Skip to main content

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.
  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 TeamšŸ’š


Sources:

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

Comments

Popular posts from this blog

16.08.2020 Animal of the week: Elephant

Hello. On the 12th of August it was International Elephant Day, so we decided that this week's post should be about elephants. Elephants are the largest living land mammals. There are three types of elephant; the African bush elephant; the African forest elephant and the Asian elephant. African elephants have larger ears, whereas Asian elephants have smaller ears. Elephants use their trunks to breath, bring food and drink to their mouths and to grasp objects. Elephants' legs are like pillars. They carry the Elephant's massive weight. African bush elephants weigh 6000kg, Asian elephants weigh 4000kg and African forest elephants weigh 2700kg. Basically, they are very heavy.Elephants eat grasses, small plants, bushes, fruit, twigs, tree bark, and roots. Elephants can live up to 70 years old in the wild. They communicate by sight, touch and smell. Sadly, these wonderful mammals are in danger. African elephants are listed as vulne

Major ocean currents and how they affect global temperatures

Hi everyone, This week we're talking about ocean currents. Ocean currents are part of the ocean's circulation system and influence local and global weather patterns. They are produced by gravity, differences in water density, winds on the ocean surface and Earth's rotation on its own axis. They cause the movements and exchanges of different ocean properties such as salinity, temperature and nutrients. Ocean currents can flow at speeds of up to 4m per second however most flow at speeds between 5cm and 50cm per second. Weather patterns and ocean currents constantly influence one another. Ocean currents follow similar paths as global wind do, transferring heat from the equator to polar regions. They create and influence ecosystems worldwide, especially marine ones. However they also spread plastics and microplastics around the world far from their original source. This system of ocean currents is often referred to as a global conveyor belt. Today w

Killing invasive species: necessary?

Hi everyone, Today's topic is a rather controversial one: is killing invasive species necessary? We'll take it apart for you to come up with your own opinion. Enjoy! Definition Firstly, let's clarify what an invasive species is. An invasive species is a species that is not native and most likely causes harm to the ecosystem where it now lives. This does not include animals that migrate to another area. Why is it a problem? Depending on the species and the ecosystem, invasive species can cause a lot of harm to their surroundings. Often invasive species have no predators in their new habitat and reproduce in such large numbers that they massively overpopulate, causing death for other species. Or they bring sicknesses the local animals are not accustomed to, and that kills them. For example black and brown rats are an invasive species on the Galapagos Islands : Black and brown rats were introduced to the Galapagos Islands in the 17th ce

10 Animals on the Edge of Extinction No. 10- The Javan Rhino

The Javan rhino is listed as the 1st animal on WWF’s list of the 10 world’s most endangered animals, and I for my part, had never heard of it! If you hadn’t either, we’re changing that now.  A bit about the rhino’s lifestyle The Javan rhinos are now exclusively found on the island of Java in Indonesia, but were once found in vast regions of northeast india and Southeast Asia. They have a dark grey colour which looks almost black when wet, and their (often pink) skin folds look a bit like plated armor. Both males and females have lower incisors which resemble tusks that they use to fight. Males have one relatively short horn of about 25 cm (10 inches).  Javan Rhinos live in tropical forests, marshy areas and in the thick bush. They are mainly browsers and eat over 100 plants species they find in the forest, weigh between 900 and 2300 kg (1984-5071 pounds) and are between 3 and 3.2 meters (10- 10.5 feet) long.  How endangered are we talking?  Javan rhinos are the most endangered animal s

Why Don't People Switch To Electric Cars? || Green World Blog

Hi Everyone! The previous post in this series really blew up, so thank you so much for your support on that one. In this article, I wanted to discuss why people are not switching to electric cars, and why the transport industry still has a way to go in terms of reaching net zero. If you missed the first part of this post, then  click here to read it! ! I talked in the post linked above, about why people should switch to electric cars, while also taking into account the potential issues with them, and coming to a conclusion about should everyone switch to electric cars. In this post, I wanted to delve further into the topic of why people don't switch to electric cars. The cost is one of the main issues at the moment. To own an electric car, you need a reliable electricity supply, which is not readily available for everyone in the developing world, let alone the cost of buying the vehicle in the first place. The cost of the vehicle coul

