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Heliogen and Bloom Energy demonstrate production of low-cost green hydrogen; concentrated solar and high-temp electrolysis

Heliogen and Bloom Energy have successfully demonstrated the production of green hydrogen by integrating the companies’ technologies: Heliogen’s concentrated solar energy system and the Bloom Electrolyzer.

Heliogen’s AI-enabled concentrated solar energy system is designed to create carbon-free steam, electricity, and heat from abundant and renewable sunlight. When combined with Bloom’s proprietary solid oxide, high-temperature electrolyzer, hydrogen can be produced 45% more efficiently than low-temperature PEM and alkaline electrolyzers.

Electricity accounts for nearly 80% of the cost of hydrogen from electrolysis. By using less electricity, hydrogen production is more economical and accelerates adoption. In addition, the ability to use heat, which is a much lower cost source of energy than electricity, further improves the economics of green hydrogen production.

Heliogen’s concentrated solar technology is different than traditional photovoltaic solar; it facilitates hydrogen generation for longer periods of time, operating near 24/7 by storing the solar energy, resulting in more compact and lower cost production. The extended operating time of Heliogen’s technology and Bloom Energy’s ability to utilize heat efficiently is designed to reduce the cost of green hydrogen production compared to competing solutions.


Source: Heliogen

Bloom Energy officially introduced the Bloom Electrolyzer in July 2021. The Bloom Electrolyzer relies on the same, commercially proven and proprietary solid oxide technology platform used by Bloom Energy Servers to provide on-site electricity at high fuel efficiency. Highly flexible, the electrolyzer offers unique advantages for deployment across a broad variety of hydrogen applications, using multiple energy sources including intermittent renewable energy and excess heat.

Because it operates at high temperatures, the Bloom Electrolyzer requires less energy to break up water molecules and produce hydrogen. As a result, Bloom Energy’s electrolyzer consumes 15% less electricity than other electrolyzer technologies to make hydrogen when electricity is the sole input source.

Unlike low-temperature PEM and alkaline electrolyzers that predominantly require electricity to make hydrogen, the Bloom Electrolyzer can leverage both electricity and heat to produce hydrogen. Bloom Energy’s high-temperature electrolyzer technology has the potential to use up to 45% less electricity when integrated with external heat sources than low-temperature PEM and alkaline electrolyzers.

Hydrogen use is forecast to grow from 115 million metric tonnes currently to 500-800 million metric tonnes a year by 2050, accounting for 15 to 20 percent of total global energy demand. Hydrogen projects already announced represent over $300 billion in spending across the value chain, and McKinsey & Company analysts expect at least $150 billion of that spend to be related to hydrogen production, which Heliogen and Bloom Energy are addressing through their collaboration.


Source: Heliogen

The companies said that their successful demonstration is an important step forward towards the goal of replacing fossil-derived fuels with green hydrogen in commercial and industrial applications. Responsible for more than one-third of the world’s energy consumption and a quarter of global CO2 emissions, industrial companies are particularly well-suited for low-cost, large-scale hydrogen utilization given their substantial energy requirements and notable carbon emissions.

Our demonstration project with Bloom Energy represents a significant leap toward full commercial-scale green hydrogen production, which will play an important role in decarbonizing heavy industry. Following this successful integration of Heliogen’s near-24/7 solar steam generation with the Bloom Electrolyzer, we expect that commercial projects will use Heliogen technology to supply their electric power as well, providing 100 percent of the thermal and electrical energy required to produce green hydrogen.

—Bill Gross, founder and CEO of Heliogen

Heliogen and Bloom Energy plan to continue their testing efforts and look forward to sharing further information at a future date.



If they can get the temperature to at least 750 deg C there are thermo-chemical reactions that will produce H2 and O2 without electric power. However, the efficiency of this process is much better if you can get the temperature to 950 + deg C. Without requiring electric power, there is no heat engine losses to be concerned with.

However, the best way to do this is probably with a high-temperature gas-cooled fast nuclear reactor.


