Over the past decade, prices for solar
panels and wind farms have reached
all time lows, leading to hundreds
of gigawatts worth of new renewable
energy generation.
As the saying goes though, the wind
isn't always blowing and the sun isn't
always shining.If, for example, it's a beautiful
sunny day and we've got a
super abundance of electricity,
we can't use it.
The question of how to firm
renewables, that is, ensuring there's always
energy on demand no matter the time of
day or weather, is one of the
biggest challenges in the industry.
We need a good way
to store energy for later.
And the main option right
now is lithium ion batteries.
You see them in products like
Tesla's home battery, the Powerwall and
utility-scale system, the Powerpack.
But though lithium ion is dropping in
price, experts say it will remain
too expensive for
most grid-scale applications.
To get to battery for the electrical grid,
we need to look at a further
cost reduction of 10 to 20x.
Right now, lithium ion batteries just
can't store more than four hours
worth of energy at a price
point that would make sense.
Plus, they pose a fire risk and their
ability to hold a charge fades over
time. To address this, there's acadre
of entrepreneurs experimenting with a
variety of different solutions.
Now we're seeing flow batteries, which
are liquid batteries, and we're
seeing other forms of storage that
are not chemical or battery-based
storage.And each has
serious potential.
We looked at materials on the periodic
table that were actually going to be
cost competitive from day one.
Primus Power's flow battery
is a workhorse.
Thermal energy storage has a pretty
unique opportunity to be extremely low
cost.Our solution will last 30 plus
years without any degradation in that
performance.Which technologies prevail remains
to be seen.
But one thing is clear.
For renewables to truly compete with fossil
fuels, we need to figure out a
better way to store energy.
From 2000 to 2018, installed wind power
grew from 17,000 megawatts to over
563,000 megawatts.
And solar power grew from a
mere 1,250 megawatts to485,000 megawatts.
And it's not stopping there.
Renewables are expected to grow an
additional 50 percent over the next
five years.We know today
that solar P.V.
and wind are the least
expensive way to generate electricity.
In particular, the price of solar
photovoltaics has plummeted far faster
than all forecasts predicted, after China
flooded the market with cheap
panels in the late 2000s.
All the Wall Street analysts did not
believe that solar was going to ever
stand on its own without subsidies.
Well, a few years later, even
the most conservative analysts started
realizing that actually solar was going to
become economic in most parts of
the world pretty quickly.
And as solar has gotten cheaper, so
too have lithium ion batteries, the
technology that powers electric vehicles,
our cell phones and laptops.
And thanks to improved manufacturing
techniques and economies of scale,
costs have fallen 85
percent since 2010.
Now, wind or solar plus battery
storage is oftentimes more economical than
peaker plants, that is, power plants that
only fire when demand is high.
Tesla, for example, built the world's
largest lithium ion battery in
Australia, pairing it with a wind
farm to deliver electricity during peak
hours. But this doesn't mean lithium
ion is necessarily economical for
other grid applications.
We don't really see the cost structure
coming down to the point where it
can serve those tens to
hundreds of hours applications.
Basically, the market is
ripe for competition.
There are dozens of chemistry
being looked at today.
There are hundreds of companies working
on scaling up and manufacturing
new battery technology.
Lithium ion has done remarkable things
for technology, but let's go to
something far better.
One of the main alternatives being
explored is a flow battery.
Unlike lithium ion, flow batteries
store liquid electrolyte in external
tanks, meaning the energy from the
electrolyte and the actual source of
power generation are decoupled.
With lithium ion tech, the electrolyte
is stored within the battery
itself. Electrolyte chemistries vary, but
across the board, these aqueous
systems don't pose a fire risk and
most don't face the same issues with
capacity fade. Once they scale up
their manufacturing, these companies say
they'll be price competitive
with lithium ion.
Hayward, California-based Primus Power has been
working in this space since
2009, and uses a
zinc bromide chemistry.
