By JD Adams
Urban planners and electrical engineers will be the architects of future transportation systems that reduce dependence on autos and fossil fuel. The emphasis will be on livable communities with mixed-use zoning and safe pedestrian and bicycle routes. Like the long-standing communities in Europe, local diversity will reduce the need for extensive travel. All alternative (not fossil fuel driven) forms of transportation will be encouraged by design: walking, bicycling, public transit, telecommuting, and light rail.
Early in the last century, American oil and auto companies conspired to buy up and dismantle the existing light rail infrastructure in order to monopolize transportation with petroleum-fueled vehicles. We’ve come full circle with the growing interest in electric modes of transportation. Amazing as it may seem, electric trains were once a popular mode of travel between Portland, Salem, and Eugene. Read about the history, not without a touch of déjà vu, from the Salem History Project and the National Railway Historical Society. The Oregon Electric Railway Historical Society maintains a museum of electric trains and trolleys near Brooks.
We have the benefit of technology sufficiently advanced to breathe new life into old ideas, such as linear motors that will find uses in future public transit. A linear motor can be thought of as a rotational motor unrolled and stretched out for linear motion.
Experimental prototypes have already proven the concept of a human-powered machine that allows a person of average athletic ability to cruise at 55 MPH; the world record for a human-powered bicycle is now over 89 MPH. When a number of these vehicles are on the road, they will have political clout and lobbying weight like bicyclists do now in the Portland area. The problem as many can attest is sharing the road with today’s crazed distracted drivers. Someday an electronic interlock will prevent texting while driving but until then human-powered transportation will be an exercise in survival. A serious effort to achieve energy independence should include funding for an alternate transportation corridor or retrofit for human-powered machines that provides reasonable safety in sharp contrast to the present situation that was literally added as an afterthought. Imagine if you will a perfect marriage of electronics, ergonomics and streamlining far beyond the bloated vinyl of lumbering smog machines. Embedded GPS, communications, and security will make these sleek craft impossible to steal, and vehicle detection and crash-avoidance technology now being perfected improves safety. With a low enough coefficient of drag, solar assisted drive is an option, utilized in the solar/electric/human-powered ELF vehicle below. Of course millions of dollars are spent each year to keep this technology from the mainstream, at least while there are still trillions of dollars to be made on petroleum. The next steps to energy independence are being made with our expanding electric car charging network that should be seen as an opportunity for entrepreneurs to create new paradigms of sales and service to accommodate fast-charge technology and the coming hydrogen-powered vehicles. Americans have never backed down from a technical challenge, and the future will be no different.
Solar Electric Bicycle
The EV-1 Murder Mystery
The EV-1 was the first battery-powered electric car made by General Motors, in production from 1996 through 1999, although only available in California and Arizona under a lease program. Despite positive feedback from customers, the EV-1 program was cancelled in 2003 under somewhat mysterious circumstances, documented in the film “Who killed the Electric Car?” The film investigates what roles the oil industry, car manufacturers, and the Bush Adminstration played in suppressing this technology.
Superconductors, Solar, and the Stirling Engine
A quantum mechanical phenomenon, superconductivity occurs in certain materials when cooled to extremely low temperatures. In this state, current flows in bound pairs of electrons that constitute a superfluid, which can move without power dissipation. With exactly zero resistance, current can circulate forever in superconducting circuits, an oddity that is being exploited in the latest applications. A new class of relatively high temperature ceramic super conductors has been discovered that has spurred advances in medical imaging, telecommunications, energy storage, and magnetic levitation.
Superconductive Magnetic Energy Storage systems have proven reliable in providing fast backup power with 98% efficiency. Maglev Systems use magnetic fields to suspend and propel a train on a frictionless bearing. Several maglev trains are in use around the world, but the experimental JR-Maglev is notable for the use of superconductor technology to generate a stronger repelling force and therefore a wider gap is possible in the track, making it more robust in the presence of dirt, debris, snow and ice. Superconductors are also being used in a new wave of motors and generators that have a superior efficiency of 99%. Clearly, the energy savings realized by superconductor technology will be part of the solution to global warming in the years to come.
In the second largest solar thermal power-generating system in the world, you won’t find acres of solar panels. Kramer Junction in California, not far from the infamous Barstow, is capable of producing 150 Megawatts of solar energy from arrays of parabolic troughs that concentrate sunlight on a pipe of thermal oil, driving a heat exchanger and steam turbine. Built in the mid 1980’s, it is conspicuous as one of the few improvements to come out of the energy crisis of the 70’s. This approach doesn’t use silicon PhotoVoltaics and it’s fairly efficient. The tracking of the parabolic reflector is computer-controlled so it’s not totally low-tech, but otherwise it could have been designed a century ago. The strategy of using a solar concentrator to generate heat is one that will compete favorably with PV in some applications. Three sites including Kramer Junction produce 354 MW of power. The Ivanpah solar thermal facility is the world’s largest but its tower design has raised concerns about bird mortality and environmental impact.
