http://www.leftlanenews.com/googles-autonomous-car-target-1m-accident-free-miles.html

http://www.cnn.com/2011/OPINION/07/17/hong.car.blind.drivers/index.html?hpt=hp_c2

http://www.engadget.com/2011/06/23/nevada-prepares-itself-for-the-imminent-rise-of-driverless-cars/

In todays world, unless you have been living with an ancient secluded tribe in the Amazon, you have no doubt heard of the effects of air pollution from car exhaust (a la LA), global warming greenhouse gases, and public unease of foreign oil dependency. Politically, these topics are still much debated and there certainly is no consensus. PHEV's help reduce all three (air pollution, global warming gases, and foreign oil dependence), though for the sake of brevity I'll mainly focus on global warming. Even further, at current gas prices, PHEV's do it cheaper for the consumer in the long run.

Emissions is a term that loosely encompasses the undesired byproducts from a car that come out of the exhaust pipe. Carbon dioxide, a global warming gas, is just one type of emission. Other gases include: nitrogen oxides, sulfur oxides, and fine particulates (particles smaller than 2.5um which can cause respiratory illnesses).

When driven in pure electric mode, PHEV's are classified as ZEV which stands for “zero emission vehicle”. Electric vehicles and their derivatives use electric power and therefore, emit neither toxic fumes nor greenhouse gases. Thus, they have received the title of ZEV. However, skeptics have rightly pointed out that electric power does not get created out of thin air and that ZEV's themselves have hidden emissions. The emissions are generated by the power plants that make up the US power grid and are composed of coal, nuclear, gas, and renewable resources which themselves create pollution.

That brings up the question of, isn't the electric car creating just as much pollution as an internal combustion engine (ICE)-based vehicle, not in the form of exhaust but in the form of pollutants from power companies? The quick answer is no. Power companies operate on a larger scale and thus can run at a higher efficiency than automobiles. Thus power plants can use less natural resources to create more energy. Furthermore, economies of scale allow power plants to employ pollutant reduction technologies which cannot be easily leveraged in automobiles.

Here is the long answer. The US is composed of a variety of power plants and every power plant is not the same. As of 2000, almost 50% of the electricity produced in the US was created from coal. While the vast majority employ the latest techniques to improve efficiency and reduce pollutants, about 5% of coal plants pollute the atmosphere in more than their fair share. Therefore, in a hypothetical situation where you compare the electric vehicle to the latest ICE vehicle, and where the electric vehicle draws electricity solely from 50 year-old coal power plants that have somehow avoided being upgraded with the latest pollutant reducing technologies as mandated by the Clean Air Act, then you will have a ZEV producing more pollution than an ICE vehicle. However, considering that the US only uses 50% power from coal and the majority of coal plants are efficient and employ the latest pollution reduction technologies, it is safe to say that ZEV's are significantly less polluting than their ICE counterpart.

To just cite some facts, CARMA (Carbon Monitoring for Action ) monitors CO2 emissions in the over 50,000 power plants world wide. According to their data, there are 600 out of 9,000 power plants in the US which emit CO2 at a rate above 2.7 lbs/kilowatt-hour. These 600 plants generate just 5% of the US electrical power but emit 441 million tons of CO2 every year which represents 12% of all US power plant CO2 emissions.

According to EPA's "Emission Facts" report (EPA420-F-00-013) 0.9 lbs of CO2/mile is the average CO2 emissions for a passenger ICE vehicle. If PHEV's drew power from just the 5% worst polluting power plants alone, then they would exceed 0.9 lbs of CO2/mile (assuming an average PHEV gets 3 miles out of 1 kilowatt-hour), and thus contribute larger amounts of CO2 to the atmosphere than an average vehicle.

However, this is a ludicrous comparison on three counts. First, it fails to take into account that electricity is drawn from a variety of sources. Thus, a more appropriate comparison is to look at the US's average CO2 emission rate for power plants. With an average US emission rate of 1.2 lbs/kilowatt-hour, CO2 emissions for PHEV'S and BEV's would be reduced by over half. Secondly, it fails to take into account the time of day battery charging would take place. The period of peak electricity demand happens during the day. Anything from air conditioning, computers, dryers, and washing machines causes a huge surge in electricity. To accommodate the surge, extra power is often supplied by “peak” power plants. These plants often generate electricity from some of the most inefficient and polluting plants in the US. In contrast, many of the PHEV's would be charged at night, when the most efficient and least polluting power plants would be used. Lastly, and most importantly, PHEV's use electricity without regards to how it was created. Whether or not PHEV's take to the road, it does not hide the fact that we already have polluting plants. In some ways, you can borrow from the expression, “don't shoot the messenger”. The discussions about PHEV's rightly point out issues with polluting plants, but most certainly these discussions do not point out fundamental faults with PHEV technology. In fact it is just the opposite. Because electricity is not fundamentally tied to any particular energy source, PHEV's represent a major shift away from an oil monopoly to an open energy market where various technologies (like oil, coal, solar, hydro, nuclear, and biofuels) can compete on a level playing field. Because such large incentives are being placed on clean, renewable energy sources, the US power plants will likely be replaced over the next few decades with cleaner ones. PHEV's, consequently, will benefit indirectly.

