this video will be a little different
i'm not sure if it's exactly correct to
call this
an opinion piece but this is largely a
story
about my personal energy management
techniques the lessons i've learned from
them
and how we might apply them in the near
future i've also been motivated to make
this video
by headlines that paint this technique
in a pretty bad
light when in fact the horror stories
have everything to do with bad
management decisions and nothing to do
with the idea itself
that idea is load side energy management
it's gotten some nasty press lately
because the way it's used today
is usually reactive and rarely proactive
as the frequency of extreme weather
events goes up
we're finding more and more instances of
energy demands on the grid
outstripping its ability to supply it in
those cases
grid operators often have no choice but
to shed
load or shut off the power to certain
areas
to prevent the grid from being
overloaded or in particularly extreme
cases
collapsing altogether that nearly
happened in texas in the winter storm of
2021
but shedding load by disconnecting
customers in rolling blackouts
is a rather blunt instrument it sucks
for a long while electric utilities have
been flirting with more precise and less
disruptive load shedding techniques
called
demand response even before internet
connected smart thermostats were
widespread
some utilities including mine offered
discounts
if you allowed them to remotely disable
your air conditioning or perhaps clothes
dryer
using a lockout device during peak
consumption periods
that could of course lead to some mild
discomfort and annoyance occasionally
but at least you still had power and so
did your neighbors
see heating and cooling is by far the
biggest energy consumer of a home or
building in general
and on hot days demand can suddenly
explode when everyone's air conditioners
start running at the same time so being
able to ease the total demand on the
grid by temporarily shutting off a few
thousand air conditioners
is a very useful tool for utilities now
i know what some of you are thinking
that sounds terrible and i would never
ever want that
but these days we have more flexibility
than we ever have
what if the utility could turn your air
conditioner
on before there was a supply problem now
that smart thermostats are so common
utilities have plenty of customers who
have installed
much more sophisticated equipment than
the air conditioner lockouts of the past
and if done correctly we can tap into
a huge source of energy storage that you
may have never realized we had
we often talk about the need for energy
storage on the grid
whether that's to increase the viability
of renewable sources of energy like wind
and solar power
or to help meet intermittent peak loads
having a reserve of energy on hand is
a very good thing in fact the idea of
temporary energy storage
isn't new at all of course the trendy
thing now is to talk about
huge banks of batteries that are charged
up when there's lots of energy available
and discharged when that energy is
needed later
electric vehicles are likely to become a
big piece of this strategy as time goes
on
but we've actually been doing this for a
very long time
just more crudely for the most part
we're doing this because the load on the
grid is variable and tends to peak in
the afternoon
you may have heard this before but the
trickiest thing about electrical
generation is that supply and demand
have to be equal all the time whenever
demand goes up
supply must increase to meet it and when
that's not possible
things start breaking that's been a
challenge for the grid since the
beginning
and is the reason pumped hydroelectric
storage facilities
exist and have for many decades
these facilities consist of two water
reservoirs at different elevations
sometimes they're natural and other
times they're engineered
when supply is greater than demand we
use that spare supply to pump
water to the higher reservoir that makes
a store of
gravitational potential energy then when
demand
starts to outpace supply we just let the
water fall back down
and capture its kinetic energy as it
does so in turbines which generate
electricity
thereby helping to meet the new demand
it's just like charging and discharging
a battery
except the battery is made of water and
gravity the biggest problem with this
technique is that it is very geography
dependent and tends to be ecologically
destructive
unless you get really lucky with a pair
of lakes on a mountainside or something
in the case of pumped hydro and other
storage we're taking care of demand
fluctuations
entirely on the supply side that's
pretty much how it's always been done
and that seems to be the framework that
many people are still thinking in
there are lots of clever ideas floating
around to make energy storage more
viable and scalable
from towers stacking concrete blocks to
molten salt and flow batteries to
massive
spinning flywheels all of these strive
