert’s sunlight were converted into electricity, it would provide 7,000 times more power than Europe’s total energy demand.
When looking to make conscious choices towards everyday sustainable energy use, installing solar panels is the go-to choice for many homeowners. Newer technologies are even making them look good. Solar roofing tiles and building-integrated photovoltaics, a multi-use material that can be used to construct features such as roofs, skylights or facades, are making it easier to seamlessly incorporate renewable energy into our surroundings.
But for many, including renters and people on a budget, it can be difficult to know exactly how to access clean energy. To address consumer demand, some energy providers are implementing renewable options. New Zealand-owned Powershop, for instance, offers Australians the option to purchase 100 percent carbon-neutral energy. That’s right – most of our clean energy options are still offshore.
Batteries – But Not As You Know Them
To keep our planet habitable, renewables need to become our main source of power. Of course, clean energy presents its own problems; we can’t control the whims of natural phenomena. On some days, we’ll only be working with a light breeze and an overcast sun. Fortunately, the tech that we have in place can work in limiting conditions. The blades on a wind turbine only need a gentle nudge to make them turn. On cloudy days, solar panels can still yield 25 percent of what they’d pump out when it’s sunny.
But what if, on one of these low-harvest days, we have a high demand for energy? Imagine a hot, humid day: it’s too hot to open the window, and you desperately need the fan on.
To keep up with our energy demands, we’re going to need lots and lots of batteries. When used in a grid system, batteries make it possible to generate and store power from renewable energy sources during low-demand periods, ready to redistribute it when the demand is high.
Among these are vanadium redox flow batteries: enormous, rechargeable batteries that use vanadium ions in different oxidation states to safely store energy. At this stage, widespread battery storage is expensive, but worth the investment as part of our collective shift towards renewable energy.
The downside is that most batteries contain lithium – a finite resource that has to be mined, which, needless to say, leads to carbon emissions. Although these emissions could be offset by the renewable energy they enable, scientists are investigating some sustainable alternatives. The answer could be found in the stuff you sprinkle over your scrambled eggs.
Salt Power
Sodium (found in salt) is prolific, hanging out in the ocean and the earth’s crust. The element is abundant and, conveniently, similar to lithium on a chemical level, making it a logical contender for use in batteries: no unsustainable materials required.
Sodium can even hold energy independent of batteries. A solar energy facility in Nevada uses sunlight to heat molten salt. It’s then stored in a thermal battery: a giant, insulated tank. Tapping the tank produces steam, which in turn powers a turbine.
On the other end of the thermal spectrum, some air conditioners can create ice batteries by storing and freezing cool air during the night. The ice is then used to control the temperature the following day.
However, lithium is our go-to for a reason. The metal can hold a significant amount of power without the need for a large or heavy battery. That’s what makes it ideal for cars, phones and computers. Sodium, on the other hand, can’t contain as much without compromising on size or weight. While we probably won’t find salt in our laptops anytime soon, when it comes to the energy grid these factors aren’t as important. Sodium batteries could yet be the answer to storing and distributing renewable power.
The Carbon Revolution – It Sucks
If you didn’t know it already, your fridge has a carbon hangover. Because of it, the planet is suffering. Chilling your Saturday takeaways day in, day out, means a whole lot of energy is gobbled up by this sneaky appliance. It’s also home to environmentally destructive refrigerants like hydrofluorocarbons (HFCs): the stuff that keeps our food from going off. HFCs are capable of emitting heat-trapping gases during manufacturing, leakage or the disposal of fridges.
Turns out it’s not easy keeping cool. Instead, it requires us to think deeply about our emissions – even the ones produced by our kitchen appliances.
So, broadly, how are our carbon emissions looking in the middle of the coal ‘renaissance’? For starters, we produce 50 percent more emissions than our 1750s predecessors, who prompted the universal burning of coal, oil and gas with the first industrial revolution. With 2030 looming, it’s becoming clear we’ve missed the boat. We should have thought seriously about phasing out coal, our largest producer of energy, decades ago.
Unfortunately, sending coal into retirement is not so simple. If we want to keep the lights on, we have to start sucking carbon out of the atmosphere. Literally.
We’re still using materials like concrete and lime to build our houses and pave our estate roads, driveways and kitchen walls. About 60 percent of the total CO2 emissions released from the construction of these materials are due to chemical reactions, not the combustion of fossil fuels. To reach the emission reduction target by 2050, creative efforts to mitigate carbon are required.
As opposed to direct air capture, an emerging technology aiming to remove CO2 from everyday air, carbon capture and storage (CCS) is already being used to suck up emissions from large factories and power plants around the world.
Many carbon capture technologies look to re-engineer the chemical reactions from factories and pull carbon dioxide from the air as it’s released. In labs from Reykjavik to Sydney, researchers are working hard to ‘future-proof’ heavy industries like concrete and lime against stringent emission restrictions. But can these technologies save us from a mass industrial exhale?
CO2-sucking solutions may be critical, but they can’t save our planet entirely. If you’re cleaning the house, you need more than the vacuum to get the job done. It’s the same for our atmosphere.
As Thomas Edison demonstrated in his quest for ‘electric light’, the path to a better world is never a straight line. He and his team tested up to 6,000 possible materials in their quest to create the lightbulb. Perhaps it’ll take the world’s experts just as many attempts to soothe our carbon hangover.
How’s the Future Looking?
As we transition to clean energy, what should we expect? Will countries around the world transition to the cycling culture of the Netherlands? Will ‘Car Free Sundays’ make a comeback? Will energy providers collectively reduce their use of fossil fuels in favour of renewable power?
There’s one thing that’s certain – it’s impossible to maintain the convenience of our lives and significantly reduce our carbon emissions. It’s our responsibility to limit our use of unsustainable services, like the luxury of having takeaway delivered straight to our homes or the amount of fast fashion we consume.
This new era won’t be smooth sailing. The journey to zilch emissions will involve a few sacrifices, but our planet will breathe easier for it.