SOEC plus heat makes more efficient hydrogen
I have said this for years

Albert E Short

I'm stuck on the "80% of 45%" number. Is that all-in cost to deliver a m^3 to the buyer? Bloom's genius is having discovered how to use rust instead of platinum with the aid of good thermal management. I can see how they could use a CS plant that's already built to their advantage, but as renewables are so dirt cheap these days, it seems that soon the cost of extra electricity will be less than building a relatively complex CS plant.


Read 1-6 in the picture
They make heat electricity and hydrogen


The target goal of $2 per KG is fine for automotive uses, but not competitive with most industrial process heating needs.


How many hours a day can they run this thing ?
If you use a heat store, you are down to 33% of the daylight.
Or have I missed something ?

I agree with sd - use a nuclear heat reactor.
(And pipe any remaining into a district heating system).
[ but good luck with getting any of that through the western press / social media. - you know :- C* and F* ]



I don't agree with Heliogen's thesis.

They are trying to sell this on the basis of the high efficiency of a less mature technology than the standard alkaline and PEM electrolysers, and longer hours from the more expensive thermal solar against standard silicon cells.

This is a pretty major study to tackle, but here it is anyway:

The bottom line is that cheap silicon cells and cheap electrolysers, not highly sophisticated SOECs, at $300Kw can make conventional solar and hydrogen economic.

Have a look and see what you think.


I meant to add but forget that that is even with limited normal solar hours, $300Kw electrolysers make hydrogen production economic.

See page 53 of the link I gave above:

' In the past, high electrolyser costs have made it important to run electrolysers at high capacity in order to reduce capital costs per unit of production, which implied reliance on more expensive electricity from the grid. But as electrolysers capital
costs fall drastically, high utilisation will no longer be crucial. As Exhibit 2.3 shows, once electrolyser costs fall below $300/kW, electricity cost becomes the almost sole driver of green production costs as long as utilisation rates are above
around 2000 hours per annum'

High efficiency and long hours of utilisation are good to have, but green hydrogen at less than $2kg does not depend on either.


Actual figures of hydrogen cost achieved by this onnovation could have been given.


@Dave, it is a long paper with no executive summary that I could find, but I'll use your comments.
We have the cheep solar cells.
"All" we need are the cheap electrolysers.
Also, we are likely to have a lot of waste or curtailed wind energy, which could be mopped up if we had cheap electrolysers.

Then what do we do with the H2 - convert it to Nh3 or methanol or longer chain hydrocarbons ?
Or use it directly ?

Are there any references to the current and historic cost of electrolysers?
[ There are loads of them on batteries ] (at least 1, that is).


Hi Mahonj

Page 53 on the link where I got my quote from talks about current electrolyser costs.
Earlier in the study they go into the rate of fall of costs in more detail, I suggest you skim or use word search.

The $300kw which means, they reckon, that only 2,000 hours use is fine is presently achieved in China, for presumably basic alkaline electrolysers, but all sorts of tech is dropping in price, and the falls are pretty much to a large extent built in, as a lot of it is due to massively increased volume, from something like 100MW total a year or so back to a projected 30-40GW for Europe alone by 2030.

As for transportation etc, lot depends on where it is produced.

For the European North sea, the plans are largely simply to feed hydrogen into the grid, as it is near to point of use.

For places like Saudi, most are plumping for Topsoe Haldor's tech, which used SOECs similar (?) to those of Bloom to make ammonia for shipment for conversion in other countries.

But they are using regular solar panels, not thermal solar.

I assume although I don't know that SOECs are currently costing way more than $300Kw, but many of the schemes for instance in Morocco plan on integrating solar and wind for higher capacity rates.

The bottom line is that the presentation from Heliogen is, understandably, downplaying alternatives which may be just as or more economic.

Hydrogen/ammonia is going to be produced in a host of ways, which is one of the reasons for the interest in it anyway.

And battery only folk have downplayed how much of that is going to come from underutilised or straighforwardly current thrown away resources, making a nonsense of the efficiency memes they have been chucking around for the last decade.


This is a demo system that shows they can get it all from the sun

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