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Post by Nathan on Apr 8, 2019 12:05:20 GMT
I have a few questions about these 'smart' hybrid buses that have been gaining popularity recently since last year.
How exactly do these buses work? I've sampled the E400 models on the 136 a fair few times since entering service. To me, the buses sound like they just have start-stop technology implemented. That doesn't really sound 'smart' to me, seeing as this type of thing has been around for years in cars.
Are smart-hybrids better than normal hybrids? In the case of the 54/75 due new buses soon, are these routes essentially getting a downgrade?
One more question: Are smart hybrids the same as micro-hybrids? If not, then what's the difference?
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Post by Eastlondoner62 on Apr 8, 2019 12:09:02 GMT
You can certainly hear a difference between the Smart Hybrids and diesels, although it'll probably be more prominent where you have a load of E40D MMCs and Smart MMCs operating side by side.
Essentially the electricity generated by the bus from braking is used on everything else except propelling the bus forward, this means the engine has far less work to do, even though in theory this might not sound quite as good it does apparently give the engine far less work to do and therefore emitting less pollution. The Batteries are also capacitors which are capable of charging and discharging charges quickly and will last the life of a bus, or at least far longer than batteries do.
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Post by busoccultation on Apr 8, 2019 12:49:16 GMT
The Smart Hybrids cost about £100k less per bus compared to a regular E400H hybrid bus so they are significantly cheaper to buy in the first place and Smart Hybrid is actually a name for Micro Hybrids that ADL use on their products.
In terms what they like sound like, whenever it pulls way the Smart Hybrids sound similar to a standard Euro 6 diesel E400 MMC, but once it starts accelerating the Smart Hybrids makes whining noise and that is point where you'll notice the difference between the Smart Hybrids and the other versions of the E400 MMC.
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Post by Nathan on Apr 8, 2019 13:01:16 GMT
You can certainly hear a difference between the Smart Hybrids and diesels, although it'll probably be more prominent where you have a load of E40D MMCs and Smart MMCs operating side by side. Essentially the electricity generated by the bus from braking is used on everything else except propelling the bus forward, this means the engine has far less work to do, even though in theory this might not sound quite as good it does apparently give the engine far less work to do and therefore emitting less pollution. The Batteries are also capacitors which are capable of charging and discharging charges quickly and will last the life of a bus, or at least far longer than batteries do. So if we take the E40H with a super-capacitor for example, would this not still be cleaner than a smart hybrid? |
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Post by Nathan on Apr 8, 2019 13:02:24 GMT
The Smart Hybrids cost about £100k less per bus compared to a regular E400H hybrid bus so they are significantly cheaper to buy in the first place and Smart Hybrid is actually a name for Micro Hybrids that ADL use on their products.
In terms what they like sound like, whenever it pulls way the Smart Hybrids sound similar to a standard Euro 6 diesel E400 MMC, but once it starts accelerating the Smart Hybrids makes whining noise and that is point where you'll notice the difference between the Smart Hybrids and the other versions of the E400 MMC.
Do you know if the Streetdecks on route 25 micro-hybrids too? Similar to the ones found on route 44) |
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Post by rif153 on Apr 8, 2019 13:24:26 GMT
The Smart Hybrids cost about £100k less per bus compared to a regular E400H hybrid bus so they are significantly cheaper to buy in the first place and Smart Hybrid is actually a name for Micro Hybrids that ADL use on their products.
In terms what they like sound like, whenever it pulls way the Smart Hybrids sound similar to a standard Euro 6 diesel E400 MMC, but once it starts accelerating the Smart Hybrids makes whining noise and that is point where you'll notice the difference between the Smart Hybrids and the other versions of the E400 MMC.
Do you know if the Streetdecks on route 25 micro-hybrids too? Similar to the ones found on route 44) As far as I'm aware, the 25's Streetdecks are micro-hybrids |
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Post by redexpress on Apr 8, 2019 13:37:54 GMT
Are smart-hybrids better than normal hybrids? In the case of the 54/75 due new buses soon, are these routes essentially getting a downgrade? One more question: Are smart hybrids the same as micro-hybrids? If not, then what's the difference? So if we take the E40H with a super-capacitor for example, would this not still be cleaner than a smart hybrid?
Smart hybrid is pretty much just another name for a micro-hybrid. The technology may be a bit better than early micro-hybrids, so perhaps the marketing people decided it would be better to come up with a new name. But they're essentially the same thing.
In terms of emissions a smart / micro hybrid will not be as clean as a proper hybrid, so in that sense the 54 and 75 are getting a downgrade. If you look at the whole life costs of a proper hybrid the picture may well be different - is the improvement worth the extra cost? Is the environmental cost of producing and disposing of the batteries worth it? I don't know the answers to these questions but it might not be straightforward to say that one type is better than the other.