to be a place to put
excess energy when we have more or
perhaps cleaner generation available
so that it can be used later when we
don't now of course we don't have as
much storage on the grid as we'd perhaps
like so many utilities offer or in some
cases require the use of
tiered rate structures again that's not
a new idea
just ask any british person but in my
particular case
i volunteered for an hourly rate that
set based on the cost my utility pays
for energy in real time
they offer this to encourage shifting
demand away from high stress periods
which
cost them more and you could argue
they've almost gamified it which
honestly is kind of fun this is what a
typical summer day looks like on this
rate schedule
this varies from day to day and on
milder days it often doesn't even go
above 6 cents per kilowatt hour
you can actually see too that on
particularly windy days
the rate's pretty cheap all day we've
got a lot of wind power around here
now this isn't the actual rate i end up
paying there is a fixed cost of about
four cents per kilowatt hour so
realistically this bottoms out at
between
five and seven cents something like that
but that's still a lot cheaper than in
the afternoon
where the cost can easily be more than
double that
anyway demand is lowest in the middle of
the night and at least with today's
energy mix
that's when it costs the utility the
least to purchase electricity from its
suppliers
that's because with this low demand
cheap and efficient base load generation
is the only supply that's needed and so
that i can take advantage of these low
rates at night
i use a roughly 16 kilowatt hour battery
that i
just happen to have lying around i
charge it up overnight starting at 10 pm
on the dot
and it's done charging usually by three
or four in the morning
i keep it topped off until around seven
and then i start using it during the day
and it doesn't need to be recharged
again until the evening
now the reason i just happen to have
that battery lying around
is because that battery is my house
confused well who's to say a battery
needs to store electricity now before i
explain this
let me acknowledge that this is somewhat
situational and i get that
not every building will be able to do
this but efforts to make this possible
for more people
could go a long way to providing a
massive source
of energy storage right now this house
is about 10 years old
is well insulated features low e windows
and
is shaded by trees in the morning and
evening all that means that even on
sweltering hot days
it takes many hours for the indoor air
temperature to
rise on a typical summer day between 6
a.m and 10 p.m
the air temperature only goes up by
seven or eight degrees fahrenheit
or about four and a half celsius so i
just
don't cool my home during the day at all
i don't need to because i charged the
battery that is my house by over cooling
it at night
sure that might sound odd but it's not
like i'm living uncomfortably
quite the opposite in fact for how i
like to sleep which is nice and cool
this works out perfectly and even with
no cooling from 6 30 am to 10 pm
it's rare that it ever gets above 74
degrees in here
that's 23.3 celsius this is even on
sunny days and with heat from using the
stove and oven for cooking
if i cool the house off at night i
simply don't need
any cooling again until the following
evening the worst it has
ever gotten in the nearly two years i've
been doing this
is 76 degrees here's what my thermostat
schedule looks like
and before i go on i want to be clear
that i'm not suggesting
everybody should have this particular
strategy i'm just explaining my tactic
which is based on pricing
however if you're in an area that is
prone to rolling blackouts
you might consider being similarly
strategic with when your air conditioner
runs during heat waves
anyway at 10 pm the set point drops to
70 degrees
and the air conditioner comes on on a
milder day the air conditioner may be
able to satisfy that within three hours
giving it a short break
but at 1 am which is technically the
next day
the set point drops again to 66 degrees
or 19 celsius
that may seem excessively cold but
remember my goal here is to
offset my entire cooling need of the day
and this works i've turned this house
into a battery
a thermal battery although since it's
colder than the outside it's a
negative battery but the concept is the
same because my utility has provided me
with an incentive to do so
and since my home is designed and cited
well enough to make it possible
i've successfully shifted all of my
cooling demand
exclusively to off-peak hours in the
middle of the night
and i do mean all at 6 30 in the morning
the set point goes to 70 before going up
to 77
that's 25 celsius at 11. i've done that
just in case there's an unusually hot
evening and the temperature rises
quickly in the morning
but i've yet to encounter a day where
the ac actually comes back on between 6
30 and 11.
