The Anonymous Widower

Form Energy’s New Low-Cost, Iron-Air Battery Runs For 100 Hours

The title of this post, is the same as that of this article on the Singularity Hub.

This paragraph sums up the genesis of the battery.

A secretive startup backed by Bill Gates’ Breakthrough Energy Ventures thinks it may have the answer, though. Form Energy, which was co-founded by the creator of Tesla’s Powerwall battery, Mateo Jaramillo, and MIT battery guru Yet-Ming Chiang, has unveiled a new battery design that essentially relies on a process of “reversible rusting” to provide multi-day energy storage at ultra-low costs.

And this paragraph describes the operation of the battery.

The company’s batteries are each about the size of a washing machine, and are filled with iron pellets and a water-based electrolyte similar to that used in AA batteries. To discharge, the battery breathes in oxygen from the air, converting the pellets to iron oxide, or rust, and producing electricity in the process. To charge, the application of a current converts the rust back into iron and expels the oxygen.

It’s all very fascinating and leads to a battery made from very affordable materials.

The article quotes between $50 to $80 per kilowatt-hour for lithium-ion batteries and around $20 per kilowatt-hour for Form Energy’s battery.


The article is definitely a must-read.

I feel that Form Energy should be added to my list of viable batteries.

August 3, 2021 Posted by | Energy, Energy Storage | , , , | 2 Comments

Form Energy Discloses A Small Amount

Form Energy has been a bit mysterious, but this article on Energy Storage News, which is entitled Renewables As Baseload Energy: Form Energy’s Multi-Day |Storage Seeks To Replace Gas And Coal.

Form Energy certainly have large ambitions, backing from organisations like Bill Gates’ Breakthrough Energy Ventures and an order for a 1 MW/150 MWh pilot for Great River Energy in Minnesota, and I suspect this is probably enough to ensure success in the mid-size market sector, which they share with the UK’s Highview Power, who are building their first grid-scale 50 MW/ 250 MWh at Carrington to the South of Manchester.

The article is certainly an interesting insight into one of the new energy storage ventures.

April 28, 2021 Posted by | Energy Storage | , , | Leave a comment

Long-Duration Energy Storage Milestones Achieved By Lockheed, Eos And Form Energy

The title of this post, is the same as that of this article on Energy Storage News.


I find it significant that Lockheed Martin have developed a new redox flow battery, which is a 500kW / 2.5MWh system.

Last year, the company had revenue of nearly sixty billion dollars, with a net income of over six billion dollars. They certainly have the resources and the name to make a big impression on the long-duration storage market.

Their GridStar Flow technology is also detailed on this page on the Lockheed Martin web site.

The page lists these features.

  • Optimized for 6+ hours of flexible discharge
  • Flexibility to switch between products to maximize revenue
  • 100 percent depth-of-discharge with minimal degradation
  • A design life of 20 years
  • Ability to size energy and power independently
  • Mildly alkaline, aqueous electrolytes that are safe (nonflammable, noncorrosive, stable)
  • Competitive total cost of ownership

It looks impressive.

EOS Energy

EOS Energy can’t be doing badly, as they’re preparing to list on NASDAQ.

Form Energy

Form Energy are also reported to have had a $70 million investment.


It appears long duration energy storage is doing well across the pond.

My money would be on Lockheed to produce the most successful product.

November 19, 2020 Posted by | Energy Storage | , , , | Leave a comment

So, What Exactly Is Long-Duration Energy Storage?

The title of this post is the same as that of this article on Greentech Media.

This is the sub-title.

Everyone’s talking about it, and Californians are buying in. Here’s what you need to know about this emerging grid sector.

It describes what California is doing and the sector, with particular reference to Hydrostor, Form Energy and Highview Power.

The article finishes with a section entitled What’s The Catch?

This is the first two paragraphs.

The obvious barrier to a thriving long-duration storage industry is convincing generally conservative power plant customers that emerging technologies quite unlike anything the grid currently uses are safe bets for decades of operation.

Lab tests can reduce the risk, but nothing beats operational, megawatt-scale installations for proving that something works. That’s why the Form deal with Great River Energy is so crucial, as are early projects by Highview Power and Hydrostor. The big exception to technology risk is pumped hydro, which has been used at scale for decades. Those projects grapple instead with high capital expense and environmental concerns.

The article is a must-read and hopefully, this and more articles like it, will convince conservative energy company owners, regulators and governments, that long duration energy storage is the missing link between renewable power and electricity consumers.

At least, the current UK Government has backed two of the most promising British long duration energy storage companies; Gravitricity and Highview Power.

