I am pretty sure that most trains in the USA are diesel-electric not just diesel. So the real question is would converting those trains to pure electric actually reduce the total carbon footprint of rail? I suspect not given some have argued that EV car have a higher carbon footprint that cars they replace, and those cars use gas, run at variable speeds and so are much less efficient that the train diesel engine's use of diesel fuel.
Are the very least you'd need to start calculating the conversion timeline for recouping the pollution from building out all the electric infrastructure and the additional maintenance of that infrastructure. Given the goal now is to reduce carbon output you might be adding at the margin when marginal increases are most damaging.
I think if you want to think about power innovations for trains things like hydrogen are probably a better way forward.
Heavy earth-moving equipment mist be a better target, and perhaps should be the target before cars. Cars should probably go to hybrid systems as they will be better. Side observation, a few years ago I read something that claimed the these days the bigger source of pollution (probably in suburban, and metro but not pure urban) was lawn mowers. Getting rid of the gas mowers and converting to electric might be both an easy target and good bang for the buck.
Wait, diesel-electric just means that they use an electric transmission, right? So 100% of the energy driving the locomotive still ultimately comes from burning diesel. IIRC the carbon footprint of electric cars is dependent on how your local power is generated. To be worse than internal combustion, there needs to be a high fraction of coal in the mix. Even the power plants that burn stuff are generally more efficient than internal combustion engines because they're larger so less heat is lost to conduction and they also burn hotter. So the actual reason for higher emissions would just be that coal has more carbon in it per joule than gasoline does. That's all just going off of memory, please correct me if I'm wrong.
It actually seems like a diesel-electric fleet would be almost ideal for converting rail lines to electric. If upgrading a locomotive to have brushes and some associated power electronics is not too expensive, then you can get a hybrid that will still operate as a normal diesel locomotive on lines that haven't been electrified yet, but will operate electrically on lines that have been, saving on fuel costs.
Not my understanding. The diesel just drives the "generator" that then powers electric motors that drive the wheels. These trains are supposed to be able to move a ton about 450-500 miles on a gallon of fuel. I do agree that conversion would be fairly straightforward but you'll have a lot of polluting activities, and destruction of carbon consuming flora. So just how much of a gain are we getting for the conversion compared to the increased pollution during the infrastructure build out. There is also the ongoing maintenance on the routes to keep the trains powered. Seems to me that unless one makes the unrealistic assumption that all that activity is non-polluting it has to be considered in the argument.
With regard to the cars, EV and hybrid I was extrapolating on the fuel consumption for the trains. I using a small ICE to drive a generator for an electric vehicle would reduce the initial carbon output in making everything for the EV. That all comes down to battery life and that seems to come down to miles driven. Generally EVs get driven fewer miles than ICE cars but as more people drive the EVs that might change. Tesla gives an 8 year warranty on the batteries. Looking around a bit seems that existing hybrids are just crappy design so from that perspective was a poor suggestion. But a car modeled off the diesel-electric train that is even a quarter as efficient (just 100 mpg) then the carbon curve shifts way down on the those gas-electric cars and the cross over point for EVs shifts much farther out -- perhaps to the point of battery replacement. Perhaps there as some scale factors, I'm not a power engineer, so maybe that 100 mpg is never possible.
The diesel just drives the "generator" that then powers electric motors that drive the wheels.
That's exactly what "electric transmission" means, no?
I'll try one more time and shutup as it sees to me people are focusing on semantics rather that the actual question.
If electro-diesel trains are transporting a ton about 450 mile on a gallon of diesel then just how much will it cost, in terms of carbon output to electrify a mile of rail in comparison to the average train loading?
How much will it cost in terms of carbon output to maintain that electrification per year annually?
How many years will it take to reach a carbon neutral position?
What are the expected costs of, assuming you agree there will be increased carbon output, the marginal increase in carbon output during the transition period compared to the current impact of electro-diesel transportation?
