The Engineering Challenges of Renewable Energy: Crash Course Engineering #30

Summary

This script discusses the environmental and sustainability issues of non-renewable energy sources and highlights the importance of renewable alternatives. It explores how hydropower, wind, geothermal, and solar power are harnessed, the challenges they face, and the innovations engineers are developing to overcome these obstacles and transition to cleaner energy solutions.

Takeaways

• 🔥 Engineering has significantly contributed to global development but relies heavily on non-renewable fuels.
• ⏳ Non-renewable resources like oil and natural gas are predicted to deplete within half a century.
• 🌍 Burning fossil fuels contributes to 87% of human-caused carbon dioxide emissions over the last 50 years.
• 💧 Hydropower converts the kinetic energy of flowing water into electricity but struggles with demand control.
• 🌪️ Wind power uses turbines to harness energy from air but faces challenges with inconsistent wind strength.
• 🌡️ Geothermal power uses underground heat to generate steam for electricity but is limited by geographical availability.
• ☀️ Solar power has the potential to be abundant and accessible but currently faces efficiency and storage challenges.
• 💹 The cost of solar power production is currently higher than that of fossil fuels due to inefficiencies and production costs.
• 🔄 Engineers are exploring new materials and technologies to improve the efficiency and economic viability of solar panels.
• 🌐 Renewable energy sources are critical for meeting future energy demands and reducing environmental impact.

Q & A

What is the primary concern with relying on non-renewable fuels for powering engineering developments?

The main concern is that non-renewable fuels, such as oil and natural gas, are being depleted much faster than they can be naturally replenished, and their use has a detrimental impact on the environment, contributing significantly to harmful carbon dioxide emissions.

How much of the power used in the United States in 2017 was supplied by fossil fuels?

In 2017, 80% of the power used in the United States was supplied by fossil fuels.

What is the process of nuclear fission and why is it less desirable despite producing less CO2?

Nuclear fission is the process of splitting atoms to release energy, which produces far less CO2 compared to fossil fuels. However, it is less desirable because it generates radioactive waste and relies on non-renewable fuel sources like uranium and plutonium.

How do renewable energy sources like wind and hydropower work in comparison to traditional heat engines?

Renewable energy sources like wind and hydropower operate using turbines, where wind turbines use air and hydropower uses flowing water to turn the blades of a generator. Unlike traditional heat engines that rely on heating a working fluid, these renewable sources harness kinetic energy from natural processes.

What is the challenge with hydropower when it comes to controlling energy generation to meet demand?

The challenge with hydropower is that the generation of energy cannot be easily controlled to meet demand because it depends on natural factors like river flow, which is influenced by rainfall and temperature, both of which cannot be controlled.

How does a hydroelectric dam overcome the challenge of controlling energy generation in hydropower?

A hydroelectric dam overcomes the challenge by creating a reservoir of water that can be controlled through an intake valve, allowing for the management of water flow through the turbines to meet the changing demands of the electrical grid.

What are the environmental concerns associated with building a hydroelectric dam?

Building a hydroelectric dam can have devastating consequences for the local ecology due to the sudden environmental changes caused by flooding an area and preventing the natural flow of water downstream. There is also the risk of the dam breaking if it was not built properly.

What is the role of location in the effectiveness of wind power and geothermal power?

Location plays a significant role in the effectiveness of wind power and geothermal power. Wind power is more effective in sparsely populated, open plains where wind is more consistent, while geothermal power is feasible in areas near the Earth’s tectonic plate boundaries where underground heat sources are accessible.

How do solar panels convert sunlight into electricity and what is the challenge with their efficiency?

Solar panels, or photovoltaic cells, convert sunlight into electricity by using two different semiconducting pieces to create an electrical field that biases the movement of free electrons, encouraging an electrical current to flow. The challenge is that solar cells are not very efficient, with the best cells converting about 40% of absorbed energy into electricity, but they are expensive to produce. On average, industrial PV cells are about 17% efficient.

What are some of the methods engineers are considering to improve the storage of solar power?

Engineers are considering methods such as using solar power to drive hydrogen fuel production, which can be stored and burned later with no carbon dioxide emissions, and exploring new materials and structures, like nanocrystals, to increase the efficiency of solar panels.

What is the significance of the efficiency of solar panels in making them economically competitive with current power sources?

The efficiency of solar panels is significant because higher efficiency would reduce the cost of solar power production, making it more economically competitive with current power sources. This could lead to increased adoption of solar power worldwide.

What are some of the environmental challenges associated with manufacturing solar panels?

Manufacturing solar panels involves processing quartz to produce high-quality silicon, which is an energy-intensive process that offsets some of the total energy production of solar panels. Additionally, this process can produce toxic byproducts like tetrachloride, which can harm the environment.