October 27, 2020 Posted by | Energy, Energy Storage | , , , , | Leave a comment

Air-Powered Energy Storage Knocks Out Coal & Gas — Wait, What?

The title of this post, is the same as that of this article on CleanTechnica.

After reading, this must read article, it could have had a title with Knocks Out Coal, Gas and Nuclear.

It makes a passionate article for Highview Power’s long term air-powered energy storage and other systems with a similar energy profile like Form Energy.

It also showed this good graphic from Highview Power, which shows how their system works.

This paragraph gives Highview’s view on what their CRYObatteries will do.

Grid operators are turning to long-duration energy storage to improve power generation economics, balance the grid, and increase reliability. At giga-scale, CRYOBatteries paired with renewables are equivalent in performance to – and could replace – thermal and nuclear baseload power in addition to supporting electricity transmission and distribution systems while providing additional security of supply,” enthuses Highview.

The author then chips in with the attitude of the US Department of Energy.

Don’t just take their word for it. The US Department of Energy is eyeballing long duration energy storage for the sparkling green grid of the future despite all the hot air blowing out of 1600 Pennsylvania Avenue.

In an interesting twist, the Energy Department’s interest in long duration storage was initially connected to its interest in at least preserving, if not growing, the nation’s aging fleet of nuclear power plants.

Will renewables be able to see off nuclear in a country with plenty of sun and/or wind like the United States?


With a lot of help from their friends in the long term energy storage business, the answer must be yes!


June 20, 2020 Posted by | Energy Storage | , , , , , , | Leave a comment

Floating Wind Swells, Hydrogen On A High And Here Comes The 150-Hour ‘Aqueous Air’ Battery

The title of this post is the same as that of this weekly summary on Recharge.

There are three major stories.

Floating Wind Turbines

A lot more floating wind turbines are under development, by the French, Swedes, South Africans and Japanese.

I do wonder, if these structures have borrowed the work done in Cambridge by Balaena Structures, for which I did the calculations, as I wrote about in The Balaena Lives.

From what I remember of my calculations fifty years ago, I suspect these floating turbines can be massive and places, in areas, where the winds are really strong.

I also believe that some could have built-in hydrogen generators and could be placed over depleted gas fields and connected to the existing gas pipes.


The article describes how oil giants; BP and Shell are moving towards hydrogen.

Battery Storage

They also talk about Form Energy and their mysterious ‘aqueous air battery, which Recharge covered earlier. I discussed that article in The Mysterious 150-hour Battery That Can Guarantee Renewables Output During Extreme Weather.


This article is a must-read.

Recharge is also a site to follow, if you are interested in the developments in renewable energy.

May 18, 2020 Posted by | World | , , , , , | Leave a comment

The Mysterious 150-hour Battery That Can Guarantee Renewables Output During Extreme Weather

The title of this post, is the same as that of this article on Recharge.

The article talks starts by talking about Form Energy, who I wrote about in 150 Hours Of Storage? Company Says That’s True To Form.

As to Form Energy’s technology, they say that there is speculation, that sulphur is the main ingredient.

The article, then lists other technologies, that are under development to store energy.

There’s certainly no lack of entrants for the contest to provide long-term energy storage.

The article is a summary of both Form Energy and the others in the field.

May 15, 2020 Posted by | Energy Storage | , | 3 Comments

Cheesecake Energy Receives Investment From The University Of Nottingham

The title of this post, is the same as that of this article on NewsAnyway.

This is the introductory paragraph.

Cheesecake Energy Limited (CEL) today announced it has received investment from the University of Nottingham to support UK-wide pilot programmes for the company’s energy storage solution.

Thse two paragraphs are a brief description of the company, their technology and what they do.

Cheesecake Energy Limited is a fast-growing startup developing energy storage at 30-40% lower cost than the current market leader, lithium ion batteries. Its system uses compressed air and thermal energy storage to achieve high efficiency, long lifetime and dramatically lower environmental impact. 

Founded in 2016, the company has already established itself within the Nottingham, and wider East Midlands energy ecosystem — having secured initial interest from local councils and bus services for pilot programmes. The company is currently designing a 150 kW / 750 kWh prototype system for completion in Q4 2020 which will be deployed with a local bus depot for charging of electric buses using renewable energy.

This is the home page of their web site, which proudly announces.

The Greenest Battery In The World

We’ll see and hear that slogan many times in the next few years.

A few of my thoughts on the company.

Cheesecake Energy’s Technology

Cheesecake Energy says it uses compressed air and thermal energy storage to achieve high efficiency, long lifetime and dramatically lower environment impact.

Three other companies also use or may use compressed air to store energy.

As Cheesecake appear to be using a thermal energy storage, have they found a unique way to create another type of compressed air storage?