If you don't agree that the infrastructure build out will increase carbon output how is that accomplished?
At a ROI of 19% you get economic payback in 5.3 years. The benefits are more weighted towards fossil fuel use than the costs so CO2 neutrality would be sooner than that, but then you start getting into issues like how you account for energy usage of workers whose labor is being used when you substitute labor for energy use.
Diesel-electric operate on electric where available, and switch to diesel when they get to unelectrified areas. Many cities are electrified within maybe a 20 mile radius of city center, with farther branches being diesel.
No. Trains that can do that are called electro-diesel locomotives. Not diesel-electric.
For the most part, these locomotives are built to serve regional, niche markets with a very specific purpose.
I suspect not given some have argued that EV car have a higher carbon footprint that cars they replace
You should go back and re-examine those arguments. They haven't been true for decades, if ever, and are usually not produced in good faith. It's not even close, unless you exclusively charged your EV from the very least carbon efficient power plants in the world.
Cars should probably go to hybrid systems as they will be better.
If you mean serial hybrids/PHEVs, then I agree, this is something I expected to see a lot more of by now, but instead companies seem to want to jump straight to pure BEVs, which I think is likely to be a worse transition overall.
these days the bigger source of pollution (probably in suburban, and metro but not pure urban) was lawn mowers.
You may want to be more specific what you mean by "pollution" and "bigger." Particulates and various fumes other than CO2 per gallon of fuel burned? Sure, makes sense. Anything about aggregate amounts? No. That may be true in some specific geographies, but is broadly false. I do agree that going electric is often a good idea, as long as your lot isn't too big and you keep up with it. I had a battery electric mower and loved it, except that if I missed a week or two I would drain the batteries several times faster b/c of the taller grass. Ditto if the grass was at all damp. But it's getting there.
I am pretty sure that most trains in the USA are diesel-electric not just diesel. So the real question is would converting those trains to pure electric actually reduce the total carbon footprint of rail?
For ideal operation, a train can access electricity from the grid at all times. Currently, that's not possible on large parts of the US grid.
Electric cars need batteries and as a result you have different dynamics.
I think if you want to think about power innovations for trains things like hydrogen are probably a better way forward.
Why? It's easier to transport electricity than it's to transport hydrogen. Electricity-driven motors are also more efficient than hydrogen-fuel cells.
Separately, the OP wrote a post on how hydrogen is likely not going to be as cheap in 2030 as officially projected: https://www.bhauth.com/blog/chemistry/electricity%20to%20chemicals.html
I would expect some efficiency gains from not having to carry a diesel generator with you, and some efficiency gains from not needing to design it to fit on a train (my understanding is that bigger generators tend to be more efficient).
There are also efficiency gains from being able to run the generators continuously, which justifies spending more on them. Combined-cycle gas turbines are more efficient than big diesel engines, and their fuel is cheaper.
I work in equipment manufacturing for construction so can comment on excavators. Other construction equipment (loaders, dumpers) have a similar story although excavators have more gently duty cycles and require smaller batteries so make sense to electrify first. Diesel-Hydraulic Excavators are also less efficient giving more potential advantage for electric equipment.
- Agree that payback period is relatively low but possibly a bit longer than here - I’ve seen 3-5 years. The ruggedised batteries required for instance can be expensive.
Purchasers of new machines will generally keep them for 5-7 years which is enough to justify the payback but not to make it an obvious easy win.
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If you have to use a diesel generator you immediately lose a lot of your cost saving. It is surprising how many construction sites lack mains electricity.
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Many machines go to the rental market. In this case the equipment buyers do not get the benefit of the reduced operating costs. In that case the rental company has to sell the increased rental cost to their customers who are happy with what they are currently using.
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Total cost of ownership just isn’t the main driver of buyer decisions. This is already a problem with diesel-hydraulic machines - there are many ways to make these more efficient which would have a decent payback period but don’t get implemented because efficiency isn’t a key purchasing driver.
