Regenerative Energy Transportation Systems

The first time I started thinking about regenerative energy systems was reading the following passage about the Milwaukee Road, the electric railway system of the late 19th and early 20th century in the book _Internal Combustion: How Corporations and Governments Addicted the World to Oil and Derailed the Alternatives_ by Edwin Black (NY: St Martin's Press, 2006 ISBN-13: 978-0-312-35907-2 https://internalcombustionbook.com/ Video of Black on his book at https://www.c-span.org/program/book-tv/internal-combustion/167929):

"Sometimes electrified railways seemed to defy the laws of perpetual motion. For example, when the brakes were applied or the train traveled down a slope, the engine actually returned electricity to the grid. Regenerative braking and similar power returns helped the engines pay for themselves. In some mountain ranges, if timed correctly, a heavy downhill train could actually regenerate enough electricity to the grid to power another train passing it uphill. Thus both trains would travel in a minuet of seemingly energy-free motion. That might have seemed to violate the laws of physics, but not the rules of General Electric's wondrous workhorses, which were designed to observe this maxim: It is better to give than receive when it comes to electrical power. Those engines lasted not for years but for decades. Their endurance was measured in millions of miles. They were monumental vehicles that created economic prosperity and environmental balance everywhere they rolled."

I imagined a transportation system based upon regenerative braking with load balancing so that energy expenditure going uphill was matched with the energy gain going downhill. That was nearly 20 years ago. Now it is happening. There are trains, trucks, automobiles which are using regenerative braking, batteries, and two-way or bidirectional charging, operating as grids and grid back-ups.

One of the largest electric vehicles on Earth, weighing in at 123 tons with a 65 ton payload capacity, is the fully electric eDumper, developed by eMining AG, using regenerative braking to charge the batteries, and in active use since 2018. Roger Miauton, the chief executive of eMining AG, says, “When you have a descent of 10 percent, from top to bottom, you never need to recharge. You generate enough energy going downhill as you need to get back up again.”
https://cleantechnica.com/2022/03/21/revenge-of-the-electric-truck-hydropower-scheme-infinity-train-edition/

Fortescue Williams, a hard rock mining company, operates an "Infinity Train” in Australia that never needs charging using this idea. Unfortunately, although saving them 10% of their fuel costs, they started shutting down the program in September 2025.
https://www.boilingcold.com.au/fortescue-slashes-electric-train-program-but-insists-zero-emissions-on-track/
https://cleantechnica.com/2022/05/31/an-electric-train-that-never-needs-charging-its-real/
https://inhabitat.com/mining-company-adopts-electric-trains-that-never-need-recharging/

Barcelona's main transit operator, Transports Metropolitans de Barcelona, or TMB, built four electrolineras - Spanish for “electric gas stations” - in which regenerative braking supplies power to the station and the fast EV chargers outside. They plan to add three more as they expand the MetroCHARGE project. “We’re trying to take advantage of the power that’s already in the metro system and use that spare energy to feed EV chargers on the street,” said Marc Iglesias, head of sustainable mobility at Àrea Metropolitana de Barcelona, a regional agency working with TMB on the project.
https://grist.org/transportation/barcelona-is-turning-subway-trains-into-power-stations/ https://cleantechnica.com/2024/09/30/barcelona-is-using-regenerative-braking-to-power-subways-ev-chargers/

There are also many vehicle to grid projects ongoing using business fleet vehicles or even school buses
https://rmi.org/electrification-101-how-fleets-and-utilities-can-work-together-to-unlock-electrified-transportation/

and China is building two-way charging stations that allow parked EVs to send power back to the grid during peak demand periods
https://restofworld.org/2025/china-electric-vehicle-bidirectional-charging/
https://english.news.cn/20240816/47b3faa6206247b8b9c79772563a213d/c.html

I asked two Large Language Models [LLMs], ChatGPT and Claude, to produce one page outlines and elevator pitches for such a system using the resources above.

ChatGPT said:
One Pager
Regenerative Load-Balanced Transportation System

Concept Summary
A multi-modal transportation ecosystem in which downhill vehicles generate energy and uphill vehicles consume it, coordinated through local microgrids, fast storage, and real-time control. Inspired by heavy-haul regenerative systems (eDumper, Infinity Train, Barcelona Metro), the architecture extends these ideas to city transit and micro-mobility.

System Architecture
1. Energy Capture
Onboard regenerative braking collects gravitational and kinetic energy.
Wayside DC microgrids at stations/grade transitions absorb high-power regenerative pulses. Braking energy instantly powers nearby chargers, station loads, or is stored.

2. Local Energy Buffering
Fast-response stationary batteries / supercaps store short bursts of regen energy.
Strategic placement: downhill termini, stations in hilly zones, transit hubs.
Heavy-rail systems can fully recharge from downhill runs; micro-mobility uses aggregated charging at hubs.