Since 50% of the power being generated from the US is from coal, some might argue coal-fired power plants are here to stay and that they will continue to pollute at or close to levels of ICE vehicles. That, too, is debatable. Newer coal plant technologies which use coal gasification offer higher efficiency. One example is the coal-fired Polk power plant put[[ into operation in 1996. In 2000, it generated 2,007,142 Megawatt-hours at an intensity of 1.2 lbs/kilowatt hour of CO2. At that rate, CO2 emissions of PHEV's could be half those of conventional ICE vehicles. So even if all US power plants were burning coal, overall automobile-related CO2 emissions could still be reduced. (it is interesting to note, however, that in 2007, the same Polk power plant generated 25% more electric energy but ended up doubling the CO2 emissions (2.4 lbs/kilowatt-hour))

Some people argue that the existing power plants in the US do not have the capacity to generate enough power for a PHEV society. To give you an idea, 12,000 miles a year from a PHEV would likely translate to about 8,000 miles of equivalent electrical energy (the other 4,000 miles would come from gasoline). That would translate to an average of 7.3 kilowatt hours per day of electricity usage, or perhaps 25% of a consumers total electric consumption. The difference between peak electricity usage from day (in California, 39 Gigawatts) compared to minimum electricity usage at night (23 Gigawatts) represents a 5:3 difference in power, which suggests that much of the electrical load can be absorbed at night without significantly affecting the existing power infrastructure.

As another point, HEV's were first introduced in 2000 (Toyota Prius). However, 8 years later HEV's market share doesn't represent more than 2% of the total light-vehicle market in the US. PHEV market penetration will likely take a number of years, which means two things. First PHEV power consumption may not increase faster than the anticipated energy demands over the foreseeable future. Secondly, companies have enough time to install new power plants to anticipate expected demand from a gradual but definitive increase in market share of electrically powered vehicles. Consumers may be more open to plant and power-line construction if it reduces smog in their home area.

Another misconception about PHEV's relates to the electric range. Some might argue that there is no real advantage to a PHEV compared to an ICE vehicle if the commute distance is greater than the range of a PHEV. The reasoning goes that the PHEV would have to use gasoline and thus is just as gas guzzling as the traditional ICE vehicles. The fallacy here lies in the fact that people take many trips in the car that are less than the average commuter distance (i.e. driving to the grocery store, bank, etc.). Furthermore, a PHEV can still use electric energy for part of the trip which in itself has considerable gas savings. For example, a PHEV with a 20 mile range can drive half of a 40-mile round-trip commute. For the remaining 20 miles , the PHEV can act like an HEV. If the individual went to work 200 times a year, over 100 gallons of gas per year could be saved.

HEV vs Diesel

Before I can compare HEV and Diesel against PHEV's, I need to preface it with a comparison of diesel and gasoline. The Union of Concerned Scientists (UCS) published “The Diesel Dilemma: Diesel's Role in the Race for Clean Cars” in January 2004. The paper outlines pros and cons for the US to pursue diesel or gasoline as a way to maximize fuel efficiency while reducing pollutants and global warming gases. Diesel was a “bad word” in the 70's because the diesel cars then were noisy, smelly and unreliable. Since then, the diesel engine has improved dramatically and now 40% of vehicles in Europe are diesel. Still, the US has not “gone diesel”, and for just 5% of cars on the road are diesel. Diesel engines operate at higher temperatures and at a higher efficiency. However, a few facts from the UCS report should be noted:

1. The processing of diesel requires 25% more oil than that for an equivalent amount of gasoline and results in 17% more emissions of heat trapping gases

2. Today's diesel engines produce substantially more toxic soot and smog forming nitrogen oxides than the average gasoline vehicle. As of 2004, no diesel vehicle was even capable of meeting the US average emissions standards

3. Diesel vehicles can travel 30 to 40% farther with an equivalent amount of fuel, but part of that comes from the fact that diesel has 13% more specific energy than gasoline.

