
Secretive energy startup backed by Bill Gates achieves solar breakthrough - ZenModeRy
https://www.cnn.com/2019/11/19/business/heliogen-solar-energy-bill-gates/index.html
======
darksaints
Heliostats are expensive and failure prone. Due to their physical design, with
lots of leveraged moments acting on a complex hinge, a simple wind gust can
break them.

Honestly I think the future of CSP is going to be a lot lower tech. Something
along the lines of this:

[http://www.storenergy.rs/](http://www.storenergy.rs/)

This is a drastic reduction in the amount of moving parts. Nothing is space
age: they've got mirrors and frames that can be built by pretty much any local
manufacturer, they're using air as a heat transfer medium, they're using
simple ceramic refractory as a heat storage medium. Everything is dirt cheap
but still extremely effective. They're claiming $0.031/kWh LCoE, which might
be exaggerated, but if they could get anywhere within 2x of that, they're
gonna be running in the same league as the top tier technology available. More
importantly, this is something that can be made readily available in places
like Mali or Bangladesh, unlike some of the other ideas out there that require
first world infrastructure, well developed supply chains, and top tier
researchers willing to work on site.

------
jmpman
So, you have a calibration target on the tower, along with the actual power
generating target? Allow each mirror a brief time slice to hit the calibration
target to ensure alignment before returning to the power generating target?
Maybe you can calibrate more than 1 mirror at a time, and like old fashioned
medical diagnostic tests, they can determine the optimal number of mirrors to
calibrate simultaneously? That seems unnecessary at least with the number of
heliostats I see in the image. Once calibrated, I’d expect the heliostats
would operate acceptably for at least a month.

------
datenhorst
This article reads like metric ton of BS but sadly I don't understand enough
about the substance to be able to tell reliably.

1) I thought the reason cement production is bad for the environment because
CO2 is released from the calcium during the process, not because fossil fuels
are using for the heating of the oven.

2) So they're solving the problem by pointing the mirrors directly at the oven
or how does that work? I don't really get why the temperature generated is
important otherwise.

3) There's also storage of the energy batteries mentioned, how exactly does
that work? Sounds like a contradiction to 2)

~~~
jsilence
The CO2 expelled from the Calcium Carbonate is quite pure compared to CO2 from
combustion which usually contains nitrous oxides. This makes it suitable for
capture and liquification and thn for example as a gasous fertilizer in
greenhouses. A heat exchanger can recuperate a good chunk of the residual heat
and pipe that to the air intake for the gas burners that are used to heat the
furnaces.

Not saying every cement plant is doing this. But it is possible and makes
sense.

Focussing solar power to the furnace would eliminate a sensible usage of the
residual heat within the process itself.

------
mikece
What the roll of AI in this? A single RaspberryPi with an accurate time source
could give continuously updating inputs to a field of mirrors to be aimed for
the most optimal heating potential. Tracking the movement of the earth and sun
for the next thousand (million?) years doesn’t require AI to make
concentrating solar power work.

~~~
ZeroGravitas
It seems to be more concentrated than alternatives to achieve higher
temperatures, which presumably needs very precise focusing and taking into
account minute tolerance differences between the mirrors.

------
ec109685
What’s the advantage heating a single point to 1000 °C in desert versus
slightly less hot & converting the heat to electricity like traditional solar
concentrator setups?

Once it’s Electricity, it’s portable. Electricity can generate > 1000 °C on
demand.

------
rcaught
There is nothing in this article that explains any type of breakthrough. This
just seems like a rehash of existing solar thermal technology. Also, what an
abuse of the AI buzzword. Maybe the only breakthrough is getting Gates to back
it.