the indoor temperature just doesn't rise
that fast
meaning that all my cooling happens
between the hours of 10 pm
and 6 30 am here's what that usage looks
like according to my thermostat over a
variety of days
on july 6th and 7th the temperatures
were near 90 or 32 celsius
and didn't drop below 70 or 21 celsius
at night
yet just over 7 hours of cooling in the
middle of the night
kept the indoor temperature from ever
getting above a comfortable
75 24 celsius of course
it's not like this doesn't have any
downsides mornings are
pretty chilly in here and when it's
humid enough outside i wake up to
windows that i
can't see out of because they're all
fogged up on the outside surface
this also means i don't get any
dehumidification except
overnight although i've always needed to
run a separate dehumidifier in the
basement
because it's just so forking humid here
and although my hvac system won't cool
during the day
i do have it run a fan schedule so it
circulates the air around
for 15 minutes every hour that combined
with the dehumidifier
keeps indoor humidity below 60 even on
rainy days
and because i'm a midwesterner through
and through
the dehumidifier is on a timer which
will disable it during the worst of the
peak hours
between 1 pm and 8 pm i mean the thing
pulls 500 watts and that's not nothing
that timer probably saves me 40 cents a
day
but honestly it's not just the cost
savings that motivate me to do this
i mean it's certainly fantastic that
even with an electric car
and plenty of cooling my power bills
rarely go over 150 bucks
and that's also with a conventional
electric water heater and clothes dryer
heat pump units coming soon but
sentimental me
simply enjoys the knowledge that when
the power grid is working its guts out
to meet the demand of my neighbors
i'm not making that any worse for most
of the day the biggest consumer of power
in this house is the fridge
and the dehumidifier but not between one
and eight
now i know that one idle air conditioner
among millions
isn't doing anything but that's why the
utility offers this rate plan
they hope they can get some of the more
adventurous people to sign up for it
shifting demand away from the times it
can be hard to meet
if you do it like i'm doing it you're
creating energy storage
i said my house is a 16 kilowatt hour
battery here's how
my two and a half ton air conditioner
consumes about 2.2 kilowatts when it's
running
over seven and a half hours that's just
shy of 16 kilowatt hours
i used all of that energy in the middle
of the night so that i
wouldn't need it during the day and as
far as i'm concerned
that's the same exact idea as energy
storage pulling energy now when you have
it
so that you don't need it later so now
let's tie this back to the idea of load
side energy management
utilities are increasingly offering
schemes similar to the ac
lockouts of the past but utilizing smart
thermostats
for some sort of discount or other
incentive you can grant your utility
access to your thermostat remotely
so they can shed load when necessary
without entirely shutting off the power
to your neighborhood
i mean that alone is good but the
trouble is
that's a reactive approach and when you
see headlines like this
loudly shouting that the utility raised
your thermostat temperature oh my god
well of course that's going to make
people leery of the idea
but here's the thing we can forecast
electrical demand
because we can forecast the weather that
also means we can forecast
generation output of renewable sources i
mean
this flexible rate structure that i'm on
those prices are determined
a day ahead we like to make fun of
meteorologists for getting stuff wrong
but you gotta admit we've got the next
day pretty well figured out at this
point
and rather than simply shedding load
when the grid gets close to capacity
a smarter idea is to proactively take on
loads before that even happens
what these energy management programs
should do is recognize when there will
be a lack of supply in the afternoon
and in the time leading up to that they
should remotely
lower the thermostats of the people who
are signed up for them
that will store some energy exactly how
i'm doing it now
i'm not saying they should set the
thermostat as far down as i do and
besides
that won't make cooling happen faster
you're limited to the system's capacity
but lowering it a few degrees in the
hours leading up to a forecasted energy
shortfall
can buy a few hours of time where no
cooling is needed by those customers or
at the very least
lessen the felt impact of a period with
restricted cooling
and of course we can apply this tactic
to heating as well
assuming your heat source is electric
heat pumps for the wind
if it's looking like there's going gonna
be an energy dry spell thanks to a lack
of wind
output or even something as simple as
everyone getting home and starting to
cook dinner in the same three-hour
window
that's a large part of why this time is
so expensive
well just bump the thermostat up a few
degrees an hour or two beforehand
and store that energy in the form of
deferred need
and now that is literal energy storage
in the form of heat energy
this could be a lot smarter than how we
manage energy right now
take for example the very idea of
programmable thermostats
they're great at saving energy for the
individual by altering the set points
when nobody's at home or
in the office but a huge portion of us
all leave home and return at similar
times so utilities have to deal with
millions of air conditioners all
starting back up
in the same hour actively tweaking the
set points based upon
available energy could do an awful lot
to ease these challenges of the grid
and in case you haven't already realized
it this is a great way to take advantage
and increase the practicality of wind
and solar power
one particular issue with solar power is
the duck curve
this is what we call the challenge of
solar output falling to
zero right as energy demand starts to
peak
a large criticism of solar power is this
very problem
without storage other plants will need
to start up to take on this
load many of which are natural gas but
what if we simply ran everybody's ac
when the sun was abundant
assuming the buildings are somewhat
modern well insulated and have good
windows
there's some energy storage right there
cool it now