4. Diesel engines cost more than gasoline engines. The reports states that using fuel efficient gasoline vehicles provides up to $700 of savings versus equivalent diesel vehicles over the life of the vehicle.

5. Diesel is cheaper than gasoline in Europe largely due to unequal taxation of the two fuels.

While diesel vehicles offer gasoline reduction, suffice it to say, that high emissions, high up-front costs, and questionable fuel efficiency when compared to HEV's may be factors prohibiting diesel's popularity in the US market. In fact, the future of diesel may depend on future US emissions regulations. If there is a universal standard for vehicle emissions that is technology blind, diesel may have trouble competing with the cleaner gasoline HEV's. However, if US policy dictates two different emission standards, where aspects of the emissions would be less strict for diesel, then diesel may have an opportunity in the US. Of course, public acceptance of diesel engines is an entirely different story.

HEV vs PHEV

HEV's offer oil savings compared to the conventional gas-run ICE vehicle with fuel economies ranging from 30 to 50 mpg (conventional vehicle 25 mpg). One might argue that the comparable gas savings from HEV would be more than adequate to stem increased oil consumption in the US. The 2007 Toyota Prius has an economy of 44 MPG and a CO2 emissions of 110 g/km (0.4 lbs/mile vs conventional vehicle of 0.9 lbs/mile). While it is true that considerable gas savings can be accomplished by taking advantage of HEV technology and smaller vehicles, worldwide demand of oil is likely to increase as countries like India and China increasingly consume gasoline. One additional factor from these two countries is the recent availability of inexpensive vehicles. India's auto-manufacturer, Tata, introduced the wildly popular Indica a few years ago. Tata is now developing an even cheaper car with a price tag of $2,200. In China, the Chery QQ3, priced around $5,000 was introduced in 2003. Inexpensive cars, double digit growth economies, and a growing middle class suggest a recipe for mammoth energy consumption in the foreseeable future. In November of 2007, the International Energy Agency estimated that by 2030, demand for worldwide energy will rise by 55% where 70% of the increased demand will come from China and India.

While demand for oil is likely to increase, available petroleum reserves are in question. The term “peak oil” is the point in time where maximum oil production is reached. As easily-extractable petroleum reserves become scarce, oil production is expected to peak. Many have suggested “peak oil” will be reached in the 2000 to 2015 time frame. In reality, on the basis of supply and demand, more expensive oil prices make it possible to employ more expensive oil extraction techniques. Oil reserves that were here-to-fore unexplorable at an oil price of $30/barrel may become economically feasible at an oil price of $100/barrel.

Thus, the price of oil alone may force an urgency to seek alternative fuel sources for vehicles. PHEV's whose energy source is anything that can produce electricity offers an attractive liberation from future oil limitations. On the issue of CO2 emissions, as more vehicles hit the road in developing countries vehicle CO2 emissions must be reduced to maintain a zero-gain global CO2 emission policy. PHEV's offer 30% to 40% reduction in CO2 emissions, but to further reduce those emissions, better vehicle technologies or alternative energy sources become a must. The PHEV, of course, is ideally suited to accommodate the latter.

Conclusion

With a forecast of increased oil consumption worldwide and consequently, high gas prices, PHEV's may make economical sense, but they make environmental and foreign policy sense, too. Compared to ICE vehicles, diesels, and HEV's, PHEV's offer the most dramatic reduction in global warming gases, smog forming gases, and oil consumption. Even with the U.S.'s coal-dominated power plants, PHEV's are still cleaner in almost every way. By using electricity instead of gasoline, PHEV's will encourage a shift away from an oil monopoly to an open energy market of fossil fuels and renewable energy. Despite all these great benefits, it still remains to be seen when manufacturers can make them affordable. Time will tell, but no doubt the count down to the PHEV has already begun.

by Seth Hollar

March 20, 2008

Increasing gasoline prices have resulted in a corresponding increase in sales of hybrid electric vehicles (HEV) which offer improved gas mileage and a reduction in emissions. A hybrid vehicle uses a combination of an electric motor and an internal combustion engine (ICE) to drive the vehicle. However, only until recently has the concept of the hybrid car become economically feasible. One prohibiting factor has been the cost of rechargeable batteries with upwards of an $1000/kilowatt-hour price tag. With oil going in the $100/barrel range, and the average U.S. consumer gasoline price at over $3/gallon, the scale has tipped in favor of the fuel efficient hybrid vehicles. Though the cost of a hybrid vehicle is a few thousand dollars over the price of a comparable ICE vehicle, these upfront costs usually can be paid back in 5 to 10 years through gas savings.

