Solar Energy - A Bright Future? | Dr. George Fish | TEDxLa Cote International School | Summary and Q&A

TL;DR

Solar energy is a viable alternative to fossil fuels, and third-generation materials like perovskite and organic photovoltaics show promising improvements in efficiency and application.

Key Insights

• 😮 The average temperature of the Earth has been increasing, and fossil fuel consumption is the main contributor to the rising carbon dioxide levels.
• 👶 Solar energy is an essential alternative to fossil fuels, and new third-generation materials like perovskite and organic photovoltaics show promising advancements in efficiency and application.
• ⚡ Perovskite solar cells offer high efficiency and can be produced through a low-energy-intensive process, while organic photovoltaics provide tunability and the ability to absorb light in various spectra.
• ❓ Tandem solar cells, combining silicon with third-generation materials, have the potential to further improve efficiency.
• 😒 The stability and environmental concerns of third-generation materials, such as the use of lead in perovskite solar cells, need to be addressed for successful implementation.
• ❓ Third-generation materials have the potential to replace or complement current silicon technology in solar energy generation.
• 🏛️ Solar energy can be integrated into various applications, such as buildings, wearable technology, and decorative purposes, expanding its potential beyond electricity generation.

Transcript

[Applause] foreign [Applause] it's obviously difficult to go more than a few days without hearing something about climate change in the news that is because it is a very real issue that we are facing so since 1880 the average temperature of the Earth has actually been increasing by around 0.08 degrees Celsius per year however the rate of the temper... Read More

Questions & Answers

Q: What is causing the increasing temperature of the Earth?

The increasing temperature is primarily caused by the higher concentration of carbon dioxide in the atmosphere, mainly due to the burning of fossil fuels for electricity generation.

Q: Why can't we simply stop using fossil fuels?

While stopping the use of fossil fuels is an ideal solution, global electricity consumption is still increasing, making it necessary to find alternative energy sources to replace fossil fuels.

Q: What are perovskite solar cells, and what are their advantages?

Perovskite solar cells are made of crystalline materials with high efficiency and can be produced through a low-energy-intensive process, such as printing. They offer potential for achieving higher efficiency and could be used in tandem with silicon solar cells.

Q: What are organic photovoltaics, and what makes them unique?

Organic photovoltaics use organic compounds as the active layer in solar cells. They can be printed, offer tunability, and the ability to absorb light in the visible and near-infrared spectrum. They could be integrated into windows, wearable technology, and even used for decorative purposes.

Summary

In this video, the speaker discusses the issue of climate change and the need to find alternative sources of energy to replace fossil fuels. They focus on two third-generation solar cell technologies, perovskite and organic photovoltaics (OPVs), and explain their advantages and disadvantages. They also highlight the potential of using these technologies in tandem with silicon solar cells to enhance efficiency and broaden the applications of solar energy.

Questions & Answers

Q: Why is the temperature of the Earth increasing?

Since 1880, the average temperature of the Earth has been increasing by around 0.08 degrees Celsius per year. However, since 1981, the rate of temperature increase has dramatically accelerated to over 0.18 degrees Celsius. The main factor responsible for this is the higher concentration of carbon dioxide in the atmosphere. The concentration of carbon dioxide, methane, and nitrous oxides are currently at their highest levels in the past 800,000 years.

Q: What is the main cause of increased carbon dioxide emissions?

The main culprit for the increase in carbon dioxide emissions is our reliance on fossil fuels such as coal, oil, and natural gas. When we burn these fuels to create electricity, carbon dioxide is released into the atmosphere. While stopping the use of fossil fuels seems like a good idea, global electricity consumption is actually increasing every year by an average of three percent. Therefore, it is crucial to develop alternative energy sources to replace fossil fuels.

Q: How does solar energy work?

Solar energy harnesses the power of the Sun to create electricity. There are two main methods: concentrated solar power and solar photovoltaics (solar cells). Solar cells work by absorbing radiation from the Sun in their active layer, which generates positive and negative charges. These charges need to be separated and extracted from the active layer to produce electricity. The efficiency of a solar panel refers to the percentage of sunlight it successfully converts into electricity.

