The Anonymous Widower

Would The Gravitricity Concept Work At Sea?

The North Sea and other similar places have lots of oil oil and gas platforms, that are coming to the end of their lives.

Many are being dismantled and scrapped.

But could some be used to store energy by replacing the refitting the deck with a Gravitricity energy  storage system. The massive weight would be hauled up and down from the sea bed.

It would be fed generated electricity from nearby offshore wind turbines and would store or feed the electricity to the shore as required.

Remember that some of these oil platforms have been built to support decks weighing thousands of tonnes, so would be strong enough to support the massive weight needed for a Gravitricity system.

If the height was say 500 metres and the weight was 10,000 tonnes, this would equate to just under 14 mWh.

 

February 10, 2018 Posted by | World | , | 2 Comments

Gravitricity Sets Sights On South Africa To Test Green Energy Tech

The title of this post, is the same as that of this article on ESI Africa, which describes itself as Africa’s Power Journal.

This is the first two paragraphs.

Disused mine shafts in South Africa have been identified as an ideal location to test UK-based energy start-up Gravitricity’s green energy technology.

The company announced plans to transform disused mine shafts into hi-tech green energy generation facilities through a system that uses gravity and massive weights.

This is surely a classic fit, as Africa has plenty of sun and some of the mine shafts in South Africa, like the TauTona mine are getting towards two miles deep.

A weight of 1,000 tonnes in a two mile deep shaft would store nearly nine MWh. By comparison, Dinorwig Power Station or Electric Mountain, has a capacity of 500 MWh.

But Electric Mountain was built in the 1970s, cost £425 million and took ten years to construct.

 

February 10, 2018 Posted by | World | , , , | Leave a comment

Funding Gives Weight To Idea For Storing Electricity

The title of this post, is the same as that of an article on Page 45 of today’s copy of The Times.

It talks of a company called Gravitricity, which has used the same principle as every weight-operated clock to store energy and especially energy generaed from intermittent sources like wind and solar power.

The company has just secured a £650,000 grant from Innovate UK.

In Solar Power Could Make Up “Significant Share” Of Railway’s Energy Demand, I looked at how solar farms and batteries could be used to power third-rail railway electrification.

Because of energy losses, third-rail electrification needs to be fed with power every three miles or so. This gives a problem, as connection of all these feeder points to the National Grid can be an expensive business.

A series of solar farms, wind turbines and batteries, controlled  by an intelligent control system, is an alternative way of providing the power.

In an article in the October 2017 Edition of Modern Railways, which is entitled Celling England By The Pound, Ian Walmsley says this in relation to trains running on the Uckfield Branch.

A modern EMU needs between 3 and 5 kWh per vehicle mile for this sort of service.

If I assume that trains are five cars and will be efficient enough to need only 3 kWh per vehicle mile, then to power a train along a ten mile section of track will take 150 kWh.

As the control system, only powers the track, when a train needs it, the whole system can be very efficient.

So why will Gravitricity battery ideas be ideal in this application?

Appropriate Size

By choosing the right weight and depth for the Gravitricity battery , appropriate energy storage can be provided at different points on a line.

Some parts of a journey, like accelerating away from stations will need more electricity than others, where trains are cruising along level ground.

Supposing my five-car example train is travelling at 60 mph, then to cover ten miles will take 10 minutes, with 15 kW being supplied in every minute.

If the train weighs 200 tonnes, then accelerating the train to 60 mph will need about 20 kWh.

I’m sure that a Gravitricity battery could handle this.

I would suspect that batteries of the order of 100 kWh would store enough power for the average third-rail electrified line.

A proper dynamic simulation would need to be done. I could have done this calculation in the 1960s, but I don’t have the software now!

Response Time

For safety and energy-efficiency reasons, you don’t want lines to be switched on, when there is no train present.

I suspect that if there is energy in the battery, response would be fast enough.

Energy Efficiency

The system should have a high efficiency.

How Big Would A 100 kWh Gravitricity Battery Be?

A quick calculation shows the weight would be 400 tonnes and the depth would be 100 metres.

Installing the batteries

Each battery will need a 100 metre deep hole of an appropriate diameter.