The Stirling engine has been rediscovered; capable of generating torque from any source of heat. Patented in 1816, many forms are possible, but it’s generally a closed-cycle, reciprocating piston device. When placed at the focus of a parabolic reflector, the Stirling engine can drive generators with an overall efficiency better than standard solar panels, and comparable to concentrated photovoltaics. I would recommend the Stirling Engine in particular as the most promising jewel from the past to be dusted off and utilized for our energy future.
Enter a Brave New World of Green Technology
See also a list of emerging technologies.
Renewable Energy Storage
Wind power generating capacity has increased at a rapid rate across the U.S., with Oregon wind farms able to produce over 3000 Megawatts as of 2013, with an estimated potential of 27,000 MW of onshore wind power, and another 225,000 MW of offshore wind power. Production of solar power in Oregon was 62.8 MW in 2013.
Efficiently integrating this power source with peak load demands is a problem because of the uncertain nature of wind and solar energy. To smooth out the energy produced and match available power to peak demand, several energy storage techniques are being considered. Many of these are scalable technologies that have found use in transportation and consumer electronics.
To store energy on a scale practical for most power grid applications, a surprisingly low-tech approach known as pumped hydro has been used with great success. In this design two reservoirs are used, and a reversible pump/generator is used to pump water uphill during optimum generating times, and during peak demand, the water flows downhill to drive a turbine generator. This plan has the advantages of being able to store large amounts of energy at an efficiency of 80%, and it is compatible with existing dam structures, so it may be possible to create hybrid hydroelectric / pumped hydro designs including fish ladders for an environmentally transparent structure.
Thermal storage techniques allow heat energy to be saved to generate power later.
Fuel cells produce electricity using a chemical reaction that is sustained by a constant supply of fuel and an oxidizing agent. Significant obstacles remain to widespread adoption; however hydrogen-producing technology using renewable energy sources is becoming viable.
Flow batteries combine characteristics of a fuel cell and a battery to generate voltage with a replaceable liquid electrolyte.
Solid-state batteries use a solid material for the electrolyte as well as the electrodes to create a thermally stable, compact module with a high power to weight ratio.
Magnetic-bearing flywheels, compressed air, and liquefied air are also being considered for storage of intermittent sources of energy.
Quantum chemistry may hold answers for harvesting renewable energy, and the evolution of so-called supercapacitors (electric double-layer capacitors) to store energy is an extremely promising development. Supercaps use electrostatic and electrochemical phenomena to achieve high capacities capable of maintaining a voltage potential similar to a rechargeable battery.
In terms of energy density, existing commercial electric double-layer capacitors range around 0.5 to 15 W·h/kg. For comparison, a conventional lead-acid battery is typically 30 to 40 W·h/kg and modern lithium-ion batteries are about 160 W·h/kg. In automobile applications gasoline has a net calorific value (NCV) of around 12,000 W·h/kg, which operates at 20% tank-to-wheel efficiency giving an effective energy density of 2,400 W·h/kg.
However, electric double-layer capacitors offer much higher power density than batteries. Power density combines the energy density with the speed that the energy can be drawn out of the device. Batteries, which are based on the movement of charge carriers in a liquid electrolyte, have relatively slow charge and discharge times. Capacitors, on the other hand, can be charged or discharged at a rate that is typically limited by current heating of the electrodes. So while existing electric double-layer capacitors have energy densities that are perhaps 1/10th that of a conventional battery, their power density is generally ten to one-hundred times as great.
The ramifications are that supercaps may one day surpass batteries in energy storage for transportation. In fact, it's happening already. China is experimenting with a new form of electric bus (capabus) that runs without powerlines using power stored in large onboard electric double-layer capacitors, which are quickly recharged whenever the electric bus stops at any bus stop (under so-called electric umbrellas), and fully charged in the terminus.
In 2001 and 2002, VAG, the public transport operator in Nuremberg, Germany tested a hybrid bus which uses a diesel-electric drive system with electric double-layer capacitors.
Since 2003 Mannheim Stadtbahn in Mannheim, Germany has operated an LRV (light-rail vehicle) which uses electric double-layer capacitors to store braking energy.
Numerous other companies are developing electric double-layer capacitor technology and more applications are evolving for transportation, renewable energy storage, tools, medical, military, aviation, and consumer electronics. Supercapacitor research is progressing rapidly.
The most popular personal computer in history was the Commodore 64, sold from 1982 to 1994. On this machine I programmed some of my first fractal graphics, mostly using a language called COMAL. We were fascinated by the strangely organic shapes revealed by the recursive mathematical plots, and intrigued by the maverick mathematician Benoit Mandelbrot and his Mandelbrot set that lay hidden until the birth of computer graphics. Since then fractals have been integrated into the mainstream of technology. The fractal exhibits self-similarity at all scales, and so inherently creates a compact, meandering pattern. I’ve noticed several research papers in Google regarding this new technology as of 2015, but I believe that the increased surface area created by fractal capacitors will make them a contender for maximum capacitance per unit volume, and therefore a useful technique for future energy storage designs.
© 2006-2015 by JD Adams