Is the Indian National Power Grid in danger?

[cnh1995]

As COVID-19 is growing exponentially worldwide, a 21-day lockdown is going on in India since 25th March. In this period, only essential services will remain open. To boost the morale of employees working in these essential services, Indian PM had asked all the citizens to show their gratitude by gathering in their respective windows/balconies at 5:00 PM on a Sunday and clapping for 5-minutes straight. People did that enthusiastically.

Today, he made another request , which, according to him is "to make everyone realize that we are not alone in this fight".
Here's what we are supposed to do on 5th April at 9:00 PM:
Turn off all the lights in our house, light a candle/turn on smartphone flashlight and stand in the window/balcony with the candle/smartphone for 9 minutes.

So ideally speaking, at around 9:00 PM on 5th April, all the lighting load in almost entire India is going to be thrown off suddenly, and after 9 minutes, all this load will again be switched on suddenly.

Wouldn't this put the national power grid at some risk? Please share your opinions.

 

[phinds]

I'm no expert in power distribution systems but it doesn't sound like a good idea to me. Still, you would think that they WOULD have given that considerable consideration. Perhaps there's a plan for staggering switching on substations. That still leaves the problem of the substations each being overwhelmed by their own spike. Anyway, it's a good question.

 

[cnh1995]

I'm no expert in power distribution systems but it doesn't sound like a good idea to me. Still, you would think that they WOULD have given that considerable consideration. Perhaps there's a plan for staggering switching on substations. That still leaves the problem of the substations each being overwhelmed by their own spike. Anyway, it's a good question.

Power grid authorities have different opinions about this event. Some are saying this can be managed as we know it beforehand, while some are still very doubtful about maintaining grid stability. The amount of power associated in this "adventure" is close to 15GW.
They might be able to manage it, but it is certainly going to put a lot of stress on the grid and the power sector employees.

I believe this is @anorlunda's area of expertise. I request him to weigh in here.

 

[anorlunda]

In the USA, lighting accounts for 1.4% of the electric energy consumption. Let's conservatively say that at 9PM, they are 3% of the load. So I would say that this lights-on-lights-off exercise is not a threat. A lightning storm that could suddenly trip major transmission lines or major power plants. That is much more common and a bigger challenge for the grid, but storms almost never lead to cascading blackouts.

But I don't have numbers for India. Perhaps some search might help you to find that number for India.

In rural Belo Horizonte, Brazil in the 1950s, lights accounted for 30% of the load, but I do not think that India is that primitive.

Every question likes this reminds me of a story (that's a symptom of getting old ) We had a case in the 1960s of a drag line shovel at a coal mine in Australia. The shovel would lift, move, then drop, then drag. The mine was supplied by a single coal power plant. The drag load amounted to 40% of the electric capacity of the power plant. Worst of all, the cycle repeated every 180 seconds, which resonated with the boiler drum water level control loop. Yes that caused big problems, but it did not black out the province. Sometimes it tripped the plant. They extended the cycle to 240 seconds and that fixed their problem.

The point of the story is that even huge load changes do not necessarily bring the grid down.

Edit: I just remembered something similar. There was a myth about Australia being asked to blink their lights on-off when John Glen flew over in a Mercury capsule in 1962. There were fears that it would black out Austrailia, but it didn't.

 

[zoki85]

The Load Rejection can cause potential problems. The consequences depend on many factors (grid interconnection structure, size of the grid, percentage of hydroelectric PPs in the grid, percentages of the rejected load with respect to max load capability of the network, type of load etc). If the event is well synchronized/timed all across the grid, the danger is smaller. And it is less dangerous to do it during smaller power demand hours than during peak power hours. Daily load curves typicaly look like this:

Don't know much about India's grid, but I hope the experts and authorities estimated the risk is small enough and they will be prepared

 

[cnh1995]

The power ministry officials have assured that the grid operators are ready to handle this power fluctuation. Apparently, they got enough time to prepare the grid lines and power plants for this event. As per a power ministry spokesperson, the situation at 9:00 PM tomorrow will be the same as that on 4:00 AM everyday and there's nothing to worry about.

