Energy Storage Flashcards
Peak shaving
The process of storing surplus energy to satisfy later peaks in demand.
How to store energy or peak shave
Batteries, pumped storage HEP, P2G (power to gas), V2G (vehicle to grid), molten salt, flywheels, electrolysis of water, supercapacitors, high volume storage
Vehicle to grid systems (V2G)
An energy storage method in which the batteries in vehicles are connected to the local electricity grid. If there is a shortage of electricity from other sources, a proportion of the energy from the batteries can be used to maintain supplies.
Power to gas systems (P2G)
A method of using surplus electricity which would be wasted to produce methane gas. Electrolysis of gas produces hydrogen, hydrogen can then be used to produce methane.
Heat Energy
storage of heat energy as molten salt in high volume, in high specific heat capacity stores
Thermal mass
A measure of the ability of a material or structure to absorb and store heat.
High volume storage
as volume increases the surface area to volume ratio decreases and the rate of heat loss declines. Very large stores can retain heat gained in summer for space heating in winter
Molten salt
Molten salt can reach temperatures of up to 550 o C before boiling so can be used to store heat that can be used later to boil water and generate electricity
High thermal mass buildings
Buildings made of materials with high specific heat capacity, e.g. concrete, help keep buildings cool in summer and warm in winter as the materials take a long time to heat up and then cool down.
Kinetic energy / flywheels
Surplus energy is used to rotate a wheel in a system with very low resistance e.g. a vacuum, The wheel will continue to spin for a significant amount of time, the kinetic energy can be used to drive machinery or generate electricity later, can keep spinning for months or years, considered for use in space
Electricity supercapacitors
surplus electricity is used to charge plates separated by an insulator, when the supercapacitor is switched on, electrons can flow from one plate to another procuring a current and electricity
Pumped storage HEP
Surplus energy is used to pump water uphill. Water is held in a reservoir at height as gravitational potential energy, releasing the water converts the energy to kinetic energy that can drive turbines and produce electricity very quickly in times of demand.
Large scale batteries
large rechargeable batteries can be used to store excess electricity from renewables for later times of demand and intermittence. Successful use in Australia, used to cope with demand fluctuations.