This sequence of operations would be performed.

  • A rail-mounted drilling rig would drill the hole.
  • The heavy weight of the battery would arrive by train and would be lifted into position using a rail-mounted crane.

As the equipment will generally be heavy, doing all operations from the railway will be a great help.

 

 

 

February 9, 2018 Posted by | Travel | , , , | 1 Comment

The Future Of Diesel Trains

Many feel that diesel trains have no future in the modern world, because of all those carbon and particulate emissions.

However, this article in Rail Technology News, which is entitled ScotRail To Trial Hydraulic Tech To Cut Of Carbon Emissions.

This is the first paragraph.

A new hydraulic pump could reduce Scotland’s carbon emissions by 4,000 tonnes of carbon dioxide per year.

This sounds impressive, but how is it done?

Many modern diesel muiltiple units, like the Class 170 trains, used in the ScotRail trial have hydraulic transmissions, where a pump fitted to the engine creates hydraulic power, which then drives a hydraulic motor to power the train.

But modern trains also need to have electricity in each car for lighting, air-conditioning and other services.

So typically, a hydraulic unit in each car is used to generate the electricity required.

It is this hydraulic unit, that has been replaced by a much more efficient digitally-controlled hydraulic unit.

That sort of hydraulic unit has one Scottish company’s stamp all over it; Artemis Intelligent Power, which started as a spin-off from Edinburgh University.

Artemis Intelligent Power has a page about Rail applications on their web-site.

This is the introductory paragraphs to their work.

Whilst electrification has enabled the de-carbonisation of much of the UK’s rail sector, the high capital costs in electrifying new lines means that much of Britain (and the world’s) railways will continue to rely on diesel.

In 2010, Artemis completed a study with First ScotRail which showed that between 64 and 73 percent of a train’s energy is lost through braking and transmission.

In response to this, Artemis began a number of initiatives to demonstrate the significant benefits which digital hydraulics can bring to diesel powered rail vehicles.

Two projects are detailed.

The first is the fitting of a more efficient hydraulic unit, that is described in the Rail Technology Magazine article.

Under a heading of Faster Acceleration, Reduced Consumption, there is a technical drawing with a caption of The Artemis Railcar.

This is said.

We are also working with JCB and Chiltern Railways on a project funded by the RSSB to reduce fuel consumption and improve engine performance by combining highly efficient hydraulic transmission with on board energy storage in the form of hydraulic accumulators, which store energy during braking for reuse during acceleration.

Note.

  1. The use of hydraulic accumulators to provide regenerative braking.
  2. The involvement of JCB, whose construction equipment features a lot of hydraulics.
  3. The involvement of Chiltern Railways, who like their parent company, Deutsche Bahn, have a lot of diesel-hydraulic multiple units and locomotives.

The article goes on to detail, how a test railcar will be running before the end of 2017.

This technology could have tremendous potential in the UK.

The Benefit Of Regenerative Braking

In the Wikipedia entry for Regenerative Brake, this is said.

Savings of 17%, and less wear on friction braking components, are claimed for Virgin Trains Pendolinos. The Delhi Metro reduced the amount of carbon dioxide (CO2) released into the atmosphere by around 90,000 tons by regenerating 112,500 megawatt hours of electricity through the use of regenerative braking systems between 2004 and 2007.

The entry also says that some London Underground trains save twenty percent.

It would be a large benefit to the train operating companies, if they could just have a similar saving on the cost of diesel fuel.

Could Existing Trains Be Converted?

In England, Wales and Scotland,currently there are around two hundred modern Turbostar diesel multiple units. of which thirty are used by Chiltern Railways.

Whether these can be converted, depends on the engineers and the result of the current trial, but the economic benefits of a successful conversion route could be very beneficial.

Conclusion

This is technology to watch!

 

 

December 30, 2017 Posted by | Travel | , , | Leave a comment

Hybrid Trains Proposed To Ease HS1 Capacity Issues

The title of this post is the same as an article in Issue 840 of Rail Magazine.

This is the first paragraph.

Battery-powered hybrid trains could be running on High Speed 1, offering a solution to capacity problems and giving the Marshlink route a direct connection to London.