Q: What are silicon solar cells?

Silicon solar cells dominate the market and are made up of a single crystal silicon wafer as the active layer. They are highly efficient, with commercial cells reaching an efficiency of around 20-22%. Silicon solar cells are also cost-effective. However, the manufacturing process for these cells is energy-intensive, often fueled by fossil fuels. Additionally, silicon solar cells have a long energy payback time and are difficult to recycle after their 20-25 year lifespan.

Q: What are perovskite solar cells?

Perovskite solar cells are a type of third-generation material and have gained significant attention in the field. They are based on crystalline materials with the same abx3 crystal structure. Perovskite solar cells have shown impressive efficiency improvements, from around 30% in 2013 to over 25% currently. The manufacturing process for perovskite solar cells is less energy-intensive, as the materials can be spread as ink on conductive glass. However, their stability and the inclusion of lead in some compositions are issues that need to be addressed.

Q: How are stability issues addressed in perovskite solar cells?

Perovskite solar cells can be made more stable by adding protective layers or encapsulating the module. These measures help mitigate the effects of environmental factors such as oxygen exposure. However, these solutions increase the cost of the material. Another option is to use lead-free perovskites based on tin, but their efficiency is not as high as that of lead-containing counterparts.

Q: What is the potential of tandem solar cells?

Tandem solar cells, which combine an active layer from silicon solar cells with a perovskite layer, show promising results. By stacking these layers, the efficiency can surpass that of a standalone silicon cell. Tandem solar cells can achieve an efficiency of over 33% compared to a maximum of 27% for silicon cells alone. The higher efficiency compensates for the stability issues of perovskite cells by generating more electricity in a shorter time frame.

Q: What are organic photovoltaics (OPVs)?

Organic photovoltaics (OPVs) are solar cells where the active layer is made of organic compounds with a carbon backbone. OPVs have been in development since the 1950s but have made slower progress compared to other technologies. Their efficiency currently stands at around 19% for the best research devices. OPVs have the advantage of tunability, allowing for fine-tuning of properties by making slight changes to organic compounds. They can also be printed on flexible materials, making them suitable for wearable technology or transparent building applications.

Q: What makes OPVs advantageous for building integration?

OPVs can be printed onto glass to create nearly transparent solar cells that still absorb a significant portion of the solar spectrum. This means that they could be used as solar cell windows in buildings. Another advantage of OPVs is their color tunability, which allows them to be used for aesthetic purposes as well. For example, solar cells based on organic compounds have been used to decorate buildings while generating electricity, such as the Swiss Tech Convention Center.

Q: What is the potential of third-generation solar cell technologies?

The speaker believes that the future of third-generation solar cell technologies, like perovskite and organic photovoltaics, lies in their integration with existing silicon technology. By combining these technologies in tandem solar cells, efficiency can be significantly improved. While perovskite and OPVs have their own advantages and disadvantages, their unique properties can enhance the overall efficiency and widen the applications of solar energy.

Takeaways

The progress and adoption of solar energy are crucial in combating climate change. Third-generation solar cell technologies, such as perovskite and organic photovoltaics, offer promising alternatives to silicon solar cells. These technologies have shown considerable efficiency improvements and present advantages, such as low-cost manufacturing processes and tunability. However, stability issues and the inclusion of lead in some compositions need to be addressed. Integrating third-generation technologies with silicon solar cells through tandem solar cells can enhance efficiency and expand the applications of solar energy.

Summary & Key Takeaways

• Since 1880, the Earth's temperature has been increasing by 0.08 degrees Celsius per year, but the rate has dramatically increased since 1981 due to higher concentrations of carbon dioxide in the atmosphere.

• Fossil fuels, like coal, oil, and natural gas, are the main contributors to carbon dioxide emissions from electricity generation.

• Third-generation materials, such as perovskite and organic photovoltaics, offer higher efficiency and tunability for solar cells, providing alternative options for sustainable energy generation.