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

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...

Announcement: Factfile

This image is owned by a blog editor.

Animals 31-35 in our '50 incredible animals' series

Hi Everyone! Welcome back to our blog, today we are sharing another 5 incredible animals. This is part of a series to celebrate our 50th blog post, all about unusual animals! Enjoy! 31. Pangolins These creatures are often mistaken for reptiles but they are in fact mammals. They are covered in scales and use them to defend themselves because similar to a hedgehog, they curl up into a ball. They eat ants, termites and larvae. They eat using their tongue, which is very long- sometimes even longer than their body! Sadly, Pangolins are in high demand as their meat is considered a delicacy their scales are used in traditional folk remedies, which means that there is an illegal trade. Luckily, there have been many initiatives put in place to help these animals by WWF and similar organisations. 32. Macropinna Microstoma This is a species of fish that live at about 600m below sea level. They hang nearly motionless in the water and have a very unusual...

Announcement: Animal of the week

The life of ... a cicada

Hi everyone, We're back to talk about another animal. Cicadas ( Cicadoidea ) are invertebrates and are 1.9cm to 5.7cm in size. There are 3 000 species that can be divided into annual cicadas and periodical cicadas. Annual cicadas can be seen annually and are found worldwide whereas periodical cicadas only leave the ground every decade or two and are only found in North America with hotspots in the eastern and central areas of the United States. Most annual cicadas have a lifespan of about two to five years and periodical cicadas can live up to the age of 17. Female cicadas lay around 400 eggs split up over several places. They normally lay their eggs on twigs, branches or other vegetation. The eggs hatch after about six to ten weeks, now known as nymphs, and dig their way into the soil. The nymphs feed on the liquids found in plant roots. They fully develop underground, before molting their shells and coming to the surface, now fully deve...

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 ...

Heatwaves - what's so bad about them?

Hi everyone, Today we’re talking about heatwaves and what effects they have on us and the environment. Heatwaves are becoming ever more common, with 2023 breaking multiple world records. In China, 52.2°C were recorded at one point and the coastal waters near Florida, USA, were as warm as a hot tub. This is because of the combination of climate change and El Niño , both of which make the effects of the other worse. But we can’t push the blame onto El Niño. When analysed it became clear that without human made climate change the USA heat records would have been almost impossible. So what exactly are the effects of such high temperatures. A study in Europe found that the 2022 heatwave possibly caused over 70 000 heat related deaths. Although it is sometimes hard to tell whether or not someone died from the heat or from something else, after analysing the data the team found that their original estimate of 62 000 people (which is still a lot) was probably ...

18.10.20 Animal Of The Week: Sloth

Hello, Sorry this didn't come out on Sunday as planned but this week's animal of the week is the sloth because the twentieth of October is Sloth Day. Habitat The sloth resides in Central and South America. It lives in the rainforests there and occasionally drops into the water for a bathe as, believe it or not, they are actually excellent swimmers! Diet Sloths eat leaves, twigs and buds which they find in the rainforest. As they don't have incisors they smack their lips together to make leaves more digestible. Sloths can survive on relatively little food as it takes a while for them to digest it. Sleep and Speed When you think of a sloth, you probably think of this slow, sleepy creature. They actually sleep for about 15 hours a day! Sloths have an extremely low metabolic rate (what basic calories your body needs to survive), which means they move at a slow pace through the trees. On average, sloths travel 40 yards per day ...

February 2021 Factfile - a bit of news from the last month and more!

Hi Everyone! Welcome to February's factfile! We are very sorry that we have not posted very much so far in 2021 but we are going to hopefully make up for it in the spring. News: Source- BBC Newsround The great yellow bumblebee has been spotted in Scotland! They used to be common in the UK but their population declined by about 80% in the last century. The find is a spark of hope as it is currently endangered. This is thought to be because of a decline in natural flower meadows and a boost in farming. The team of conservationists that found it were thrilled and when we heard about it we wanted to share it with you in case you hadn't heard! Source- Guardian In the 1840s a bird was caught in the East Indies. It had never been seen before and Charles Lucien Bonaparte (Napoleon's nephew) named it the black-browed babbler. The species wasn't seen again, so the only proof that it had ever existed was a stuffed specimen. ...

Green World

Search This Blog