Life's all about striking a balance isn't it? At least that's what the lifestyle gurus tell
us anyway. Although looking at the current world events it's difficult to see any great
examples of where we're actually achieving that goal. And finding a way to balance the power
consumption of our modern societies is proving to be a difficult task too as more and more
intermittent renewables are added to our grids grid operators are constantly on the lookout for
more and more sophisticated solutions to help solve this increasingly intricate conundrum.
And now a team of researchers at the University of Vermont in the United States
has developed a genius system based closely on the way the internet works
which can talk to all the large devices on a grid and negotiate with them about whether
or not they really need power any given moment in real time 24 hours a day. So how do they do that?
Hello and welcome to Just Have a Think. I'm sure many of us have had some kind of experience
of the inconvenience of power outages. We all saw what happened over in Texas in the winter
of 2021 when an unprecedented cold snap blanketed the state with snow ice and sub-zero temperatures
leaving two million households without power for days and causing at least 210 deaths with
economic losses estimated at something like 130 billion dollars. And the hard truth is
that unless state grid operators around the world throw some serious resource into upgrading their
systems for the 21st century, these sorts of events will become more and more commonplace
as we decarbonize our power sources and rely more heavily on electricity for heating and cooling our
homes energizing our electric vehicles and running ever more appliances and communication systems.
Right now that generally means building bigger and bigger centralized infrastructure
with vast amounts of energy storage like grid scale batteries and pumped hydro
to handle the intermittent power output of renewables, and building
high voltage transmission lines to interconnect different regions or states or even countries
so that the supply can be sent wherever it's needed whenever it's called for, which is
something I've talked about many times on this channel. It all works pretty well in principle
and it's a strategy that's being implemented at great scale and pace all over the world,
but it is eye-wateringly expensive and of course it requires domestic political consensus and
diplomatic cooperation between countries. And let's face it those are two things we definitely
don't seem to have an oversupply of just at the moment. So how else can the problem be tackled?
Well that's where these clever bods in the green mountain state come in.
They've got expertise in utility scale power grids and wireless communication systems and algorithms
and their proposal won funding from the U.S. Department of Energy's Advanced Research Projects
Agency's Energies Network Optimized Distributed Energy Systems Program, which mercifully is
abbreviated to the Arpa- E Nodes program. The team took their inspiration from two concepts
that have allowed the internet to be scalable to the point where billions of devices are connected
globally all running more or less seamlessly without any centralized scheduling or control.
Those two concepts are packetization and randomization. Now if those are two words
that you're unfamiliar with then you're probably not alone. So let's have a look at what they mean
and why they're so powerful. There are billions of things calling for power from electricity
grids all the time and they roughly fall into two main categories. You've got the big commercial
and industrial loads and then you've got the residential loads that you and I use in our homes.
Those residential loads are inevitably far more widely dispersed than the more centralized
industrial and commercial operations. There are more than 120 million homes in the United States
for example, and they account for something like 40 percent of annual electricity consumption.
Some of the devices that we use in our homes like lights or TVs are things that we expect to work
instantly at the flick of a switch. And that's okay because nowadays they generally consume very
small amounts of energy and the grid can cope with the blips that these relatively low demands cause.
By contrast devices like air conditioners, water heaters and electric vehicle charges typically
have ratings of a kilowatt or more, which makes them relatively large electricity consumers,
which if they all came on at once would definitely give grid operators a very big
headache! But here's the thing - we don't treat those devices in the same way as we treat our
TVs or light switches. As long as the house is at the correct temperature at the correct time
and the hot water is hot and the EV is charged every morning,
then we really don't care when the energy was delivered to enable those things to happen.
And when the usage of those large devices is analyzed across an entire region or nation,
a pattern emerges that suggests their potential power consumption flexibility
could be extremely helpful to our grids. According to the Vermont team, if every household in
California and New York had just one device that was capable of consuming power flexibly at any
time then that would free up about 15 gigawatts of extra capacity on the power grid. That's more
than 10 times the amount currently available from utility scale battery storage in those two states.
Now, there are schemes already in place to reduce demand during peak periods,
where utility companies agree with consumers that they can switch off things like water heaters and
AC units during heavy demand periods in the day. And those schemes work okay to reduce the load at
those specific times. But if you want to balance the ebbs and flows of intermittent power sources
like wind and solar you need a system that can adapt to supply and demand in real time,
minute by minute, or even second by second. Which is pretty much exactly how the internet
works. And it does it by breaking down all digital information, whether it's your voice,
an email or a movie into packets of data. The packets all then go through different routes to
their destination whichever way is available at the time, and then when they've all arrived at
the end point they get reconstructed back into their original form. And all of that happens in
less than a blink of an eye, even if the journey is from one side of the planet to the other.
