Somewhere in our last blogs, we saw that energy is used to do the work. And to do work we need power. So what is the relation among all three? Especially the power and the energy.
Consider the case of biking across a steep gradient. Here the work required to reach the top from bottom would be some Joules. Now let us first do it with manually paddled bicycle and then with a motor cycle.What difference do you notice? Which one will be fast? Motor cycle or paddled cycle? Why? Difference of power between motor cycle and paddled cycle? Perfect. You are right. We shall reach the top faster by motor cycle than by paddled cycle because motor cycle has more power than the paddled cycle. So the work is done faster if the power is more.
Now we can draw a relationship as –
Power is the Energy drawn per unit of time or work done per unit of time.
Suppose a machine of 50 HP is operating fir a shift of 8 hours, then can we calculate the actual energy i.e. how many units consumed by that machine? For time being let us consider that the machine is running with full capacity and the power factor is unity.
50 HP is converted into kW as –
1 HP is 0.7457 kW so 50 HP is 37.285 kW
Now 1 unit of electricity is 1kWh means – if a load of 1kW is running for 1 hour, it shall consume 1 kWh i.e. 1 unit of electricity.
So if 50 HP i.e 37.285 kW machine runs for 8 hours, it shall consume 37.285 kW x 8 hours (h) = 298.28 kWh = 298.28 units of electricity.
Hope you have now clear with relationship of energy and power. In case of any queries, please put them in comments and I shall reply to those.