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Post by Helmut Eller on Jul 26, 2012 19:47:20 GMT 9.5
Sam Shelton is offering an online course about energy: www.coursera.org/course/energy101In the FAQ he writes:
What are some surprising things I might learn about energy during the course?
A couple of examples are that building nuclear, wind and solar energy systems does not save any oil in the US.
Why would that be? Is that some peculiarity that only applies to the US? |
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Post by LancedDendrite on Jul 26, 2012 20:03:47 GMT 9.5
No, that's pretty standard for developed nations. Oil is primarily used for transportation energy requirements, not stationary electricity generation. You need EVs, electrified public transport and logistics to save oil.
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Post by anonposter on Jul 26, 2012 22:58:45 GMT 9.5
In the past back when oil actually was used for electricity generation building nuclear power plants did indeed save oil, but now that nuclear (along with methane) have replace oil in electricity making…
Still, reducing coal and methane use isn't a bad thing (and freeing up more methane for transportation use could also help reduce oil use, although only nuclear is really capable of doing that as wind and solar require the methane to back them up).
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Post by Helmut Eller on Jul 27, 2012 5:03:28 GMT 9.5
No, that's pretty standard for developed nations. Oil is primarily used for transportation energy requirements, not stationary electricity generation. You need EVs, electrified public transport and logistics to save oil. It probably depends on the assumed timeframe. It seems to me that electrified transport or synthetic fuels will not be widely used in the next 30 years, but in 50 years it could be quite common. |
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Post by anonposter on Jul 27, 2012 6:42:15 GMT 9.5
Transition to electric for public transport could happen quicker, just string up overhead along railway lines and switch from diesel (or whatever other combustible fuel) buses to light rail and trolleybuses.
Progress in electric cars has also gone rather well, they still aren't there yet but it isn't completely unbelievable that they'll be big in 30 years (they won't make up the majority of new car sales in ten years though, or at least I'd be very surprised if that happened).
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Post by LancedDendrite on Jul 27, 2012 13:23:57 GMT 9.5
Transition to electric for public transport could happen quicker, just string up overhead along railway lines and switch from diesel (or whatever other combustible fuel) buses to light rail and trolleybuses. There's a fair bit more to railway electrification than just string up wires on catenaries. For one, you need to install substations and buy new locomotives (for country rail, urban rail has become electrified already due to other factors). As for buses, they're already really efficient in terms of fuel consumption - hybrid buses are about the best you're going to do unless you're in the city and can afford to put up wires for trolleybuses. Light rail is a good solution and if executed correctly is a decent subway alternative in the inner city (tunnelling is expensive and energy-intensive). A better thing to do is to just focus on making really good public transport systems so that people don't use their highly-fuel-inefficient cars as much. |
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Post by QuarkingMad on Jul 27, 2012 14:49:08 GMT 9.5
Depends on how the nuclear, solar, and or wind calculation is summed up. Thinking how the Dept. Resources, Energy, and Tourism do it here in Australia it's done in PJ and covers the whole system, not just electricity generation. While it may cover some (elec. gen.) it may not cover the entire system. It's not a good measure considering the primary objective of Nuclear is electricity generation (steam generation), and Oil's is as a fuel for many engines.
However Nuclear does replace Oil in electricity generation, look at France's main sources before 1973 (Oil), and after 1973 (Nuclear). That's on production only, physically there can be cases where relative new plants are mothballed for depth of security in supply.