Battery Sizes

How do the sizes of the three companies batteries compare?

  • Cheesecake Energy prototype – 150 kW – 750 kWh – five hours
  • Form Energy for Great River Energy – 1MW – 150 MWh – 150 hours
  • Highview Power for Vermont – 50MW – 400 MWh – 8 hours
  • Hydrostor for South Australia – 50+MW – 4-24+ hours

The Cheesecake Energy prototype is the smallest battery, but Highview Power built a 750 KWh prototype before scaling up.


  1. The first figure is the maximum power output of the battery.
  2. The second figure is the capacity of the battery.
  3. The third figure is the maximum delivery time on full power.
  4. The capacity for Hydrostor wasn’t given.

The figures are nicely spread out, which leas me to think, that depending on your power needs, a compressed air battery can be built to satisfy them.

Charging Electric Buses

Buses like this Alexander Dennis Enviro200EV electric bus are increasingly seen in the UK.

And they all need to be charged!

Cheesecake Energy say that their prototype will be deployed with a local bus depot for charging of electric buses using renewable energy.

  • An electric bus depot should be a good test and demonstration of the capabilities of their battery and its technology.
  • Note that according to this data sheet of an Alexander Dennis Enviro200EV, which is a typical single-decker electric bus, the bus is charged by BYD dual plug 2×40kW AC charging, which gives the bus a range of up to 160 miles.
  • With a 150 kW output could Cheesecake’s prototype charge two buses at the same time and several buses during a working day?
  • Would DC charging as used by Vivarail’s charging system for trains be an alternative?

To me, it looks like Cheesecake are showing good marketing skills.

I do wonder if this size of charger could make the finances of electric buses more favourable.

Suppose, a bus company had a fleet of up to a dozen diesel single-decker buses running services around a city or large town.

  • How much would they spend on electricity, if they replaced these buses with electric ones?
  • Would being able to use cheaper overnight energy to charge buses in the day, be more affordable?
  • Would electric buses run from renewable electricity attract passengers to the services?

These arguments for electric buses would also apply for a company running fleets of vans and small trucks.

To me, it looks like Cheesecake are showing good engineering/marketing skills, by designing a product that fits several markets.



May 11, 2020 Posted by | Energy Storage | , , , , , , | 3 Comments

150 Hours Of Storage? Company Says That’s True To Form

The title of this post, is the same as that of this article on Power Magazine.

It is very much a must-read about the emerging technology of high-capacity and long term energy storage, with particular reference to Highview Power and Form Energy.

The article fills out a lot of what I wrote in Will The Real Form Energy Please Stand Up!

I also feel that there’s also an old kid on the block, when it comes to long term energy storage and that is new methods of deploying pumped storage, that I wrote about in The New Generation Of Pumped Storage Systems.

May 10, 2020 Posted by | World | , , , , | 1 Comment

Will The Real Form Energy Please Stand Up!


Form Energy appears to be a start-up, that claims it has the solution to low-cost long-term energy storage.

The home page of their web site is little more than this headline.

We are developing long duration energy storage systems to enable a fully renewable, affordable and reliable electric system.

And a few links to press releases and a link marked See How.

I clicked it and got this page, with this mission statement.

We are going about this by developing a new kind of battery that would eliminate the need for coal and gas entirely, and allow for a 100% renewable, carbon free grid.

They say this about the technology.

Form Energy has identified and is developing a novel approach that is low-cost, safe, and scalable. This battery would allow for a 100% renewable, carbon free grid.

And this about the software.

Form Energy offers a software solution to the industry that models the efficiency and cost-saving benefits of using Form’s long duration storage and identifies value to the entire electricity ecosystem.

Now that I can understand.

When I was writing software, I wrote any number of models in project management, finance and engineering systems and I don’t doubt, that they have developed a sophisticated software system, that can model a large electricity network.

It would allow the following.

  • Predictions to be made for the future, based on historic data and schedules for new plant coming on stream.
  • It would have a graphical interface, so that changes to the power network could be performed quickly and easily.
  • It would predict the size and capacities of Form Energy’s batteries, that would be needed.
  • It could be used to model ways out of a serious breakdown in part of the grid.

I suspect that National Grid in the UK, EDF in France and other national equivalents, have been running such software systems for many years.

A Deal With Great River Energy

Does this press release on their web site, which is entitled Form Energy Announces Pilot with Great River Energy to Enable the Utility’s Transition to an Affordable, Reliable and Renewable Electricity Grid, give any more details about Form Energy’s technology?

This paragraph lays out the basics of the deal with Great River Energy.

