This is Thomas Pedersen's Typepad Profile.
Join Typepad and start following Thomas Pedersen's activity
Join Now!
Already a member? Sign In
Thomas Pedersen
Recent Activity
I positively loathe low-floor buses, including in particular the Mercedes Citaro. The interior is cramped and like a 3D maze. In winter operation with huge jackets and school bags, it is nearly impossible to get around. The windows are so high that your elbow is below the window sill. This sounds like a minor thing but is actually a major inconvenience and space- and comfort-reducing factor. Having the elbows, which is typically the widest point of the body of a person, above the window sill effectively gives 2'' extra seating width. If the buses didn't have to be low-floor, you'd naturally place all the heavy, bulky equipment low, improving the handling of the bus and the serviceability. I'm wondering why a 12 tonne bus should have less power than a Tesla..? A bit more zip to the buses (with CPU-controlled acceleration profile to minimize the jerkiness of the bus) would improve their operation and adapt better to the other city traffic.
Mahonj, In the US, you see very little container trucking. For two reasons, I suppose: 1) This trailer holds a lot more than a 40' container 2) Trucking distances can be very high, with up to 2000 km from the ocean For hauling from shipping port to central storage in the middle of the country, this truck would be great. For delivies to a multitude of customers, it may lack too much in practicality. P.S. All refer trailers should be fitted with solar panels. Installation cost should be negligible in a factory.
What's under the hood? Literally! Bla bla fifth generation bla bla fresh package of technology bla bla. "We lowered the floor of an X3 to make space for the batteries, and then we have half a cubic meter of unused space under the hood where the gas engine used to be." 400 km range from a 70 kWh battery with that bodyshape..? HA!
Brian P., Good analysis. A quick glance at the system architecture sketch shows that roughly 5 times more battery volume could be put in place, provided that they are taken into account sufficiently early in the engineering. This boosts the claim of many, including myself, that vans and trucks are actually better equipped to accommodate an adequate battery pack than passenger cars.
Looking at the rendering and photo it appears that they could fit twice as much battery volume with only minor tweaks. But I respect the choice to custom-fit batteries to a tried and tested platform to gain experience. They could have installed a little more motor power to make it more nimble in the city, and to recover more brake energy. But again, it appears they went with tried and tested components. The good news is that the next iteration/generation will definitely be better!
Aren't we approaching a situation where it is much cheaper to increase the size of the battery pack by 3.5% than so use such advanced materials? Seriously, I foresee a situation where bulk energy production (kWh) by wind or solar becomes so cheap that you'd rather install more solar panels on the roof than tear out the interior of your house to improve insulation. The same could be true for BEV's, considering that much of the stored kinetic energy of cars in motion can be recovered with high efficiency. For ICE cars, however, vehicle weight savings are very important.
Lad, It just so happens that VW have been quite clear about when we can expect output from their MEB platform. And they even provide regular updates. I believe the expected delivery of first vehicles is early 2020 or late 2019. The first cars will, if memory serves me, by I.D. Concept, probably slated for the European market. As many others, VW have realized that the only way to make a proper BEV is with a skateboard configuration with a rectangular battery pack at the bottom, below the cabin. However, this is totally different than all their other cars. The way VW have set up their organisation, and is able to achieve low cost of production, is by engineering these platforms, that run through all their sub-brands as well (Audi, Seat, Skoda, mainly), a process that takes years. It's German thoroughness in its essence and in their DNA. The opposite of Tesla, if you will (fast, agile, burn the old crap down!). This platform strategy also means that they can make more than 10 different cars (not including intra-model variations) on the same production line, at the same time. This enables fast response to consumer demand, at least within their planned product line ;-). The fact that the new model is cheaper than the outgoing can likely be attributed to its use of the MQB platform. Much to the dismay of many readers in this forum, most people still buy gas cars. It can hardly come as a surprise to anyone that VW taps into this market where they are, if I'm not mistaken, at least in the top three global suppliers. This Jetta update can not be seen as a divestment from BEV; but more like inertia. They can only have so much talent working on the MEB platform, I.D., I.D. Buzz, I.D. Crozz, etc. at one point in time. The rest, most with different skill sets, keep updating the ICE cars.
