The Anonymous Widower

Rolls-Royce To Develop mtu Hydrogen Electrolyser And Invest In Hoeller Electrolyser

The title of this post, is the same as that of this press release from Rolls-Royce.

These are the three main points in the press release.

  • Holdings in start-up companies in northern Germany secure Rolls-Royce Power Systems access to key green hydrogen production technology.
  • Electrolysis systems for several megawatts of power.
  • First demonstrator in 2023 using a Hoeller stack.

This is the introductory paragraph to the deal.

Rolls-Royce is entering the hydrogen production market and acquiring a 54% majority stake in electrolysis stack specialist Hoeller Electrolyzer, whose innovative technology will form the basis of a new range of mtu electrolyzer products from its Power Systems division. Hoeller Electrolyzer, based in Wismar, Germany, is an early-stage technology company that is developing highly efficient polymer electrolyte membrane (PEM) stacks, under the brand name Prometheus, for the cost-effective production of hydrogen.

This page on the Hoeller Electrolysis web site gives details of Prometheus.

  • Hoeller are planning small, medium and large electrolyser modules, the largest of which is rated at 1.4 MW.
  • Load changes of between 0 and 100 % within seconds.
  • Cold start capability.
  • It will produce 635 Kg/day.
  • They are talking of a cost of 4€/Kg.

It all sounds good to me.

This paragraph is from the press release.

Founded in 2016, Hoeller Electrolyzer has positioned itself, with Prometheus, as one of the few highly specialized expert players in the field of high-efficiency PEM electrolysis stacks. Its founder, Stefan Höller, has more than a quarter of a century’s experience of developing electrolysis technology and has already registered 14 patents connected with Prometheus. Particularly high efficiency is promised by special surface technologies for the bipolar plates which significantly reduce the use of expensive precious metals platinum and iridium as catalysts, as well as increased output pressure.

I know a small amount about electrolysis and feel that Rolls-Royce may have got themselves a high-class deal.

Rolls-Royce’s large German presence in companies like mtu, will also help to smooth any doubts about the deal.

This paragraph indicates a shared belief.

Rolls-Royce and Hoeller Electrolyzer are united by a shared belief in the opportunity of zero-carbon energy – both for power supply and the propulsion of heavy vehicles. With decades of experience and systems expertise, Rolls-Royce is going to develop a complete electrolyzer system and has a global sales and service network, which opens up the potential for significant worldwide sales.

But perhaps, this is the most significant paragraph of the press release.

Armin Fürderer, who heads up the Net Zero Solutions business unit of Power Systems, said: “We’re going to launch electrolyzers with several megawatts of power right from the start. A total output of over 100 megawatts is conceivable by combining several electrolyzers.”

A quick search of the Internet, indicates that 100 MW is the size of the world’s largest electrolysers.


I can see applications for these large electrolysers.

Rolls-Royce Power Systems

This is a sentence from the press release.

Hoeller Electrolyzer, whose innovative technology will form the basis of a new range of mtu electrolyzer products from its Power Systems division.

The Rolls-Royce Power Systems web site, has this mission statement.

The Power Systems Business Unit of Rolls-Royce is focused on creating sustainable, climate neutral solutions for drive, propulsion and power generation.

In Rolls-Royce Makes Duisburg Container Terminal Climate Neutral With MTU Hydrogen Technology, I describe one of Rolls-Royce Power Systems projects.

The title of this post, is the same as this press release from Rolls-Royce.

This is the first sentence.

Rolls-Royce will ensure a climate-neutral energy supply at the container terminal currently under construction at the Port of Duisburg, Germany.

There is also this Rolls-Royce graphic, which shows the energy sources.

It would appear batteries,  combined heap and power (CHP), grid electricity, hydrogen electrolyser, hydrogen storage and renewable electricity are being brought together to create a climate-neutral energy system.


  1. The system uses a large hydrogen electrolyser.
  2. I suspect the hydrogen will be generated by off-peak electricity and local renewables.
  3. Hydrogen will probably power the container handling machines, ships, trucks, vehicles and other equipment in the port.

Hydrogen appears to be used as a means of storing energy and also for providing motive power.

I would suspect, the ultimate aim is that the port will not emit any carbon dioxide.

Other ports like Felixstowe and Holyhead seem to be going the hydrogen route.

Refuelling Hydrogen Buses and Charging Electric Buses

If you look at the Duisburg system, I can imagine a similar smaller system being used to refuel hydrogen buses and charge electric ones.

