In this edition of Spot on Science, Natalia takes us to a solar farm to learn about renewable energy.
Solar panels are devices that are designed to capture sunlight and convert it into electricity.
Solar panels are an increasingly popular form of renewable energy, as they offer a clean and sustainable source of electricity without emitting greenhouse gasses or other harmful pollutants.
They are installed in a variety of locations, from residential and commercial rooftops, to large-scale solar farms.
Discussion Questions:
- Research green energy sources. Are any of them available in your community?
- Write a letter to your mayor stating your position on green energy.
- What would be the most effective green energy sources for your community?
READ THE SCRIPT:
[NATALIA GARCIA / IDEASTREAM]: DID YOU KNOW THAT THE SUN GIVES EARTH 173,000 TERAWATTS? THAT’S ALMOST 10-TIMES THE AMOUNT OF ELECTRICITY THE ENTIRE PLANET WILL USE IN A YEAR.
THE ENERGY GIVEN OFF BY THE SUN IS RENEWABLE ENERGY. RENEWABLE ENERGY IS ENERGY THAT COMES FROM A NATURAL SOURCE, AND THAT IS REPLENISHED AT A FASTER RATE THAN IT’S CONSUMED.
BUT HOW CAN WE CONVERT THIS SOLAR ENERGY INTO ELECTRICAL ENERGY? SOLAR PANELS
TODAY I’M AT A PARK IN SUNBURY NEAR COLUMBUS, OHIO AT A SOLAR FARM.
I’M READY TO ROLL UP MY SLEEVES AND GET DIRTY TO HARVEST SOME SOLAR ENERGY.
[JAKE KUSS / SHARED POWER NETWORK]:THAT'S NOT HOW IT WORKS.
[NATALIA GARCIA / IDEASTREAM]: WAIT, WHAT?
[JAKE KUSS / SHARED POWER NETWORK]: HI, MY NAME IS JAKE KUSS, I'M THE EXECUTIVE DIRECTOR OF SHARED POWER NETWORK.
WHEN THE SUN COMES DOWN AND HITS THE GROUND HERE, THERE'S A PORTION OF SUNLIGHT CALLED A PHOTON. THAT PHOTON WILL HIT THE SOLAR CELL HERE. THERE'S A NEGATIVE SIDE AND A POSITIVE SIDE WITHIN THE SOLAR CELL, AND THE PHOTON COMES OUT AND KNOCKS OUT AN ELECTRON.
THOSE ELECTRONS WHEN THEY PASS FROM THAT NEGATIVE TO POSITIVE SIDE, THESE LITTLE FILAMENTS IN HERE COLLECT THE ELECTRONS AND FUNNEL THEM ALL DOWN INTO LARGER ROADS. SO THE SMALLEST FILAMENTS ON HERE GOES TO THE LARGER, TO THE LARGER. AND THEN ALL, AT THE END, THERE'S A COLLECTION SYSTEM ON THE BACK HERE, THE SOLAR PANEL, AND THAT'S WHERE IT'S ALL COLLECTED IN THAT ONE POINT, AND IT FLOWS OUT FROM THAT POINT.
THIS IS AN OFF-GRID SYSTEM. SO THE BATTERY BACKUP HERE COLLECTS ALL OF THE ELECTRICITY THAT'S BEING MADE. IF YOU AREN'T STORING IT OR YOU AREN'T USING IT ON THIS SYSTEM, THAT ELECTRICITY IS LOST IN THAT MOMENT. BUT IF YOU CONNECT IT ON YOUR HOUSE OR A BUILDING NEARBY, THOSE ARE USUALLY CONNECTED TO THE GRID. SO THAT'S ALL THE BIG TRANSMISSION WIRES THAT YOU SEE UP ON THE TELEPHONE POLES. BUT ON A SYSTEM ON YOUR HOME OR YOUR BUILDING, THAT ELECTRICITY WILL GET USED THERE FIRST. AND IF THERE'S ANY EXCESS, IT'LL THEN GO OUT ONTO THE GRID.
SO MOST SOLAR PANELS ARE MADE MOSTLY OUT OF GLASS AND ALUMINUM, WHICH IS GOOD. THAT'S A LOT OF RECYCLABLE MATERIALS, A LOT OF RELATIVELY EASY-TO-FIND MATERIAL. SO THERE'S A GLASS COATING ON ALL SOLAR PANELS. BUT THE CELLS THEMSELVES, THE BLACK PART HERE, IS MADE OF SILICA, WHICH IS BASICALLY SAND. AND THEN THE HOUSING IS MOSTLY ALUMINUM. THERE ARE SOME METALS IN HERE THAT ARE A LITTLE BIT MORE EXPENSIVE AND THAT'S KIND OF WHERE THE COST COMES FROM WITH SOLAR PANELS.
MOST PANELS LAST FOR, YOU KNOW, 30-PLUS YEARS AND SO IT'S SOMETHING YOU DON'T HAVE TO WORRY ABOUT FOR A WHILE. SOLAR PANELS CONTINUE TO BECOME MORE AND MORE EFFICIENT AND CHEAPER ALONG THE WAY. PANELS NOW ARE ANYWHERE FROM KIND OF 25 TO 35% EFFICIENT.
A LOT OF THINGS THAT YOU CAN DO TO KIND OF THINK ABOUT THE ELECTRICITY THAT YOU USE. LITTLE THINGS LIKE UNPLUGGING, YOU KNOW, APPLIANCES THAT YOU'RE NOT USING; ALWAYS TURNING OFF THE LIGHT SWITCH WHEN YOU LEAVE A ROOM. LITTLE DECISIONS LIKE THAT CAN REALLY IMPACT OVERALL HOW MUCH ELECTRICITY YOU'RE USING AT HOME OR AT YOUR SCHOOL.