Different Types of Energy Storage Quiz

Answer: Flywheel

Flywheels store energy as kinetic-mechanical energy. A flywheel's spinning wheel is levitated by a magnet inside a vacuum, which reduces almost all friction. The concentric wheel is made of high-tensile-strength fibers embedded in epoxy resins. These wheels spin at 200,000 - 100,000 rpm. Speed is everything: the faster the flywheel can go, the more power it can store. If scientists could make even stronger material, then someday flywheels could hold many terajoules of energy.

A terajoule is equal to a thousand billion joules.

It takes about 30,000 joules to make a cup of tea. Only a few terajoules were used to power astronauts to the moon and back. Flywheels can charge in fifteen minutes, and do not need maintenance for twenty years. They are lightweight, reliable and have a ninety-five percent power efficiency. Flywheels are not affected by the weather like chemical batteries, and do not hurt the environment.

In the 1950's, flywheel powered buses were used in Yverdon, Switzerland. Flywheels were also used in steam engines of the 1970's.

The main disadvantage of flywheels is that they can explode at any second because the wheel inside is spinning so fast.

Answer: Superconducting

Superconducting magnetic energy storage stores energy in the form of electromagnetic energy. This system is made up of a coil of ceramic superconducting wire that is being cooled by liquid. The coil of ceramic needs to be cooled because ceramics will only be superconductive at -400 degrees Fahrenheit.

This superconductive temperature is much higher than all other materials. The advantages of this storage system are that the system can turn on within a millisecond, as opposed to normal batteries which take minutes. Also, superconducting magnetic energy storage systems have virtually zero energy loss.

Another advantage is that superconductors can hold 7,000 times more energy than copper wire with respect to their size. However, they can only be made with expensive materials, which are hard to shape.

Answer: Pumped Hydroelectric

Pumped Hydroelectric energy storage systems store energy as potential energy. They only have a thirty-percent energy efficiency because the water needs to be pumped back up to the dam. But the real problem is that dams have a major ecological effect on the environment.
The biggest pumped hydro storage plant is in Ludington, Michigan. It can store 15,000 megawatt hours of energy. In the future pumped-hydro storage areas might be in underground rivers and streams. This would minimize damage to above ground rivers, which support more living things, and would hide the ugly dams from sight.

Answer: Alessandro Volta

A chemical battery releases potential energy in the form of electricity through a chemical reaction, causing electrons to move. Chemical batteries have three different sections: the anode, cathode and electrolyte. A negatively charged electrode, called the cathode, conducts electrons. A separator, called the electrolyte, conducts ions. (Ions are electrically charged molecules and electrons are smaller negatively charged particles of an atom.) This separates the cathode from the positive electrode (called the anode) which also conducts electrons.
The cathode and the anode can be made of various materials. Lead-acid batteries are used for cars. They are expensive and bulky. Silver-oxide batteries are used for hearing aids. Alkaline-Manganese batteries are used for radios and tape recorders. Carbon-Zinc batteries are used for flashlights. Nickel-Iron batteries are primarily used for back-up lighting systems.
The first chemical batteries may have been made by the Parthians, who dwelled in the area of Iraq, around 200 BC. However, Alessandro Volta is considered the father of chemical batteries. He first made the voltaic pile, a battery made of a pile of zinc and copper, which had brine soaked cloth between them. The voltaic pile was the first chemical battery that produced direct current. Direct current is electrical current that can only flow in one direction. Direct current is good for automobiles, ships and locomotives, because it is steady. Alternating current is electrical current that moves both ways based on whether the dynamo is turning up or going down. A dynamo, which converts mechanical energy into electrical energy, is necessary for the production of alternating current.
Chemical batteries have an energy efficiency of 80%. They are compact, heavy, and toxic, and take hours to charge. If the batteries get too cold, they have a reduced capacity. If the batteries get too hot, the battery's life is shortened. Chemical batteries work from one to seven years. The biggest advantage of chemical batteries is that they are very cheap. This is the result of many decades of specialization in chemical batteries. The world's largest chemical battery storage system is in Chino, California, which has 8,000 lead-acid batteries.

Answer: Compressed air

Compressed air storage compresses air with excess electricity. This is another example of potential energy. Energy is produced when the pressure that is built up is released. This pressure powers a turbine and creates electricity. Since the air is pressurized, it gets really hot. To avoid heat-related damage, the storage area needs to be cooled down. Also, the storage area must be airtight.

Many compressed air energy storage plants are built in abandoned mines. Because mines are usually very large, compressed air storage can hold lots of energy.

The pressure in the storage area is between 800 and 1,600 pounds per square inch. (Normal air pressure is fourteen pounds per square inch.) Earthquakes can collapse the abandoned mine, which would destroy the plant.

Another problem with compressed air storage is that it does not respond quickly. It takes thirty minutes to start producing electricity, whereas other types of batteries take seconds. Compressed air storage has an energy efficiency of eighty percent.

The largest compressed air storage plant is in Norton, Ohio. Compressed air storage does not hurt the environment as much as pumped hydroelectric storage because it is underground.