so that when people get home it's a few
degrees colder than what they set it to
and they won't need to run the air
conditioner for a few hours
and in fact some utilities are already
doing this sort of planning ahead and
not simply reacting to oops we're
running out of juice
and good for them and here's the best
thing
because so many of us have already
installed smart thermostats of our own
accord
this is possible at scale now
sure some people aren't going to be
thrilled with the idea for various
reasons but
they don't have to participate if they
don't want to and besides if this is
managed well enough
you might not even be able to notice it
if my utility offered something like
this
i would definitely sign up for it but as
it is
i'm able to offset the entire day's
cooling need to off-peak hours and i'm
very pleased to continue doing that
our local energy mix still favors
shifting demand to the middle of the
night
and that ends up utilizing a fair bit of
nuclear power so
in theory the carbon emissions from my
air conditioning are fairly low
which feels nice now of course this is
not
the one thing that'll fix the grid
a heat wave like the pacific northwest
just experienced
is going to make everybody's air
conditioners run constantly
well the people who are fortunate enough
to have one in the first place
and we'll run into the same problems in
extreme cold
but i think this idea has a lot of
potential and that we should be using it
with such granular control over some of
the largest loads present on a power
system
we can optimize for just about any
situation
all without impacting individual comfort
beyond a few degrees
and frankly if you can't tolerate your
thermostat being bumped up or down a
couple of degrees for the benefit of
your neighbors
well i don't think we'd be very good
friends it's worth pointing out that
although this idea may not work in many
older homes and buildings
for example it certainly would not have
worked where i used to live
retrofitting these structures with
better windows and more insulation will
do a heck of a lot to reduce our energy
needs in the first place
in addition to making them better
candidates for this energy storage idea
i'd also like to point out that my
parents are utilizing the same strategy
that i am
in fact they've been doing it for nearly
a decade and their house isn't
nearly as shaded as mine plus it's a
little older
yet the idea still works for them
they're only limited by the fact that
their homes air conditioner is
a little bit undersized so even starting
at 8pm
it sometimes can't get the house down to
even 68 by the next morning
but the time it takes to rise back up is
pretty much the same as in my home
even though their house is in direct
sunlight for many hours daily
installation is pretty neat stuff in
fact
better building design with concepts
like the passive house
are also great areas of interest however
that's a different topic altogether
this is about more wisely using what we
have now
i also want to touch on the fact that if
we decide this idea is worth pursuing
we probably should reevaluate how we
determine hvac system capacity
an ideally sized system won't be able to
drop or raise the temperature quickly
in the case of air conditioning this is
on purpose because
short cycling can reduce the life of
components and
doesn't provide much dehumidification
but
these sizing guidelines are all based on
more or less
constant thermostat set points so three
hours of continuous cooling
may only drop the temperature by three
or four degrees
with the advent of multi-stage and
variable capacity systems
we can have the best of both worlds
these days and so if we are going to
start using a building's thermal mass as
a source of energy storage at a large
scale
oversizing hvac systems might be wise
we're probably going to want to do that
anyway with these deadly heat waves
we're getting
for some reason we should also discuss
because i'm sure i'd never hear the end
of it if i didn't ideas such as storage
heaters
and ice storage air conditioning these
are technologies that allow us to store
heating and cooling energy
but with a bit more control ice storage
air conditioning involves freezing a
large volume of water into a giant block
of ice when electricity is cheap and
or available and a series of pipes
traveling through this ice block
water bath reject heat picked up in the
building's air handlers
and put it into the ice over the course
of a day
it melts providing active cooling while
using very little energy
the biggest benefit of course is that
you retain most or
all of the temperature control while
using minimal energy
typically these systems are only found
in large commercial buildings however
then there are storage heaters these
have been around for a long time
with notable use in britain during the
economy 7
energy tariff period during overnight
hours when electricity is cheaper
electric heating elements heat up
something like a stack of bricks in an
insulated box
then during the day the box is opened
allowing the heat from the hot bricks or
whatever
to escape stupidly simple yet very
effective
though some may say inelegant but anyway
the point is
there are a lot of ways we could be
implementing energy storage on the grid
that don't actually involve storing
energy on the grid itself
the biggest consumers of electrical
energy will always be pretty predictable
and although some of the energy
technologies we are likely to rely on as
the decade progresses are intermittent
they are pretty predictable too while i
certainly think there's a lot more work
to be done
i hope that this video has made you a
little more optimistic about the future
there's more we can do right now than
perhaps you ever thought
thanks for watching
[Music]
this is going pretty well this is what
happens when you actually rehearse by
reading the script beforehand
and if done correctly we can tap into a
huge
amount shoot that probably wasn't
audible
but whatever my my toe had clicked
i mean this for a very long time just
more crudely
crudely crudely did i say it like that
well i'm not sure so i'm gonna record it
again
i charge it up overnight starting at
about 10 pm no
it's not about stop it stop it
sentimental me
simply enjoys the knowledge that when
the power grid is working
it's guts out
[Music]
[Applause]
you