Energy comparison: solar (PV) panels

Hi everyone,

Today I'm looking into the first on a long list of energy sources: solar (PV) panels. Are they actually sustainable and could they become our main energy source in the near future? After all, enough energy from the sun reaches the earth in 90 minutes to cover the entire world's energy consumption for a whole year!

How they work

There are a couple of ways to transform energy from the sun into electricity. The one we are looking at today is solar panels also known as solar photovoltaic technology. Photovoltaic (PV) technology is the key to solar panels. A solar panel is made of many PV cells. A single PV cell will produce 1-2 watts of power. They are very thin and are normally protected by glass and/or plastics. This is the best explanation I could find (click here for the source):

When the semiconductor is exposed to light, it absorbs the light’s energy and transfers it to negatively charged particles in the material called electrons. This extra energy allows the electrons to flow through the material as an electrical current.

The electric current produced is a direct current, so a converter is added to convert it into an alternating current used in households. Some PV systems will have structures that angle the panels to face the sun for maximal energy production.

Energy storage

Solar panels themselves do not store energy. However, there are batteries for storing solar energy. They are quite expensive. Lithium-ion batteries are at least 90% efficient. That isn't terrible but you would still lose 10% of your electricity. Lead-acid batteries may be the most affordable, but they have an efficiency of 60%-80% (depending on model and brand). That's quite bad. Flow batteries, which are the newest model have 85% efficiency. So all in all, solar batteries aren't amazing and it's definitely one of the biggest problems for the industry.

Energy in production

To produce one 100-watt solar panel, you need about 200kWh (varying massively). With enough sunlight, the 100-watt solar panel would produce enough electricity to cover that in about 2 years. A solar array (multiple solar panels) has a carbon footprint about 20 times smaller than a power plant (when both produce the same amount of energy). A solar panel becomes net zero after about 4 years of being used. We're hoping that it will soon be possible to use solar panels to power the factory making solar panels. However, there would still be CO2 emissions due to transportation and maintenance.

Downsides

In 2016, 250 000 tonnes of 'solar panel waste' were generated in the whole world. Estimates say it could be 78 million tonnes in 2050. Cadmium and lead are contained in this waste and can be washed into local rivers and bodies of water, causing extreme health risks for nearby people.

As mentioned above, fossil fuels, normally coal, are needed to produce solar panels. During production, hydrofluoric acid and sodium hydroxide are used. Most of this is dumped in local bodies of water, where they release toxic substances and chemical waste. There are also allegations of a lack of the needed safety gear and regulations that protect the workers producing the solar panels.

19 different rare metals are needed for PV cells, and most of them require mining. So we cannot create endless solar panels without running out of materials.

Covering the Sahara?

Many people think we should cover the Sahara desert with solar panels. This may sound like a good idea at first. After all, it would produce enough electricity to easily power the whole world, there is plenty and as not many species live in the desert, it wouldn't destroy too much habitat. However, it is a very bad idea.

We have already mentioned the fact that we do not have the needed resources to produce that many solar panels.
We do not have the infrastructure to build a massive solar field.
Such a project would produce massive greenhouse gas emissions during production.
As already mentioned, we can't effienciety store solar energy and transporting it to another part of the world would be difficult.
We would have to replace the solar panels after about 25 years, which would cause massive amounts of waste.
It would cost trillions of dollars.
While it is night in the Sahara, there will be no electricity production. However at this time, it is broad daylight in Australia meaning that they need electricity. As said before, the storage is not optimal.
A power cable from the sahara to the rest of the world would have at least a 20% power loss.
The solar panels would cool the desert, meaning plants would grow. Then it wouldn't be a desert anymore and we would be destroying more habitat.
The dust and sand that the wind in the sahara picks up, fertilises the Amazon rainforest. With all those solar panels in the way, the dust wouldn't fertilise the Amazon. The amazon dying would be a catastrophy.
Due to point 9. hurricanes and storms would rampage the Americas more frequently.
Global oxygen levels may drop due to losing the amazon (point 10.) and the atlantic also being affected.

I could go on and on, but I think you get the point. Covering the entire Sahara and trying to power the whole world with it, is a really bad idea. However, it could be implemented on a much smaller scale to provide local populations with electricity. Morroco has the world's largest solar farm in the Sahara.

All in all, solar panels aren't great for the environment. However, the idea of using the sun's energy is actually not too bad. If the technology surrounding the production, waste and storage of solar panels could be drastically improved, then we could use solar panels as the world's main power source. We just need the technology to be efficient first. This is already in the making, hundreds of scientists world-wide are working on how to improve solar panels. There are also ideas of creating solar farms in space, which would eliminate the problem of solar farms being reliant on the weather.