EP, Of course, V2G can't soak up a week's worth of energy demand. However, the storage demand is much less than the energy demand, because all renewable energy sources do not drop to zero for a week. In my country the average house-hold power demand is roughly 10 kWh. It's not too far out to assume that BEVs 10-15 years from now will average a capacity on the order of 100 kWh, of which perhaps 20-30% can be used by the power utility company for storage, given the right incentives. I guess I also left out the assumption that it will become more feasible to shift electricity consumption in time to catch most of the daily swings. A/Cs for instance could be fitted with cold storage to make the most use of cheap solar power in the middle of the day. Yes, that would require a larger compressor and higher power draw, making it particularly well suited along with solar panels on the roof. There are many options to time-shift energy consumption for change-of-temperature use on the time-scale of hours. But then again, this might never happen because the house A/C constitutes a trivial power draw from a 100 kWh battery. No doubt, going 100% (more likely 90%) renewable is much easier in Europe with denser population and better power grid. The giga-Watts that need to be moved has to move less distance and can be paid for by more people, using less electricity than in the US. There is a techno-economical optimum between moving electricity from cloudy to sunny places and simply storing electricity locally for the period it takes the sun to come back. Btw, Audi is doing the same P2G scheme to off-set the consumption of their compressed gas cars. Here we're really talking greenwashing because here the purpose is to count those vehicles as zero-emission (CO2) to enable sales of more A8 gas guzzlers without the European fleet average.
SJC, A move like this, especially in France, is not driven by large commercial interest, or because there is a belief that synthetic methane will become cheaper than fossil methane any time soon. Instead - in my view - it is driven by a belief that once synthetic methane has been demonstrated at a reasonable cost and with a path for further cost reduction, it will pave the way for a ban of fossil natural gas and move to synthetic nat gas for those consumers remaining. It also doubles as an effective measure to get out from under the natural gas thumb of Putin or whomever succeeds him. Don't forget, the Paris agreement was signed in France ;-) So they better do something about it. Contrary to the US, there is an actual political will to do something about anthropogenic greenhouse gas emission in Europe. For a gas company, this is also the natural way to go to 1) hedge your bets, and 2) stay relevant in a market where wind a solar dominate all new capacity being installed. The world (or at least Europe) will need hydrocarbons as fuels for some processes (air planes) and as long term (seasonal and year-to-year) backup and storage of energy with near-100% renewable energy generation in the coming decades. V2G will most likely soak up all energy storage demand for up to a week or so, once large-scale adoption of BEVs kick in. But for longer time-scales, I have seen no substitute for hydrocarbons, yet, in terms of storage-able, deploy-able energy source.
I have a 325d with the same engine, only double turbo (a small and a large working in parallel). It's not even once a month that I get above 3,500 rpm. Many days I don't even break 2,500 rpm. Pollution above 3,500 is a non-issue. If you spend more than a few seconds at those rpms, you're driving your diesel engine wrong! That said, there might still be a defeat device in there somewhere.
Prediction: More than half of the passengers of these vehicles will be people who would otherwise use public transport or bikes. The concept of having to install an app means that you first have to know that you have to install that app and learn to use it. That means: young people and/or people who already use a slew of public transport apps. Only two things can drag me out of the comfort of my own car (at least presently): Hassle finding a parking space and wanting to have more than one drink before going back home. Other than that, the mini-bus looks cool! Great for airport shuttle service. PS: the seats are shaped for young, fit bodies... I think they know already.