What buyers really need is performance and reliability (plus low up front cost). The advantage of electric is more difficult to sell for reliability because of a lack of track record so going electric is a risk. Users are also rightly concerned that battery range will not be sufficient on high usage days - batteries in current machines often claim a full day but not necessarily with high usage.
- Most likely route for electric in short term is for them to get used in environments where emissions are important (due to regulations or low ventilation such as mines) plus companies wanting to be/look green. This will allow a track record to build up which will give more confidence to buyers.
I suspect the most useful thing a government could do (assuming carbon tax is politically infeasible) would be to legislate for low emissions in cities which would build the track record faster.
BNSF is owned by Berkshire Hathaway. Very unlikely that Buffet leaves huge ROI on the table because his execs hoodwink him.
Rail tracks are connected, so patchwork electrification doesn't make sense. If everybody electrifies and gets a good ROI on operational costs, if there's good competition between carriers, what happens is lower prices, not increased profits.
This still doesn't explain why companies would spend effort lobbying against electrification, which is why I had to get into other explanations.
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%.
- used in some equipment already for improved control
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.
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.
2. The pay of rail executives depends on short-term profits, so they're against long-term investments.
I think that is not as obvious an explanation as it may intuitively seem:
a. a company's profit is not equal to it's cash-flow. Profit includes the value of the assets invested in; so a valuable investment should normally not look bad on the balance sheet, even when evaluated in the short run.
b. If there really was a clear 19% or so ROI, even if the accounting ignored a.: You'd typically expect a train company to debt-finance an overwhelming share of the electrification capex, as is common for large infrastructure projects, attenuating the importance of the cash-flow issue, and making the investment even more attractive for equity investors.
Just FYI for many cases, heavy electric motors you leave running same as a diesel. The inrush on them is massive and is often charged separately as peak 'demand', the costs of which can dwarf the pure kilowatt hour charges of running the motor (the kind which most residential users are used to).
Switching large currents also will wear the components, they have limited a cycle life, so leads to expensive replacement and downtime.
Places I have worked would chew you out if you turned something off that was coming back on within an hour.
Large motors will also likely be 3 phase, which greatly limits locations they can be used.
That used to be true, but these days, electric motors all have variable-speed drives using modern power semiconductors. Anybody still using electric motors like you're describing is running obsolete equipment.
While lots of hobbyists use VSDs on their equipment so they can run 3 phase motors off standard US line voltage (I do this for my 1/2hp CNC spindle, 1 1/2hp bandsaw in the past), these are mostly non-certified and small Chinese VSDs, that require programming and knowledge beyond the scope of what even skilled operators are normally capable of, yet alone allowed to do in electrical regulations.
The reality is a certified piece of equipment, professionally installed, can cost in the $500/horsepower range. On even a fairly modest piece of equipment with say 5x 3hp motors, that starts to become quite large percent of the cost of the equipment tacked on, and a huge amount of added complexity. The cost of these drives does not scale linearly with size.
The only motors I have used in a professional setting with a VSD required very precise speed control (spindles), not heavy equipment.
I'm sure you can find companies charging that much, but...for example, wind turbines use variable-speed motors, and those are more like $70/hp including the drivers. Electric cars use variable-speed motors, look at how much those motors cost. It's not $500/hp, that's for sure. A Tesla Model 3 doesn't have $140k worth of electric motors in it, does it?
Tesla motors would not be rated at a tesla vehicles rated hp for an industrial application, they are not expected to operate at 100% duty cycle.