Hitachi Rail Europe CEO Jack Commandeur is quoted as saying.

We see benefit for a battery hybrid train, that is being developed in Japan, so that is an option for the electrification problem.

I found this article on the Hitachi web site, which is entitled Energy-Saving Hybrid Propulsion System Using Storage–Battery Technology.

It is certainly an article worth reading.

This is an extract.

Hitachi has developed this hybrid propulsion system jointly with East Japan Railway Company (JR-East) for the application to next-generation diesel cars. Hitachi and JR-East have carried out the performance trials of the experimental vehicles with this hybrid propulsion system, which is known as NE@train.
Based on the successful results of this performance trial, Ki-Ha E200 type vehicle entered into the world’s first commercial operation of a train installed with the hybrid propulsion system in July 2007.

The trains are running on the Koumi Line in Japan. This is Wikipedia’s description of the line.

Some of the stations along the Koumi Line are among the highest in Japan, with Nobeyama Station reaching 1,345 meters above sea level. Because of the frequent stops and winding route the full 78.9 kilometre journey often takes as long as two and a half hours to traverse, however the journey is well known for its beautiful scenery.

The engineers, who chose this line for a trial of battery trains had obviously heard Barnes Wallis‘s quote.

There is no greater thrill in life than proving something is impossible and then showing how it can be done.

But then all good engineers love a challenge.

In some ways the attitude of the Japanese engineers is mirrored by those at Porterbrook and Northern, who decided that the Class 769 train, should be able to handle Northern’s stiffest line, which is the Buxton Line. But Buxton is nowhere near 1,345 metres above sea level.

The KiHa E200 train used on the Koumi Line are described like this in Wikipedia.

The KiHa E200 is a single-car hybrid diesel multiple unit (DMU) train type operated by East Japan Railway Company (JR East) on the Koumi Line in Japan. Three cars were delivered in April 2007, entering revenue service from 31 July 2007.

Note that the railway company involved is JR East, who have recently been involved in bidding for rail franchises in the UK and are often paired with Abellio.

The Wikipedia entry for the train has a section called Hybrid Operation Cycle. This is said.

On starting from standstill, energy stored in lithium-ion batteries is used to drive the motors, with the engine cut out. The engine then cuts in for further acceleration and running on gradients. When running down gradients, the motor acts as a generator, recharging the batteries. The engine is also used for braking.

I think that Hitachi can probably feel confident that they can build a train, that can handle the following.

  • High Speed One on 25 KVAC overhead electrification.
  • Ore to Hastings on 750 VDC third-rail electrification.
  • The Marshlink Line on stored energy in lithium-ion batteries.

The Marshlink Line has a big advantage as a trial line for battery trains.

Most proposals say that services will call at Rye, which is conveniently around halfway along the part of the route without electrification.

I believe that it would be possible to put third-rail electrification in Rye station, that could be used to charge the batteries, when the train is in the station.

The power would only be switched on, when a train is stopped in the station, which should deal with any third-rail safety problems.

Effectively, the battery-powered leg would be split into two shorter ones.

 

November 23, 2017 Posted by | Travel | , , , , , | Leave a comment

How Much Energy Does A Crossrail Class 345 Train Use?

I will start with the Crossrail Rolling Stock Technical Fact Sheet, which dates from 2012.

The Class 345 trains were built to this specification.

This is said about the power required.

Energy efficiency of 24 KWh per train kilometre (equivalent of 55g CO2 per passenger kilometre)

So what does this mean now that trains are running and trains will have been designed and probably accepted to this specification.

Assuming, that trains will be nine-car when completed, 24 KWh per train per kiometre translates into 2.67 KWh per car per kiometre or 3.29 KWh per car per mile.

Ian Walmsley’s Train Energy Usage Figure

In an article in the October 2017 Edition of Modern Railways, which is entitled Celling England By The Pound, Ian Walmsley says this in relation to trains running on the Uckfield Branch.

A modern EMU needs between 3 and 5 kWh per vehicle mile for this sort of service.

My calculated value is in line with this figure, as the Uckfield Branch is not that different to some of the Crossrail branches.

What Is The Kinetic Energy Of A Crossrail Train?

I ask this question to show the energy values involved.

