Why isn't electricity cheaper?


#1065

They should have went with batteries not Hydrogen IMO

Dublin bus have just ordered 100 hybrid buses and will have over 600 in the next five years, but they also should have bought battery powered buses


#1066

Why batteries? Lower energy storage density, more energy required to manufacture (I think)

Hydrogen has its complications for private cars but for a bus fleet it’s ideal.


#1067

Yes its true that the energy density is lower, but in the case of double decker buses you need a lot weight low on the bus anyway, so in this case batteries are perfect, the extra energy needed to manufacture the batteries will be offset very fast in a high energy application like a city bus

I suspect the lads in Dublin and Belfast know this, but right now the Chinese are leading in battery electric buses, maybe they are trying to give their usual suppliers time to develop a pure EV option


#1068

Wait till one of them explodes in an area with lots of glass - e.g. London/Dublin docklands. I’m speculating that after such an event the insurance on them will increase exponentially. Hydrogen goes boom in a markedly more attention getting way.


#1069

Battery-only buses are not very practical yet. The equivalent of a Nissan Leaf battery would propel a Dublin bus for just over one kilometre. The hybrid-electrics that Dublin bus have ordered are pretty smart – the 2.5 km electric range can be used in the most built-up areas to reduce local pollution. It has all the other benefits of diesel electric efficiency and regenerative breaking.

The hydrogen option is even lower emission and also uses renewable energy that might otherwise be stranded / curtailed. Hydrogen is a way to increase the penetration of wind power without additional strain on the grid infrastructure. The initial numbers are puny though. The Energia 500kW electrolyser is only a fifth of the power rating of a single large wind turbine. The proposed 70,000 kg of hydrogen would power around 400k bus kilometres. Dublin Bus does well over 50m kilometres per year (70m in the last boom). Compression of hydrogen requires about 10% of the embodied energy. Not sure if this is factored into the Energia numbers.

Hydrogen is not inherently less safe than batteries. The latter involve electrocution risk and require training of maintenance crews and first responders. Hydrogen is explosive only when mixed with air. Tanks are tested up to 500 bar. All enclosed parts of hydrogen vehicles have vents and fans to prevent build up in the case of a leak.


#1070

Agreed, but batteries aren’t going to blow in all the windows for 100m of a city block either. Yes, that’s a low probability event but it’s been modelled:


#1071

Ah yes. The HindenBus … coming to a mooring stop near you. :icon_biggrin:

image

… or maybe not …


#1072

I’ve seen similar Carbon tank designs tested for holding compressed air for air rotary engines and its the same deal, the gas shoots out very quickly and dissipates. The tank is designed to snap and crack open, while retaining the bulk of its it structural form.

No explodIng tank shrapnel to worry about, other than fast and violent exit of gas. Ya know, like after a heavy lunch…

Also is there not some wafer thin cell already developed that produces hydrogen from water when in direct sunlight or have I mixed it up with artificial photosynthesis tech.


#1073

I’ve witnessed a couple of small (laboratory scale) explosions at close quarters and it left quite an impression I can tell you so maybe I’m don’t have the most objective outlook. The sudden intense violence and destruction even from small containers is shocking.


#1074

A gen one leaf battery of 24kWh would be good for a range of about 30KM

We would be better off coming up with a system of smart charging for EVs, EVs now store more power than Turlough hill, it won’t be long before EVs store multiples of that

If battery prices keep dropping we might see a large number of people with home batteries, I don’t see the same happening with Hydrogen


#1075

The company supplying the new hybrid buses to Dublin bus do have a pure EV double decker, so I don’t understand why DB didn’t buy 5 or 10 as a trial

The new Enviro400EV possesses the same ‘DNA’ as its proven Enviro200EV stablemate albeit with a new chassis and lightweight aluminium double deck bodywork measuring 10.9m in length, 4.3m high and 2.55m wide. Power is delivered via BYD’s fully electrtic drivetrain technology featuring high capacity 382 kWh BYD Iron-Phosphate batteries providing an impressive 160 mile range. The drivetrain features BYD’s innovative wheel-hub-motor – meaning no gearbox, driveshaft or differential componentry.


#1076

Not sure if you mean it would propel a Leaf for that distance. The Enviro400ER bus in question has a “32 kWh next-generation lithium-ion battery” and a battery range of 2.5 km (although elsewhere they claim 3 miles).

Although I don’t disagee, I’ve yet to see details of how EV charging times and other electricity usage match up by time of day, so that one could be used to load balance the other while still ensuring the EV is ready to go when needed. Grateful for any links.

Wait until the first few home lithium fires. Storing large amounts of energy in any form can be a hazard.


#1077

If a pure electric bus like the one in the video above can get 160 miles out of a 382kWh battery then in theory a 22kWh battery could get about 30KM, unless my calculations are way off, I’m sure its more than 1KM

So they don’t have a 32kWh battery or they are using it in an extremely conservative way to extend its life cycle, who knows, or could they be using a 3.2kWh battery


#1078

Yep, something odd there. Or, as you say, a misplaced decimal point. :stuck_out_tongue_winking_eye:


#1079

#1080

We now know what the answer isn’t – compressed natural gas. As reported in the Business Post today, the Department of Transport’s report on recent bus trials showed CNG to be the worst option for carbon emissions, even worse than diesel.