Hello, friends! In Rajasthan's Jodhpur district, lies the village Bhadla. It gets very hot here. During the summers, the temperature here reaches around 46°C to 48°C. There are severe sandstorms as well. If you look at this area from the satellite, it looked somewhat like this in 2015-16. But if you look at the present-day satellite images of it, this is what you'll see. Bhadla Solar Park. Friends, did you know that this is the biggest solar park in the world? Spread across an area of 14,000 acres of land, In terms of km, the land measures around 56.6 km². Solar panels have been installed here. When you zoom out of this satelite view, You will truly realise how huge it is. It can fit half the city of Paris. It has a total capacity of 2,245 MW, This single solar park can produce enough electricity to meet the electricity requirements of the city of Kolkata. Can you imagine that? These huge solar power plants show you the true potential of solar energy. Internationally, Morocco is considered to be a world leader in terms of solar energy. 20% of the electricity produced in the country comes from solar energy. And the world's largest Concentrated Solar Power Plant can be found in Morocco. Concentrated refers to the solar power plants that generate heat from the sunlight
by concentrating it at one spot, in the tubes that you see in front of the panels. And later the thermal energy is used to produce electricity. On the other hand, the normal solar panels are Photovoltaic Solar Panels, like the ones installed in Rajasthan. They directly convert sunlight into electrical charges. But this raises an interesting question. How big can we scale these giant solar projects? Can we cover the entire desert with solar panels? What'll happen if we cover the Sahara desert with Solar Panels? Can the global electricity demand be met solely with solar panels? "We need less of this, and more of this." "The solar energy is likely to account for 60% of the global renewable power goals in 2022." "We can fly an airplane entirely solar-powered." "With solar power panels in orbit, we'll be able to provide energy day and night. All day long, no matter what the weather's like." Actually, friends, speaking realistically, To meet the global electricity requirements we won't even need to completely cover the Sahara desert with solar panels. So much solar energy reaches the Earth, that it's unimaginable. At all times, 173,000 terra watts of solar energy reaches the Earth. This is more than 10,000 times the global electricity requirement. It is estimated that the sunlight reaching the Earth in 1.5 hours Can meet the annual global energy consumption. It means that even if solar panels are installed in a relatively smaller area, it can meet the global requirements. How small can the area be? How much of the land needs to be covered with solar panels? It was estimated by Nadine May, in her research thesis in 2005. She said that if you zoom in on North Africa, in the small area depicted by the red square, by installing solar panels here the electricity requirements of Europe can be met. In a slightly larger square, with sides of 254 km, solar panels installed here would be enough to meet the global electricity requirements. Isn't it mindblowing? But this estimate is not a bit outdated. It was done in 2005. Since then, the global demand has risen significantly. A better and more realistic estimate was published that looks like this. You can find it on landartgenerator.org website. Here, it is assumed that the efficiency of the solar panels would be at 20%. In this estimate, the solar panels aren't installed in only one part of the Earth. You can see multiple squares in various parts of the World. They have been fairly distributed, claiming that if solar power plants are installed in these sqaures, the global requirements can be met. The other assumptions while calculating these, and the exact calculations, if you want to know these, I've put the link to the website in the description below, Go check it out. But the bottom line is, we'd need about 500,000 km² land, We'll have to install solar panels in this area to meet the global energy demands. 500,000 km² may sound like a big area, But don't forget that the world's biggest solar power plant in Rajasthan that I showed you at the beginning of this video, spanned around 56 km². So with 9,000 more such solar power plants across the world, we'd be done. India's peak electricity demand as on 9th June 2022, was at a record high at 210,793 MW. Approximately 200,000 MW. And the Bhadla Solar Power Plant can produce more than 2,000 MW. So if we set up 100 such solar power plants in India, we can meet the electricity demands of our country solely by using solar energy. Coming back to the global estimates, the 500,000 km² estimate, there are some interesting comparisons. The total area of highways in America is 94,000 km². It is about 20% of the 500,000 km² required. America accounts for 20% of the global energy consumption. It means that the resources spent by America to lay the roads, for the vehicles, If solar panels are installed in an area of an equal size, America's electricity demands can be met solely by solar energy. There's an interesting comparison involving the golf courses. The size of a typical golf course is 1 km². There are about 40,000 golf courses around the world. So if solar farms are set up instead of the golf courses, it'll account for 10% of the land requirement. Obviously, this plan sounds wonderful. But if it is so good, why aren't governments across the world executing it? Because friends, when we think about it practically many more problems crop up. First and foremost is the geopolitics. If solar panels are installed in the countries in the Sahara desert, other countries will need