If I take a nine-car Class 345 train, this has a mass of less than 350 tonnes and a maximum speed of 145 kph.

1500 passengers at 80 kg each works out at another 120 tonnes.

So for this crude estimate I’ll use 450 tonnes for the mass of a loaded train.

This gives the train an energy of 365 megajoules or 101 KWh.

This amount of energy is only a couple of KWh larger than the largest battery size of a Tessla Model S car.

It leads to the conclusion, that batteries could be large enough to store the regenerative energy generated by the train, when it stops.

How Far Could A Crossrail Train Run On Batteries?

If the batteries were sized for the regenerative braking, then a battery of 100 KWh would probably be sufficient in most circumstances.

Using Crossrail’s figure of 24 KWh per train per kiometres, gives a convenient range of four kiometres, which is probably in excess of the largest distance between stations.

But Crossrail trains are effectively two half-trains with two pantographs.

So perhaps they will be fitted with two batteries!

The battery capacity would be arranged to give the desired amount of emergency power.

Conclusion

There’s a lot more to learn about these Crossrail trains.

 

November 16, 2017 Posted by | Travel | , , | 1 Comment

Stadler Comes Up With A New Take And A Big Order For Hybrid And Battery Trains

This article on Global Rail News is entitled Vegetable Oil Fuel Trains To Run In The Netherlands Ahead Of Battery Conversion.

This is said.

  • Arriva has ordered eighteen hybrid diesel trains from Stadler to operate its Northern Lines services in the Netherlands.
  • The trains will initially be powered by Hydrotreated Vegetable Oil (HVO).
  • The trains will have regenerative braking.
  • Stadler have called the trains Flirtinos.
  • The trains are capable of conversion to battery trains, when there is sufficient electrification.
  • The first HVO trains will enter service in 2020.
  • Arriva has committed to putting batteries into all of its fleet  of fifty-one trains.

This a very strong environmental statement from Stadler and Arriva.

In July 2017, I wrote Battery EMUs For Merseyrail.

These trains are also being built by Stadler.

Conclusion

Have Stadler found the secret for better battery trains?

Certainly, the amount of money that Arriva is paying Stadler and the fact that Arriva are creating sixty-nine trains with batteries, indicates that they have confidence in the product!

You can’t fault Stadler’s marketing either!

 

November 14, 2017 Posted by | Travel | , , , , , | Leave a comment

Regenerative Braking On A Dual-Voltage Train

Yesterday, I found this document on the Railway People website, which is entitled Regenerative Braking On The Third Rail DC Network.

Although, the document dates from 2008, it is very informative.

Regenerative Braking On 25 KVAC Trains

The document says this.

For AC stock, incoming power from the National Grid at high voltage is stepped down by a transformer. The AC power is transmitted via OHL to the trains. When the train uses regenerative braking, the motor is used as a generator, so braking the axle and producing electrical energy. The generated power is then smoothed and conditioned by the train control system, stepped up by a transformer and returned to the outside world. Just about 100% of regenerated power is put back into the UK power system.

But I have read somewhere, that you need a 25 KVAC overhead electrification system with more expensive transformers to handle the returned electricity.

Regenerative Braking On 750 VDC Trains

The document says this.

After being imported from the National Grid, the power is stepped down and then AC power is rectified to DC before being transmitted via the 3rd rail. Regenerated Power can not be inverted, so a local load is required. The power has to be used within the railway network. It cannot be exported.

So the electricity, is usually turned into heat, i there is no train nearby.

The Solution That Was Applied

The document then explains what happened.

So, until such time as ATOC started to lobby for a change, regenerative DC braking was going nowhere. But when they did start, they soon got the backing of the DfT and Network Rail. It takes a real combined effort of all organisations to challenge the limiting assumptions.

In parallel, there were rolling stock developments. The point at which all the issues started to drop away was when the Infrastructure Engineers and Bombardier, helped out by some translating consultants (Booz & Company), started to understand that new trains are really quite clever beasts. These trains do understand what voltage the 3rd rail is at, and are able, without the need to use any complicated switch gear – just using software, to decide when to regenerate into the 3rd rail or alternatively, use the rheostatic resistors that are on the train.

