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.