Sustainability taken to a whole new level
When the word “sustainable” is mentioned, most people consider it as a synonym for renewable energy. Well, that’s almost true. The term “sustainable” is actually similar to “renewable” except that it’s wider and includes all types of renewable energy.
Sustainability is about balancing the need for social, economic development with their impact on the environment and how it would affect different areas such as energy, water and agriculture or access to electricity and socio-economic development.
For years, the great obstacle facing renewable energy has been storage. How can energy, generated from unpredictable sources such as solar and wind, be stored so that it can then be dispersed during spikes in demand? Until recently, battery technology simply didn’t deliver the capacity needed. That was until a series of breakthroughs in the lithium-ion battery. It now has the ability to store and disperse energy over extremely long periods of time; a feature that has already fuelled a revolution in consumer technology, enabling tablet and Smartphone usage and now, finally, allowing the roll-out of electric vehicles that have a range similar to their petrol-powered equivalents.
Ian Lowe, a professor of science at Australia’s Griffith University said: “Cost-effective storage of electrical energy is the only problem holding us back from getting all of our power from wind and solar … this project is a significant innovation to demonstrate the feasibility of large-scale storage.” And the world is looking on. But this progress is not without risk. Lithium-ion battery technology is not perfect and demand for the raw materials that make up the batteries will likely create supply challenges and price spikes. And the construction of the lithium-ion battery itself comes with serious environmental and social challenges.”At the moment, the technology is being ramped up to power whole cities.
And, since we’re talking about Tesla, I have to mention the Tesla Model 3. Model 3 is the first of Tesla’s highly anticipated lower-cost electric cars. Tesla Model 3 is the first vehicle built on Tesla’s third-generation platform. It aims to reduce the entry price for electric vehicles while not making any compromise on range and performance. The Model 3 will start at $35,000 in the US and deliveries should begin in late 2017. Stay tuned for the long-awaited launch.
Another source for sustainable energy is the solar heat and light. Lately, a Korean research team has developed semi-transparent perovskite solar cells that could be great candidates for solar windows. These solar cells are highly efficient and functions very effectively as a thermal mirror. You won’t have to add solar panels to your rooftop anymore; they’ll be already a basic part of your home. But this has proven challenging, because transparency in solar cells reduces their efficiency in absorbing the sunlight they need to generate electricity.
Typical solar cells today are made of crystalline silicon, which is difficult to make translucent. By contrast, semi-transparent solar cells use, for example, organic or dye-sensitized materials. But compared to crystalline silicon-based cells, their power-conversion efficiencies are relatively low. Perovskites are hybrid organic-inorganic photovoltaic materials, which are cheap to produce and easy to manufacture. They have recently received much attention, as the efficiency of perovskite solar cells has rapidly increased to the level of silicon technologies in the past few years.
To achieve efficient semitransparent solar cells, you need to develop a transparent electrode for the cell’s uppermost layer that is compatible with the photoactive material. The Korean team developed a ‘top transparent electrode’ (TTE) that works well with perovskite solar cells. The TTE is based on a multilayer stack consisting of a metal film sandwiched between a high refractive index layer and an interfacial buffer layer. This TTE, placed as a solar cell’s top-most layer, can be prepared without damaging ingredients used in the development of perovskite solar cells. Unlike conventional transparent electrodes that only transmit visible light; the team’s TTE plays the dual role of allowing visible light to pass through while at the same time reflecting infrared rays.
The semi-transparent solar cells made with the TTEs exhibited average power conversion efficiency as high as 13.3%, reflecting 85.5% of incoming infrared light. Currently available crystalline silicon solar cells have up to 25% efficiency but are opaque.
The team believes that if the semi-transparent perovskite solar cells are scaled up for practical applications, they can be used in solar windows for buildings and automobiles, which not only generate electrical energy but also allow smart heat management in indoor environments, thereby utilizing solar energy more efficiently and effective.