Effectively, the trains can sense from the voltage if the extensive third-rail network can accept any more electricity and the train behaves accordingly.

As most of the electric units with regenerative braking at the time were Bombardier Electrostars, it probably wasn’t the most difficult of tasks to update most of the trains.

Some of the Class 455 trains have recently been updated. So these are now probably compatible with the power network. Do the new traction motors and associated systems use regenerative braking?

This document on the Vossloh-Kiepe web site is entitled Vossloh Kiepe enters Production Phase for SWTs Class 455 EMU Re-Tractioning at Eastleigh Depot and describes the updating of the trains. This is said.

The new IGBT Traction System provides a regenerative braking facility that uses the traction motors as generators when the train is braking. The electrical energy generated is fed back into the 750 V third rail DC supply and offsets the electrical demands of other trains on the same network. Tests have shown that the energy consumption can be reduced by between 10 per cent and 30 per cent, depending on conditions. With the increasing cost of energy, regenerative braking will have a massive positive cost impact on the long-term viability of these trains. If the supply is non-receptive to the regenerated power, the generated power is dissipated by the rheostatic brake.

So thirty-five year old British Rail trains now have a modern energy-saving traction system.

Has The Solution Worked On The Third-Rail Network?

The Railway People document goes on to outline how they solved various issues and judging by how little there is about regenerative braking on the third-rail network, I think we can assume it works well.

One Train, Two Systems

If you have a train that has to work on both the 25 KVAC and 750 VDC networks, as Thameslink and Southeastern Highspeed trains do, the trains must be able to handle regenerative braking on both networks.

So is there a better way, than having a separate system for each voltage?

In Do Class 800/801/802 Trains Use Batteries For Regenerative Braking?, I investigated how Hitachi’s new Class 800 trains handle regenerative braking.

A document on Hitachi’s web site provides this schematic of the traction system.

Note BC which is described as battery charger.

The regenerative braking energy from the traction motors could be distributed as follows.

  • To provide power for the train’s  services through the auxiliary power supply.
  • To charge a battery.
  • It could be returned to the overhead wires.

Hitachi’s system illustrates how using a battery to handle regenerative braking could be a very efficient way of running a train.

Hitachi’s diagram also includes a generator unit or diesel power-pack, so it could obviously fit a 750 VDC supply in addition to the 25 KVAC system on the Class 800 train.

So we have now have one train, with three power sources all handled by one system.

What Has Happened Since?

As the Hitachi document dates from 2014, I suspect Hitachi have moved on.

Siemens have produced the Class 700 train for Thameslink, which is described in this Siemens data sheet.

Regenerative braking is only mentioned in this sentence.

These new trains raise energy efficiency to new levels. But energy efficiency does not stop at regenerative braking.

This is just a bland marketing statement.

Bombardier are building the first batches of their new Aventra train, with some Class 345 trains in service and Class 710 trains about to enter testing.

Nothing has been said about how the trains handle regenerative braking.

But given that Bombardier have been experimenting with battery power for some time, I wouldn’t be surprised to see batteries involved.

They call their battery technology Primove and it has its own web site.

There is also this data sheet on the Bombardier web site.

Class 387 Trains

There is another train built by Bombardier, that is worth investigating.

The Class 387 train was the last and probably most advanced Electrostar.

  • The trains have been built as dual-voltage trains.
  • The trains have regenerative braking that works on both electrification types.
  • They were built at around the time Bombardier were creating the Class 379 BEMU demonstrator.
  • The trains use a sophisticated propulsion converter system called MITRAC, which is also used in their battery trams.

On my visit to Abbey Wood station, that I wrote about in Abbey Wood Station Opens, I got talking to a Gatwick Express driver about trains, planes and stations, as one does.

From what he said, I got the impression that the Class 387/2 trains, as used on Gatwick Express, have batteries and use them to keep the train and passengers comfortable, in case of an electrification failure.

So do these trains use a battery to handle the regenerative braking?

How Big Would Batteries Need To Be On A Train For Regenerative Braking?

I asked this question in a post with the same name in November 2016 and came to this conclusion.

I have a feeling that using batteries to handle regenerative braking on a train could be a very affordable proposition.