  • The hydrogen electrolyser would be sized to create enough hydrogen for a day or so’s work.
  • Hydrogen would be generated by off-peak electricity and local renewables.
  • If an operator bought more buses, I’m certain that the architecture of the electrolyser would allow expansion.
  • Hydrogen fuel cells would boost the electricity supply, when lots of buses needed to be charged.
  • Any spare hydrogen could be sold to those who have hydrogen-powered vehicles.
  • Any spare electricity could be sold back to the grid.

It should be noted that manufacturers like Wrightbus have developed a range of hydrogen and electric buses that use the same components. So will we see more mixed fleets of buses, where the best bus is assigned to each route?

I have used buses as an example, but the concept would apply to fleets of cars, trucks and vans.

Green Hydrogen

Large efficient electrolysers will surely be the key to producing large quantities of green hydrogen in the future.

It appears that about 55 MWh is needed to produce a tonne of green hydrogen using existing electrolysers.

The Hoeller electrolyser appears to be about 53 MWh, so it is more efficient.

Green Hydrogen From An Onshore Wind Farm

If you look at the average size of an onshore wind farm in the UK, a quick estimate gives a figure of 62 MW. I shouldn’t expect the figure for much of the world is very different, where you ignore the gigafarms, as these will distort the numbers.

An appropriately-sized electrolyser could be added to onshore wind farms to provide a local source of hydrogen for transport, an industrial process or a domestic gas supply for a new housing estate.

A single 5 MW wind turbine with a capacity factor of around 30 % would produce around 680 Kg of green hydrogen per day.

Green Hydrogen From An Offshore Wind Farm

There are basic methods to do this.

Put the electrolyser onshore or put the electrolyser offshore and pipe the hydrogen to the shore.

I think we will see some innovative configurations.

In ScotWind N3 Offshore Wind Farm, I described how Magnora ASA are developing the ScotWind N3 wind farm.

The floating turbines surround a concrete floater, which in the future could contain an electrolyser and tankage for hydrogen.

The ScotWind N3 wind farm is designed to be a wind farm rated at 500 MW.

I can see an electrolyser on the floater, of an optimal size to make sure all electricity is used.

Pink Hydrogen

Pink hydrogen, is zero-carbon hydrogen produced using nuclear-generated electricity.

There are industrial processes, like the making of zero-carbon chemicals, concrete and steel, that will require large quantities of zero-carbon green or pink hydrogen.

Rolls-Royce are developing the Rolls-Royce SMR, which will be a 470 MW small modular nuclear reactor.

One of these placed near to a steel works and coupled to one or more 100 MW electrolysers could provide enough zero-carbon electricity and hydrogen to produce large quantities of zero-carbon green steel.


Rolls-Royce and their subsidiaries like mtu, seem to be extensive users of advanced manufacturing techniques and I would expect that they can improve Hoeller’s manufacturing.

Research And Development

The press release says this about the founder of Hoeller.

Its founder, Stefan Höller, has more than a quarter of a century’s experience of developing electrolysis technology and has already registered 14 patents connected with Prometheus.

If Rolls-Royce can develop and support Stefan Höller and his team, development could easily go to a higher level.


I think that Rolls-Royce have taken over a company, that will in the end, will design excellent efficient electrolysers.




June 29, 2022 Posted by | Hydrogen | , , , , , , , , , , , , , , | Leave a comment

A Planned Trip To Belfast

I’m thinking about going over to Belfast for a couple of days to have a look at the transport systems in the city and the wider Northern Ireland.

I have several things, I would like to do.

  • Ride in the latest Wrightbus hydrogen and battery-electric buses.
  • Ride in a Glider. I also intend to go to Pau to ride in a hydrogen-powered version of these Van Hool Equicity articulated buses, but Belfast is nearer.
  • Perhaps, if I have enough time, I’ll visit a few touristy bits.
  • Do a bit of research into offshore wind farms in Northern Ireland.

Has anybody got any advice?


April 25, 2022 Posted by | Hydrogen, Transport/Travel | , , , , , , | 3 Comments

UK On Track To Reach 4,000 Zero Emission Bus Pledge With £200 Million Boost

The title of this post, is the same as that of this press release from the Government.

These are the main points of the press release.