I think it's relevant to point out, regarding average gas mileage that the user has a great influence as well. I average 15-20% better gas mileage than my wife, despite driving faster, because I understand the physics of the driving and the combustion engine. Sticking to speed limits also helps (a lot). Or so I've been told ;-) And it's OK to maintain enough distance to the car in front to not have to brake all the time, when it reduces its speed a bit. I have a 4-cyl BMW 325d (the one with a small and a large turbo working in parallel) with, I suppose, an inflated NEDC rating. However, if I stick to the speed limits, drive in ECO PRO mode and avoid a greater fraction of city driving than in the standards, I can almost reach the advertised value. However, I can also make it use twice as much fuel. Easily! To me it's fair that fuel economy ratings reflect what a trained driver can achieve with predictive driving. It's obviously not OK to tweak all other parameters like car weight, taping over openings, tire pressure, and all those other tricks they play before they resort to outright fraud.
I haven't been to Toronto but if it's anything like in the US, I'm not surprised by the conclusions of the study. When I first visited the US, I was appalled by the noise level everywhere. From construction trucks sounding like they had no muffler, to clanging steel wheels (hint: air suspension works wonders with isolating the noise and not having the steel car work as a loudspeaker), to droning A/C's everywhere. The dishwasher sounded like it was tumbling the dishes, while the ones we bought in Europe at the time were marketed with noise level (around 45 dB at the time) as one of the main selling points. The buses had extremely loud engines with a horrendous straining sound. But I guess it was a little cheaper than getting noise down to a decent level...
I'd venture that 80 km/h (50 mph) top speed is outright dangerous... Why the sudden regression back to under-powered golf-cart capacity? Less power than a Nissan Leaf. About the same capacity in a vehicle way more expensive and with 2-3 times higher Wh/mile usage. I am seriously underwhelmed. And this is coming from a non-Tesla-fanboi, who usually defends German auto makers for their late entrance to the party.
GT's are nice, but have some drawbacks: - Not dual-fuel; no HFO capability - Failure-prone gearbox (direct propeller drive simple and efficient) - Expensive and difficult service (large-bore engines can close-out individual cylinders and can largely be serviced by inexpensive labor) - While the GT is compact, the waste heat recovery unit (WHRU/HRSG) is quite large - Steam turbine = more components to fail Large-bore diesels get ~50% efficiency, which would be hard to better significantly in a small CCGT configuration with tropical sea water.
When you are at the top and have the best-seller, you don't need to disrupt yourself - just follow the market. BYD, Proterra, et al could not make ordinary diesel buses and expect to compete with the established players. Therefore - or for other reasons - they create something new. MB has been able to make this all along, they just didn't have any reason to. Technically, converting a diesel bus into a battery-powered bus is at least an order of magnitude less difficult than converting and ICE car into a BEV (hint: space for batteries, and market requirement for range, vs. actual range driven between charges). The commercial side is a little less straight-forward, since development costs can be recouped over a number of vehicles two-three orders of magnitude less than battery powered cars. However, buses are often under political influence, so a city can specify that only battery buses need submit tenders, regardless of the CAPEX/OPEX split compared to diesel buses.
There is no space available to install equipment to utilize the exhaust impulse right out of the exhaust valve, which is why the effort is reduced to recover the kinetic energy as pressure ('gentle' slowdown) before the turbine of the turbo. A multi-cylinder marine diesel has an exhaust receiver with the express purpose of reducing the pulsating nature of the exhaust and turn it into a steady flow in order to increase the aerodynamic efficiency of the turbo charger (which has too much inertia to utilize the pressure pulses). Concerning sulfur content. Maybe you're right, but according to a refinery guy i heard, when I used to be in the 'utilize exhaust energy from marine diesels' business, it costs about the same to extract sulfur from heavy fuel oil (HFO) as it does to convert it to diesel + a pile of coke + a pile of elementary sulfur. And the latter combination has a much higher sales value. So right now, afaik, the strategy is to bunker HFO for ocean sailing and LGO (light gas oil - diesel) for near-shore sailing. But even without the sulfur in the exhaust, HFO has so much sticky, unburnt 'stuff' (all the accumulated crap from the oil field through the refinery) that clogging is a high risk below temperatures where anything (sulfuric acid or organic compounds) can condense. And, as refineries get more efficient in extracting all the valuable stuff, the remainder - HFO - gets worse. And the quality of the crude oil is also generally declining, because all the best oil was produced first. Note: Diesel (LGO) generally costs about twice as much as HFO
From the looks of it, this bike has at least two and probably three in-wheel motors. Should be quite the rocket when unloaded. Also, plenty of space for batteries under the cargo container. Good initiative. Although, biking in really cold weather is just no joy. It's fine, when the temperature is constant and you can dress for it. But stepping off the bike in 20°F and into a 68°F elevator will leave you sweating like the troops in Iraq! And if the stop is long enough, you could end up getting very cold when you come back to the bike. Factor in half an hour a day to go back for forgotten mittens...
