Renewable Energy

Summary

Highlights

• Fossil fuels are finite and pollute, necessitating a shift to renewable energy. 🌍
• Renewable resources must also be sustainable; overuse can cause ecological harm. 🌳
• Hydroelectric power can significantly affect ecosystems, though its return on investment is high. 💧
• Solar energy, especially photovoltaics, is showing remarkable growth and potential. ☀️
• Geothermal and wind energy currently offer some of the best return on investment ratios. 💨
• Hydrogen fuel cells are a futuristic prospect, yet to be economically feasible. 🚀

Key Takeaways

• Fossil fuels are finite and pollute the atmosphere, pushing us towards renewable energy. 🌍
• Renewable doesn't always mean sustainable; overuse of resources like wood can lead to issues like deforestation. 🌳
• Hydroelectric power can provide a high return on investment but may disrupt ecosystems. 💧
• Solar energy has vast potential, with technologies like photovoltaics growing rapidly. ☀️
• Geothermal and wind energy are leading in return on investment ratios. 💨
• Future possibilities include hydrogen fuel cells, though currently not economically viable. 🚀

Overview

Chapters

• 00:00 - 00:30: Introduction to Renewable Energy The "Introduction to Renewable Energy" chapter begins with Mr. Andersen highlighting the reliance of modern society on fossil fuels and the issues associated with them. Fossil fuels are non-renewable and contribute to carbon dioxide emissions, which leads to global warming. The chapter underscores the necessity to not only reduce energy consumption but also transition towards renewable energy sources. Mr. Andersen introduces the primary focus of the video, which is a discussion on six categories of renewable energy.
• 00:30 - 01:00: Renewable vs. Sustainable Energy The chapter delves into the distinction between renewable and sustainable energy sources. It highlights that while some energy sources like wood and hydroelectric power are renewable, they may not always be sustainable. Deforestation can occur if wood is overused, and altering river ecosystems can result from hydroelectric power. The importance of ensuring energy sources are both renewable and sustainable is stressed. The chapter begins with a discussion on biomass, specifically focusing on solid forms like wood and charcoal.
• 01:00 - 03:00: Biomass Energy The chapter discusses various forms of renewable and sustainable energy sources. It begins with biodiesel and ethanol, progresses to small-scale hydroelectric power using waves and tides, and covers various types of solar systems including both passive and active systems. It also delves into thermal heating systems and photovoltaics that convert solar energy directly into electricity. Geothermal electricity and heat pumps for residential use are explored, followed by a discussion on wind power and wind turbines. The chapter concludes with insights into future energy solutions like hydrogen and its potential use in fuel cells.
• 03:00 - 04:00: Economic Factors of Energy Sources The chapter discusses the challenges and economic considerations in the infrastructure required for different energy sources. It highlights the consistency of fossil fuels in comparison to renewable sources like solar and wind, which are less consistent. The chapter further explores the scale of energy consumption, using a sphere representation to depict that the planet consumes 16 terawatts of energy annually.
• 04:00 - 05:00: Biomass: Wood and Charcoal The chapter discusses the various sources of potential energy available in nature, emphasizing both renewable and non-renewable resources. Key points include the vast energy potential of the Sun as compared to other resources like coal, uranium, oil, and natural gas, which are non-renewable and will eventually deplete. Despite the abundant energy from the Sun and other renewable sources, global energy consumption predominantly relies on non-renewable resources, creating a disconnect between potential energy availability and actual energy consumption patterns.
• 05:00 - 06:00: Biomass: Biodiesel and Ethanol The chapter discusses the concept of energy reserves and sustainability, particularly focusing on the energy return on investment (EROI). The key concept highlighted is the ratio between energy returned and energy invested, emphasizing the significance of reaching at least a 3:1 ratio before considering an energy source viable. The chapter concludes by prompting a reflective question on the energy return ratio for coal, inviting readers to consider its efficiency and sustainability.
• 06:00 - 08:00: Hydroelectric and Solar Energy The chapter discusses the efficiency and economic viability of various energy sources, particularly focusing on hydroelectric and solar energy. It starts with a comparison of coal, which has a high energy return on investment (EROI) at eighty to one, versus corn ethanol in the U.S., which has a much lower EROI of one-point three to one. This comparison highlights the lack of economic incentive to switch to ethanol or other similar renewable energy sources until their EROI improves. The chapter also mentions biomass as a form of renewable energy, with wood being one of the oldest types used by humanity.
• 08:00 - 09:30: Geothermal and Wind Energy The chapter discusses the use of renewable energy sources, particularly geothermal and wind energy. It highlights the high energy return on investment from using wood-burning stoves, common in northern latitudes like Montana, where cutting down trees for heat yields a 25:1 energy returned over energy invested ratio. Despite its efficiency, this method is not considered perfect due to problems it causes, such as pollution and deforestation, as well as significant soot production.
• 09:30 - 10:30: Future of Hydrogen Energy The chapter explores the environmental impact of using charcoal as a source of energy in developing countries. Charcoal, derived from wood through an anaerobic heating process, offers more potential energy but poses significant environmental challenges such as increased carbon monoxide emissions, pollution, and deforestation. The deforestation issues are exemplified by Haiti, where forest cover has drastically reduced from 60% to about 2%, leading to resource conflicts with the Dominican Republic.
• 10:30 - 13:00: Conclusion and Energy Infrastructure The chapter discusses the sustainability challenges associated with current energy infrastructure, specifically focusing on biofuel production. It highlights the issues related to biodiesel production from crops like canola and soybean, and the low energy return on energy invested in these processes. Additionally, the chapter examines corn ethanol production, which involves fermenting the sugars in corn to produce ethanol. Overall, it points out the inefficiencies and unsustainable nature of current biomass energy solutions.