Form Energy, a company developing ultra-low-cost, long-duration energy storage for the grid, today announced it signed a contract with Minnesota-based utility Great River Energy to jointly deploy a 1MW / 150MWh pilot project to be located in Cambridge, MN. Great River Energy is Minnesota’s second-largest electric utility and the fifth largest generation and transmission cooperative in the U.S.

The next paragraph gives a few details of the battery.

This system will be the first commercial deployment of Form Energy’s proprietary long-duration energy storage system. Form Energy’s aqueous air battery system leverages some of the safest, cheapest, most abundant materials on the planet and offers a clear path to transformationally low-cost, long-duration energy storage. The project with Great River Energy will be a 1-MW, grid-connected storage system capable of delivering its rated power continuously for 150 hours, far longer than the two to four hour usage period common among lithium-ion batteries being deployed at utility-scale today. This duration allows for a fundamentally new reliability function to be provided to the grid from storage, one historically only available from thermal generation resources.

A battery capable of storing 150 MWh and capable of delivering 1 MW for 150 hours is certainly impressive.

More About The Deal

This article on Green Tech Media is entitled Long Duration Breakthrough? Form Energy’s First Project Tries Pushing Storage To 150 Hours.

A few points from the article.

  • Bill Gates, Macquarie Capital and Eni are backers of Form Energy.
  • The aim is to have the plant online in 2023.
  • Great River Energy depends heavily on Coal Creek power station, which is a 1151 MW lignite-fired power station, which is to be shut down in the second half of 2022.
  • Form expect their battery to be competitive with lithium-ion on a per KW basis.
  • A battery takes up about an acre.
  • Batteries have a twenty-year life.

The article also says that Form is not sharing many details of its technology.

Can Great River Energy Replace The Power From Coal Creek With Wind Turbines And A 150 MWh Battery?

Consider these points from the Green Tech Media article and Wikipedia.

  • Coal Creek power station provides half of Great River Energy’s needs.
  • Coal Creek power station is rated at 1151 MW,
  • Coal Creek power station will shut in 2022.
  • Great River Energy intends to add 1,100 MW of wind turbines.
  • North Dakota, South Dakota and Minnesota seem to be states where it is worth reaping the wind.

So can all this power and the disruption of shutting Coal Creek power station be balanced by one relatively small 180 MWh battery?

I have modelled systems as complex as this in finance, project management and process engineering and if Form Energy have done their modelling to a very detailed level and they say that a 1MW/180 MWh system will be big enough, then I’ll go along with that!

In my long experience of mathematical modelling of complex systems, the answer at the end, is often not what many expect.

So the answer must be extensively tested.

What Technology Are Form Using?

The press release about the deal with Great River Energy mentions an aqueous air battery system!

Water and air are not exotic materials and are readily available in most parts of the world. I would suspect that the only way to store large amounts of energy in air is to liquify it, as Highview Power is doing in their CRYOBattery. But where does the water come in?

Could both companies be following different routes using similar properties of two of the greenest and most abundant substances on the planet?

I also know from a very beneficial personal financial experience, that aqueous-air mixes have unusual properties.

Highview Power liquify air and then use a turbine to recover the energy.

Are Form also using liquified air and then using a different method based on the unusual properties of aqueous-air mixes to recover the energy?

I can’t wait for the secret of their technology to emerge!

A Comparison Of Form Energy And Highview Power

The Wikipedia entry for Highview Power, says this about their capabilities and what they are proposing to deliver.

It has permission for a commercial-scale 50 Megawatt/250 Megawatt-hour plant in England, building upon its earlier 5 Megawatt and 350 Kilowatt pilot plants. It plans to develop a 50MW plant/400MWh (eight hours of storage) in Vermont

Is 5 MW for eight hours more impressive than 1 MW for one hundred and fifty hours?

  • Highview Power’s proposed Vermont battery is not far short of three times the size of Form’s Great River battery.
  • Highview Power’s battery can supply five times the maximum current, than Form’s.
  • Liquid air storage is very scalable, as you just add more tanks. I wouldn’t be surprised to see systems storing around a GWh of electricity.
  • Could Highview’s battery supply 2 MW for two hundred hours? I suspect it could!

If it was a relay race, I would think that Highview Power are ahead after the first leg.

The following legs will be interesting.

  • Both companies have backers with enormous pockets.
  • Form have disclosed they have sophisticated modelling software.
  • Form seem to have a firm order.
  • Highview Power are in a country, that in the next couple of years will bring vast amounts of wind power on-line.
  • Great River will have a power shortage, when Coal Creek lignite-fired power station is closed.

But above all the world needs terra-watt hours of affordable, zero-carbon energy storage.


May 9, 2020 Posted by | Energy Storage | , , , | 2 Comments