to be dependent on it. These countries will gain immense power no other country will want that. And anyhow, history is full of wars fought for energy like oil. Similar to how oil is produced only in a few countries, if the same happens with solar energy as well, the same problems will be created again. Then the second problem will be distributing the energy. Suppose we built huge solar power plants in the Sahara desert, or in multiple places across the world, taking the electricity to every part of the world would need a lot of money, electricity, and it will create a lot of wastage too. That's right, when electricity is transmitted from one place to another, there are some unavoidable losses in the transmission. The third problem will be maintenance. Who will maintain these solar panels? They require regular cleaning. Especially if they are installed in a desert with frequent sand storms, when the sand accumulates on the solar panels, they do not work as well. You'll wonder how the Bhadla solar power plant deals with this problem. Friends, more than 2,000 cleaning robots have been set up there. We have a solution, but this needs to be worked on some more. After this, the next biggest problem would be the life cycle. Once installed, the solar panels will not continue producing electricity till eternity. The solar panels have a life span. It is normally around 25 years. We will get electricity energy for 25 years, before having to replace them. A lot of resources and funds will be spent on it. And while we're talking about money, one of the biggest problems is money itself. Why don't we set up 100 solar power plants similar to the Bhadla Solar Power Plant? Because we don't have the funds to do it. Where will we get the money for that? There are so many problems here. But are there any solutions to these problems? There indeed is a solution. Perhaps the biggest solution that we can see is to stop imagining the enormous solar power plants, and start imagining solar energy on an individual level. Most of the problems that we encounter at a big scale, are irrelevant on an individual level. If people start installing solar panels in their homes, geopolitics will not be a problem. Maintenance will be easy at an individual level. The solar panel company will provide maintenance. Energy distribution will not be a problem. Because people will use the electricity in their homes first, and then think about disturbing the surplus. And in terms of the cost, it will benefit everyone. Today, there's no cheaper alternative than rooftop solar electricity. It doesn't matter in which state you live in, if you have space to install solar panels on your rooftop, it will be very beneficial to you. Friends, individual solar systems are of 2 types. On-grid and Off-grid. On-grid means that the solar system that you install at your home, will be connected to the grid. There you will get the facility of net metering. Meaning, during the day, the electricity produced by your solar panels, will first power you house, and if there is any surplus, it will be transmitted to the grid. So that it could be used by others. And at night, when the solar panels do not produce electricity, You use the electricity from the grid. You will have to pay for the electricity that you use from the grid, And you will get paid for the electricity that you transmitted to the grid. The net of the two will be your electricity bill. This is known as net metering. The second option is off-grid system. It means that you do not connect your solar system to the grid. instead, it is connected to a battery, when there's no solar energy at night, the energy stored in the battery will be used to meet the electricity requirements at night. The problem here is that the cost of the batteries is often very high. That's why, on-grid solar system is more beneficial. And as I told you, the average life cycle of a solar system is 25 years. From the perspective of an individual, it is a one-time investment with the returns spanning over the next 25 years as free electricity. And eventually, there will be a break-even point for the investment that can be somewhere around 3-5 years. The first 3-5 years you need to invest, And then you'll start getting the return, and from the 5th year to the 25th you get unadulterated profit. Specifically talking about India, there's an additional benefit there are subsidies by the Indian government If we take installing solar panels in homes to the next level, what is stopping us? Look at these structures, they are known as Heliotropes. The first such house was built in Freiburg, Germany in 1994. This looks like a futuristic concept It is a house that is completely solar-powered. A German architect and environmental activist, Rolf Disch, built the first house. The cylindrical shape that you see serves a major purpose. During the winters, the windows of the house face the Sun so that more heat can be absorbed and the house can be kept warm. The back is highly insulated. In the summers, the sun shines at the back, so that the house can be kept cool. This reduces the cost to keep the house warm or cool. Additionally, solar panels are installed on the roof which meets the energy requirements of the house. These solar panels rotate independently. They follow the Sun throughout the day, pointing towards it, so that the energy production is at maximum. Even the hot water in the house is provided through vacuum-tube solar panels. The design of the building is the most energy efficient in the world. Such a house produces 5-6 times the energy that it consumes. The architect calls it Plus Energy. This is completely emission-free, CO2-neutral, and is 100% regenerative. Since then, more such heliotrope houses have been built. This phenomenon is known as