Renewable Energy Transcription

• 00:00 - 00:30 Hi it's Mr. Andersen and this is AP environmental sciences video 28. It's on renewable energy. we really live in a society that's driven and governed by fossil fuels. The whole infrastructure is built on fossil fuels, but they have problems. They're non-renewable, so they're finite, will run out, and they're polluting the atmosphere, especially with carbon dioxide that's leading to global warming. And so we have to reduce the amount of energy that we're using, but we also have to move towards more renewable forms of energy. And so in this video, we'll talk about the six following categories.
• 00:30 - 01:00 But just because it's renewable doesn't mean it's sustainable. So wood, for example, is a wonderful form of renewable biomass energy, but if you use too much of it, it leads to deforestation. Or hydroelectric power is great, but can change the natural flow of a river, can change that whole ecosystem. And so we have to make sure that our energy sources are not only renewable, but sustainable. So we'll start by talking about biomass, one of the most ancient forms. We'll talk aabout solid forms, wood and charcoal.
• 01:00 - 01:30 And then we'll talk about more recent forms biodiesel and ethanol. We’ll then talk about small-scale hydroelectric power in the form of waves and tides. We’ll then talk about all the different types of solar systems, both passive and active. And then thermal heating systems and photovoltaics, those that actually convert the energy of the Sun into, directly into electricity. We’ll then talk about geothermal electricity, generating forms of energy, and then heat pumps that can be used residentially. We’ll then talk about wind power and wind turbines. We’ll then talk about hydrogen in the future. As a way we could harness that power in fuel cells.
• 01:30 - 02:00 But the big problem is going to be the infrastructure itself. In other words, how do we store this energy, and how do we move it where it needs to go. Because if we're looking at fossil fuels, we can get consistent energy. but the solar energy and the wind energy is not always going to be consistent. So let's look at the size difference between renewable and non-renewable. if this sphere represents the amount of energy that we consume on our planet every year, 16 terawatts of energy,
• 02:00 - 02:30 then each of these spheres represents the potential energy that we can find in both non-renewable and renewable resources. The one that dwarfs everything else is going to be the Sun. So the potential energy found within the Sun is huge, but we have a lot of it in coal uranium oil and natural gas. The problem with all of these on the right side is that they're non-renewable. We will run out of these. Now if we look at how much are we using the global energy consumption, as I mentioned earlier is, almost on all non renewables. And so it seems puzzling that we have a lot more energy potential on the left side,
• 02:30 - 03:00 but we're using energy reserves that are eventually going to run away. Well, it all comes down to economics or energy returned over, energy invested. And this is a term that I'll keep coming back to. So if we look at a one to one ratio, that would mean we're investing $1.00 in this form of energy, and we're getting $1 back. So we could call that the break-even. And we don't even look at energy sources until they become around a 3:1 ratio. If we're investing $1 we're getting $3 back. What do you think coal is?
• 03:00 - 03:30 Well if we look at coal, it's about eighty to one. It's a very small amount of money that's invested in coal mining and coal production, compared to the amount of energy that we get back. Now if we look at something in the U.S. like corn ethanol, it's a one-point three to one. So you can see, there's no economic incentive for us to start using ethanol until this ratio becomes more compatible with that of the nonrenewables. So let's start with biomass. Wood is one of the most ancient forms of biomass.
• 03:30 - 04:00 And so we use it in Montana. We use it all across the northern latitudes. Cut down some old trees, put them in a wood-burning stove. And you can heat your house. Now if we look at the energy returned over energy invested, it's a 25 to 1 ratio. This is going to be the highest ratio that we'll show you of any the renewables. And so why isn't this the perfect form? Well, it leads to other problems. It leads to pollution and can lead to deforestation. So if you're using this cooking, you're going to get a huge amount of soot that's coming off of it.
• 04:00 - 04:30 And that's not usually how it's used, especially in developing countries. They'll make that wood into charcoal. So you cover it up, and then you heat it up. And aerobically you get charcoal, which has a lot more potential energy, but also a lot more problem. And so as you use charcoal, we can have increases in carbon monoxide. It's going to be dirty, and also can lead to deforestation. So in Haiti, so this is Haiti, on the left side, they have a huge amount of deforestation. It used to be, I think 60% of Haiti was trees. And now something like 2%. And they're sneaking into the adjacent Dominican Republic to take charcoal back to where they are.
