CSP Startup Heliogen Cranks Solar Thermal Up to 1,000 Degrees Celsius

Industrial heat, vital for making things like glass and
concrete, has been lumped in with the “hard problems” of
decarbonization.

There’s a roadmap to decarbonize the electric grid and ground
transportation. The pathway is not so clear for tasks like air
travel, long-distance shipping and energy-intensive industrial
processes.

Serial entrepreneur Bill Gross decided to tackle the heat
problem, not by inventing a new heating technology, but improving
one that already exists. Concentrated solar power (CSP) plants
reflect sunshine into a small area that reaches high heat; they can
produce steam, but have not reached sufficient heat for many
high-value industrial applications.

Gross’ new company, Heliogen, brought in machine vision to crank
things up a notch. By attaching a camera rig to a CSP plant and
using visual feedback to fine-tune the angles on a field of mirrors
in real time, Heliogen produced temperatures of more than 1,000
degrees Celsius at a demonstration plant in California two weeks
ago.

“By achieving more than 1000 degrees Celsius, we open up a whole
range of industrial processes that were previously not easily
decarbonizable,” Gross said in an interview Monday. “We really
wanted to make that impossible possible.”

That promise won investment from venture capital firm Neotribe
and three prominent billionaires: Microsoft founder Bill Gates, AOL
founder Steve Case and cancer drug entrepreneur Patrick Soon-Shiong
(who also invests in energy storage). With money to grow, Heliogen
now must sell its unconventional, clean process to heavy
industry.

Software eats solar heat

Traditionally, CSP plants use thousands of mirrored, motorized
heliostats to reflect sunlight at a receiver on top of a tower. A
lot of engineering work has gone into making those mirrors sturdy
and resilient, so they point where they’re supposed to point.

But the whole framework governing the tracking could use some
improvement, Gross said.

“It’s all open loop: It’s all tracking by prediction of where
the sun is and prediction of where the mirror should be,” he
said.

As a result, new CSP plants can take around nine months to
calibrate, and then have to deal with the elements shifting around
them and throwing off the fine-tuning. Slight deviations from
perfect aim give the beam a fuzzy focus and diminish the heat it
generates.

Heliogen turned to machine vision, a technique for processing
vast amounts of visual data very quickly. Another Bill Gross-backed
startup, Energy Vault, uses machine vision to automate a six-armed
crane as it stacks and lowers giant blocks at high speed to store
renewable electricity. For solar thermal, the idea was that cameras
on the tower could assess how well aimed the mirrors were and
adjust them to perfection.

Success with this concept, however, grapples with a pyrotechnic
limitation.

“The problem is the camera would melt because the camera would
get to 1000 degrees,” Gross explained.

So the company iterated from there, tweaking the placement and
design of the camera rig until, some four dozen versions later,
they got one that worked.

Heliogen mounts four cameras around the high-temperature
receiver, set back enough to avoid the fiery blast. These cameras
track not the sun itself, but the halo of light around the
celestial orb. When the cameras see the halo perfectly reflected in
each of the mirrors, it means the sun itself is bouncing straight
into the receiver. The system assesses the image of the field at a
rate of 30 frames per second, following the sun through its daily
migration and signalling the mirrors to move if they are out of
line.

This technique relies on simple ingredients from the mainstream
tech industry: a graphics processing unit of the sort developed for
high-end video gaming, and a $1,000 computer that processes data
onsite. With those modest means, Heliogen flipped the switch on its
self-funded demonstration plant in Lancaster, California, two weeks
ago.

“It hit 1000 degrees Celsius immediately,” Gross said. “We were
jumping for joy.”

Who’s buying?

Gross’s energy ideas have a way of seeming too clean and simple
to possibly work. The energy industry operates by incrementally
optimizing its equipment over years and decades; showing up with a
software-inflected breakthrough defies the normal order of
business.

Now it’s on Heliogen to prove that this successful demonstration
can turn into a sustainable business model.

“We really want to be the operating system for solar
concentration,” Gross said. “We can go to every existing CSP plant
and offer better focus.”

Specifically, Heliogen would be the technology supplier, and
partner with engineering, procurement and construction firms to do
the building. It already signed up the Parsons Corporation as one
such partner.

The deeper question is whether industrial customers are as
excited about this as Gross is.

The target market is facilities that burn natural gas, coal or
even trash to produce heat for making things like cement, steel and
glass. They would need to have factories in dry, sunny regions
where the CSP can work best, and space to erect a hot tower with a
field of mirrors.

These companies also need to approach intermittency with an open
mind. The initial offer would only operate during the eight or so
hours a day that the sun shines. Customers are still excited about
that, Gross said, noting that even the limited run eliminates 25 to
33 percent of a factory’s carbon emissions from heat production.
Down the road, Heliogen will equip its plants with ceramic thermal
storage to run round-the-clock.

Given the limitations, the product will need customers with
serious drive to reduce greenhouse gas emissions, or it will need
to promise substantial cost reductions versus the status quo. 

“Our goal is to make our heat cheaper than burning fuel, and
then the carbon benefit is just gravy on top,” Gross said. “I’m
not relying on the carbon credit to make money.”

Either way, the proof will come if this splashy unveiling leads
to firm contracts.

Source: FS – GreenTech Media
CSP Startup Heliogen Cranks Solar Thermal Up to 1,000 Degrees Celsius