So far it's raised over $100 million
dollars in funding, including a number
of government grants from agencies like
the Department of Energy and the
California Energy Commission.
Primus's modular EnergyPod provides 25 kilowatts
of power, enough to power
five to seven homes for five hours
during times of peak energy demand and
for 12 to 15
hours during off-peak hours.
Most systems use multipleEnergyPods though,
to further boost capacity.
The company says what sets it
apart is its simplified system.
So instead of two tanks, which every
other flow battery has, Primus only
has one. And we are able to
separate the electrochemical species by taking
advantage of the density differences between
the zinc bromine and the
bromine itself, and the more
aqueous portion of that electrolyte.
To date, Primus has shipped 25 of
its battery systems to customers across
the U.S. and Asia, including a San
Diego military base, Microsoft and a
Chinese wind turbine manufacturer.
It expects to ship an additional 500
systems over the next two years.
Future customers are either independent
power producers that are doing
solar plus storage at utility-scale
or larger commercial enterprises.
Also operating in this space is
ESS Inc, an Oregon-based manufacturer of
iron flow batteries, founded in 2011.
Its systems are larger
than Primus Power's.
They're basically batteries in a shipping
container and they can provide
anywhere from100 kilowatts of power for four
hours to 33 kilowatts for 12
hours, using an electrolyte made entirely
of iron, salt and water.
When we came into this market, we wanted
to come into it with a technology
that was going to
be very environmentally friendly.
It was going to be very low cost.
It didn't require a lot of volume
on the production line to drive down
costs.ESS is backed by some major
players like SoftBank Energy, the Bill
Gates-led investor fund, Breakthrough
Energy Ventures, and insurance
company Munich Re.
Having an insurance policy is a big
deal, since it will make risk-averse
utility companies much more likely
to partner with it.
So far, ESS has six of its
systems, called Energy Warehouses, operating in
the field and plans to
install 20 more this year.
It's also in the process of developing
its Energy Center, which is aimed
at utility-scale applications in the
100 megawatt plus range.
That would be 1,000 times more
power than a single Energy Warehouse.
We're planning to be at 250 megawatt
hours of production capacity by the
end of this year, which is probably a
little over 10 times the capacity we
had last year. And then eventually getting
to a gigawatt hour of production
capacity in the next couple of years.
So far, key customers includePacto GD,
a private Brazilian energy supplier,
and UC San Diego.
But for all their potential, flow
battery companies like Primus and ESS
Inc still aren't really designed to store
energy for days or weeks on end.
Many of those flow battery technologies
still suffer from the same
fundamental materials cost challenges that
make them incapable of getting
to tens or hundreds of
hours of energy storage capacity.
Other non-lithium ion endeavors,
such as the M.I.T
spinoff Ambri, face the same
problem with longer-duration storage.
Form energy, a battery company with
an undisclosed chemistry, is targeting
the weeks or months-long storage
market, but commercialization remains far
off. So other companies are
taking different approaches entirely.
Currently, about 96 percent of the
world's energy storage comes from one
technology: pumped hydro.
This system is
pretty straightforward.
When there's excess energy on the grid,
it's used to pump water uphill to
a high-elevation reservoir.
Then when there's energy demand, the
water is released, driving a turbine
as it flows into a reservoir below.
But this requires a lot of land,
disrupts the environment and can only
function in very
specific geographies.
Energy Vault, a gravity-based storage
company founded in2017, was inspired
by the concept but thinks
it can offer more.
And so we wanted to look at
solving the storage problem with something much
more environmental, much more low cost,
much more scalable, and something
that could be brought
to market very quickly.
Instead of moving water, Energy Vault uses
cranes and wires to move35 ton
bricks up and down, depending on
energy needs, in a process that's
automated with machine
vision software.
We have a system tower crane that's
utilizing excess solar or wind to drive
motors and generators that lift and stack
the bricks in a very specific
sequence. Then when the power is needed
from the grid, that same system
will lower the bricks
and discharge the electricity.
This system is sized
for utility-scale operation.
