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

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 ...

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 ...

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...

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

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....

2021: How Our Year Went, Favourite Posts and Some Goals For 2022 | a wrap up

Hi Everyone! Today we wanted to share some thoughts on how our blogging year went in 2021 and some goals for 2022. We are now at the end of January, which is very scary, but we hope you will still enjoy this slightly belated wrap-up. In 2021, we published 36 posts in total. This is pretty good, we posted on average roughly every 10 days. However, there was a lot of time when we didn't post at all and our posts became increasingly just the monthly fact file. Many of you enjoyed the fact file, and for the most part, we enjoyed writing it but it became a bit of a chore by the end, hence the change we have made over to top tips. We think it would be nice to change our monthly post every year, and we will of course involve you in that just as we did this year. Our best posting months were by far August and September, which is understandable because we were on holiday for August and could schedule a lot of posts for September! Something we want to wor...

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...

How much do you know about migrating birds? - Quiz

Hello everyone, We've got another quiz for you and this time it's about migrating birds. As most of you probably know, there are loads of birds that fly to a different country or even continent to avoid harsh weather and to find better feeding and breading areas. Questions True or False? Birds use the Earth's magnetic field to navigate while migrating? How many miles does an arctic term migrate? a) between 10 000 and 20 000 km b) between 20 000 and 30 000 km c) more than 40 000 km True or False? Arctic terns can fly 600km in a day. What percentage of birds migrate? a) about 40% b) about 60% c) about 80% True or False? Great snipes travel 5 000 miles at 70mph. How long can the bar-tailed godwit fly non stop for? a) nearly 5000 miles b) nearly 7000 miles c) nearly 9000 miles True or False? Bar-headed geese can fly up to 5.5 miles above sea level. ...

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...

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

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...

Turning waste into valuables

Hi, So this post was requested on Twitter after our September Top Tips about recycling . Today we will be talking about how to turn complete waste into something reasonably valuable. This is basically a form of upcycling but to a more extreme level. 1. Ecobricks So, almost a year ago we did a post about ecobricks , but they are such a good example of turning waste into valuables that we decided to put it here anyway. Ecobricks are a building material made from plastic. The waste plastic is washed and then compacted into a clean plastic bottle (also waste). The bottle becomes very hard and durable. Multiple bottles can then be used as bricks and cemented together. The 'bricks' are strong and do not decompose. For more info, read our post where we go into more detail. 2. Metals Although this may seem like something not worth the time. When you separate the metals in waste (for example an old car), you can get usable metal out ...

Green World

Search This Blog