What is a HEV?

Conceptually, the HEV’s added fuel efficiencies derive from three major factors: 1) In HEV’s, an intelligent control system optimizes fuel efficiency by balancing the loads between the ICE and the electric motor, 2) with the addition of an electric motor, the ICE can be smaller. During peak acceleration demands, both the ICE and electric motor can work together, 3) energy can be recaptured using regenerative braking which charges the battery instead of dissipating heat.

While HEV’s offer improved fuel efficiency, energy is wholly derived from gasoline. The battery capacity is usually relatively small, just enough to balance the load between the ICE and electric motor, and is too small for the vehicle to travel any reasonable distance by the electric motor alone.

On the other hand, plug-in hybrid electric vehicles (PHEV) offer the choice of using either gas or electricity. Architecturally, the PHEV is identical in make-up to the HEV. Both have an ICE, battery and electric motor. The fundamental difference, however, lies in the energy capacity of the battery. PHEV’s battery capacity typically allows the vehicle to go 25 to 60 miles on a single charge. With such a large battery, most commuters can do all their driving in a day on a single battery charge and, therefore, without ever using the gasoline.

What is a PHEV?

The PHEV contains a “plug” which can be connected to a vehicle charger to recharge the batteries. “Plugging” in the vehicle is almost identical to plugging in a home appliance into an electrical outlet. The vehicle can be charged at home at night when electricity rates are low. In cases where the PHEV drives a distance longer than what can be supplied by battery, the ICE takes over. In the concept car, the Chevrolet Volt by GM, the ICE is not connected to the drive train, but instead is connected only to a generator which in turn supplies electricity to the battery and electrical motor. Other conceptual PHEV’s, act much more like HEV’s in the sense that the ICE is mechanically connected to the wheels through a drive-train, driving the car and charging the battery at the same time.

When do PHEV’s become economically feasible to the consumer?

There are two important metrics in evaluating the market of PHEV’s: the gas and electricity costs (measured as USD/mile) and upfront battery cost. The 2007 Toyota Prius’ claim an efficiency of 3 miles/kilowatt-hr in electric mode. Some suggest, small to medium sized PHEV vehicles could do as well as 5 miles/kilowatt-hr. At 10 cents/kilowatt hour, a PHEV modified Prius would be about 3 cents/mile. At $3/gallon for gas, a Prius with 45 miles/gallon fuel efficiency would have a fuel cost of 6.7 cents/mile. An ICE vehicle car having 25 miles/gallon would yield 12 cents/mile. The total savings for pure electric driving for 15,000 miles in a year would be about $1300 compared to a conventional car. This figure is bit a biased because it assumes the vehicle would never be driven beyond the battery range, and thus never use any gas. I suggest a more reasonable savings would be in the range from $1000. The point at which PHEV’s become affordable, therefore, depends on the price of the batteries.

Batteries Costs

HEV’s cost about $3,000 more than conventional vehicles. PHEV’s would have a higher cost due to the larger batteries. Current automotive battery technology for HEV’s is based on nickel metal hydrides (NiMH). Even though NiMH batteries have passed through the rigors of the automotive industry, their potential pales when compared to next generation lithium batteries. NiMH batteries have an energy density of 70 Watt-hours/kilogram and, they generally need to maintain a narrow state of charge – deviating out of this narrow window degrades the battery’s lifetime. Furthermore, NiMH batteries are limited in temperature range and recharging lifetime. Additionally, because Nickel metal is a supply limited resource, the price of nickel fluctuates and consequently, so do the battery prices.

The HEV-industry is now moving towards lithium-based batteries whose energy densities (over 100 Watt-hours/kg) are higher than NiMH batteries. Furthermore, lithium is a plentiful resource and will not likely, be subjected to large swings in prices. In contrast to the 2007 Prius HEV which uses a 1.3 Kilowatt-hour NiMH battery cell (cost $1-2K), PHEV’s may need a battery capacity of 9 Kilowatt-hours which, if we were to estimate the price of automotive lithium batteries, would be at least $1K/kilowatt-hour or $9K total. Include another $3000, for the additional electronics, motors, and drive-trains, then the total cost would be about $12,000 total above the cost of a conventional vehicle. With those numbers, it would take at least 10 (maybe even 15 to 20) years to make up the cost of the PHEV. Nonetheless, a number of companies are developing automobile batteries using Lithium Ion technology and banking on the fact that mass production will dramatically reduce the price.