The company says a standard
installation could include 20 towers,
providing a total of 350 megawatt
hours of storage capacity, enough to
power around 40,000 homes
for 24 hours.
Some of our customers are looking
at very large deployments of multiple
systems so that they'll have that power
on demand for weeks and months and
whenever it's gonna be required.
The company recently received110 million
dollars in funding from SoftBank
Vision Fund, and it's building out a test
facility in Italy as well as a
plant for India's Tata Power Company.
But some say the sheer size of the
operation means it just can't be a
replacement for chemical batteries.
Sounds very simple. However, the energy
density in those systems are very
low. And so that's where we
believe chemical-based storage still has an
advantage in terms of a footprint.
You can't install a gravity-based system in
the city, but you'd have to
install it outside in
the remote areas.
Then there's thermal storage.
It's still an emerging technology in this
space, but it has the potential
to store energy for longer than
flow batteries with a smaller footprint
than gravity-based systems.
Berkeley, California-basedAntora Energy, founded in2017,
is taking on this
challenge. Basically, when there's excess
electricity on the grid, that's
used to heat upAntora's cheap carbon
blocks, which are insulated inside a
container. When needed, that heat is
then converted back into electricity
using a heat engine.
Typically, this would be a
steam or gas turbine.
But Briggs says this tech is just
too expensive and has prevented thermal
storage solutions from working
out in the past.
SoAntora has developed a novel type
of heat engine called a
thermophotovoltaic heat engine, or TPV for
short, which is basically just a
solar cell, but instead of capturing
sunlight and converting that to
electricity, this solar cell captures light
radiated from the hot storage
medium and converts
that to electricity.
So it's electricity in, electricity out,
and it's stored in ultra-cheap
raw materials as heat
in the meantime.
Recently, Antora received funding from
a joint venture between the
Department of Energy and Shell, who
are excited by the company's potential
to provide days
or weeks-long storage.
We think that that solves a need that
is currently and will continue to be
unmet by lithium ion batteries and that
will sort of enable the next wave
of integration of renewables
on the grid.
It's still early days forAntora and
Energy Vault though, and there's
definitely other creative solutions
in the mix.
For example, Toronto-basedHydrostor is
converting surplus electricity into
compressed air. And U.K.
and U.S.-based Highview Power
is pursuing cryogenic storage.
That is, using excess energy to cool
down air to the point where it
liquefies. These ideas may seem far out,
but investment is pouring in and
projects are being piloted
around the world.
While these companies are all vying to
be the cheapest, safest and longest
lasting, many also recognize that this is
a market with many niches, and
therefore the potential
for multiple winners.
In the residential and commercial areas,
you're gonna have a certain type
of technology. A lot of
it will probably be battery-based.
I think as you get to utility-scale
and grid-scale, you're going to see
some batteries, you're going to see
other types of compressed air and
liquid air solutions, and then you're going
to see some of the gravity
solutions that could be scaled.
Overall, the energy storage market
is predicted to attract$620 million
dollars in investments by 2040.
But as always, it's going to be tough
to get even the most promising ideas
to market.No matter if the raw materials
were dirt cheap, the initial cost
of a first system
is essentially astronomical.
Of course, government policies and incentives
could play a major role as
well.There is a production
tax credit on wind.
There's an investment tax
credit on solar.
We in the battery community would like to
see an ITC for batteries in the
same way that it is
in existence for solar.
Implementing a storage mandate, as California
has done, is another policy
that many are advocating.
When we get to roughly 20 percent
of our peak demand available in storage,
we will be able to run a
renewable-only system, because the mix of solar
and wind, geothermal, biomass all backed up
with storage will be enough to
carry us through even some
of these potentially long lulls.
With the right mix of incentives
and ingenuity, we're hopefully headed
towards a future with a
plethora of storage technologies.
The future is not going to
be a mirror of the past.
We've got to do something
that's radically different from everything
that's been done up until now.
I'm really excited about that.