If you want to look at industrial motors for sale at a gold standard place like Grainger, a 250hp (sticker hp Model 3 equivalent) motor is $30,000 - $40,000 just for the motor, no VFD, no mounting, no installation.
https://www.grainger.com/category/motors/ac-motors/definite-purpose-motors?attrs=HP%7C250&filters=attrs
Another $15,000 - $30,000 for the VFD
https://www.grainger.com/search/motors/motor-drives-speed-controls/variable-frequency-drives-accessories/variable-frequency-drives?attrs=Maximum+Output+Power%7C250+hp&filters=attrs&searchQuery=VFD&sst=4&tv_optin=true
Just the power cable that you need for a 400A 3 phase service might run something like $40-50/foot on the floor? It is so expensive you can't even get a good reference on Google. Have to hope you have 3 phase available at all, and that you are close to the pole. A housing site with an excavator you might want 300'? 500'? Another $12,000 - $20,000
So far it is at $67,000 - $90,000 just sitting on the floor, and you need to be highly certified to touch any of those things in a commercial settings.
Edit: Just to add, the above motor weights 3000lb and uses something like 130kw/hour, so even a Tesla 3 battery would last approximately 30 minutes.
You're using Grainger list prices? Seriously? If you actually dealt with buying stuff for industry, you'd know that their prices are much lower when you have a big account with them, and that there are cheaper options.
1Grainger is the first thing that came to mind as a legitimate reference that has pricing online.
I don't think you have invalidated any of my points, that the hp of a tesla motor doesn't make any sense to compare with hp ratings of an excavator motor, that high hp electric powerplants are very expensive, that adding VFD's which are not operationally necessary is a large cost and is most often left off in favor of running the motors.
Battery electric trains with a small proportion of electrified (for charging) sections seems like a decent and perhaps more economic middle ground. Could get away with <10% of rail length electrified, and sodium batteries are expected to come down to ~$40/kWh in next few years. High utilisation batteries that are cycled daily or multiple times a day have lower capital costs. May also work for interstate trucking.
Earth moving electrification is probably the last application that makes sense or needs focusing upon, due to high capital costs of electrification and low equipment utilisation (a lot of it spends only a few percent of year being used), as well as difficulty in getting electric power to them in difficult to access off-grid locations.
Farm equipment is more important, but incredibly bad economics due to high peaks (using up to several MW to run a few large machines for a few days several times a year for cropping) but very low average utilisation.
Both of these are probably best served long term by some renewable liquid fuel and IC engines, for high power, low mass-fuelling and low capital costs. Synthetic hydrocarbon, Ammonia or Liquid Hydrogen.
Sometimes I have trouble understanding the thought process of other people, and I think you're wrong here in ways that I've seen before, so I'd appreciate if you could explain your thought process a bit more.
Battery electric trains with a small proportion of electrified (for charging) sections seems like a decent and perhaps more economic middle ground. Could get away with <10% of rail length electrified
What's your basis for saying "10%" or that this would be cheaper? Have you done some calculations yourself? Did you read a paper that does the math? What charge/discharge rates are you thinking of being used? How long would electrified sections be?
sodium batteries are expected to come down to ~$40/kWh in next few years
I assume you read that somewhere, but why would you consider a source saying that trustworthy over other sources? It's an extraordinary claim, which IMO seems implausible and would require good evidence to believe - so what's the evidence? What are the specific tech advancements making that possible?
Earth moving electrification is probably the last application that makes sense or needs focusing upon, due to high capital costs of electrification and low equipment utilisation
You know there is already electric mining equipment, right?
Synthetic hydrocarbon, Ammonia or Liquid Hydrogen
Why do you think those are good options? Where are you getting the idea that liquid hydrogen fuel is practical from?
Battery augmented trains: Given normal EV use examples, Tesla et al, and Tesla Semi a charging time of 10% of usage time is relatively normal. Eg charging for 20 minutes and discharging for 3 hours, or in Tesla Semi's case might be more like an hour for 8-10 hours operation but trains have lower drag (and less penalty for weight) than cars or trucks so will go further for same amount of energy. The idea is therefore that you employ a pantograph multi MW charging system on the train that only needs to operate about 10% of the time,. This may reduce electrification capital and maintenance costs. Another option would be battery engines that can join up or disconnect from trains in motion between charging cycles in sidings.
