Sustainable Energy Storage
BATTERIES
What is a battery? A battery, in concept, can be any device that stores energy for later use. Batteries do not make electricity; they store it, just as a water tank stores water for future use. Common use of the word, "battery" in electrical terms, is limited to an electrochemical device that converts chemical energy into electricity. Let’s look at why batteries can be an important part of living sustainably!
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Batteries are all over the place - in our cars, our PCs, laptops, portable MP3 players and cell phones. They also play a role in renewable energy.
A battery is essentially a container full of chemicals that produce electrons. Chemical reactions that produce electrons are called electrochemical reactions.
POWER in all SHAPES & SIZES
f you look at any battery, you'll notice that it has two terminals. One terminal is marked (+), or positive, while the other is marked (-), or negative. In an AA, C or D cell (normal flashlight batteries), the ends of the battery are the terminals. In a large battery, there are two heavy lead posts that act as the terminals.
Electrons collect on the negative terminal of the battery. If you connect a wire between the negative and positive terminals, the electrons will flow from the negative to the positive terminal as fast as they can (and wear out the battery very quickly - this also tends to be dangerous, especially with large batteries, so it is not something you want to be doing). Normally, you connect some type of load to the battery using the wire. The load might be something like a light bulb, a motor or an electronic circuit like a radio.
Inside the battery itself, a chemical reaction produces the electrons. The speed of electron production by this chemical reaction (the battery's internal resistance) controls how many electrons can flow between the terminals. Electrons flow from the battery into a wire and must travel from the negative to the positive terminal for the chemical reaction to take place. That is why a battery can sit on a shelf for a year and still have plenty of power - unless electrons are flowing from the negative to the positive terminal, the chemical reaction does not take place. Once you connect a wire, the reaction starts and energy flows.
REchargeable batteries help the planet!
Did you Know?
2000 year old battery
This clay jar with an iron rod surrounded by a copper cylinder was used over 2000 years ago. When filled with vinegar and an electrolytic solution it produces 1.1 volts DC. It is believed that the Parthians who ruled Baghdad (circa 250 BC) used batteries to electroplate silver.
REchargeable batteries:
Alkaline manganese
* Zinc-carbon
* Nickel Cadmium (NiCd)
* Lithium Ion (Li-ion)
* Nickel Metal Hydride
* Single-use Lithium
* Silver Oxide
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STAND ALONE POWER
When a house can provide its own power without the need to connect to the electricity grid or ‘mains power’, we call this a Stand Alone Power System.
Generating your own power from renewable energy sources and then storing it, allows you to be environmentally friendly and independent at the same time.
It often takes many batteries to store enough power to run a house. This means batteries must be linked together in certain configurations known as parallel and series circuits. When assembling a stand-alone power system, you need to work out how much power you need for heating and cooling, hot water, appliances, lights and computers before you start.
It's important to remember that a battery does not store electricity, but rather it stores a series of chemicals, and through a chemical process electricity is produced. Basically, two different types of lead in an acid mixture react to produce an electrical pressure called voltage. This electrochemical reaction changes chemical energy to electrical energy and is the basis for all wet cell batteries.
What’s inside a battery?
Batteries can either be a primary
cell, such as a flashlight battery (once used, send it to the local recycling plant), or a secondary cell, such as a car battery (when the charge is gone, it can be recharged).
Caution - safety first!
Lead-acid batteries can be dangerous. Ask your teacher or parents before looking at one.
The Facts
The words "POS" or "NEG" are often used instead of the + or - symbols.
Electrical energy is converted into chemical energy in batteries and then re-converted when needed.
22,000 tonnes – the equivalent weight of 110 Jumbo Jets – are sent to landfill unnecessarily every year in England.
Batteries take a lot of energy to make. Often far more energy than they give out. Using rechargeable batteries saves money and the Earth.
QUIZ 9: Batteries & Renewable Energy Storage
Did you know you can make a bio-battery from lemons? They are used normally for educational purposes and they use electrochemical reactions that generate low voltages, usually shown in the form of a led or light bulb glowing. Next time you hold a lemon, remember, the power is in your hands! Are you ready for the next quiz? Most of the answers can be found in the previous section but some questions may require you to dig deeper. So, consider the internet, go to the library or ask a friend. Power on, Power Ranger!
1. What is a battery?
2. List 3 devices which use batteries.
3. How have batteries helped society today?
4. What environmental problems exist with batteries today?
5. What's the solution to this environmental problem and why?
6. What are some things that you used today which require a battery (in whole or part) to work?
7. Name some types of rechargeable batteries?
8. What are the names and symbols given to the terminals on a battery?
9. Why are batteries so important to people who live in remote areas?