Your Green World Blog Team💚

Sources:

https://www.energy.gov/eere/solar/how-does-solar-work
https://www.energy.gov/eere/solar/solar-photovoltaic-technology-basics https://www.energy.gov/eere/solar/solar-photovoltaic-cell-basics
https://www.solar.com/learn/how-solar-panels-absorb-and-store-energy/
https://www.solarsystemaustralia.com.au/how-efficient-are-solar-batteries/
https://solvoltaics.com/energy-make-solar-panel/
https://solarpowerfocus.com/disadvantages-of-solar-energy/
https://earthfirst.org.uk/environmental-impact-of-solar-panels/
https://medium.com/predict/why-dont-we-cover-the-sharah-in-solar-panels-3692a5bf89bd
https://www.theguardian.com/science/2023/sep/17/tim-peake-backs-idea-for-solar-farms-in-space-as-costs-fall
https://www.sciencedaily.com/releases/2023/09/230920111217.htm

Image:

This image, owned by Wolfram Burner (on flickr.com) is liscensed under CC BY-NC 2.0.

Comments

The life of ... an alcon blue butterfly

Hi everyone, Today we are going to be looking into the life of an alcon blue butterfly (Phengaris alcon). After mating, the females lay their eggs on marsh gentian, a blue-coloured wildflower. The eggs can only be laid on these flowers, as this is what the newly hatched caterpillars will eat. Although in some alp regions, they can also be found on willow gentians, a close relative of the marsh gentian. Once the caterpillars have hatched from the eggs, their main predator and danger are the ants that swarm below. But high on their plant homes, the caterpillars are safe. However, this isn't where the alcon blue caterpillars are going to stay forever. Eventually, they drop down to the ground using silk strings. With no protection, they are soon dragged off by the ants. The most amazing part is, the alcon blue caterpillars give off the same scent and chemicals as the ant larvae. So the ants take the caterpillars back to their brood chamber, wher...

The life of ... a koala

Hello everyone, Today we're talking about koalas. Also known as koala bears, koalas are marsupials. So they're actually not bears. Koalas, phascolarctos cinereus , are tree dwelling and probably best known for spending most of the day sleeping. They live for up to 15 years in the wild although captive koalas generally live for longer. Koalas have a stout, gray body and a cream-coloured chest. They have a broad face, small yellow eyes and big fluffy ears. In adaptation to climbing, their feet are strong and clawed. Adult individuals in South Australia weigh 14kg and are 60-84cm big. Their Eastern cousins are considerably smaller. Koalas are found in Eastern and Southern Australia, where they live in eucalyptus trees. They feed on the leaves of these eucalyptus trees, eating up to 1.3kg a day. With a body weight of up to 14kg, this means they eat just under 10% of their body weight every single day. However, the le...

How well do you know the ocean floor? - Quiz

Hi Everyone and welcome back to Green World! Today we have another quiz to test your knowledge about the natural world. This is, of course, part of our monthly series of quizzes, so please give us some feedback on how you are finding it so far in the comments! This time, it's all about the ocean floor. Questions How much percent of the earth's surface consists of ocean floor? a)50% b) 60% c) 70% True or False? Just like on dry land, the ocean floor has mountains, plains and valleys. Which ocean can the Mariana Trench be found? a) Pacific Ocean b) Altantic Ocean c) Indian Ocean True or False? The Mariana Trench is 11km deep. How much of the earth's surface is covered by abyssal plains? a) about 33% b) about 50% c) about 10% True or False? Studies estimated that 90% of deep sea species haven't been discovered yet? Tr...

Eco system Galápagos: Part 1 Geography

Hello and welcome to the first post about the Galapagos Islands. Currents and Winds The volcanic islands of Galápagos started to form 4 million years ago. Where they lie, is unique. They are situated directly on the equator, on the Nazca tectonic plate. The Galapagos Islands are on the crossroads of three currents. The cold South Equatorial Current flows westward towards Galapagos. The warm Panama Current runs in from the north. And finally, the deep sea Cromwell Current runs from the west. The Galapagos Islands are also where the Northeast Trade Wind meets the Southeast Trade Wind. Galapagos Hotspot 21 Volcanoes make up the Galápagos Islands with 13 still active. The reason for this volcanic activity is a giant hotspot under the island. A hotspot is a gigantic column of super heated molten lava, rising up towards the surface. It is immense; at least sixty miles (97 kilometers) across and 1800 miles (2897 kilometers) deep. It connects the islands to ...