As time goes on, with the development of energy storage technology, the concept can only get more affordable.

Bombardier make a Primove battery with a capacity of 50 kWh, which is 180 mega-Joules.

So the braking energy of what mass of train could be stored in one of these batteries?

I got these figures.

  • 100 mph – 180.14 tonnes.
  • 110 mph – 148.88 tonnes.

What is the mass of a Class 387 train?

This is not available on the Internet but the mass of each car of a similar Class 378 train averages out at 32 tonnes.

Consider these points.

  • A Class 387/2 train, has 219 seats, so if we assume each passenger and baggage weighs eighty kilograms, that adds up to 17.5 tonnes.
  • As the Class 387 trains have a maximum speed of 100  mph on third-rail electrification, it would appear that a Primove 50 kWh battery could handle the braking energy.
  • A Primove 50 battery with its controller weighs 827 Kg. according to the data sheet.

It all looks like using one of Bombardier’s Primove 50 batteries on a Class 387 train to handle the regenerative braking should be possible.

But would Bombardier’s MITRAC be able to use that battery power to drive the train in the most efficient manner? I suspect so!

If the traction layout is as I have outlined, it is not very different to the one published by Hitachi in 2014 on their web site for the Class 800 train.

Conclusion

Hitachi have got their traction layout right, as it can handle any number of power sources.

 

 

October 26, 2017 Posted by | Travel | , , , , | 2 Comments

OVO Offers Solar Panels And A Battery

There are a couple of reports on the Internet, that the smaller energy supplier; Ovo Energy, is now offering deals on solar panels and a battery.

I have been thinking of adding a battery for some time, but I don’t think the time is quite right yet, as the price of batteries is becoming more affordable.

However, I do think that Ovo’s move is the first of many we will see in the next few months and years.

This march towards solar and batteries could have various consequences for the UK.

  • Many house builders will add solar panels and a battery to new houses.
  • Domestic electricity needs will reduce.
  • Solar panels and batteries may have some interesting effects on the property market.

Battery owners could also charge up overnight on low-price electricity, so the daily operation could be something like.

  • Overnight the battery is charged on low-price electricity.
  • Morning ablutions and breakfast, thus uses low-price electricity.
  • Hopefully, the sun charges the battery during the day.
  • Evening electricity would in part be what has been stored during the day.

One overall effect of the battery is to smooth the energy needs of a property.

So as the proportion of houses with batteries increases, the National Grid will see a reduction in the spikes of electricity demand, as evetybody makes a cup of tea in the advert breaks.

But the biggest effect will be on how the UK would generate its electricity.

I am not against nuclear power for any technical or environmental reasons, but I do think that the cost of new nuclear power stations like Hinckley Point C are not good value for money compared with other methods of generation. On the other hand, if we are going to have much smoother electricity needs, then we do need the nuclear power station’s ability to produce a steady baseload of power.

I am against inappropriate on-shore wind in many locations, but I am not against off-shore wind or perhaps a few large turbines in an industrial estate.

I feel that solar, batteries and off-shore wind could give the UK very affordable electricity, but they need to be backed by some form of baseload power stations, which at the moment can only be nuclear.

Conclusion

Following my logic, I believe, that as more batteries are installed in the UK, the following will happen.

  • Those who install a battery will save money whether they have solar panels or not!
  • Batteries will be allowed to be charged on low-cost overnight electricity.
  • As more batteries are installed in the UK, the UK power needs will be smoother.
  • Overnight off-shore wind could be used to charge all these batteries.

This leads me to the conclusion, that the Government should create incentives for homes to install batteries, which would be charged with low-cost overnight electricity or solar panels.

October 7, 2017 Posted by | World | , , , , , | 1 Comment

CAF Secures Tram Contracts In The United States

The title of this post is the same as this article in Global Rail News.

The sale of two batches of trams is not that remarkable, but this is an extract from the article, about the vorder for Seattle.

The trams will have a 100 per cent low floor and come with onboard energy storage to run on catenary-free sections of the network.

Trams with these characteristics are becoming increasingly common.

October 4, 2017 Posted by | Travel | , , | Leave a comment