Today (April 5th, 2020) at 9:00 PM IST, people across India are expected to switch off lights for 9 minutes.
This has apparently raised concerns that there would be problems to the power-grid, due to under-utilization of power.
Can any one explain this (in layman's terms)?
a)
Specifically, will the generator be overloaded and stall because the power lines will eventually be saturated and achieve the same potential as that of the generator (given that energy flows from a source of higher potential to that of a lower potential)?
b)
If it is the case, is there no control to simply reduce the amount of power generated to match the consumption?
c)
Or is it the sudden decrease in power consumption that is the cause for concern?
PS: There is a similar question here –
Why does the frequency of power generation change when there is a change of load on the power grid?
But I'm looking for an explanation that can be understood by a layman.
Best Answer
If you are pushing a cart up a hill, you need to push harder if the cart is full of bricks and not as hard if it is empty. If the load falls off and you keep pushing with the same effort, the cart will go faster.
With electric generators, a certain amount of effort is required to turn the generator. If the load is shut off, the same effort will make it go faster. If it goes faster, the frequency and voltage will increase. Generators have regulators that sense the load and automatically reduce the effort if the load decreases. Reducing the effort of the engines, turbines etc. that turn large generators takes some time and care. That is the cause of concern. The power grid equipment and operators should be able to handle demand variation without too much concern, but they apparently are not universally trusted.