Why COVID-19 could cause major energy blackouts this summer
image credit: David Shankbone, CC 3.0
- Apr 9, 2020 8:54 pm GMTApr 9, 2020 4:35 pm GMT
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100%, there will be blackouts across the US this summer if people are still sequestered. In some places, energy networks aregoing to melt. But it’s not just coronavirus; it’s a sign of things to come….
You might think a US-wide shutdown of busy manufacturing factories, high-rise offices and retail and service businesses would create a DROP in energy usage – and you’d be correct. It will.
But if you think that will put the electricity networks under less pressure, think again.
Quite the opposite, in fact: in some areas, it could send it into meltdown.
Already, the electricity grid is fragile by design, not because of TOTAL demand but because of LOCATIONAL demand. And as the US hunkers down at home for the long haul, just when the summer heat begins to arrive, residential networks maynot have the capacity to cope with the Increased daily load – and soon some of uswill no longer be able to take power for granted.
This situation is about to make it painfully obvious to everyone that time and location is critical in the day-to-day functioning of the energy network.
To understand the problem, you need to understand how the power networks were created. You need to understand grid architecture.
POWER TO THE PEOPLE
An electricity network is comprised of wires, substations and transformers.
Electricity flows from power stations on large, high voltage transmission wires, to local substations and transformers. Then, to reach our homes and businesses, it is distributed on wires of varying sizes and voltage levels, depending on the level of expected demand. (see diagram)
As electricity flows, it experiences resistance and that causes heat. The more energy that flows through each part of the system, the hotter it will get. Big high voltage wires can cope with more electricity flowing through them, but smaller wires, substations or transformers cannot handle as much electricity before they start to get too hot.
In major cities, commercial high rises and offices are fed by big, high voltage wires and are ‘plugged in’ high in the network hierarchy, sometimes fed directly from the transmission network.
Further out, in the suburbs where most of the homes and communities are, the wires get smaller and smaller. They don’t have capacity to handle high electricity demand.
Think of it like a system of roads.
In city centers, where lots of people need to move around, there are large highways and roads that can handle high volumes of traffic. In small suburbs there are narrower roads designed to handle only residential traffic.
If you put all the traffic going into the city onto the small suburban roads, you create gridlock – and that’s effectively what we’re now doing to the electricity network as people are forced to stay at home.
But there is a crucial difference between traffic and electricity.
Unless the electricity network is carefully controlled, whenever there is demand, supply doesn’t stop; it continues to try to feed that demand - and that’s when things start to melt and burn.
The centre of Manhattan has a network with significantly more capacity than it needs for the typical peaks. In contrast, the suburban networks around it have a much lower capacity- so if you go beyond the usual demand, they are quickly going to start to struggle.
These networks were built a long time ago and already, with home computers, AC units, refrigerators, not to mention increasing numbers of electric vehicles, they have far more demand than they were designed for.
The fragility of power networks is shown in blackouts and brownouts and higher summer temperatures have been increasingly pushing them to their limits – as demonstrated last year.
In New York last July, the West Side of Manhattan lost all power after a fire in a substation. The following weekend, power companies had to ask residents to shut their curtains rather than turn on their air con units to help protect their networks and keep the power on.
At the time, Con Edison’s Allan Drury told USA Today: ‘The demand for power can increase as the heat wave goes on because people become less resistant, more willing to turn their air conditioning on and up.’
Also last summer, Californian residents had to cope with a series of deliberate blackouts, caused by rising temperatures. At times, operator PG&E was forced to turn off the power to avoid infrastructure overheating and reduce the risk of transformer fires.
Silicon Valley escaped because the larger wires that serve it can handle increased load – but the smaller residential communities were the ones that were hit, with millions of people having their power turned off.
It’s not just the US either. The same is happening in many other countries, The UK, for example, has suffered outages while India’s electricity network has been plagued by blackouts for years. They suffered the world’s worst outage in 2012, when half the country was left without power.
Now, with coronavirus enforcing millions of Americans to stay at home, these already under-pressure residential networks face a new challenge.
