Examples of Resources: Solar, Wind, and Hydropower

A few weeks ago, a group of people from all over the world got together in a Google+ Hangout
to discuss the future of energy. The participants were drawn from a diverse range of
industries, including technology, cleantech, and environment, and represented more than
30 countries.

One of the questions we were asked about how to reduce our dependence on fossil fuels
and move towards sustainable energy sources, particularly in developing countries. As
experts in our respective fields, we took the opportunity to share examples of innovative
projects and technologies that make green energy more accessible to more people. These
are some of the examples that stuck with us.

Off-Grid Power

Off-grid power generation is a solution that gives individuals and communities the
freedom to generate their own electricity, without having to rely on the grid. This type of
energy is particularly attractive in emerging economies where access to the electricity grid
is limited.

This type of energy is produced using alternative sources like solar, water
power, and wind. A common source of off-grid power is small-scale solar panels that are
mounted on the roofs of houses. When the sun shines, the panels generate electricity that can
be stored in batteries or used directly by homes and businesses.

Other forms of alternative energy, such as wind and water power, can be used in
turbines that generate electricity that is fed into the grid. When the sun doesn’t shine or
the wind doesn’t blow, these forms of energy cannot be directly used and have to be stored
in batteries or other devices. For this reason, solar and wind power are often considered
dual-use technologies – they can both produce electricity and be used for other purposes
like heating and cooling.

Energy Mirrors

Energy mirrors are a great way to generate electricity and heat with bright sunlight –
even when the sun is not directly shining on a facility. They work by bouncing the
sun’s energy back into the source or in the direction it came from. This can help
generate enough electricity for a home or business.

The mirrors can be adjusted to change the angle of incidence of the incoming sun
rays, allowing the system to operate under different conditions than just direct sunlight.
This makes energy mirrors ideal for regions with intense sunlight and high temperatures,
such as desert areas and Southeast Asia. In some places, the sun doesn’t set for more than
10 hours a day, which makes this type of energy harvesting technology extremely
attractive.

Energy Cubes

Similar to solar power, energy cubes are another great way to harvest energy.
However, these are designed to be placed in the ground and connected to the
electricity grid. When sunlight hits the surface of the cube, it is converted into
electricity.

As the name would suggest, these are cubes – usually made from concrete or
metal materials – that house solar panels. The top surface is usually covered in absorber
materials like gravel, so when the sun shines on it, the heat is transferred into
electricity.

The world’s biggest collector of solar cubes, Roofsational, installed one
million solar panels on over 300,000 roofs around the world. The company was
established in the UK in 2015 and runs campaigns to raise awareness of
sustainability and the benefits of renewable energy. The panels are connected
to the grid and allow users to generate electricity whenever there’s sunlight
– regardless of the time of day or weather conditions. The system is fully
automated and monitored, so there’s no risk of incorrect operation.

Wave Power

Wave power is one of the most promising future sources of renewable energy, since it is
harvested from the open sea. It can be generated using various technologies like
oceanic thermal energy conversion (OTEC) and ocean current energy conversion (OCCC).

In OTEC, energy is extracted from the heat of the ocean using large underwater
constructions called ‘seawalls’. The heated water is then used to generate
electricity. The technology was first developed in Japan in the 1960s and has been
successfully implemented in some regions of the world, mostly in the form of
submarine power plants. The biggest challenge with this form of energy
harvesting is the construction of the seawall. It can only be done at certain
locations, as the depth of the water must be such that it creates an
artificial island that can support the weight of the structure. The walls
have to be strong enough to withstand the pressure of the water above
and prevent any damage to the generating mechanism inside. This causes the
seawalls to be rather expensive and, occasionally, the environment
restrictions that are put in place to protect the shoreline from damage
(such as the UNESCO-protected Akoya Islands, off the coast of Japan).

In OCCC, ocean currents are used to generate electricity. The current is
typically drawn from a body of water like a lake or the sea using large
buoys. These devices are known as fish generators and produce electricity
when large fish pass by or under them. The movement of the fish creates
vibrations that are transferred to a generator connected to an electricity
grid. There are several benefits to using marine species for
energy purposes, as they are abundant and provide an easy way to produce
electricity – both sustainable when considering the environment and
cost-effective. However, if the marine life is endangered or protected by
governmental regulations, other sources of renewable energy may become
more attractive.

Tidal Power

Tidal power is another renewable energy source that is primarily sourced from the
ocean. It’s generated using the gravitational force of the moon on the
ocean. When the moon aligns with the gravitational force of the sun and
the earth, the ocean’s movement is increased and this leads to an
increase in the power generated by tides. The world’s biggest tidal power
plant, the London Array, was launched in 2016 and operates 10
pencil-beam tracking devices on the seabed off the coast of
England. This energy is then transmitted through underwater cables to
shoreline substations, where it is fed into the grid.

Tidal power is a mature source of energy that has been around for
ages and has been successfully implemented all over the world. The biggest
challenge with this form of energy is getting the infrastructure in place
to capture the energy – particularly in areas where there are rough
seas and strong currents, like in the Atlantic and Pacific oceans. The
London Array solves this by combining several existing technologies in one
integrated system. However, the tidal force is rather limited and
unpredictable, so it is difficult to generate large amounts of
electricity with this form of energy. For this reason, it is not
usually considered a sustainable energy source.

Nuclear Power

Nuclear power is generated using nuclear fission – the process by which uranium is
broken down into smaller molecules as a result of nuclear reactions. This form of
electricity is considered a ‘clean’ alternative to fossil fuels and it’s one of the
primary energy sources used in countries like France and Japan. However, it is not
without its problems. The biggest one is that it is rather costly to run a nuclear power
plant. The cost of building one is between US$10 billion and $20 billion, not including the
cost of fuel. Considering that Japan is currently paying about $15,000 per
megawatt-hour, this definitely makes it an expensive option.

Another challenge is making sure that there are enough resources available to
fuel the nuclear reactors. Uranium is currently one of the most sought-after and
most expensive minerals on earth, which puts paid to the idea of creating a
sustainable energy source using this method. Mining it directly from the
earth is rather expensive and adds about $150 to the cost of a
megawatt-hour. This is one of the reasons why most nuclear power plants are
located in regions far away from major population centers, where there is
cheaper and more abundant uranium ore. The mining and enrichment processes
also generate a lot of radioactivity, which causes some health problems
for those exposed to it.

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