Ever since I was a kid, I was amazed at the idea of electricity, and how it just magically seemed to allow things to work. As an adult. not much has changed, except now i have Ebay and a credit card. Over the past year or so I have bought some great solar powered devices to experiment with and I want to share them with you. Theres so many awesome things out there that you can ge solar powered, and I’ll also explain how the solar energy process works at the end of this blog post.
Our relationship to energy and electricity
I guess most people’s first time in creating electricity themselves would either be with new carpet, and zapping yourself and others all the time (static electricity), or by making a light glow with a potato (using a nail and an old penny). These days there are great solar versions of devices that have commonly been battery powered.
Every hour, on the half of the earth that receives sunlight, we get enough energy to power all the devices on earth for one whole year. Of course, we cannot make the whole side of the earth a solar cell, as we use solar energy in many other ways, as it heats up the water to cause currents (think about the interesting double entendre there) as well as the solar energy of photosynthesis which grows our vegetables, which instead of producing electricity produces sugar for plants but in a very similar way.
So the Sun is a pretty amazing source of energy. Humans have become more and more reliant on energy from the sun and we will certainly use that source more and more in the future. In the beginning the solar cells we produced were so expensive to produce and use, as to outweigh the cost of using them. These days we are producing ever more productive cells for better costs, both financially and environmentally.
This map shows the best solar coverage on the earth. Deep red is the most effective areas.
My favorite solar powered items
Well what I’m young to show you today is a few simple items I have in my hose that use solar power. I’m going to explain how they work and hopefully give you some ideas about how to use solar more usefully in your lives.
SOLAR BIKE LIGHTS
The best use of solar products, are things that already spend a lot of time outside. What better way than to ride around during the day and have bike lights powered up by the time the night comes. These little guys last for a couple of days easily on one charge. They are pretty cheap, and a very simple design. i opened the back light to see how it was made and as you can see its a tiny board with two batteries wired right to the back of the panel itself. It uses the refraction of the plastic to make most of the light. I would recommend everyone having solar powered bike lights as they really chew through batteries and this is a convenient and perfect place for this technology.
THE RAINBOW MAKER
This little wonder uses sunlight in two different ways. It only need to run when its sunny, so needs no battery to store power for later but instantly turns that energy into kinetic energy but turning a few little cogs. Every day i see it as i come into the kitchen for breakfast. (it gets up way before i do).
When you see a rainbow its just opens up some part of your brain. For some its … “Ooooh pretty colors!”, but for me its more like, holy shit we have a device on my window that processes sunlight to power a small motor with a crystal on the end that we know shifts the same sunlight into wavelengths along the visible spectrum (of course the invisible spectrum is just off to the sides but i can’t see them), and it makes me think. Maybe there is hope for the human race after all. Now thats an exciting thing to wake up to every morning.
Another device that is perfect for solar is a watch. It travels around with you and uses quite low power, but is annoying to change the batteries of and causes waste by doing so. The solar panel in my watch is so tiny you can’t even see it well. It’s that slit just below the watch face.
This little guy is probably one of the most used handy little gadgets i own, regardless of the solar function. Its perfect for djing, so you can see when plugging in cables in clubs etc, but comes in handy in many situations. It also has the magical ability of being dual power, so if its not sunny or you have used it for too long, you can wind a handle on the side which powers it up for some time. Its also only about 5cm long. Its really a revolutionary (pardon the pun) device. I had to know what made this little guy run.
I opened it up to see how it works. The green is the battery, above it is the transformer that converts the cogs turning into electricity to power the battery. The solar panel feeds into the same battery. An array of led lights are off to the side.
AUTOMATIC SOLAR CHRISTMAS LIGHTS
One of the best devices I have is a set of solar powered Christmas lights. They charge a battery during the day, and when it gets too dark to absorb power, it automatically turns on the lights (as it assumes the sun is going down) and the lights go on until they run out of power (it usually lasts until sunrise,depending on the weather). Then whole process repeats indefinitely. It’s the opposite of the rainbow maker as it conserves all the energy it gets during the day, and activates at night. I have them on every night in my lounge room and never get sick of them. They don’t flash thankfully, but did you know flashing LEDs can last for 3 to 4 times longer than ones that stay on?
