The purpose of using renewable
energy is to reduce our reliance of scarce natural sources such as fossil
fuels. Our natural resources are being depleted at an exponential rate and
these sources will not be able to sustain our high usage in the long run. There
is hence a need to turn to more sustainable sources that also involves cleaner
energy generation methods as burning of fossil fuels entail grave environmental
impacts such as the release of acidic oxides and greenhouse gases which will
contribute to climate change.
The use of renewable energy
involves the following criteria. Firstly and most importantly, sustainability.
The energy source must be able to keep up with the demands of society without
affecting or limiting future usage. It must not affect future generations’ ability
to meet their own demands and needs. Secondly, its “cradle to cradle”
design. Most manufactured products end up being unrecyclable and cannot be
reused for other purpose. Unlike this, renewable energy sources should create
products that can be reclaimed or if not, products that can be disposed of and
degraded safely. This reduces the waste produced. Thirdly, innovation. The
switch from fossil fuels to renewable energy sources requires advanced
technology that is clean to ensure that it is effective.
Unlike fossil fuels which are scarce, finite and
take millions of years to regenerate, renewable energy sources are much more
sustainable and can regenerate at a much faster pace. Generally, there are five
commonly used renewable energy sources.
This includes wood, municipal solid waste, landfill
gas, biogas, ethanol and biodiesels.
Hydropower involves the harvesting of
energy produced from fast running water or water that falls from a height.
Watermills and dams are often used to collect this energy. For example, water
from the Niagara Falls and the Columbia River are led to flow through a pipe
towards a watermill. The force of the flowing water will push the blades of the
turbine, causing it to turn ad spin a generator which produces electricity.
Despite the need for some sort of technology to generate the electricity, this
form of energy is still very much accessible even for developing countries. In
April 2017, the Ivory Coast of West Africa will being their production of a 275
megawatt hydropower station. This hydropower station is predicted to boost the
economy’s total capacity by about 10%.
Geothermal energy is heat energy
derived from the natural heat stored in the Earth’s core which is made of
flowing lava currents. Because the temperature of the earth’s core and its
surface differ greatly, it creates a geothermal gradient for lava currents to
continuously flow towards the Earth’s crust, bringing thermal energy from the
core to the surface. The most simple form of geothermal energy are hot springs,
whereby water sources at specific locations are naturally heated up by the
Earth. Hot springs were originally used for bathing during the Paleolithic age
and for heating space during the Romans but today, it has been smartly and
efficiently used for the generation of electricity. In 2010, 28 gigawatts of
direct geothermal heating was used for district heating, spas, industrial processes,
desalination and agricultural activities.
Geothermal energy is a
cost-effective, reliable and sustainable energy source as lava currents in the
Earth’s core will never stop flowing and this heat will always be supplied to
the Earth’s surface. Its long-term sustainable has been demonstrated at The
Geysers field in California since 1960 and the Wairakei field in New Zealand
since 1958. Today, these fields are still in their prime condition. The only
downside of relying on geothermal energy is that geothermal heat is only
supplied to specific locations of the Earth’s crust and is usually restricted
to areas near tectonic plate boundaries, where there is room for lava to flow
upwards. However, thanks to recent technological advances, we have managed to
expand the range of geothermal sources, opening up tremendous potential for
even more application.
Wind energy is one of the most widely
used renewable energy source around the world as it is the easiest to harvest.
In fact, US has predicted that by 2030, 20% of its electricity would be
produced by wind power. This number is extremely impressive considering the US
has a huge population size and even 20% means many households will be using
electricity generated by wind power.
Wind energy can be
considered to be the most reliable and the cleanest source of renewable energy.
It does not generate any negative consequences and since wind is created due to
differentials in air pressure which is always present in the atmosphere, the
energy harvested is at a constant. Additionally, no extra costs are involved
except for the building of the turbines. Once the wind starts to push the
blades, all else runs naturally.
Yet, because of the
fact that wind is dependent on air pressure, the extent of its strength is
variable with most turbines usually functioning at only 30%. On another note,
though not a huge concern, there is a slight risk that the spinning turbines
pose a threat to flying creatures.
Solar power makes
use of sunlight. Light energy is converted into electricity directly via photovoltaic
(PV) or indirectly via concentrated solar power. Solar power is another source
of energy that is tapped on greatly, alongside wind power. Last year, 50% more
solar power was added worldwide due to the sun rush in US and China. The
industry grew significantly, and seems to be a common action plan used to
reduce combustion of fossil fuels and carbon emissions to meet the Paris
Climate Agreement targets as using solar energy does not generate emissions,
hence is sustainable in the long run.
In Singapore, solar
energy is the most promising source of renewable energy for electricity
generation. This is because Singapore has a small land size, thus we are
incapable of building wind turbines which require large open area and we lack
natural waters such as waterfalls or rivers. Therefore, Singapore cannot rely
on wind and hydropower, leaving us to turn to solar power. Even with the
restriction of options, solar energy remains extremely effective in Singapore
as we have an average solar irradiance of 1580 kWh/m2/year and 50% more solar
radiation that temperate countries, giving solar power a lot more potential.
mentioned above, Singapore’s small land size is a great disadvantage to us in
that there is not a lot of space to deploy solar energy. Standing at only a
mere 716.1km2, our scarcity of land has left us no choice but to build solar
panels on the rooftop of buildings instead.
This involves the
conversion of kinetic energy from movement to electrical energy. In Rio de
Janeiro, this plan has been executed by gathering kinetic energy from
youngsters playing on one of the newly built football pitch. When these
youngsters run across the Astro Turf, 200 hidden energy capturing tiles will
capture their energy, helping to power the neighborhood’s street lighting.
The very same
company that installed these tiles are also responsible for harvesting energy
from motor vehicles and producing pseudo-batteries from high footfall areas.
Waterboxx is a new type of technology that helps plants to grow healthily in
dry areas. It aims to restore greenery
and vegetation cover to not only make up for the years of deforestation
previously, but also increase agricultural production by planting trees that
are able to edible bear fruits and vegetables. This technology has been
extremely well received and even won the Innovation of the Year Award at the Popular
Science Green Tech Best of What’s New in 2010.