• 04:30 - 05:00 And so there are huge problems again, not sustainable. If we look at biomass, two big areas is biodiesel. So we're taking things like canola and canola oil or soybean oil and we're refining it to make a diesel. And if we look at the energy return to energy invested, it's a very small number. If we're looking at ethanol, so corn ethanol, we're fermenting the sugars inside it to make ethanol.
• 05:00 - 05:30 It's like drinking alcohol, but we can eventually combust it. If we're looking at corn again, it's a one point three to one ratio. If we were to go to sugarcane, in the U.S., it's going to be a three to one ratio. But in Brazil, it's going to be up to an eight to one ratio. So it depends on what our energy source is. And where it's actually being grown can change the amount of energy we get back. I talked about hydroelectric power on a large scale in a separate video. I'll put a link to that here. But hydroelectric power can have a huge return on investment. For looking at small scale
• 05:30 - 06:00 hydroelectric, waves over time, as the, as the wind blows over the surface of the water, we generate these waves. We can harness some of that. We can have a 15 to one ratio. If we're looking at tidal energy, as the tide comes in and out, we can harness that energy with a similar, similar kind of a ratio. Again, it doesn't scale as large as large-scale hydroelectric. If we're looking at solar energy, we've got passive energy. That’s when we’re just letting light in, especially during the winter, and we're collecting it, So this would be an example of a passive heating system,
• 06:00 - 06:30 where we have all of the windows on the south-facing side of the house, and then a huge amount of insulation to hold that thermal heat on the inside. If we're talking about more active systems, so this would be a thermal heating system, where we're heating up water and we're using it to heat our house. It's got a really low efficiency or low return on investment. If we're looking at photovoltaics, converting the energy right into electricity, there's been huge growth in this technology. The ratio is closer to seven to one. And if we're looking at these giant concentrating power plants, where we condense
• 06:30 - 07:00 all of that energy on one point to heat up, heat up water, and then generate electricity through steam, we can get a high ratio. There's a huge amount of potential for solar energy in the future. If we're looking at geothermal, this is energy from within the earth. So in Iceland, for example, they've gone a hundred percent renewables. A lot of that's hydroelectric, but they're also using geothermal power. As you heat up that material underneath the earth, it's generating electricity as it flows through turbines, get a huge ratio on that.
• 07:00 - 07:30 And then we can use a heat pump in your own house, where we're pumping fluids or air down into the earth, where it's being heated during the winter. And it returns some of that energy to us. And even during the summer, it can pump back some of the cool air underneath the earth. And then we can use wind. Wind has probably the greatest potential at this point right now, especially these offshore wind turbines. And so they're, they're massive. If we look at the size of this person here, compared to the turbine and the generator. We can get a huge amount of return, eighteen to one ratio.
• 07:30 - 08:00 And then as we look to the future, a lot of people say the future is in hydrogen. So if we can separate water into hydrogen and oxygen, and then we have them on either side of an electrolyte, we can generate electricity, as they flow together generating just water, as a by-product. And so this is a bus that's running just on hydrogen fuel. The ratio is incredibly small now. It's less than that break-even point. But it could be in the future that we can get some way to harness the power of algae, or harness the power of plants
• 08:00 - 08:30 to do the breaking of the hydrogen and oxygen apart for us. It could be something that we look at in the future, but again the major constraints are at this point is that we have the the whole infrastructure built on fossil fuels, the movement, the storage of the material. And so what we have to do is move towards an area of, maybe a smart grid, where we're figuring out, where's energy being produced, how do we move it to where it needs to go. It's not only power lines. but it's also harnessing the power of metering and the internet
• 08:30 - 09:00 to figure out where the energy is and where it has to go. And so again did you learn the following? could you pause the video at this point and fill in all the blanks? If you can, I'll try to do it for you. So renewable energy, we've got solid and liquid. This would be like biodiesel and ethanol. Hydroelectric small scale could be the winds and the tides. We've got passive solar, and then we have active solar heating water systems. And then the photovoltaics. We got geothermal heat pumps and then we've got hydrogen in fuel cells, wind and turbines, a huge way that we can generate energy.
• 09:00 - 09:30 But it all comes down to storage of that energy, and then moving it, where it needs to go. And I hope that was helpful.