Skip to main content

Energy comparison: solar (PV) panels

Image
By
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.
  1. We have already mentioned the fact that we do not have the needed resources to produce that many solar panels.
  2. We do not have the infrastructure to build a massive solar field.
  3. Such a project would produce massive greenhouse gas emissions during production.
  4. As already mentioned, we can't effienciety store solar energy and transporting it to another part of the world would be difficult.
  5. We would have to replace the solar panels after about 25 years, which would cause massive amounts of waste.
  6. It would cost trillions of dollars.
  7. 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.
  8. A power cable from the sahara to the rest of the world would have at least a 20% power loss.
  9. 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.
  10. 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.
  11. Due to point 9. hurricanes and storms would rampage the Americas more frequently.
  12. 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:

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

Comments

Post a Comment

Popular posts from this blog

Deforestation and why it’s a problem

By
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...
Post a Comment
Read more

Climate change: what is it and what's the problem

By
Hello, I've noticed that we are always mentioning climate change. Not only us blog editors but also politicians, activists and so on. The words climate change are bounced around in the media and probably in your households, but do you actually know what it is or how it works? I know that for a long time, I didn't know what it really meant. I hope that this post changes that. What is climate change and how does it work? The words climate change describe a slow shift in the earth's temperature and changes in the weather patterns. Having a single warm winter does not instantly mean climate change. Climate change happens over a long period of time. If you look at a temperature graph over the years, it doesn't go up in one day and then stay the same for another hundred years. It curves up slowly but steadily. This is a average temperature graph from 1880 to just after 2000. You can see how the temperature gradually gets warmer....
Post a Comment
Read more

The Responsible Traveller by Karen Edwards || a practical guide to reducing your environmental and social impact // BOOK REVIEW

By
HI Everyone! Our January monthly post was a zero-waste challenge, but as we explained in our  2023 wrap up , this year we will be alternating a monthly challenge with a book review, of course related to the environment. This week, I'm going to share a recommendation for a fantastic book, all about how you can travel more sustainably and responsibly. I absolutely love travelling, but I'm also very aware of the impact it has on the world, and I am very keen to learn more about how I can further reduce my impact. That's why I bought this book around a year ago, and I've really enjoyed reading it and learning from it.  This is a practical, small-format guide, sharing both basic information about the climate crisis and the impact of various travel activities, and how you can do your bit. It shares specific journeys that are more environmentally friendly options, for example long distance train journeys such as The Alaskan Railroad with its stunning alpine forests and wide ar...
Post a Comment
Read more

April Top Tips: ten tips for environmentally friendly travel

By
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...
Post a Comment
Read more

10 Animals on the edge of extinction, You did not know about no.1 - Yangtze Finless Porpoise

By Anonymous
The first animal of this series is the Yangtze finless porpoise, a dolphin living in fresh water in southern China in the Yangtze river. It is one of the very few dolphins living in fresh water and the only species left in the Yangtze river. Unfortunately, the porpoise is facing extinction. What is it? The Yangtze finless porpoise is a dolphin species living in the Yangtze River in southern China. It is one of the very few dolphin species that live in freshwater, and the only one that survived in the Yangtze river after the Baiji Dolphin was declared functionally extinct in 2006. It characteristically is about 2 meters long, has no fins -as the name suggests- and no beak. Its mouth however is curved upwards like a smile, giving the Porpoise and cute and friendly face. It feeds on small fish, crustaceans and molluscs. Sadly, the Yangtze finless Porpoise is considered "critically endangered" as there are only about 1000 of them left.  Why i...
Post a Comment
Read more

Linking climate change and inequality - 'The Great Carbon Divide'

By
Hey everyone, Have you heard of 'The great carbon divide‘? It is often referred to as the 'carbon footprint gap' or the 'emissions imbalance‘, and produces frightening numbers. The great carbon divide describes the huge gap between the amount of carbon dioxide the rich versus the poor emit, and these numbers shocked even us.  What does this mean?  There have been many different studies, and all of them show terrifying results. One study from the Guardian and Oxfam, reports that the richest 1% of the world's population emit more carbon than the poorest 66%. The richest 1% consist of 77 million people, which may seem like a lot at first, but the poorest 66% refers to over 5 billion people! Africa, which is home to 17% of the world's population, only causes 4% of the world's emissions. This top 1% emitted 16% of global CO2 emissions in 2019, that's 5.9 billion tonnes of CO2. Modelling suggests that it would take someone who isn't in the top 1% about 150...
Post a Comment
Read more

Animals 11-15 in our '50 incredible animals' series

By
Hello, We have another five amazing animals for you today. Enjoy! 11. Dhole This is a dog species which looks rather like a red fox . They are difficult to put into any of the dog subfamilies. They aren't foxes, nor wolves, nor domestic dogs. Dholes are fast runners and live in packs of 5-12 individuals. Although sometimes, different packs will join forces to become a pack of 30 or more individuals! However, these super packs are broken up after a successful hunt. The different packs rarely attack each other as neighbouring packs are often closely related. Dhole packs live in burrows with multiple entrances. They can be found in eastern and southern Asia. They eat wild berries, insects and lizards and as a pack hunt deer, rodents and other wild mammals. Interestingly, unlike other dogs, they rarely kill by biting at the throat. They are also good swimmers! 12. Irrawaddy dolphin The Irrawaddy dolphin can be found in coastal areas of south a...
Post a Comment
Read more

The life of ... Atlantic salmon

By
Hello everyone, Today we're talking about Atlantic salmon. Atlantic salmon are found in the north Atlantic and the rivers that flow into it. They can grow up to a meter long and are classified as Least Concern by the IUCN . Atlantic salmon start their lives in rivers. The pea-sized eggs are laid in autumn and hatch in April or May. The tiny salmon are called alevins. They feed on aquatic invertabrates and eventually devolop into parr. Parr are easily recognised by destinictive patterns and markings on their flanks. After up to several years, the parr develop a silvery sheen. These replace those characteristic parr markings. Their bodies change in preparation for the salt water and they are now called smolts. They swim downstream with the current all the way to the ocean. In the deep sea waters, the smolts feed on crustaceans and small fish for 15-50 months. However they are hunted by a number of predators including, sharks, seals and of ...
Post a Comment
Read more

10 animals on the edge of extinction you didn't know about no. 9 - South Island takahē

By
Hello Today we’re talking about the South Island takahē, porphyrio hochstetteri . They are flightless birds, endemic to New Zealand. Takahē are brightly coloured and weigh 2.3-3.8 kg. They have red legs and a large red beak. Their feathers are coloured blue and green. They have wings, but these are only used during courtship or rivalry displays. They are territorial, with one family’s territory reaching anywhere from 4 ha to 100 ha (0,04-1km^2). Pairs will live in the same territory each year. They breed once a year and will raise 1-3 chicks (normally 2) each year.  Both parents raise the chicks together.  In the wild, takahē live in native grasslands and have a lifespan of 16-18 years. If snow covers the ground then they will move into nearby forests. They eat tussock grasses, sedges and sometimes rushes. But they are opportunists, so they will occasionally go for insects or even ducklings and...
Post a Comment
Read more

Coral reefs

By
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...
Post a Comment
Read more