Typically, just 3.6% of US workers worked more than half their time from home before COVID-19, according to Global Workplace Analytics’ analysis of 2018 American Community Service (ACS) data.
In recent weeks, reports suggest that figure has jumped up as high as 56%.
Add to that the people who are at home and need to stay occupied and cool – such as school children and the out of work - and you have a vast amount of additional beings wanting more electricity on a day-to-day basis.
Worse still, the high efficiencies that come with large buildings in terms of heating, lighting and keeping large numbers of people fed and functional are lost when the same services are required at home.
In an office of 1,000 people, for example, you have one big and efficient air con system keeping everyone cool. When those 1,000 people are working from home, that’s 1,000 smaller but less efficient units drawing power on a part of the grid where the wires that feed them are small.
The same goes for cooking facilities to make hot lunches, less efficient home lighting set-ups, independent Internet routers, individual home servers, single-person coffee percolators, the list goes on.
When we are out at work, our houses go dark from a grid perspective. When we’re all quarantined away, every house is lit up like a Christmas tree, using way more energy than normal.
A Microgrid Knowledge article recently estimated a home-based worker adds 3,000 kWh per year to household electricity use. Considering the average annual consumption for a US household is about 11,000 kWh, that’s an increase of just over 25% in annual electricity demand.
But that is just an annual average – and because the highest demand comes then air con units are switched on, that increase will be an even higher percentage in months the summer.
As mentioned before, demand is not the problem – overall demand is going to go down, not up - it’s the LOCATION of that demand that is the issue.
All these people are all at the edge of the network, all being served by small wires with lower capacity. The higher the demand, the more electricity is flowing through the system and the hotter it gets - so as we move into summer, unless drastic measures are put in place, keeping the power on will be a very real issue.
NO REST FOR THE SYSTEM
You may think this situation is no different to a normal weekend, when lots more people are staying at home. That is true to a certain extent - but the problem with the lockdown is that this is a never-ending weekend.
Networks have entropy, so when they transmit and distribute more energy they warm up. And when they warm up they need to cool down again.
In a normal cycle, energy use increases in the residential networks on a weekend and the network gains thermal energy. But then when people go back to work in the week, the houses turn off in the day and the residential networks are allowed to cool.
This time, we don’t have that opportunity. With people at home 24-7, the network doesn’t have a moment to cool down and the heat continues to build in the wires, the transformers and the substations day after day.
Without deliberately shutting it off and giving it time to cool, it will just get hotter and hotter until things start to burn.
All states will face the same issues, but California, whose network is already at breaking point, is potentially facing the additional challenge of coincident demand – which will affect how green their energy can be.
The way the state’s network is built, the big solar utility state power plants plug into the high end of the network, directly into the transmission and directly feed the big buildings, which normally have the biggest demand.
But with nobody in the big buildings, the big solar utility power plants have no demand to feed – and solar generation from these plants will have to be switched off. Meanwhile, the distributed generation that supports the residential networks does not have enough capacity, so non-renewable power will have to be called on to supply that demand.
With such a short time to come up with a solution, there are only two ways we can solve the problem: people will have to go back into offices where they will then spread the virus, or we have to find a way to manage the network very quickly.
Unfortunately, right now we do not have the capability to easily manage the infrastructure at the grid edge. In the future, local energy networks would be able to cope with this situation, but they are not widely in place yet.
So, soon enough, network operators will not just face the inconvenience of shifting business models – they will have to physically prioritize and optimize their networks.
Just like people are being told who must stay at home and who can’t; who is an essential worker and who is not; the same thing could end up happening with the management of electricity.
People will start being told when they should and shouldn’t use it.
Because if they don’t, in some areaswe WILL see wires melting, fires in substations and entire utility vaults shutting down on a daily basis.
IN OUR NEXT ARTICLE OF THIS SERIES, WE EXPLAIN THE IMMEDIATE SOLUTIONS THAT CAN HELP REDUCE DEMAND AND SAVE US FROM BLACKOUTS.