Coral reefs

Hello! We would love to introduce you to the topic of coral reefs and especially coral reef bleaching, as it is a greatly ignored but certainly significant topic. Have fun! 5 coral reef facts 1. The Great Barrier Reef is the largest living structure on the planet and is 2300 km long! 2. Less than 0.1% of the world's ocean surface is covered in coral reefs. 3. At least 25% of all marine animals live there. 4. Coral reefs are often known as the rainforests of the ocean. 5. In 1 square kilometre of coral reef, up to 35 tons of fish can be 'produced'. The 5 biggest coral reefs in the world 1. Great Barrier Reef (near Australia) 2. Red Sea Coral Reef (near Egypt, Israel and Djibouti) 3. New Caledonia Reef (Pacific Ocean near New Caledonia) 4. The Mesoamerican Barrier Reef (near Mexico, Belize, Guatemala and Honduras) 5. Florida Reef (Atlantic Ocean/Gulf of Mexico near Florida) What is coral? Coral is actually made up of small anim...

How much do you know about extinction? | quiz

Hi Everyone! Welcome back to the blog! This week is our last monthly quiz! We'd love to hear which one was your favourite in the comments! We also have a quick online survey for what our monthly post should be next year. We really appreciate any feedback and this is the best way for you to tell us what you want to see us post about and share! From a monthly challenge to an environmental book of the month - we just want to know what you think! 🍂 click here to vote! So, how much do you know about extinction? You may know some from our " animals you don't know are on the edge of extinction " series, or from the news as extinction is such a buzzword. All of these facts are from reliable sources such as National Geographic, as well as the statistics being cross checked with other websites. 1. How many years ago was the most recent mass extinction? a) 44 million b) 55 million c) 66 million 2. How many species could be threatened ...

April Top Tips: ten tips for environmentally friendly travel

Hi Everyone! We haven't been very present on the blog again recently but we are back today with ten top tips for environmentally friendly travel. Most forms of travel over long distances (unless you are willing to put in a lot of physical effort) use fossil fuels and are generally not good for our planet. So today we will be giving you a few tips which although won't mean that your travel is 100% planet friendly, will be a good start to doing as much as you can. Your Green World Blog Team💚 1. Use trains and boats rather than planes where possible Planes are awful for the environment. They are, however, extremely practical and so easy to use, cheap...It's hard to avoid them! They are so quick too so you don't have to spend as much time travelling. However, they are really bad for the environment. For example, you could fly once to Edinburgh from Heathrow for the same carbon dioxide levels as driving to Edinburgh 336 times! 2. Fly...

Deforestation and why it’s a problem

Hi everyone, Welcome back to another post. Today we’ll be talking about deforestation and its impacts on our earth. Deforestation, the widespread clearance of natural forests, has been happening for thousands of years. One example is Western Europe, where, two millennia ago, 80% of the land was cloaked in dense forest cover. However, over time, a significant portion of this green expanse was sacrificed to create room for crops, livestock grazing, and as a source of fuel and building materials. Presently, a mere 34% of Western Europe retains its woodland. Today, the tropics deal with the brunt of deforestation. Activities such as mining, agriculture, road construction, and the establishment of vast cattle ranches drive the mass clearance of tropical rainforests. This results in the release of huge amounts of carbon dioxide into the atmosphere, exacerbating the global climate crisis. The consequences come in two waves: first, the reduced number of...

How much do you know about climate change? - Quiz

Hi Everyone and welcome back to Green World! For this week's quiz, we thought we would do one on climate change. By this point, climate change is a well known issue, however, we wanted to share some of the specific statistics, some of which are still really surprising. We hope that this is an informative post for you, and it inspires you to take a small action to reducing your own carbon footprint. Questions Roughly how much CO2 is in the atmosphere? (May 2023) a) 380 parts per million b) 400 parts per million c) 420 parts per million True or False? The last time CO2 levels were as high as they are today was 4.5 million years ago. Which summer month in 2021 had the highest temperature since records started almost 150 years ago? a) June b) July c) August True or False? Antarctica loses the same weight as Mount Everest in ice each year. How many p...

National parks - how do they help the environment?

Hello National parks are a place of immense beauty. They are know as tourist attractions and are best recognised by their incredible landscapes. Today we are talking about their effects on the natural world! Yosemite National Park, United States National parks are normally created and protected by governments. In most cases, they have public access, meaning that visitors can walk around in them and admire them. The IUCN defines what is a national park and what isn't. In 2006, over 6 500 areas met the criteria and are defined as a national park. However, there are many areas called National Park, that aren't a national park according to IUCN and there are places that the IUCN defines as a national park but the government doesn't. So some countries have their own definitions. In the UK and some other countries, a national park referes to an u...

Green World

Search This Blog