I must say I question the motives of this request, since neither of the 'ideas' make any thermodynamic sense at all. TEG's have, what 1-3% efficiency (where the heat is lost at sink temperature), a factor of 10 lower steam generators. 'The kinetic energy of the exhaust gas'... Give me an F'in break! If the exhaust gas is moving at an unreasonable high speed of 30 m/s (100 ft/s), its kinetic energy is 292 J/kg, whereas the energy potential is 110,000 J/kg (by cooling 100 K to avoid sulphuric acid condensation and/or clogging from heavy fuel pollutants). And this kinetic energy could be 95% recovered by reducing its speed to 5.4 m/s (18 ft/s). Either some brainstorm was not filtered through someone who passes Thermodynamics 101, or they are pretending to do something about their emissions by throwing a hail Mary at 'some future development'.
In Phoenix and Houston it is probably correct that more CO2 would be saves by making the house (insulation + AC) more efficient, provided that the power comes from high-CO2 sources. However, I we are to do anything serious about climate change - and many other pollutants from energy generation - (nearly) all electricity production has to be switched to zero-emission sources within a couple of decades. That is why the transportation sector needs to electrify itself. Luckily, the power-hungry sun belt cities are also the easiest to switch to solar (and wind and nuclear), because of the concurrence of power production and demand. Also, here solar energy is fast becoming 'too cheap to meter'. Well, not quite, but prices are plummeting faster than most projected just a few years ago. Solar + cold (ice) storage for the A/C + batteries for lights, TV, etc. and you could practically go off-grid in those states (not that I recommend that). And you see clearly that a number of BEV's in the garage with a combined capacity of 2-300 kWh would dovetail quite nicely in this scenario. Making the A/C more efficient or installing more/better insulation will compete with the prospect of just installing more panels, with the incremental cost of adding another panel dropping daily. As much as I am personally in favor of energy efficiency, I'm just not sure it makes business sense in many cases with cheap, clean energy.
Very positive to see this kind of stream-lining and standardization of diesel-electric power trains and systems after a quite slow take-up in large parts of the bus industry. Should be a very short time now before the last diesel-only bus is sold for anything other than long-distance coaches.
Curious, 47% improvement is pretty darn close to exactly the improvement of both e-Golf and BMW i3 with the the same battery pack size...
When I'm pumping diesel, I have to stand there waiting in the 45° rain, because too many people were stupid enough to disconnect the nozzle before they drove off. With electrical 'fueling', I expect I can get back in the car and play games on my phone for 5-10 minutes, or go to the store, while leaving the car unattended, so I can drive 100-230 minutes more. Huge improvement!
There are some very, very good safety reasons to limit e-motor power to 250 W and cut-off speed to 15 mph/ 25 km/h. Mainly the safety of the other thousands of bike riders riding along side you: https://evolvetours.com/wp-content/uploads/2017/02/Biking-Copenhagen-Scandanavia.jpg Having the gear integrated into the drive unit is genious because it avoids the weight and complexity of rear wheel gears, whether an derailleur system (central motor) or planetary gear (usually with front wheel motor). This way both wheels become clean and easy to take on and off when you get a flat tyre. It also reduces the 'un-sprung' weight, in case of wheel dampers. 3.8:1 gear ratio is very respectable and should be plenty for everyone with up to 250 W assist.