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Post by anonposter on Jul 28, 2012 4:33:11 GMT 9.5
There's a fair bit more to railway electrification than just string up wires on catenaries. For one, you need to install substations and buy new locomotives (for country rail, urban rail has become electrified already due to other factors). True, but the infrastructure cost is the big one (and you can still run older diesel locomotives and multiple units under the wires until you get around to replacing them or converting them (I understand Adelaide is going to be converting most of the poxboxs to electric)). As for buses, they're already really efficient in terms of fuel consumption - hybrid buses are about the best you're going to do unless you're in the city and can afford to put up wires for trolleybuses. Light rail is a good solution and if executed correctly is a decent subway alternative in the inner city (tunnelling is expensive and energy-intensive). I'd view light rail as more a bus alternative (higher infrastructure costs, but lower recurring costs). Of course it turns out that the dominant determinant of costs is how much you separate your right of way. Brisbane's busways are very separate from car traffic but also not all that much cheaper than they would have been had they just gone with light rail (though maybe they could have saved some money not designing for possible conversion to light rail). A better thing to do is to just focus on making really good public transport systems so that people don't use their highly-fuel-inefficient cars as much. That is a good idea although you need to get people to actually ride it (a bus carting around air all day long isn't very fuel efficient). It seems that if you want public transport to be anything other than a welfare service you must have dedicated right of way which could be anything from a bus lane that's actually enforced to a rail tunnel. |
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Post by proteos on Jul 28, 2012 7:56:26 GMT 9.5
There's another area where nuclear can save some oil: it's with electrical heating. This will not be all savings of course: as electrical heating will add to seasonnal consumption, part of it will be provided by fossil fuels. On the other hand, all refineries output at least some fuel oil, so you can't totally get rid of it. But it can work up to a point. For example, german households use 40% more fuel oil on average than the french households (per household). (Source is this eurostat table) But as the others have said, most of oil is now consumed in the transportation sector where liquid fuels reign supreme. There are exceptions like Saudi Arabia, of course. |
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Post by LancedDendrite on Jul 28, 2012 15:29:54 GMT 9.5
(I understand Adelaide is going to be converting most of the poxboxs to electric)). They've cut back on that - they're only electrifying the Noarlunga/Seaford line and suspended the Gawler and Outer Harbor electrification works for the present time. Bit of a pity, but such is politics. I'd view light rail as more a bus alternative (higher infrastructure costs, but lower recurring costs). Depends on the situation. Trams/streetcars are inner-city bus alternatives. With some traffic separation works and proper stops (see Melbourne) they can be a subway substitute. Light rail is different to streetcars - the rollingstock is similar but the emphasis is on a longer distance between stops, grade separation from traffic, higher speeds and more passengers per Light Rail Vehicle. They're better as heavy rail alternatives, where you don't want to invest heavily in civil works and need to serve less passengers than a proper heavy rail line. They can also work as logical follow-ons to Bus Rapid Transit systems. It seems that if you want public transport to be anything other than a welfare service you must have dedicated right of way which could be anything from a bus lane that's actually enforced to a rail tunnel. Arguably you don't need to grade separated rights-of-way to increase patronage. What you need is a properly integrated, well-thought-out public transport system. That means: - Services that connect with each other properly (synchronised timetables and the like)
- High service frequencies so that people don't have to plan their day around catching the right train/bus/tram
- Integrated ticketing systems and service information across a region
Grade separated rights-of-way helps with only one of those requirements - improving service frequencies. Granted, not all of those points have equal merit but you will need all of them to have a PT system that works. |
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Post by max on Jul 28, 2012 17:17:26 GMT 9.5
Another option to get around which is often overlooked are long-distance sleeper trains. They don't even need to be that fast, just comfortable and not too pricey.
Get on the train in the evening, sleep and arrive at your destination in the morning, well rested. You don't waste daytime traveling and you protentially don't even need to book a hotel room.
I suppose that with dramatically rising oil prices, sleeper trains could replace planes on at least some medium-distance routes. Point-to-point high speed sleeper trains could even go two thousand km in one night, if an appropriate network is in place.