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Post by 15002 on Apr 8, 2019 13:44:22 GMT
Do you know if the Streetdecks on route 25 micro-hybrids too? Similar to the ones found on route 44) As far as I'm aware, the 25's Streetdecks are micro-hybrids I thought they was full on hybrids. |
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Post by Londonbuses54 on Apr 8, 2019 13:57:24 GMT
You can certainly hear a difference between the Smart Hybrids and diesels, although it'll probably be more prominent where you have a load of E40D MMCs and Smart MMCs operating side by side. Essentially the electricity generated by the bus from braking is used on everything else except propelling the bus forward, this means the engine has far less work to do, even though in theory this might not sound quite as good it does apparently give the engine far less work to do and therefore emitting less pollution. The Batteries are also capacitors which are capable of charging and discharging charges quickly and will last the life of a bus, or at least far longer than batteries do. They still do have an electric propulsion, but the main driveline being diesel. These are only 48 volts, whereas 96 volts are normal hybrids (E400H) |
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Post by Eastlondoner62 on Apr 8, 2019 13:58:49 GMT
As far as I'm aware, the 25's Streetdecks are micro-hybrids I thought they was full on hybrids. An Easy way to tell the two apart is that initially full Hybrids require extra space somewhere on them to cater for the batteries which usually results in a layout change as opposed to the diesel or Micro-Hybrid variants. Another way to tell is that Micro-Hybrids cannot pull away under their own electric power at all, so when stop start kicks in on Micro Hybrids the engine will start before the bus pulls away as opposed to it starting up while the bus being on the move. |
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Post by snowman on Apr 8, 2019 14:00:51 GMT
As far as I'm aware, the 25's Streetdecks are micro-hybrids I thought they was full on hybrids. No, micro hybrids. The hybrid system is much smaller and is primarily used to power auxilaries (the electric items, eg lights, fans, blind motors, etc) by using braking energy (which would otherwise be wasted as heat in friction brakes) to power alternator to charge up small electric storage device (batteries or capacitors). Some can use some of this stored energy to give a short boost to the drivetrain during acceleration, as there is an electric motor (the same one that is used as an alternator during braking, by electrically switching its circuits). This boost is quite short (something like 20 seconds max) Micro hybrids are basically diesel buses, the diesel fuel saving is nearer 6-11% (depending on how frequent braking and acceleration is) whereas a full hybrid saves about 24-30% fuel compared to a normal full diesel |
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Post by rhys on Apr 8, 2019 15:11:16 GMT
I thought they was full on hybrids. No, micro hybrids. The hybrid system is much smaller and is primarily used to power auxilaries (the electric items, eg lights, fans, blind motors, etc) by using braking energy (which would otherwise be wasted as heat in friction brakes) to power alternator to charge up small electric storage device (batteries or capacitors). Some can use some of this stored energy to give a short boost to the drivetrain during acceleration, as there is an electric motor (the same one that is used as an alternator during braking, by electrically switching its circuits). This boost is quite short (something like 20 seconds max) Micro hybrids are basically diesel buses, the diesel fuel saving is nearer 6-11% (depending on how frequent braking and acceleration is) whereas a full hybrid saves about 24-30% fuel compared to a normal full diesel The 25 has Streetdeck HEV96’s which are full hybrids. They have the capability of reverting back to micro hybrids if there is a fault with the EV system. |
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Post by Nathan on Apr 8, 2019 17:21:47 GMT
No, micro hybrids. The hybrid system is much smaller and is primarily used to power auxilaries (the electric items, eg lights, fans, blind motors, etc) by using braking energy (which would otherwise be wasted as heat in friction brakes) to power alternator to charge up small electric storage device (batteries or capacitors). Some can use some of this stored energy to give a short boost to the drivetrain during acceleration, as there is an electric motor (the same one that is used as an alternator during braking, by electrically switching its circuits). This boost is quite short (something like 20 seconds max) Micro hybrids are basically diesel buses, the diesel fuel saving is nearer 6-11% (depending on how frequent braking and acceleration is) whereas a full hybrid saves about 24-30% fuel compared to a normal full diesel The 25 has Streetdeck HEV96’s which are full hybrids. They have the capability of reverting back to micro hybrids if there is a fault with the EV system. They sure do sound like micro-hybrids though. What about the buses on the 44? |
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Post by Eastlondoner62 on Apr 8, 2019 17:49:18 GMT
The 25 has Streetdeck HEV96’s which are full hybrids. They have the capability of reverting back to micro hybrids if there is a fault with the EV system. They sure do sound like micro-hybrids though. What about the buses on the 44? Looking at this quote from RouteOne magazine It's 96 Volts, this is the standard Voltage for most full Hybrids. The HEV96 buses are said to be significantly cheaper, although Wright seem to not want to tell anyone how they actually work. The last time we heard significantly cheaper was when ADL release their Smart Hybrids. The second part of the quote says that it has Micro Hybrid technology  We should also take a look at the price, it's made to sound as if it barely costs more than the Diesel version and I don't see how they can economically make such a saving with full Hybrids. So talk about speculation! |
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Post by rhys on Apr 8, 2019 17:59:12 GMT
They sure do sound like micro-hybrids though. What about the buses on the 44? Looking at this quote from RouteOne magazine It's 96 Volts, this is the standard Voltage for most full Hybrids. The HEV96 buses are said to be significantly cheaper, although Wright seem to not want to tell anyone how they actually work. The last time we heard significantly cheaper was when ADL release their Smart Hybrids. The second part of the quote says that it has Micro Hybrid technology So talk about speculation! From what I understand, going off RouteOne's article, the Streetdeck HEV-96 utilises a parallel hybrid drivetrain, that can also utilise micro hybrid technology if there should be a fault with the HEV-96 system. “HEV-96 is a parallel hybrid system available in the StreetDeck and StreetLite. Two 75kW motor-generators are attached to opposite sides of the gearbox output shaft. They remove load from the engine when the bus starts from stationary,” “A further benefit is that if there is a fault with HEV-96, the bus can still be driven and complete its day’s work. It returns to being Micro Hybrid only,” Here's a link to the article, that gives a more in depth explanation. www.route-one.net/articles/Wrightbus_demonstrates_buses__fuel_saving_potential. |
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We should also take a look at the price, it's made to sound as if it barely costs more than the Diesel version and I don't see how they can economically make such a saving with full Hybrids.