Keeping fingers crossed!

 

[Wrichik Basu]

In rural Belo Horizonte, Brazil in the 1950s, lights accounted for 30% of the load, but I do not think that India is that primitive.

True, but the problem is, due to the lockdown, industrial (bulk) consumers are not demanding power at the rate they normally do, so a lot comes down to the domestic consumers. According to this source,

There have been concerns that the blackout may impact the electricity grid due sudden drop in peak power demand, which was already down 25 per cent at 125.81 GW on April 2 compared to a year ago.

 

[anorlunda]

True, but the problem is, due to the lockdown, industrial (bulk) consumers are not demanding power at the rate they normally do, so a lot comes down to the domestic consumers. According to this source,

That's interesting. Normally, low demand is not considered a reliability threat to grid operations. But if prolonged, it can become an economic threat to the utilities and power generation owners. They need money to buy fuel. They need the labor of their employees.

Grid operators keep "reserves" for the purpose of meeting sudden load changes or sudden failure of transmission or generation. The fastest category is called "spinning reserve". Traditionally, that means generating capacity with the turbines spinning and the generators synchronized to the grid and thus ready to respond at an instant's notice. Usually, the difficulty is to find reserves at the time of maximum peak demand. During reduced demand, there should be more than adequate reserves available.

So I do not understand the source of concern in India. Isn't low industrial demand and high lighting also typical of some national or religious holidays?

 

[cnh1995]

Isn't low industrial demand and high lighting also typical of some national or religious holidays?

Yes, that is exactly what energy experts in the power sector are saying. They have got enough time to plan this whole event in advance, so it's going to be just like another festival day for them.
I guess people were (at least I was) worried because nothing like this had been done before.

 

[zoki85]

True, but the problem is, due to the lockdown, industrial (bulk) consumers are not demanding power at the rate they normally do, so a lot comes down to the domestic consumers. According to this source,

Nevertheless, according to the source they had few exercises before:

"Meanwhile, an official on the condition of anonymity said power demand may fall by 10 GW to 12 GW during the blackout, which will have no bearing on stability of the national power grid.
The official further said this is not the first time the country is going for a blackout, as earlier too such exercises have been conducted for initiatives like 'Earth Hour'."

 

[sysprog]

I think that in general we shouldn't do anything for merely symbolic reasons that potentially can produce significant physical consequences. But at least most, if not all, of India, like other places, can produce much more electric power than is needed to meet peak demand, especially in situations in which advance notice is given. Here (mid-western USA), we can fire up diesel-powered turbines if we need to, and dump the excess electricity into the ground if we overdo the production.

 

[Wrichik Basu]

Isn't low industrial demand and high lighting also typical of some national or religious holidays?

But it seems to me that the demand has gone lower compared to holidays/festivals. For example, I know one person whose office has a number of factories across the country. These factories do not shut down ordinarily (they have rules for managing holidays of workers). He said that his office had shutdown their factories for the lockdown. If there are more cases like this, then the demand could be lower than other holidays. Anyways, I just hope that we do not have to sit in the dark for more than nine minutes.

 

[cnh1995]

Whew!
The grid is fine.

 

[Windadct]

I was surprised by the source (Fig 1 LINK - granted it is a little old, but lightning efficiency has probably improved more than any other use) - but it appears that lighting accounts for less than 50% of the household consumption - this mixed with non-household loads ( even not during business hours) - should not be a problem for the grid ( IMO)

 

[zoki85]

@cnh1995 , can you tell us what's going on with India's plans to raise the grid's highest transmission voltage to Megavolt range, in what phase of development are these things?

 

[anorlunda]

Please stay on-topic.

 

[digitalamit22]

nothing has been issued in powergrid.