If you put the technology fro the rainbow maker and the christmas lights into one device, you could get a device that runs forever.
SOLAR KIDS TOYS
Why not get your kids something that not only expands their knowledge but introduces solar power to them in a fun way. When they realize they have in infinite source of power to play with,( which is totally safe, they will entertain themselves for hours coming up with new ideas, and these are the building blocks of the ideas that we will use to save our civilisation (maybe over dramatic but somewhat true) in the future. I bought this kit that becomes 5 different toys. One of them is a fan, which is probably the most useful on a sunny day.
The solar car is basically the most primitive but most fun solar toy. It’s basically a solar panel with a minute motor connected to wheels. It will continually drive while in the sun and stops almost immediately in the shade. As you can see its the basic same design as the solar cars of the past.
Of course the sun moves during the day, so we can use the solar power created by solar panels to move the panels to receive the most effective levels of light at all times. If every time the car was in the shade it used stored power to get back to the sun, it could last forever that way. Imagine if a Rhoomba (those robotic vacuum cleaners) or other devices like that can out during the day to sun themselves to store power automatically. Now that would be amazing.
Other uses of solar power
Of course if you use solar power to trigger a switch, the possibilities are almost infinite.of course a different technology, the battery allows us to store energy and use it later. That is a very important step in the solar power process, as basically no one needs lights when the sun us shining, and lighting is our most commonly used electrical appliance by most people, unless you are a lonely housewife with a vibrator obsession.
But silliness aside, if each of us thought about it, we would find a few ways to use solar around our house, and like most things in life, you don’t need to change 100% to make a significant impact on the world around you.
Here is an interesting device. The solar oven. We used it at my work in Japan. Truthfully it was a bit of a failure, but the idea is there. I’ve seen sunlight used with the fresnel lens inside a rear projection TV that can melt through solid metal in seconds. Have a look at the video at the end of this article.Makes for a pretty awesome photo though!
ok, now for the lesson in how all this stuff works.
What is Solar?
So the word solar, we hear all the time. Most people basically know what it means but heres a simple definition. Its anything related to a star/sun. In our case, we use the term Sun for our closest star. There is no difference between our sun and the starts we see twinkling in the sky, except that the other stars are generally much bigger, but much, much, much further away that they appear tiny. Its also a good indication of how big our universe is.We hear the term “Solar System” all the time and that is all the planets trapped in the gravitational field of our sun. You undoubtably have heard of the performers, Cirque du Soleil, which in English, is “Circus of the Sun”. the word “sol” meaning sun has been in use since ancient Roman times and appears in many languages in similar formats.
When researching solar panels, you will find out there is more than one method for creating electricity using the light for the sun. The only unchangeable thing is the light (can be substituted for other sources which emit photons), whose photons, once passed through a semi-conductor, like silicon, are passed out the other end as electrons. Solar cells are also called Photovoltaic (PV) cells (photo meaning “light” and voltaic meaning “electricity”) and are named as they convert the energy from light into the energy we call electricity, which we can store in batteries.
So how does it work?
The process is when sunlight hits very thin sliced silicon (basically sand – and also what your computer chips are made from), called wafers, and knocks an electron off the silicon which travels around the circuit and powers your devices. Silcon wafers joined together is called a solar cell, solar cells joined together are called solar panel, and solar panels are joined together to make solar arrays. ‘array!
On one side, the silicon wafers are slightly negative (by adding phosphorous). The other side are slightly positive (by adding boron). When i say slightly , i mean almost a 1:1 000 000 ratio, as its the tiny impurification that allows the electrons to be able to be free from the silicon. Pure silicon is too strong and would not let go so easily and the Boron and Phosphorous have 5 electrons which doesn’t allow all the silicon electrons to make connections. So, an electron is knocked loose from its bond. this process is basically never-ending and will happen billions of times in each cell every second. Yeah. electrons are pretty small. After doing their job (once used in an appliance), they go around the whole circuit and come back to the silicon and the electron joins on again ready to be knocked off again. They must be pretty annoyed. It’s a rewardless job being an electron.