CATL (largest battery producer in the world) are innovating heavily on Sodium ion batteries and have stated that they believe cost per kWh can come down to $40/kWh as they scale up manufacture on their second generation. "CATL first-generation sodium-ion cells cost about 77 USD per kWh, and the second generation with volume production can drop to 40 USD per kWh."
I work professionally developing Liquid hydrogen fueled transport power technology. It's very practical for some applications, particularly aircraft and ships that I expect will transition to hydrogen in next 2-3 decades, and possibly trains and agriculture. Using low cost power sources such as grid scale pv in low cost desert regions the price is expected to come down over next 1-2 decades to being competitive or even undercutting fossil fuels (commonly expected/roadmapped to be ~$1.5/kg H2, which translates to about $0.10/kWh useful output power, similar to fossil fuels before taxes). This is likely the only realistic route to fully renewable power for human civilisation - producing in cheapest sunny or windy areas and using at high latitudes/through winters. But LH2 is difficult to transport, transfer and employ at small scales due to lack of economic cryocooling and complexity, insulation and cost scale (r² vs r³) issues with tanks (LH2 and GH2 are very low density) and GH2 is even worse for non-pipeline distribution, so a more convenient dense and long-term easily and cheaply stored energy carrier such as Ammonia or synthetic hydrocarbons made using future cheap hydrogen feedstocks may be a better option. That is especially true for off-road uses.
Agriculture is particularly intractable, cropping farmers in my region frequently run 100+ hours a week using many MW of power during harvest which is a terrible issue for power economics without exceptionally cheap energy storage - liquid fuel is probably the only economic option.
And yes I am well aware of mining electrification, but I am very suspicious of it's utility given many cases will see it powered by fossil fuel generation. Likely that a lot of it is PR greenwashing rather than effective CO2 reduction.
I work professionally developing Liquid hydrogen fueled transport power technology.
So your job depends on believing the projections about how H2 costs will come down?
It's very practical for some applications, particularly aircraft and ships that I expect will transition to hydrogen in next 2-3 decades, and possibly trains and agriculture.
[...]
This is likely the only realistic route to fully renewable power for human civilisation - producing in cheapest sunny or windy areas and using at high latitudes/through winters.
[...]
so a more convenient dense and long-term easily and cheaply stored energy carrier such as Ammonia or synthetic hydrocarbons made using future cheap hydrogen feedstocks may be a better option.
It's possible that direct production of synthetic hydrocarbons will be more effective than going through H2 production. Given that we already have ships that can drive well if you fuel them with gas, it's possible that all the money invested into trying to get ships to run on hydrogen will be wasted.
"So your job depends on believing the projections about how H2 costs will come down?"
I wouldn't waste my life on something I didn't see as likely - I have no shortage of opportunities in a wide variety of greentech fields. Hydrogen is the most efficient fuel storage 'battery' with 40-50% round-trip energy storage possible. Other synthetic fuels are less efficient but may be necessary for longer term storage or smaller applications. For shipping and aviation however LH2 is the clear and obvious winner.
Desert pv will likely come down in price to consistent ~$0.01-0.02 in next decade with impact of AI on manufacturing, installation and maintenance costs (a few large pv installations are already contracted in this cost range). And electrolysis and liquefaction tech are on track to yield the stated $1.50/kg (learning curves are magic). That 'stranded' desert pv power needs to be delivered to far distant users and hydrogen pipelines or shipping provides most realistic option for doing that.
Capturing carbon for synthetic hydrocarbons is not a trivial issue/cost. And their round trip energy storage efficiencies for synthetics hydrocarbons are worse than for hydrogen. There will still be some applications where they make the most sense. Ammonia might work too, though it also needs hydrogen feedstock and is often lethal when inhaled.
But in general I see a pretty clear path to renewable hydrogen undercutting fossil fuels on cost in the next decade or two, and from there a likely rapid decline in their use - so reasons for optimism about energy part of our civilisational tech stack at least, without breakthroughs in nuclear being needed.