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Post by anonposter on Jul 29, 2012 7:31:24 GMT 9.5
Another option to get around which is often overlooked are long-distance sleeper trains. They don't even need to be that fast, just comfortable and not too pricey. Australia already has them on the Melbourne to Sydney route and their almost never actually used for capital to capital transport (those trains tend to empty out at Wagga and then fill back up as they are mostly used by people from the regional cities to get the nearest capital). Of course probably the biggest problem with those trains is the lack of single berths. The same trainsets are also used for the Sydney to Brisbane route though they only travel one way at night (and are sitting trains the other way). Other than that there is also The Ghan and the Indian Pacific which offer sleeper service though those are luxury trains that basically no one uses except as part of a holiday to see the outback (they take days to cover the distance) as well as the Sunlander which is also mainly used for holidays (though with plans to replace the current locomotive hauled train-set with a tilt train (which will also have sleeper cars)). As for how the costs are now (and this will likely explain why almost no one from each capital uses the Melbourne–Sydney train): For departing Melbourne 30 August and returning 02 September with 1 Adult I get $216.30 for the Melbourne–Sydney trip in a sleeper and $243.80 for the Sydney–Melbourne leg. Meanwhile Qantas are offering me $133 (or $89 if I take a Jetstar flight) to get there and the same price back (and there are many flights to choose from). Virgin are offering $109 to Sydney and the same back (assuming I order now). Even economy (which is just seats) on the train is $91.18 there and $110.72 back so it's really quite hard to justify taking the train (of course if it were a last minute booking the cheap airfares wouldn't be available, but last minute bookings are typically for business and who really cares what their company pays? or are for family emergencies in which case the airlines will often offer a compassionate fare). Though Greyhound are offering $79.04 each way. Taking the car the Hume highway is 874 km long and if your car has a 10 L per 100 km highway fuel consumption (which is I think above average for Australia, even the Land Destroyer does better than that) you'll use 87.4 L of petrol, the Australian Institute of Petroleum gave an average retail pump price of Unleaded of 143.8¢/L over the past 12 months which gives $125.68 in fuel to drive. With the 3.7 L per 100 km of the Pious it would be $46.5 in petrol (so if you have a Pious you may well be better off economically driving than flying, unless of course you've got to book a motel room at Gundagai or somewhere). Back when the government was pricing fixing the domestic air travel market in Australia (i.e. banning the airlines from offering the cheap fares they offer now and requiring that regional services be subsided by intercapital services) sleeper trains managed to do pretty well, once airline deregulation happened patronage on the intercity trains dropped (the old niche they served was for those who couldn't afford to fly but didn't want to drive the whole way). Get on the train in the evening, sleep and arrive at your destination in the morning, well rested. You don't waste daytime traveling and you protentially don't even need to book a hotel room. The idea has it's attractions, though for Melbourne–Sydney and even Melbourne–Brisbane you could do there and back in the same way with the plane (the airlines fly frequently enough for it). I suppose that with dramatically rising oil prices, sleeper trains could replace planes on at least some medium-distance routes. Depends on how high oil gets to, synthetic fuels will in the long term put a price ceiling on oil and if synfuels are cheap enough aviation will likely continue without much change (just more efficient planes, likely increase in plane sizes for long distance routes). It does seem that if you want the train to compete with the plane you need to be able to do the trip in about 3 hours or so (a 1 hour plane trip is usually about 3 hours total due to the airports being out of the city centre and needing to go through security) and over the kinds of distances planes are typically used this means high speed rail (and in Australia I can't see any compelling case for high speed rail, though a Melbourne–Sydney via Canberra line could largely replace air travel between those three cities, personally I suspect it'd only be justified to relieve congestion at Sydney airport instead of a new airport and not on its own merits). Point-to-point high speed sleeper trains could even go two thousand km in one night, if an appropriate network is in place. I'd wait until we've got high speed rail on the shorter routes where it might compete with a plane on day trips (in Australia this is Melbourne–Sydney via Canberra and probably Wollongong and Albury, Sydney–Brisbane (presumably via the Gold Coast and Newcastle and Melbourne–Adelaide)) before trying to make such a long line (Sydney–Perth built to high speed standard will not be cheap). I'd also upgrade the existing freight lines to allow for faster tilt trains to be used for passenger services (most of the upgrades are probably things that should be done anyway to improve freight performance, something we shouldn't underestimate). |
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Post by Rodger on Dec 16, 2013 6:23:30 GMT 9.5
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Post by jimbaerg on Dec 17, 2013 7:16:55 GMT 9.5
Up the thread I notice that "LancedDendrite" said
"There's a fair bit more to railway electrification than just string up wires on catenaries. For one, you need to install substations and buy new locomotives."