3. Bidirectional Charging + Grid Coordination
V2G/V2X allows vehicles and stationary storages to trade energy with the grid.
Enables selling surplus regenerative energy or absorbing grid overflow.
Micro-mobility docks use bidirectional charging or standardized battery swaps.

4. Real-Time Energy Management
Model Predictive Control (MPC) forecasts downhill energy pulses and uphill demand.
Optimizes when to route energy directly, store it, or export it.
Includes constraints for battery health, thermal limits, power flows, and safety.

Micro-Mobility Integration
E-bikes/scooters recover small per-trip energy, but fleet aggregation + smart docking makes it impactful.
Docking stations act as edge batteries, passively absorbing regenerative surges from nearby rail/tram systems.
Standardized high-C battery modules enable rapid, safe bidirectional energy exchange.

Value Proposition
Environmental
Cuts grid draw for uphill operations; in heavy rail, can approach net-zero propulsion.
Reduces peak loads, enabling more renewable penetration.

Economic
Downhill energy becomes an asset, lowering operational costs.
Utilities benefit from predictable load behavior and distributed storage.
Reduces battery cycling costs via optimized dispatch.

Urban Benefits
Turns transit hubs into clean energy nodes.
Micro-mobility fleets become distributed flexible storage, improving urban electrification resilience.

Deployment Pathway
Identify corridor with predictable downhill → uphill flow.
Install DC wayside buffer and bidirectional chargers at nodes.
Deploy MPC controller for energy forecasting and routing.
Add micro-mobility docking/storage hubs to share captured energy.
Pilot → measure → refine → scale.

ELEVATOR PITCH (45 seconds)
Imagine a transportation system where going downhill powers going uphill. Heavy trains, trams, and even micro-mobility devices feed their regenerative braking energy into local batteries at stations. Instead of wasting that energy as heat, we store it and route it—instantly—into the next uphill climb, EV charger, or grid service. This creates a self-balancing transportation microgrid: heavy rail systems like the Infinity Train can recharge entirely from gravity, while city transit turns stations into clean-energy hubs that also power e-bikes and scooters. The result is lower operating costs, reduced grid stress, and near-net-zero mobility, all achieved by capturing energy we already have and using smart control to share it across an ecosystem of vehicles.

Claude:
The Regenerative Transportation Ecosystem: Energy-Neutral Transportation Through Intelligent Load Balancing

The Elevator Pitch
What if transportation systems could power themselves? Mining trucks already generate more energy going downhill loaded than they use going uphill empty. Barcelona's subway trains capture braking energy to power stations and EV chargers. China's building a network where 100 million electric vehicles become the grid's battery. We're creating an interconnected transportation ecosystem where gravity-fed heavy vehicles subsidize urban transit, which powers neighborhood EV charging, which supports micro-mobility - turning every vehicle into part of the energy solution.

One Page:
The Problem
Transportation consumes massive energy while grid infrastructure struggles with peak demand. Meanwhile, energy is wasted daily: heavy vehicles braking downhill, trains stopping at stations, vehicles sitting idle. Each transportation segment operates in isolation, missing opportunities to share and balance energy loads.

The Solution: Four-Tier Energy Network

TIER 1: Heavy Industrial (Net Producers)
Mining trucks and trains on downhill routes generate surplus energy through regenerative braking
Example: eDumper (123-ton electric truck) generates more energy than it consumes, feeding excess to grid
Fortescue's Infinity Train eliminates 82M liters diesel annually while producing net energy

TIER 2: Urban Transit (Distribution Hubs)
Every subway/light rail station becomes an energy hub capturing braking energy
Barcelona: 41% of train power from regenerative braking, powering 25 stations + EV chargers
440M annual passenger trips = continuous energy generation and distribution

TIER 3: Personal EVs (Mobile Storage)
Bidirectional charging turns vehicle fleets into distributed batteries
China deploying 5,000 V2G stations by 2027; 100M EVs = 1 billion kW capacity by 2030
Owners earn revenue through energy arbitrage while stabilizing grid

TIER 4: Micro-Mobility (Efficient Last Mile)
E-bikes, scooters, monowheels charge from neighborhood hubs
Minimal energy needs filled by transit regeneration overflow
Complete the zero-emission journey from heavy industry to doorstep

How Energy Flows
Morning: Industrial vehicles descend loaded → generate surplus → charge urban transit + neighborhood stations → power morning commute EVs and micro-mobility
Midday: Transit braking during rush hour → feeds station amenities + street-level chargers → charges parked EVs + micro-mobility fleets
Evening: EVs discharge to grid during peak demand → stabilize grid → earn owners revenue → recharge overnight during off-peak
Continuous: Smart systems balance loads in real-time, routing energy where needed most

