 |
| Public domain image by Sandia National Laboratories via Wikimedia Commons. |
A new energy storage facility opened at the Poolbeg Power Station which according to The Irish Times has the ability to source 75 MW of power for two hours. Hopefully it'll act as a stop gap in times of energy need. For comparison, the pumped storage hydroelectric station at Turlough Hill in Wicklow can provide 292 MW of electricity from its four alternators (AC generators) for 6 hours (so the energy storage capacity is 292 MW x 6 = 1752 MWh)
More details are available in this Irish Times article.
What is the Relationship Between Power and Energy?
Power is measured in watts and is defined as the rate of use of energy or rate of doing work.
So
Power = energy/time (dividing something by time gives a rate)
Therefore, rearranging the equation
Energy = power x time.
In the SI system, energy or work done is measured in joules (or calories in imperial units)
One joule is equivalent to 1 watt for 1 second.
A one kilowatt (1000 watts) heater uses 1000 W x 3600 seconds = 3.6 million joules in one hour
However
in the context of electricity, the watt-hour (Wh), kilowatt-hour (kWh)
and megawatt-hour (MWh) are more commonly used as units of energy.
One
kWh (or a unit on your electricity bill) is the amount of energy used
by a 1000 W or 1 kW appliance in one hour (or 100 W in 10 hours etc)
An example of doing work and using power to do it is lifting an object off the ground. To lift an object a certain distance requires work to be done to give the object potential energy by way of its height above the ground. If you lift the object faster, your arm produces more power, but the object takes less time to be lifted. Similarly if the object is lifted less forcefully, i.e less power is used, the time is greater. In both cases although the power is different, energy = power x time is the same.