Everything Everywhere Daily: History, Science, Geography & More - All About Solar Power

Episode Date: May 6, 2022

In 1839, a French scientist by the name of Edmond Becquerel was experimenting with an electrochemical cell when he discovered something interesting.  When it was exposed to light, it produced an electrical current.  For over a hundred years, this was mostly a scientific curiosity. However, with the advent of the space age, this curiosity began to find practical uses.  Learn more about solar cells and solar power, its history, and how it works on this episode of Everything Everywhere Daily. Subscribe to the podcast!  https://podfollow.com/everythingeverywhere/ -------------------------------- Executive Producer: Darcy Adams Associate Producers: Peter Bennett & Thor Thomsen   Become a supporter on Patreon: https://www.patreon.com/everythingeverywhere Update your podcast app at newpodcastapps.com Discord Server: https://discord.gg/UkRUJFh Instagram: https://www.instagram.com/everythingeverywhere/ Twitter: https://twitter.com/everywheretrip Website: https://everything-everywhere.com/everything-everywhere-daily-podcast/ Everything Everywhere is an Airwave Media podcast." or "Everything Everywhere is part of the Airwave Media podcast network Please contact [e-mail] to advertise on Everything Everywhere. Learn more about your ad choices. Visit megaphone.fm/adchoices

In 1839, a French scientist by the name of Edmund Beccarell was experimenting with an electrochemical cell when he discovered something interesting. When he exposed it to light, it produced an electrical current. For over 100 years, this was mostly a scientific curiosity. However, with the advent of the space age, this curiosity began to find practical uses. Learn more about solar cells and solar power, its history, and how it works, on this episode of Everything Everywhere Daily. What if your perceptions about the past were wrong?

ThruLine is a podcast that takes you back in time to uncover the parts of the story that may have gone unnoticed. It effectively turned day into night. And how it shaped the world now. Time travel with us every week on the Thurline podcast from NPR. Solar power started out with very modest beginnings. As I noted in the introduction, the discovery of the story of the story of the internet. the photovoltaic effect dates back to 1839. Edmund Becorell was experimenting with a liquid electrochemical cell, and he found that when he exposed it to sunlight, a very weak current would be

produced. This was interesting, and Bekarel documented what he found, but he neither understood why it was happening, nor did he realize any practical use for what he discovered. I should note, he was only 19 years old when he made this discovery. Nothing was done with this fact for decades. It wasn't until the late 1870s and early 1880s that a host of experiments were done with the element selenium. In 1873, an English engineer by the name of Willoughby Smith found that selenium exhibited a photovoteic effect, and in 1883, an American inventor named Charles Fritz, created the first real solar cell by putting a thin layer of gold on a thin layer of selenium. The first solar cell wasn't very good, as it only had an efficiency of 1%, but it was a start. There was very little advancement in the practical design and development of solar cells over the next several decades.

The effect was simply too weak to be of any practical use. What did happen, however, was advancements in the theoretical understanding of light and matter. Albert Einstein won his Nobel Prize for his explanation of the photoelectric effect. The big advancement in solar cells was in the use of silicon, in particular single crystal silicon. Single crystal silicon is not only the basis for most solar cells, but also the foundation for most integrated circuits. In 1940, a Bell Labs researcher by the name of Russell Shoemaker Oll made an accidental discovery. He was examining a piece of silicon that had a crack in it.

He found that this particular piece of silicon had an electrical current when exposed to light. It turns out that there were impurities in the silicon on either side of the crack, such that one side was positively doped and one side was negatively doped. This inadvertent discovery was the first P.N. junction, for positive and negative. What happens is that on one side of the junction, a positive electrical charge builds up, and on the other side a negative electrical charge builds up, and a photon kicks things off once a circuit is created. All of this came together in 1954 when Bell Labs, who, if you remember from a past episode,

invented pretty much everything, released the world's first practical silicon-based solar cell. This solar cell had a whopping 6% efficiency. The intent was to create a power source for warm, humid areas to power the telephone, phone system where regular batteries would quickly degrade. When the solar cell was announced at a press conference, it powered a small toy ferris wheel and a small radio transmitter. The New York Times said that the new invention, quote, may mark the beginning of a new era, leading eventually to the realization of one of mankind's most cherished dreams, the harnessing

of almost limitless energy of the sun for the uses of civilization, end quote. One year later, Hoffman Electronics released the first commercial solar cell. It was a single cell that sold for $25 and was 2% efficient. But the cost per watt was $1,785. That is a number to remember. Hoffman Electronics took an early lead in this technology. They created a solar cell with 8% efficiency in 1957, 9% efficiency in 1958, and 10% efficiency in 1959. And in 1960, they created a cell that was 14% efficient.

And I should note, the theoretical maximum efficiency for a solar cell with a single P.N. junction, optimized for sunlight is only 33.16%. However, it is possible to get around this number, as we'll see in a bit. There still wasn't really much demand for these devices. They were very expensive and inefficient, and there weren't many use cases. There was eventually a use case that arose that solar cells were not only a perfect fit for, but they were also really the only choice, satellites. When NASA launched their second satellite into orbit, Vanguard 1, they needed a power source. A battery would have quickly been depleted in a matter of weeks. The solution they chose was solar cells. Six solar cells were attached to the body of the satellite with a total of 100 square centimeters of area. This allowed the satellite to remain in service from March 1958 until May 1964, and no battery could have possibly lasted that long. The history of solar cells entering the 1960s and onward is one of continued.

continual incremental improvement in efficiency and price. The potential of solar cells was evident from the very beginning. The big problem was cost. In particular, the cost per watt of electricity that it could produce. An expensive, efficient solar cell could be the same as a less efficient cheaper cell from an economic standpoint. The use of solar cells and satellites was great and all, but it did little to reduce costs. If you're launching a satellite, you really aren't concerned about costs so much as you are about efficiency and reliability. The 1960s saw continued use in satellites, but it was the 1970s that saw major advances in solar cells,

mostly due to the energy crisis. The first gallium arsenide cells were developed in 1970, and the first amorphous silicon cells were created in 1976. Amorphous silicon isn't as efficient as a single crystal silicon, but it's much cheaper to produce. Amorphous silicon can also be used in a thin film and placed on flexible substrates like plastic. 1974 saw the very first building run solely on wind and solar power in New Mexico. There have been many advances in solar cells, most of which have been incremental, so it would be too time-consuming to go through all of them, so I'm mostly going to focus on the cost per watt, which is really what matters.