The Vermont team applied that principle to a technology they call Packetized Energy Management,
or PEM. As an example, let's take a typical water heater controlled by a thermostat. When the water
temperature drops below the prescribed limit the heater kicks in using something like four or five
kilowatts of power for perhaps 20 minutes or half an hour or so to bring the water back
up to temperature. In the PEM system, instead of heating whenever the thermostat demands it,
the device will periodically send a request to the grid via a cloud-based communication platform,
asking if it can consume a packet of energy, with a packet of energy being,
say, five minutes of usage. The platform then approves or denies each packet request based on
grid conditions like the availability of renewable energy, the price of electricity, and so on. Now,
some devices are more critical than others, so to ensure that devices with a greater need for energy
are more likely to have their requests approved each device adjusts the rate of its request based
on its needs. When the water's colder the water heater can make requests more often,
and when the water's warmer it sends its packet requests less often. The PEM coordinator manages
all the incoming packet requests to shape the total load in real time without the need to
centrally optimize the behaviour of each device. It'll be imperceptible from our point of view
as consumers. It'll all just happen in the background, and it'll work just the same for
EV charges or your home battery storage system. It might take them a bit longer to charge,
but if they're charging overnight or when you're doing something else anyway, then who cares?
From the system coordinator's point of view, all it sees is a bunch of identical packet requests.
It doesn't care where they're from or what they're for. It just treats them all the
same. That's very similar to the concept of net neutrality in data communication systems.
And because each device will be working to meet its own unique need for energy
rather than being dictated to by some sort of centralized power saving scheme that shuts
millions of devices on and off at the same time, then the resulting requests for packets of power
will be inherently randomized, which means the destabilizing effects of mass synchronization
become much less of a problem. And the PEM system is much better at accommodating
individual consumer preferences than those top down power saving schemes as well.
If for example the water temperature in your heater drops below its lower limit and a packet
request hasn't been authorized but for whatever reason you need your water heated without delay,
then the device is allowed to temporarily opt out of the PEM scheme and switch on
until the temperature recovers. The heater simply informs the PEM coordinator that it's temporarily
changed its operating mode and the coordinator adjusts its accounting of the aggregate demand
to keep everything balanced. The overall impact on the grid of these individual overrides will be
small, but it provides us consumers, in this example, with the important guarantee of hot
water whenever we need it. This kind of device driven approach means the system coordinator
doesn't have to centrally monitor or model each device to develop an optimized schedule. It just
needs to know three things : the condition of the grid, the condition of the energy market, and the
status of incoming packet requests including information about those opted-out devices.
That's just three sets of numbers that modern day algorithms can easily take in their stride.
In 2016 the Vermont team set up a company called Packetized Energy to deploy its cloud-based energy
coordination platform in several utility-sponsored pilot projects throughout the United States and
Canada, starting with their own hometown utility, the Burlington Electric Department. In 2018, BED
began America's first 100% renewable powered water heater program using smart thermostats developed
by the Packetized Energy company. And the scheme's now been expanded out to include EV charges too.
This real-time demo shows how the PEM system coordinated the load from more
than 200 residential water heaters in Vermont and South Carolina over a typical two hour period.
The heaters followed a rapidly changing target that ranged from about half the nominal load
to about twice that load. As the system scales to thousands or even millions of packetized devices,
the packet requests will start to appear as a continuous signal. The team's simulations
have demonstrated that at that large scale the gaps between the target and the actual will
disappear. The aggregate load is at least as responsive as the reaction times of a modern
gas power plant, but of course without the expense of building and operating a physical installation.
We all know that smart home technology is becoming more and more prevalent in our everyday lives. In
the very near future, power loads, energy storage and energy generators will all be much more
closely coordinated to keep their grids stable and take full advantage of renewable energy.
It probably won't be an easy transition, but technologies like this PEM system look set
to help smooth the pathway to a more sustainable world. I'm sure you've got your own views on how
our power consumption is developing, so as always, feel free to jump down to the comments section
below and leave your thoughts there. That's it for this week though. Before I go, quite a few of you
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Thanks very much to all of you for watching and supporting the channel,
have a great week, and remember to just have a think. See you next week.