Is Tidal Power the Future of Green Energy?

Imagine a structure, 24 times longer than the Hoover Dam, stretching out into the sea. Its 9-kilometer wall curves towards the horizon before returning to rejoin the coast, creating a giant artificial lagoon. Under the water line, a channel fitted with 16 turbines connects the lagoon to the ocean. As the tide goes in and out, the lagoon fills and drains, spinning the turbines to generate more than 530 gigawatt-hours of clean electricity each year—enough to power 155,000 homes.

If this sounds like an engineering challenge too far, it’s not. The Swansea Bay tidal lagoon in South Wales might have taken as little as three years to start generating power if approved. Yet it was never built. The issue? Money. The UK government turned down the £1.3 billion ($1.46 billion) project in 2018 on the grounds that it was too expensive.

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Transparent Solar Cells To Boost Personalized Energy

Today, the imminent climate change crisis demands a shift from conventionally used fossil fuels to efficient sources of green energy. This has led to researchers looking into the concept of “personalized energy,” which would make on-site energy generation possible. For example, solar cells could possibly be integrated into windows, vehicles, cellphone screens, and other everyday products. But for this, it is important for the solar panels to be handy and transparent. To this end, scientists have recently developed “transparent photovoltaic” (TPV) devices–transparent versions of the traditional solar cell. Unlike the conventionally dark, opaque solar cells (which absorb visible light), TPVs make use of the “invisible light that falls in the ultraviolet (UV) range.

Conventional solar cells can be either “wet type” (solution based) or “dry type” (made up of metal-oxide semiconductors). Of these, dry-type solar cells have a slight edge over the wet-type ones: they are more reliable, eco-friendly, and cost-effective. Moreover, metal-oxides are well-suited to make use of the UV light. Despite all this, however, the potential of metal-oxide TPVs has not been fully explored until now. To this end, researchers from Incheon National University, Republic of Korea, came up with an innovative design for a metal-oxide-based TPV device. They inserted an ultra-thin layer of silicon (Si) between two transparent metal-oxide semiconductors with the goal of developing an efficient TPV device.

Our aim was to devise a high-power-producing transparent solar cell, by embedding an ultra-thin film of amorphous Si between zinc oxide and nickel oxide,” explains Prof Joondong Kim, who led the study.

This novel design consisting of the Si film had three major advantages. First, it allowed for the utilization of longer-wavelength light (as opposed to bare TPVs). Second, it resulted in efficient photon collection. Third, it allowed for the faster transport of charged particles to the electrodes. Moreover, the design can potentially generate electricity even under low-light situations (for instance, on cloudy or rainy days). The scientists further confirmed the power-generating ability of the device by using it to operate the DC motor of a fan.

These findings has been published in a study in Nano Energy.

Source: http://www.inu.ac.kr/