Photovoltaic (PV) is a developing field and utilizes several different technologies: mono-crystalline (single crystal), polycrystalline (multiple crystal), cadmium telluride, gallium arsenide, or amorphous silicon deposited as a thin film. The major advantage of mono-crystalline cells is their higher efficiency and therefore smaller space requirements. Thin film can be cheaper to manufacture but is significantly less efficient, requiring more area and higher initial setup cost. Once we perfect the transparent solar cells, we will be able to “stack” them which will save a bunch of space, but ultimately the second row will be running on much less photon interaction.
The future of solar
Its my strong belief that instead of producing massive solar arrays like is becoming common, we will use much smaller solar cells, but instead us them on the end of a reflective dish to maximize the power in to power out ratio (see top left-pic above). many places already do this, but for some reason we don’t use it on homes. Another quite viable option would be that we add a thin film of solar reactant film inside our windows, which will generate energy that way. Just think, the screen on your mobile phone could be what is actually powering it one day. Although you wont get much from the actual device itself. Here is why….
I did an experiment by holding my solar powered car up to a range of light sources to see if it would work. Its amazing how much light it needs to start turning the wheels, and this was upside down so no friction or car weight was involved. So you need a photon rich light source. Interestingly enough, the lights that emit lots of photons,also take the most amount of electricity to run, as they are technically wasting the photons they shoot out which also cause much larger amount of heat.
The best ideas I have seen involve not supplemental solar panels, which does use a lot of extra resources, but solar incorporated in the main structure. For example, the carport that is made form solar panels (see pic above). you need to make it from something, so why not them.
The next stage of evolution would be the mega sun shade for cars which also recharges them. the next stage would be the car with a solar panel on top, and possibly a wind generator for when you are driving. Its innovations like these that will make these renewable energy sources really start to have a positive impact.
Do solar cells degrade?
Yes and No. like anything in the world they slowly disintegrate, but in general, they will not degrade significantly over time. The electrons never run out and can make the journey technically infinitely. The batteries which store the power will degrade over time and there are many battery types which have different lifespans. Actually most of the viability of this idea depends on battery technology more than anything else, which, as you can tell be todays laptops and mobile phones, is jumping forward in leaps and bounds.
The next step
When researching solar power I had a huge paradigm shift in how it thought about it. I have recently been impressed by governments around the world becoming very active in the promotion of solar energy.
There are a few haters out there, but in general people generally see solar as a supplement for other energy, when it doesn’t need to be this way at all. Some say that the amount of energy used to make solar cells takes so long to recover that i is not a sustainable source after all but this is rapidly changing as the mass production of solar arrays, or the ingenious ideas of using an array of mirrors to concentrate the sun onto much smaller and more durable solar panels, possibly even, massive fresnel lenses to pin point the suns rays, but at the moment the heat of the sun is a major factor which easily destroys anything in its path.
Theres certainly a revolution taking place. There is a whole city in Spain that is run by this very beautiful array, made form one mega voltaic cell in the middle surrounded by robotically controlled mirrors to track the suns movement and give it maximum power. Good work! …and its working models like these that will make the rest of the world realize its not a dream but an inevitable reality. Lots of arab nations are looking into is as they have awesome sun cover over there. Most likely America will get more involved more for the sake of “trying to beat the opposition” than desiring the change themselves. Who gives a shit how it comes about, ill be happy when it does.
Some interesting videos
This video has a great diagram of how a solar array can power your home – http://www.youtube.com/watch?v=hJ01UUZrHqI
(you could replace the generator with any other power source, like a wind generator… or a modified bicycle if you are really energetic)
Using a fresnel lens with the sun – http://www.youtube.com/watch?v=XFw7U7V1Hok
How solar cells work(11 pages) -http://science.howstuffworks.com/environmental/energy/solar-cell.htm
How solar Yard lights work(4 pages) – http://home.howstuffworks.com/solar-light.htm
Make a solar powered dog house (a cooled and heated dog house from your own custom built solar panels) – http://solarpowereddoghouse.com/
How to make solar panels in series. If this goofy couple can, anyone can – http://www.youtube.com/watch?v=5Zy3ELxwdtE
This video is about the new range of “organic” photovoltaic cells produced by BASF – http://www.youtube.com/watch?v=5Wi5zWSD-6I
Also -for a bit of fairly unrelated but interesting learning.
How to make a penny battery – http://www.youtube.com/watch?v=rIdPfDHeROI