  • Nearly 1,000 more zero-emission buses to be funded in towns and cities across the country, bringing the total funded in England to 2000 so far under this government.
  • A further 600 zero-emission buses have been funded in Scotland, Wales and Northern Ireland.
  • Comes as consultation launched on ending sale of all new non-zero emission buses from 2025 to 2032.
  • Government continues taking unprecedented action to hit net zero and level up transport across the country.

Areas to get the new buses include.

  • Blackpool
  • Greater Manchester
  • Hertfordshire
  • Norfolk
  • North Yorkshire
  • Nottingham
  • Oxfordshire
  • Portsmouth
  • South Yorkshire
  • West Midlands
  • West Yorkshire
  • York

I would also like to see the government fund trials for the conversion of suitable buses to zero carbon. I certainly believe that London’s New Routemaster buses could be converted to hydrogen.



March 27, 2022 Posted by | Hydrogen, Transport/Travel | , , , | 7 Comments

106 Solaris Zero Emission Buses Headed To ÖBB Postbus’ Fleet In Austria

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

This is the body of the story.

Up to 106 zero emission buses are headed to Austria, where ÖBB Postbus is going to deploy them starting from 2022 – 2025. Solaris has signed another framework agreement with the Austrian bus company Österreichische Postbus AG. It stipulates a possibility to deliver up to 106 battery-electric and hydrogen buses that would be deployed throughout Austria. The models offered include Urbino 9 LE electric and Urbino 12 hydrogen buses.

Solaris Bus and Coach is a Polish company, that is a subsidiary of CAF.

March 5, 2022 Posted by | Hydrogen, Transport/Travel | , , , , | Leave a comment

The Big Beast In Your Electric Bus

This article on is entitled BAE Systems Takes Orders For 340 Hybrid Drive Systems.

This is the first paragraph.

The Southeastern Pennsylvania Transportation Authority (SEPTA) has selected BAE Systems to supply up to 340 hybrid electric drive systems for its new fleet of low emission transit buses. BAE Systems will provide 220 electric drive systems to New Flyer of America, with an option for 120 additional systems, over the next three years.

The article also reveals that the company is working with AlexanderDennis.

The system appears to be hydrbid, with a lot of intelligent choosing of when to use a polluting engine.

February 21, 2022 Posted by | Energy, Transport/Travel | , , , , , | 4 Comments

Riding The Latest Alexander Dennis Electric Double-Decker Bus

This morning, I had a first ride in one of the latest Alexander Dennis electric double-decker buses.



  1. The bus is definitely an improvement on previous electric models, that I have ridden on routes 43 and 212.
  2. Bus route 63 goes between Kings Cross and Honor Oak.
  3. If you want to go South from King’s Cross, the bus is caught at Stop D in front of the station.
  4. I’ve never seen a bus before with a wooden floor. Was it real or fake?
  5. The stop buttons were in the back of the seat in front. I’ve never seen this before.
  6. The are charging points for mobile phones.

Overall the standard of finish seemed high, but then it was in the new Wrightbus hydrogen buses I’ve ridden lately.


February 13, 2022 Posted by | Transport/Travel | , , | 2 Comments

Equipmake & Beulas Join Forces With Go-Ahead London: In-Service Trials Of New Double Deck Electric Bus To Begin Q1 2022

The title of this post, is the same as that of this press release on the the Equipmake web site.

I was alerted to the bus by an item on BBC Breakfast this morning. It was before seven, so it should be easy to find on iPlayer.

These two paragraphs describe the bus.

Designed and developed in the UK, Equipmake’s Zero Emission Drivetrain (ZED) offers operators three modular battery pack options of up to 543kWh ­– the largest capacity battery of any two-axle double decker electric bus in the world. This delivers an unmatched electric driving range of up to 300 miles, which is more than sufficient to ensure the Jewel E can easily complete an entire duty cycle without the need to stop and recharge. Equipmake’s modular design enables operators the flexibility to scale the amount of battery throughout the life of a bus future-proofing it for a range of routes and distances.

The Jewel E is set to be manufactured in 2022 at an all-new facility in Norfolk. The vehicle body is produced by Beulas in Girona, Spain, a company with more than 87 years of experience in the sector. The vehicle chassis has been specifically designed for the Equipmake Zero Emission Drivetrain (ZED) by Agrale in Buenos Aires, Argentina, a leading truck and Bus chassis manufacturer established in 1962.

Apparently, there’s a lot of Formula One expertise in the design.

