The more curious case for excavators would be open pit mines or quarries where you know you’re going to be in roughly the same place for decades and already have industrial size hookups
A bit more compelling, though for mining, the excavator/shovel/whatever loads a truck. The truck moves it much further and consumes a lot more energy to do so. Overhead wires to power the haul trucks are the biggest win there.
This is an open pit mine. Less vertical movement may reduce imbalance in energy consumption. Can’t find info on pit depth right now but haul distance is 1km.
General point is that when dealing with a move stuff from A to B problem, where A is not fixed, diesel for a varying A-X route and electric for a fixed X-B route seems like a good tradeoff. Definitely B endpoint should be electrified (EG:truck offload at ore processing location)
Getting power to varying point A is a challenging. Maybe something with overhead cables could work, Again, John deere is working on something for agriculture with a cord-laying-down-vehicle and overhead wires are used for the last 20-30 meters. But fields are nice in that there’s less sharp rocks and mostly softer dirt/plants. Not impossible but needs some innovation to accomplish.
Agreed on most points. Electrifying rail makes good financial sense.
construction equipment efficiency can be improved without electrifying:
some gains from better hydraulic design and control
regen mode for cylinder extension under light load
varying supply pressure on demand
substantial efficiency improvements possible by switching to variable displacement pumps
used in some equipment already for improved control
skid steers use two for left/right track/wheel motors
system can be optimised:”A Multi-Actuator Displacement-Controlled System with Pump Switching—A Study of the Architecture and Actuator-Level Control”
efficiency should be quite high for the proposed system. Definitely >50%.
Excavators seem like the wrong thing to grid-connect:
50kW cables to plug excavators in seem like a bad idea on construction sites.
excavator is less easy to move around
construction sites are hectic places where the cord will get damaged
need a temporary electrical hookup ($5k+ at least to set up)
Diesel powered excavators that get delivered and just run with no cord and no power company involvement seem much more practical.
Other areas to look at
IE:places currently using diesel engines but where cord management and/or electrical hookup cost is less of a concern
Long haul trucking:
Cost per mile to put in overhead electric lines is high
but Much lower than cost of batteries for all the trucks on those roads
reduced operating cost
electricity costs less than diesel
reduced maintenance since engine can be mostly off
don’t need to add 3 tonnes of battery and stop periodically to charge
retrofits should be straightforward
Siemens has a working system
giant chicken/egg problem with infrastructure and truck retrofits
Agriculture:
fields are less of a disaster area than construction sites (EG:no giant holes)
sometimes there’s additional vehicles (EG:transport trucks at harvest time)
Cable management is definitely a hassle but a solvable one.
a lot of tractors are computer controlled with GPS guidance
cord management can be automated
John Deere is working on a a system where one vehicle handles the long cable and connects via short <30m wires to other ones that do the work
There’s still the problem of where to plug in. Here at least, it’s an upfront cost per field.
The more curious case for excavators would be open pit mines or quarries where you know you’re going to be in roughly the same place for decades and already have industrial size hookups
A bit more compelling, though for mining, the excavator/shovel/whatever loads a truck. The truck moves it much further and consumes a lot more energy to do so. Overhead wires to power the haul trucks are the biggest win there.
“Roughly 70 per cent of our (greenhouse gas emissions) are from haul truck diesel consumption. So trolley has a tremendous impact on reducing GHGs.”
This is an open pit mine. Less vertical movement may reduce imbalance in energy consumption. Can’t find info on pit depth right now but haul distance is 1km.
General point is that when dealing with a move stuff from A to B problem, where A is not fixed, diesel for a varying A-X route and electric for a fixed X-B route seems like a good tradeoff. Definitely B endpoint should be electrified (EG:truck offload at ore processing location)
Getting power to varying point A is a challenging. Maybe something with overhead cables could work, Again, John deere is working on something for agriculture with a cord-laying-down-vehicle and overhead wires are used for the last 20-30 meters. But fields are nice in that there’s less sharp rocks and mostly softer dirt/plants. Not impossible but needs some innovation to accomplish.
Any time overhead electrical lines for mining trucks would be worthwhile, overland conveyors are usually better.