Hydrogen is the most efficient fuel storage 'battery' with 40-50% round-trip energy storage possible [...] Desert pv will likely come down in price to consistent ~$0.01-0.02
If energy prices come down so much, the round-trip efficiency is not central.
You need much larger storage tanks in both ships and airplanes if you go for hydrogen than if you use denser fuel.
And electrolysis and liquefaction tech are on track to yield the stated $1.50/kg (learning curves are magic).
If that's true why are the subventions for its production so high? What sources do you find trustworthy for those costs in an environment where plenty of the players have incentives to make people believe in a certain future?
Thanks.
charging time of 10% of usage time is relatively normal
Charge time partly depends on power available, but is typically set to 1 hour to reduce battery degradation. Discharge time depends on battery size relative to power usage. They're not directly related.
have stated that they believe cost per kWh can come down to $40/kWh
I understand battery chemistry fairly well, and my view is, they're lying for strategic reasons.
commonly expected/roadmapped to be ~$1.5/kg H2
see this post for my comments
Many countries are supporting electric cars for environmental and independence reasons. But perhaps there are some targets for electrification with better economics than those, cost-effective without any government incentives. For example, trains and hydraulic excavators.
trains
In some countries, most trains are powered by overhead electric lines. In America, most trains are powered by diesel engines. Why?
The competent estimates I've seen for ROI of electrifying US rail lines have it being worthwhile. This isn't a new thing. Here's a paper from 40 years ago estimating ~19% ROI. Arguments that the economics are bad in America because of geographic differences are wrong.
Why, then, hasn't that happened? Yes, US high-speed rail programs have not gone well, but unlike new high-speed rail lines, building electric lines over existing rail doesn't require purchasing a lot of land.
One major reason is that the Association of American Railroads has lobbied against electrification programs. Apart from private lobbying, they've put out some reports saying "it doesn't make sense for America because American rail networks are special" (wrong), "we should wait for hydrogen fuel cell trains instead" (ultra-super-wrong), and various other bad arguments. Why would they do that? Some hypotheses:
My understanding is that (2) and (4) are the dominant factors. Those aren't specific to rail; they're properties of US business management, so I think rail electrification is a good example of wider problems in US companies. Management is evaluated on shorter timescales than good investments provide returns on, so US companies eventually end up using outdated equipment and processes, and lose out to foreign firms. See also:
When you look at the internal evaluations of proposed projects at large companies, it's fairly common for 15% ROI to be the minimum value for serious consideration. That is, of course, higher than the cost of borrowing. The usual explanation has been that a substantial buffer is needed to account for inaccurate estimations, but that doesn't make sense to me, for 2 reasons:
I have a different theory: the reason you see requirements for 15%+ ROI so often is because executives are often at their position for around 6 years, and they want most of the investment to have been returned by the time they're looking for a promotion or new job. What's really important isn't the true ROI estimated as best it can be, but rather the ROI in practice over the first few years. Fans of independent games have repeatedly seen some beloved game company get bought by a larger company, which then rushes out a release and squeezes out as much short-term revenue as they can with microtransactions, wrecking the company's reputation and causing employee burnout but producing a revenue stream that executives can claim is permanent and a great ROI. Meanwhile, investments with longer-term benefits get ignored despite the true ROI being better.
excavators
When you look at a construction site, you'll usually see a hydraulic backhoe. Those use a diesel engine to drive a hydraulic pump, which moves fluid to a pressurized tank ("accumulator"). Valves connect the high-pressure tank to various hydraulic cylinders.
Why do they always use diesel engines? That's because governments allow tax-free diesel fuel for use off roads, because the fuel taxes are nominally for road maintenance.
Most of the energy of fuel is, of course, wasted by the engine. And then, no matter how much force is needed, fluid is provided at the same pressure by the tank, so most of the hydraulic energy is wasted by throttling in the valves. Modern equipment uses variable-pressure tanks, so it can adjust somewhat, but different forces are needed by different actuators and at different times, so most of the energy is still wasted.