January 19, 2022 Posted by | Transport/Travel | , , , | 2 Comments

Could The Pantograph Make A Return To London’s Buses?

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

Reading Ian’s article, the plan is for the 358 bus route to be converted into an electric bus route, where the buses are charged at both ends of the route during the turn round.

The Feasibility Of A Battery-Electric Route 358

This morning, I took a train to Crystal Palace station and then took a 358 bus to Orpington station before coming home.

These were my thoughts.

Crystal Palace Parade

The buses actually leave from Crystal Palace Parade where there are several bus stops in a bus station.

This Google Map shows the bus station.

I also took these pictures.


  1. There is certainly a lot of space to put a charger.
  2. As there is the main Crystal Palace television transmitter close by, I suspect that power is not a problem.

There didn’t appear to be any sign of work relating to a charger.

Orpington Station

This Google Map shows Orpington station.


  1. The bus station is on the East side of the station.
  2. Buses are lined up at the Northern end of the bus station.
  3. Orpington station is step-free.

I took these pictures.

As at Crystal Palace there appeared to be no work in progress to install a charger.

The Route

The route is mainly flat with hills or inclines at the following places.

  • There is a steep hill up to Crystal Palace Parade.
  • There are hills at Bromley and Farnborough.
  • There is a steep incline up to Orpington station.

At times, the bus was running at just under forty mph.

I suspect that Transport for London will have to be careful with specifying the battery size.

The Buses

This is the ie tram product page on the Irizar web site.

This is a video of the twelve metre ie tram.

It looks rather smart and purposeful.

The Charger

The image on Ian Visits could be one of Furrer + Frey’s chargers shown in this doocument on their web site.


It looks a viable zero-carbon bus route, but as no work is visible, has it been cancelled because of TfL’s financial problems?






December 12, 2021 Posted by | Transport/Travel | , , , , , | 5 Comments

When It Comes To Buses, Will Hydrogen Or Electric Win?

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

The WIRED article is a serious comparison between the merits of battery and hydrogen-powered buses.

The writer of the article talked to two people, who should know.

  • James Dixon, who is a Research Fellow in the Transport Studies Unit and Environmental Change Institute at Oxford University
  • Neil Collins, who is Managing Director of Wrightbus.

I think the philosophy of Wrightbus with four basic zero-carbon buses could be right.

This surely is a basis for satisfying customers, who like to buy what they feel is best for their networks and passengers.

This paragraph from the Wired article, illustrates how terrain and climate might favour one bus or the other.

Still, hydrogen may be a better option in a city with lots of hills, like Hong Kong, where it’s also very warm and humid, says Collins. “That’s going to be a problem for electric buses, because the cooling and the hills are just going to drain the batteries,” he says. “But if the city is relatively flat, and the journey times are relatively short, and it’s not either significantly warm or significantly cold, battery electric can do a very good job.”

In addition, you wouldn’t choose hydrogen buses, if supply of hydrogen was difficult.

Could this be why Jo Bamford, who is the owner of Wightbus, has established a company to help bus operators with the transition to hydrogen. I wrote about it in New Company Established To Help Transition Bus Fleets To Hydrogen.

I have also heard stories of garages in city centres, where it is not possible to get enough power to charge a garage full of battery buses. Some of these garages are in residential areas, which perhaps may not welcome tankers of hydrogen going through to supply the buses with hydrogen.

Perhaps, the solution for garages like this is to relocate the garage to a site, which fulfils one of these conditions.

  • Good connections to the motorway and trunk road network, so that hydrogen can be brought in by truck.
  • A high-capacity electricity supply to either charge battery electric buses or generate hydrogen using an electrolyser.

Buses would operate according to this daily cycle.

  • Buses would either be charged or refuelled with hydrogen overnight.
  • They would position to a convenient place to start their daily diagrams.
  • At the end of the day, they would return to the garage.


  1. Battery-electric buses may need to be topped-up during the day.
  2. Hydrogen buses with their longer range should be able to service routes further away.
  3. Routes would be arranged, so that hydrogen buses would not need to be topped up.

The big advantage of a remote bus garage is that the city centre site could be redeveloped to pay for the new buses and garage.


December 10, 2021 Posted by | Hydrogen, Transport/Travel | , , | 12 Comments

Northern Ireland Spends £100m On Clean Buses

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

If Wrightbus can’t rely on the Northern Irish government to buy their buses, who can they?

November 12, 2021 Posted by | Transport/Travel | , , , | Leave a comment