In 1975, in inflation-injusted dollars, the cost per watt of solar power was about $85. But remember, this is down from $1,785 just 20 years earlier. By 1980, the price had dropped to $29.30.30 per watt. By 1990, it was $8 per watt. In 2000, it was $5.10 per watt. And in 2010, it had fallen down to $2.20 per watt. And in 2020, the price for traditional silicon solar cells was only $0.20 per watt. Now, I should note that these are only the prices for raw solar cells, not the price per

watt for full installation of a system. More on that in a bit. Today, the record for solar cell efficiency is 47.1%, which was set in 2021. This was done using a cell with 6 p.n junctions and a concentrator, which is a lens that concentrate sunlight. So for something like this, they were really pulling out all the stops, but it's not something that can be used in a regular environment. As of the end of 2019, there is an estimated 629 gigawatts of solar power installed globally.

The largest country, with over a third of the installed solar grid, is China. And behind China, it's the United States and India. The countries with the highest percentage of their electricity coming from solar power are Honduras at 12.5% and Australia at 11%. So far, I've talked about efficiencies and cost, which are both really important. However, there is a lot more to solar power than just these numbers. There is one obvious major problem with solar power that I'm sure you are already well aware of. Solar powers do not produce any electricity when it's dark out. Not only that, but the amount of power it can produce

will depend on the latitude, the number of days of sunshine, and the time of the year. There are maps which show just how effective solar power is based on all of these factors. For example, the best cities for solar power in the United States are, not surprisingly, Honolulu and Phoenix, and the worst are Seattle and Anchorage. This variability means that if you want to extensively use solar power, you need one of two things. A grid that the solar power can feed into, or batteries. Most solar installations will be connected directly to the electrical grid. The good thing about solar is that it tends to produce the most electricity

at the very same time when demand is the highest, in the middle of the day. It can provide a variable amount of electricity into the grid, but it requires some other source to provide the base load of electricity, and this would usually come from gas, coal, or nuclear power. In many jurisdictions, electrical companies have net metering for homeowners with solar installations. They will pay you for electricity that you produce, and put into the grid, and then you pay them for whatever you use from the grid. The grid basically functions as a giant battery.

The other option is to actually use batteries to store the electricity. Now, this sounds simple, but it completely changes the cost equation for solar. In addition to the solar panels, you now need batteries, inverters, and other equipment. Moreover, grid-scale batteries really aren't a thing. There are a few large-scale grid batteries which have been installed, but they are nowhere near able to support an entire grid. For example, the recently installed big battery in Victoria, Australia can store enough electricity to power 1 million homes for 30 minutes. And there are way more than a million homes in Victoria, Australia.

There are battery alternatives that exist, but even these are limited. One of the best systems is pumping water from a lower reservoir to a higher one during the day, and then letting it flow down using hydropower at night. However, you can only do this in places with the right job. Another big problem that solar cells have that need to be addressed is the reliance on rare earth minerals. There are about 15 rare earth minerals that are commonly used in the production of photovoltaic panels, and the amount of rare earth minerals has increased over the last decade. But I've done an entire episode on rare earth minerals that I'll refer you to for this subject.

So far, I've only talked about photovoltaic cells, which is the most common form of solar power. However, it's not the only form of solar power. The other method is known as concentrating solar thermal power, or CSP. CSP is pretty simple. You take a whole bunch of mirrors and shine them up to the top of a tower. The top of the tower collects the heat, usually through something like molten salt, and then that is used to boil water and turn a turbine. CSP systems really only work at scale.

You can't have a small system to, say, power a single house. You'll usually find these installations in the middle of a desert. You can find the Crescent Dune Solar Energy facility outside of Las Vegas, Nevada. and it has 10,347 mirrors that focus solar heat onto a central tower that holds 32 million kilograms of molten salt. It took two months to melt all of the salt, and once melted, it should remain molten during the entire operation of the plant. The heat from the molten salt can also continue to provide energy even after the sun is set. Solar power has gotten significantly cheaper and more efficient over the last seven years. Its share of the global energy market has increased commensurately, and it will continue to grow into the future.

However, there are still major hurdles that solar power has to overcome in terms of its variable production and energy storage. Unless those problems can be overcome, solar will remain an important but partial part of our energy solution. Everything Everywhere Daily is an Airwave Media podcast. The executive producer is Darcy Adams. The associate producers are Thorpe Thompson and Peter Bennett. Today's view comes from listener Edgar Guerrero over at Apple Podcasts in the United States. He writes, Awesome podcast, very well explained in full of facts.

Keep up the great work, Gary. FYI, if you ever come to Sonoma County, I have tons of wine for you. Thanks, Edgar. It's been a while since I've been to Sonoma. But if I'm ever back out that way again, and I'm sure I will be at some point, I'll make sure to let everyone know. Remember, if you leave a review or send me a boostogram, you two can have it read on the show.