Heliotropism, we can spot this in nature as well. The sunflowers face the Sun. They bloom during the day, and the petals close at night. Similar to how those flowers work, so do these houses. Overall, there is a lot of potential in solar energy even if we talk at an individual level. The best solution isn't to have individuals install solar panels in their homes, and we stop creating solar parks. Or having solar parks only, without individual setups. Considering the location, the funds available, and the needs, we need to have a combination of both. I have sung a lot of praises of solar energy in this video So let me show you the other side of this. Solar energy isn't some magic that can solve all problems. There are several drawbacks and shortcomings. The drawbacks aren't the ones that you're probably thinking about. The biggest disadvantage of solar energy that people consider is when it's cloudy, or during the winter, people think that the solar energy wouldn't work as well. This is a myth. You'd see that if during the summer, 6 units per KW per day is produced, It is 3 units per KW per day in the monsoon, and 4 units per KW per day in winter. Though there is a slight difference, it isn't significant. Because the concept of photovoltaic depends on the light. As long as there is sufficient light around it, irrespective of any rain or cloud, it'll keep working. This is why in many cold places you will still see solar panels. In Northern European countries, many houses have solar panels even though it is very cold there. Because as long as there's light, they'll work. So if this wasn't a disadvantage, what is it? First, the carbon emissions. This is because most of the solar cells, is made of silicone, semiconductors, and glass. Additionally, metals such as silver, copper, indium, and pillerium are used. These materials need to be extracted to manufacture the solar panels, this has a huge environmental cost. Collecting silicone and glass isn't problematic. They are found everywhere and are non-toxic. But the metals that I mentioned. Silver, copper, and the other metals, need to be mined. And that mining leads to the soil, water, and air pollutions. The greenhouse gas emissions are increased. And the entire process to manufacture solar panels in the factories produce its own set of carbon emissions. Obviously, you need to consider that if we compare this with the fossil fuels like coal, gas, and oil, compared to them, using solar energy is definitely better. But the point is that it's not that the solar energy has zero impact on the environment. It is estimated that the carbon output of solar energy and solar panels is 20 times lower than that of coal. The second biggest disadvantage is the life cycle of solar panels. What happens when the life cycle of solar energy runs out? You'd consider simply replacing them. But what happens to the older solar panel? Can that be recycled? Today, it isn't very economically profitable to recycle the solar panels. Well, now, we haven't needed to recycle solar panels much. Because the solar panels installed in the 1970s are still working. Their efficiency has dropped 50 years later, but they can still be used. But there will be a point in the future, when a lot of solar panels will need to be replaced. These are a few of the things we'll have to be considerate towards in the future. But the future of solar energy is very bright. Each year, the cost of producing solar panels is going down. New technologies and innovations are seen. The efficiency of the solar panels is increasing. People are coming up with more creative ways to generate solar energy. Not only on land, or in houses, even on waterbodies. You can find floating solar power plants in Kerala. Such solar panels are used in the Maldives as well. To power tourist resorts. These have been introduced in the transport section as well. Perhaps having solar panels on vehicles may not seem as interesting to you, but boats and aeroplanes with solar panels are also being tested. The SUN21 solar boat holds the Guinness World Record to cross the Atlantic Ocean in the shortest duration using only Solar Energy. Solar Impulse 2 is an aeroplane with 17,000 solar cells on its wings. This plane flew 40,000 km without any fuel. Going into the future with these creative ideas, even more futuristic ideas are being discussed such as installing solar panels in space. Actually, a fun fact, this might seem surprising to you, The first use of solar energy was in spacecraft. The spacecraft Vanguard I was launched in the 1950s with the first artificial satellite with solar panels on it. "After two much-publicised failures, Project Vanguard scores a bullseye on its third firing at Cape Canaveral. The grapefruit-sized satellite is set into the nose cone of a three-stage rocket. And the launching routine begins." This satellite is still in the orbit. Today, more than 50 British Technology Organisations such as Airbus, UK Space Energy Initiative have come together to collaborate and create a solar power plant in space. They plan to create an orbiting power plant similar to how other satellites orbit the Earth They intend to set up so many solar panels that the solar energy produced can be beamed down on Earth to be used. They will try to use microwaves to beam the energy to Earth to be used here. Several problems that exist on Earth, such as night, rain, clouds, dust, do not exist in space. So it is estimated that the solar system that's installed in space will produce 13 times the energy that it can on Earth. They plan to make it a reality by 2035. But time will tell how possible it can be. That's all for today's video. If you liked this video, you can watch more technology and science related videos by clicking on this playlist. Thank you very much!
