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

The limits of the Earth - the planetary boundary model

By
Hi everyone, So today we're talking about a model that was introduced in 2009 and has offered a new perspective to thinking about environmental issues. The planetary boundary model has 9 boundaries, each has a safe zone. Once the safe zone is exceeded, the stable conditions on our planet are considered at risk, and there can be severe and possibly irreversible changes. The nine boundaries are considered separate however, they greatly affect each other. Novel Entities describes the introduction and accumulation of man-made novel chemical compounds. These include pesticides, nuclear waste and microplastics. Stratospheric Ozone Depletion refers to the depletion of the ozone layer which was a major problem in the 90s. Atmospheric Aerosol Loading is air particle pollution.  Ocean Acidification is self-explanatory. The boundary Biochemical Flows is composed of two separate boundaries; nitrogen and phosphorus. Both of the ele...
Post a Comment
Read more

16.08.2020 Animal of the week: Elephant

By
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...
Post a Comment
Read more

October 2021 Factfile | news, animals and more!

By
Hello, October is over and November is here - let's hope it's a cosy month full of stunning Autumn colours and beautiful rainy days! News Good news Judge postpones wolf hunt in Wisconsin Every year in Wisconsin there is a wolf hunt in autumn. But this year, something amazing happened: A judge halted the season. For years there has been a dispute, on one side environmentalists, and on the other hunters and farmers. The farmers claim that wolves destroy their crops and that killing them is the only solution. Environmentalists argue that wolf populations are too weak and that the animals shouldn't be killed. Let's hope that this is the first step toward stopping the wolf hunt altogether. Bad news Pacific islands are disappearing For many of us, the threat of climate change feels distant. But for the people of the Pacific islands, the terror is all too real. These are their homes, and they are rapidly becoming submerged b...
Post a Comment
Read more

July 2021 Factfile - some news from the past month, animals and plants!

By
Hi Everyone, July is over and August is here. This month we've divided the 'News' section into 'Good news' and 'Bad news'. This will hopefully make the post more structured and easier to navigate. News Good news: Pandas classified as vulnerable Giants pandas are now classified as vulnerable according to Chinese officials. They were originally classed as endangered , but now that numbers in the wild have gone over 1 800 they have been reclassified. This is due to hard conservation work in China and funds from volunteers all over the globe. However, they are still vulnerable so it is important that the good work continues. For all those who have supported giant pandas through websites or those who work actively with them: keep up the good work!    First baby beaver born on Exmoor in 400 years A baby beaver has been born on Exmoor, England, for the first time in 400 years! This is due to ...
Post a Comment
Read more

November Top Tips | sustainable activities and hobbies

By
Hello everyone, So this week, we are going to be talking about sustainable free time activities. This area can quite big when it comes to environmental impact, so here are some things that you can do in your free time, that are more sustainable. 1. Reading So reading is one of our favourite things to do. However, books are made of paper and the paper industry isn't great. Some ways you can get around this is by reading online (for example, on a kindle), or through borrowing books from a library or using book boxes. If there aren't any in your area then at least try to support independent bookshops! 2. Running If you love being active then this one is for you. Running is probably one of the most sustainable forms of sport. All you need are some running shoes and somewhere to run. There is obviously more high-tech gear but that isn't really necessary if it's just a hobby. 3. Gardening If you've got a small area of land o...
2 comments
Read more

The life of ... a koala

By
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...
Post a Comment
Read more

Pollination

By
Hello everyone, Today we're talking about pollination and its importance in the world's ecosystems.  First a bit of basic plant biology. To reproduce most plants do have a differentiation into male and female, but not in the same way that we see in mammals. Both male and female reproductive organs can be found on the same plant, although not in the same place. Male gametes are produced in the stamens and are then found in pollen. On the other hand, female reproductive organs are called pistils and egg cells are found in the ovule (normally in the flower heads). Pollination describes the process of transporting the pollen to the egg cells, making it an essential part of the reproduction of plants. Nearly all seed plants worldwide require pollination to reproduce. Cone bearing trees also need pollination.  Pollination is almost always assisted by other organisms such as insects, birds and mammals to transport the pollen. In some species wind ...
1 comment
Read more

September Top Tips | recycling

By
Hi everyone, Today we are going to be talking about recycling. Recycling is quite big thing in the media, with some critics saying that it doesn't help. But I would say that even though it isn't going to save the world, it will make a small difference and probably save you some money! So here are some recycling ideas (although depending on your personal situation it might be up cycling or down cycling): An old t-shirt turned into an apron An old t-shirt turned into a cushion Tin cans turned into plant pots Tin cans turned into pencil holders Plastic bottles or clear plastic tubes turned into bird feeders An old handbag turned into a picnic basket Lotion, shampoo and conditions bottles turned into storage A shoebox turned into a make up organiser Old t-shirts turned into a baby blanket Plastic spoons turned into mirror decorations Bike parts into a lamp shade An old piano turned ...
Post a Comment
Read more

January Top Tips // 5 ways you can individually tackle climate change

By
Hi Everyone! This is the first of our new monthly posts for 2022! We will be sharing top tips every month, near the beginning, for things you can do during that month for the better. It's almost like a whole year of new year's resolutions (though let's hope they are achieved)! In these posts, we aren't just going to talk about climate change , of course, there will also be posts about animals , plants, habitats, plastic pollution and so much more! They will not be huge tips though, they won't demand too much of you (usually!). We need rebellions and people in the public eye spreading the word of course but we also need people like you, who can just do their bit. So, welcome to our top tips posts! We all know that we need to come together to fight the climate crisis, but we don't seem to be doing that right now. So here are our top tips for ways you can individually tackle climate change, even if this means simply spreading ...
Post a Comment
Read more