Ozone layer

Hi everyone, What even is ozone? And the ozone layer? Where does the hole in the ozone layer come from and what does it mean? Is it dangerous? What can be done? Often the ozone-talk can be complicated and confusing, keeping an overview is hard and understanding all the problems always difficult. Let us break it down a bit for you: What is the ozone layer? We'll start with the basics: The ozone layer is part of the stratosphere, which is the second layer of the Earth's atmosphere, between 10 and 50 km above the Earth's surface and made up of protective gases. One of these protective gases is ozone. There is not much ozone in the atmosphere, only 0.3 molecule of ozone per 1 million molecules of air. This is because ozone is chemically unstable and only forms when ultra violet radiation (UV light) hits oxygen and breaks the bonds between the atoms. It fact it is so unstable that even when it has formed, it breaks down again relatively quickly. This leads to ozone turning back

April 2021 Factfile - some news from the past month and animals that you voted for

Hi Everyone! In this factfile we are bringing you some more news from the past month, animals you voted for, an exciting announcement and more! News: The Guardian reports that 'the new research shows that since the 1990s, the loss of hundreds of billions of tonnes of ice a year into the oceans resulting from the climate crisis has caused the poles to move in new directions.' Previously, the poles could only move due to ocean currents and other natural factors. Apparently, glacial losses accounted for most of the change but some were also due to the pumping of groundwater which once pumped up by humans isn't replaced. This shows just how much climate change is having an impact on our beautiful planet. You may have heard about M&S's plans to release 30 million  honey bees  to the countryside. It has faced many complaints from experts saying that this could damage the balance of natural pollinators. It is important t

Discussion || Should Everyone Switch To Electric Cars?

Hi Everyone! Thank you so much for joining me today, as I hop on the blog to discuss whether everyone switching to electric cars would really help the environment. In other words, should everyone switch to electric cars? This is the first part of a two-part series, discussing electric cars, so stay tuned for part two!! I would like to start this post by stating that I am by no means an expert. This is knowledge I have from my own experience, and from research I have done. If anything is incorrect please take it as it is and accept that this is a discussion and I am taking on board all opinions from reliable sources on this complex topic. Electric cars are a huge topic when it comes to sustainability and "saving our planet". There is no debating the fact that electric cars are better for the environment than diesel or petrol once they are on the road. But the production of them is often very polluting, with one study show

Animals 41 - 45 in our '50 incredible animals' series

Hi everyone, 41. Ghost shark So first of all, this is a real animal and not a horror movie! Ghost sharks, often referred to as chimaeras, include around 50 species. They mostly live in the deep ocean and are seldom seen, hence the name. They can be found all over the world. Some species have a large range, for example, the rabbit fish which inhabits the entire northern Atlantic Ocean, or a small range, like the Galapagos Ghost shark which only lives in the waters around the Galapagos . Not much is known considering their population status however they are currently not considered threatened. It is assumed that they reproduce in the same way as most sharks. Not much else is known about ghost sharks. They are as mysterious as their name suggests! 42. Sea pig Again, this is a real animal! But it is not in any way like a pig (I have no idea why they called it a sea pig ). It is a type of sea cucumber, that lives in the ocean depths. Their bodies are fille

5 Environmental Movies and TV shows

For all the TV lovers, Recently I have been getting more into watching inspiring movies and TV shows, and I started a list of environment-themed ones I want to look at. I spent a lot of time just exploring and the ones below are the ones I found. I actually haven't seen most of them, but if you have watched any of these, post a comment to let us know what you thought of it and if you would recommend it. Have a lovely weekend! 1. Tales by light - 3 Seasons This series follows the Australian photographer Darren Jew in his travels and lets the viewer explore untold stories, not all of which are nice and pleasing to look at, but nevertheless important. I saw episodes 1 and 2 of season 3, they are called "Children in Need" and are very eye-opening. 2. Into the Wild - 2 hours and 22 minutes I haven't seen this movie, but it is about a young man giving up everything and exploring new ways of life. It is based on the true story of Chri