The US Energy (Renewable Energy) Information Administration recently reported that the world will consume over 21,000 TWh of electricity overall in 2020. And over the next three decades, global consumption will probably increase by 50%.
However, more important than the rise in energy usage, is the source from where the energy comes. Even today, over four-fifths of the world’s energy, comes from burning non-renewable fossil fuels. We know how dangerous these fuels are for the environment.
Day by day, more natural disasters are being reported across the globe. The situation is getting worse with climate change. And not surprisingly, climate change has become the biggest reason for driving the world to focus on sustainability. Researchers worldwide are now exploring ways to change how humans interact with nature. One of the most crucial areas of this endeavour is finding new ways to generate renewable energy.
There is a significant shortage of renewable energy to meet global demand. Even the largest wind farms, solar farms and other sources are not sufficient. Hence, researchers are trying to find new green energy sources. Some are dreaming of the “blue energy” from oceans. Whereas, others are trying to generate electricity from raindrops. Seemingly, for smart cities, this could be the opportunity to win the race against climate change. And in the effort, tackle the energy crises.
Read on to explore more about these novel efforts taking place in different corners of the world.
Ocean’s Blue Energy
Ocean engineer Ian Young and mathematician Agustinus Ribal analysed satellite data and a global network of floating buoys. They found that the tallest ocean waves are getting taller. And ocean wind speeds are increasing possibly due to climate change. Therefore, in such a situation the ocean could have more energy to yield.
Back in 2017, the International Energy Agency estimated that energy stored in waves worldwide is about 80,000 TWh. Out of this, 4000 TWh could be harvested and converted to electricity. Naturally, the ocean is an engine that converts solar energy into mechanical energy. Hence, since decades, visionaries have dreamt of harnessing its constant motion to power the world.
Today, coastlines, ports, and tidal rivers worldwide are becoming testbeds for systems that can generate power. Take, for example, Gibraltar, the British territory that extends from Spain into the Mediterranean Sea. Here on the east side of The Rock, eight blue mechanical arms are attached to far-flung buoys. These rise and fall when waves roll in from the sea at a height of 0.5 m.
At this point, the oscillating arms drive pistons that pump hydraulic fluid into an onshore power station. This is where the fluid spins a hydro motor that generates electricity flowing into Gibraltar’s grid. This is one of those few places where sea waves are used to generate electricity.
However, every such project has not been successful. Finance and the power of the sea are seen as the biggest challenges that have ruined several efforts. That said, as per Stephen Omes’ discovery, the dream of “blue energy” breathes on. All thanks to many devoted teams of researchers and hit-tech business pioneers. If researchers can find the right approach, the energy demand of the entire world can be met by the ocean. But that is still far from reach.
One Raindrop = 100 LED Bulbs
A team of scientists from the City University of Hong Kong have recently developed a droplet-based electricity generator. The new model features a structure that slightly resembles a field-effect transistor. It enables high energy-conversion efficiency and instantaneous power density that is thousands of times compared to equivalents without FET-like structure.
The creation of this raindrop-powered generator was outlined by the scientists in a study published in Nature. As per reports, a single drop of rain can enable the generator to produce 140V. This much energy is enough to power approximately 100 small bulbs. Water droplets can hit the generator constantly like natural rainfall. And the generator will collect the charge and reach a saturation point.
This study can have a global impact in a way to meet energy crisis and support sustainability. This is as stated by Professor Wang Zuankai, one of the lead researchers. He added that the instantaneous power density is not the result of additional energy. Instead, it results from the conversion of the kinetic energy of water. This kinetic energy is due to gravity. It is free, renewable and hence can be better utilised.
Furthermore, their study also shows that the reduction in relative humidity does not affect the efficiency of power generation. Besides, both rainwater and seawater can be used to generate electricity. In 2016, rainwater was used to power solar cells. This research takes renewable energy generation from raindrops one step ahead. Further, it will help to advance scientific research.
Sand-like Drops To Generate Electricity
Engineers of Sandia National Laboratories, US, have invented a falling particle receiver at the National Solar Thermal Test Facility. The technology is intended to be used in generating electricity from solar power towers.
The receiver works as small sand-like ceramic particles are dropped through a beam of concentrated sunlight. This stage heats up these particles that act as a heat storage medium for producing electricity using a steam turbine.
Here, the important point that comes to light is the use of the sand-like particles. They are used in the place of molten salt currently used as the energy storage medium in solar power towers. These particles have the capacity to store heat at a much higher temperature than molten salt – without undergoing a chemical breakdown. This factor alone helps in making electrical generation more efficient.
As per Sandia, these sand-like particles can operate at a temperature exceeding 1,000 °C. This is 400 degrees higher than the operating temperature of the molten salt system. Having an energy storage system means that electricity can be produced even when sunlight is not available. In other words, we can have electricity even when at night or when it is cloudy outside.
Energy From Thin Air – Not From Wind Turbines
A research team at the University of Massachusetts have discovered a way to generate power from thin air in the environment. The team has developed a device that uses natural protein to produce electricity from humidity and moisture in the atmosphere. As per the team, this new technology could change the face of renewable energy. The air-powered generator called the ‘Air-gen’ comprises tiny electricity conductive wires. These wires are protein nanowire produced by microbes. When the generator connects electrodes to nanowires electricity is produced from water vapour in the atmosphere.
As said by Jun Yao, an electrical engineer, the Air-gen can generate green energy 24/7. The technology is non-polluting, low-cost and renewable. The researchers claim that this technology can produce electricity even in areas where humidity is extremely low. One of the best examples is Sahara Desert. It allows the power generation indoors without the need for sunlight or wind.
Yao further explains that the ultimate goal is to develop large-scale systems. For example, technology can be incorporated into wall paint that could help power our homes. At industrial scale for wire production, it can greatly contribute to sustainable energy production.
Researchers hope that these innovations can help smart cities respond to the global problem of renewable energy shortage – and climate change. As per scientists, there is a need not only for efficient energy conversions, but it is also required to move away from massive machines. Currently, the work is going on in this line, to power anything for sustained periods. However, it will take time before these innovative energy sources can power our homes.