Can anyone tell me what the difficulties are with adding a pantograph to a diesel electric locomotive & only burning the diesel fuel on the sections of rail with no overhead wires?
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Post by David B. Benson on Dec 17, 2013 11:26:33 GMT 9.5
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Post by Roger Clifton on Dec 17, 2013 20:53:30 GMT 9.5
Ahem. On a fully electrified line, a train that never stopped would have particularly low power consumption. True? Okay... A motorised carriage could accelerate away from a station as the train approached, to dock at speed, open up and let its passengers through to the interior. The train would have picked up its passengers without stopping. Similarly, it could drop off its passengers without stopping. Much of the power for the accelerating carriage might be regenerated from the deceleration of a just-previously disconnected last carriage, as it slows to stop at the station just passed. Like grandfather's axe, the train changes all its passengers and carriages, while its through-service continues non-stop. It also offers a remarkably fast commute, because passengers would stay in the continuing carriages until it is time for them to enter their selected last carriage and be delivered – express – to their destination station. Such an "all-stops-express" wouldn't keep you standing in it for long as it would cover 30 km in only 20 minutes or so. PS. Heath Robinson (~1942) caricatured the use of an army of brakemen to slip unpowered goods wagons from overloaded wartime trains. As Ed Ireland points out, slipping of (goods) wagons is traditional, the brakeman "riding the brake" into a siding after throwing the points. Brakemen had a time-honoured occupation, but in the vision above, the train and its carriages would be driven remotely. |
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Post by edireland on Dec 18, 2013 23:39:11 GMT 9.5
This is called a 'slip carriage'.
It was done for a long time but the advent of ultra high power multiple units that can accelerate for a long time has rendered them pointless.
Additionally their are safety implications, which is why they were never used for joining trains, only ever for leaving them.
Trains can now do 0-170mph in under 3 minutes, which sort of eliminates much of the time saving.
In japan trains cover 30km in ten minutes stop to stop on the Shinkansen.
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Post by trag on Jan 30, 2014 3:05:55 GMT 9.5
Well, during the cold snap, Vermont is once again burning oil for electricity generation. So, nuclear could reduce oil consumption there. I imagine their oil burning will be even large during the next winter with a cold period, given that Vermont Yankee will no longer be available on the grid.
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Post by eclipse on Feb 9, 2014 19:39:36 GMT 9.5
Trolley buses are my pick for an emergency deployment of public transport for the following reasons. - Can be hybrid electric and synfuel, allowing them to go ‘off the line’ and service side streets.
- Do not require the installation of rail, which will only slow down the process of moving off oil in a hurry
- Require rail in the roads, which can be a hazard to cyclists and pedestrians tripping
- Are stuck if there is an obstacle on the rail ahead, while hybrid or battery trolley buses can leave the line and simply drive around the obstacle
- Trolley buses are 5 times cheaper
- www.lowtechmagazine.com/2009/07/trolleytrucks-trolleybuses-cargotrams.html
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Post by Roger Clifton on Nov 9, 2014 16:02:35 GMT 9.5
It seems that there is currently no heavy duty process to add nuclear energy to (hydrogenate and polymerise) CO2 into output transport fuels. At least, none more efficient than the century-old Fischer-Tropsch process. Such a process might have to evolve from modern-day fuel refineries. Seeing as a big refinery throughputs about 10 GW of chemical energy while using ~2 GW of it for heating and hydrogen, it would seem a logical entree for nuclear to join in by replacing that 2 GW. Jagdish has looked further forward, to a future using nuclear steam to hydrolyse coal (below) or biomass ( above). Further to that vision, nuclear can also provide high pressures, so that hydration would result in heavier polyols rather than C1 and C2 compounds. Energy density could be raised too: nuclear electrolysis could remove the oxygen from the hydrated product, effecting hydrogenation. Taking a charitable view of coal, it may become possible to carry out underground hydrous pyrolysis of coal using nuclear steam, adding energy to it without creating dust. The chemicals formed in the process particularly hydrocarbons, alcohols, aldehydes and ketones could be taken out as vapors, condensed, and used for various purposes including fuel.
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