It's possible to instead have an electric motor and hydraulic pump for each hydraulic cylinder. (Those assemblies are sometimes called "electrohydraulic" or "electrohydrostatic" actuators.) Then, there's no throttling that wastes pressure. This approach is much more energy-efficient, perhaps 6x as efficient. It also makes movement smoother, increasing productivity by perhaps 15%.
Using electric motors makes starting with electricity a better option, either from a battery, a generator truck, or a grid electrical connection. Grid electricity is substantially cheaper than diesel fuel, and excavators generally move around less than cars, so it's easier to keep them connected to an electrical cable.
Excavators using separate electric motors and pumps for each cylinder are obviously more expensive to buy. What's the ROI on that investment? My crude estimate was payback in ~2 years of full-time operation - assuming you can usually plug in the machines while they're working. This thesis concluded payback would typically be ~26 months; that doesn't seem to account for slightly improved productivity from smoother movement. So, that's basically consistent with my guess.
The manufacturers of heavy machinery are aware of the advantages of electric actuators, and several of them have made prototypes of fully-electric excavators. But currently, those seem to be more of a long-term and contingency plan than a near-term replacement for their current products.
Another option for electrification is to not use hydraulics. Electric rope shovels are sometimes used; they're more expensive to buy than hydraulic excavators, but large ones have lower total costs. (Back in my day, all the excavators were driven by cables, and the winches were turned by steam engines.) My view is that electrohydrostatic actuators should usually be cheaper than using wire rope that way.
Using electrohydrostatic equipment is a different financial issue from railway electrification: faster returns on investment and equipment that doesn't last as long. I think the problem is largely risk aversion and uncertainty:
It makes some sense for these companies to be risk-averse. The potential benefit to them is relatively small compared to total costs, some new procedures would be needed, and the potential risk is something unknown going wrong that makes their initial purchase worthless. A round of equipment purchases being completely lost could bankrupt some smaller construction companies.
What, then, might governments do about this situation?
One option is to tax diesel fuel to account for pollution. How large a tax would be appropriate for that? This paper concluded that ~$3/gallon (in 2023 dollars) would be appropriate for diesel fuel in the US. I can believe that: I can often smell air pollution from construction sites before I see them, and air quality monitors often show hazardous air quality in a small radius around them. That's not great for construction workers, either. Well, if diesel fuel for excavators and farm equipment had a $3/gallon tax, you'd certainly see some changes, but that might be politically...problematic.
Also, in the US, the structure of agencies involved is an issue. The EPA is tasked with environmental regulation, but while it can ban things, it can't tax things. There are other agencies with the power to tax things, but they aren't tasked with considering environmental harms.
Another option is for government to mitigate some of those risks. For example, if companies are worried about electric equipment being unsuitable for them and not being able to resell it, the US government could agree to buy equipment according to some reasonable depreciation schedule, at prices that probably wouldn't be the best but would reduce risk for companies involved. Things like the politically successful (if economically questionable) "cash for clunkers" program indicate to me that such a system could be politically feasible.
As for extending this into some broader point about companies or management, what comes to mind for me is actually food ingredients. Companies used partially hydrogenated oil for years, and then it was banned, and replacing it was a non-issue. Some US companies are still using brominated vegetable oil, and now it looks like that will be banned soon, and it won't be a problem. But companies still didn't want to change their old recipes until they were forced to. And leaded aviation gasoline will probably be around until it's banned, at which point switching to one of the existing alternatives suddenly won't be a problem. This kind of dynamic is how you can get upcoming or temporary government bans on things that are actually necessary up until it turns out there's really no replacement: the regulators don't understand the technology well, and the companies lie to them even when switching is a non-issue because the executives can't tell how hard something is, so a credible threat of a ban is the only way to get them to honestly try to solve a problem.