The Business Case

Proven Results:
eDumper: 50,000+ liters diesel saved annually, generates net energy
Fortescue: $80M annual cost savings projected
Barcelona: $8.6M investment, 4-5 year payback through energy savings
China V2G: Early adopters earning $200+ in days

Market Opportunity:
350M EVs expected by 2050 = 24 billion kWh annual storage capacity
Every city with transit + topography can implement
Existing infrastructure (subway systems, industrial routes) already has electric backbone

Why Now?
Technology proven at every tier (eDumper since 2019, Barcelona since 1980s, V2G scaling now)
EV adoption accelerating globally
Energy storage costs dropping
Grid modernization creating bidirectional infrastructure
Climate urgency demanding transportation solutions

The Vision
Transform transportation from energy consumer to energy producer. Every vehicle, from 123-ton mining trucks to e-scooters, participates in an intelligent energy network. Heavy vehicles on favorable terrain subsidize light urban transportation. Transit systems power neighborhoods. EVs stabilize the grid. Micro-mobility completes emission-free journeys. The result: Self-powering transportation that reduces emissions, generates revenue, and turns physics—gravity, mass, momentum—into our advantage.

Next Steps
Phase 1 (2025-2027): Deploy industrial regenerative systems + expand urban transit programs + V2G pilots
Phase 2 (2027-2030): Scale V2G nationally + integrate micro-mobility + unified standards
Phase 3 (2030+): Full ecosystem integration + smart grid management + global adoption Target Cities: Hilly metros with transit systems (San Francisco, Hong Kong, Pittsburgh, Lisbon, Seattle) + mining regions with elevation-based operations

-30-

All my adult life I’ve had three sayings which inform the way I think:

We remain alert so as not to get run down, but it turns out you only have to hop a few feet to one side and the whole huge machinery rolls by, not seeing you at all. - Lew Welch

Quite clearly, our task is predominantly metaphysical, for it is how to get all of humanity to educate itself swiftly enough to generate spontaneous behaviors that will avoid extinction. - R. Buckminster Fuller

the war that matters is the war against the imagination
all other wars are subsumed in it. - Diane di Prima

I imagine we can educate ourselves swiftly enough to transition our existing fossil fuel transportation system to a regenerative electric system more swiftly than most would believe and that the whole huge machinery that rolls by will be powered by a much more efficient, maybe even close to net zero energy system.

Another saying I’ve picked up along the way from Walt Kelly’s Pogo: We are surrounded by insurmountable opportunities.

Happy Merry New

100% Clean, Renewable Energy and Storage for Everything

On October 29, 2025, Mark Z Jacobson, Professor of Civil and Environmental Engineering, Stanford University, gave a succinct one hour lecture to Elders Climate Action (https://www.eldersclimateaction.org) on 100% Clean, Renewable Energy and Storage for Everything

https://www.youtube.com/watch?v=YOXwMb3kPBk


Dr Jacobson has been designing 100% renewable energy systems using wind, water, and solar [WWS] for countries and states most of this century and reality is quickly catching up with his calculations. The speed of change is accelerating as battery costs and new/old energy storage techniques come into use to provide 24/7 power, for all intents and purposes.

Here are my notes:
electrifying everything brings demand for total energy down 54.2%
19.8% through higher efficiency in Building Energy [BE] & Internal Combusion Engines [ICE]
4.1% in electric industry
13.1% heat pumps
10.6% eliminating mining for fuel, processing, transporting fossil fuel and uranium
6.6% efficiency beyond BAU

10% of the energy we produce goes into mining, processing, & transporting fossil fuel and uranium. Bill McKibben wrote in Here Comes the Sun (my notes at https://solarray.blogspot.com/2025/09/notes-on-here-comes-sun.html): "Forty percent of the world’s ship traffic, for instance, consists of moving coal and gas and oil back and forth across the ocean..."

electric and fuel cell vehicles reduce energy requirements by 75%
which is almost a 20% reduction in total demand

Leveled cost of electricity 2023 (IRENA [International Renewable Energy Agency] 2024)
fossil fuels $100/MWh
utility PV $44/MWh
onshore wind $33/MWh
onshore wind $75/MWh
hydro $57/MWh

Onshore wind is a third of the cost of fossil fuels and utility PV is less than half. They have also been the fastest growing source of new generation and jobs, growing year by year.

14 countries with electric generation 95-100% WWS 2023
12 USAmerican states with consumption 49-100% WWS Q324 -Q225

Transition world to 100% WWS
creates 28 million more jobs than lost
requires only 0.18% of land
avoids about 7 million air pollution deaths per year
slows then reverses global warming
stabilizes the global grids

The economics of renewables are now so overwhelming that the energy transition we need to deal with much of our greenhouse gas pollution problems is happening, accelerating, and, seemingly, inexorable.

We just have to recognize what is happening before our eyes.