Recently, a considerable amount of private sector money has poured into the lithium battery market. Two companies leading in this space are A123 Systems who received $132 million in funding and Boston-Power, a portable lithium battery company, which received $68 million in funding. Some, like battery consultant, Menahem Anderman, have even suggested the automotive lithium battery market could be over $1 billion by 2015.

Lithium batteries are not anything new to the consumer industry. First introduced commercially in the early ’90s by Sony, lithium is the battery technology of choice for portable electronics. Over the years, manufacturers have been steadily increasing the energy density and improving upon price. Current consumer lithium batteries cost about $350/kilowatt-hour. However, the batteries lose significant charging capacity from year to year and total battery failure occurs at a quick 3 to 5 years. Manufacturers have steadily put increasing amounts of energy in lithium batteries. Current batteries have an electrical energy density of about 1/6 that of TNT explosives. However, battery manufacturers have only sought to band-aid safety problems without really addressing the issue. In so doing, reports of laptop fires have increased steadily since 2005, but still remain low. From 2001 to August 2006, the Consumer Product Safety Commission has received 47 reports of laptops that were either smoking or on fire. Although small in number, a handful of incidents which included Sony’s battery recall in 2006 thrust the safety issue into the public spotlight.

Lithium batteries will likely find their way into the PHEV market, but safety has become a forefront issue in its adoption. Never mind the fact that gasoline itself is highly combustible, and the U.S. Fire Administration estimates that 325,100 vehicle fires occurred annually between 1999 and 2003, and 2% of those started in the fuel tank or fuel line area. Comparatively speaking, lithium batteries seem safer than gasoline tanks, but new technologies are always held to a higher standard than the status quo. Car accidents themselves could precipitate fires if conventional lithium batteries were punctured, and fire from a 9000 watt-hour battery could be much larger than one from a laptop’s 60 watt-hour battery. Because of the larger size required for automobile applications, such batteries would need to be much safer than their portable battery counterparts.

Additionally, automotive batteries may need to last much longer than the 3-5 years of a consumer electronic device. A common metric used is the number of charge/recharge cycles. Conventional lithium batteries need to have 80% capacity at 300 charge/discharge cycles. If a PHEV were recharged everyday, such batteries may start to significantly degrade after just a year. NiMH batteries in the Toyota Prius are guaranteed to last 100,000 miles or 8 years. It would not be surprising to see auto-manufacturers looking for batteries lasting 10 years or, equivalently, 3000 recharge cycles. A handful of companies have claimed their batteries can last anywhere from 5,000 to 20,000 recharges bringing up the possibility that batteries may last longer than the vehicles, themselves.

Much of the research into Lithium batteries explores the anode-cathode materials and chemistry. Conventional Li batteries use cobalt oxide cathodes which are sensitive to temperature and make the battery susceptible to thermal run-away (explosive). New chemistries explore metal phosphate cathodes which less dependent on temperature and therefore, inherently safer. Tesla Motors, an EV start-up company, uses conventional lithium batteries, but to avoid overheating, separates packs of cells with liquid cooling and includes a number of sensors to constantly monitor battery temperature. Academic research since 2006 exploring both nano-structured cathodes and different chemistries has suggested that lithium battery energy density can by increased multiple-fold. However, much of the technology is still in research and it could be a number of years before the technology becomes commercializable.

Despite the relatively large obstacles of cost, safety, and reliability, lithium ion batteries have made important strides towards commercialization. Sanyo Electric and Sony have traditionally been the leaders in Lithium ion technology for hand-held devices, but a few US start-ups are trying to leap-frog the big Japanese makers. A few of these companies have already started manufacturing lithium ion batteries of their own.

GM has contracted with an MIT startup, A123 Systems, and a South Korean chemical maker, LG Chem Ltd. to produce batteries for the Chevrolet Volt. Altair Nanotechnologies’ NanoSafe lithium ion batteries power Phoenix Motors’ EV Trucks (to be made available to the public in 2009). The battery prices range from $1500 to $2500/kilowatt-hour. Other than using the consumer lithium batteries as a benchmark ($350/kilowatt-hours), these new companies have not been very clear on how mass manufacturing can significantly reduce price. Think Nordic, an electric vehicle company based in Oslo Norway, is contracting with EnerDel, a subsidiary of Ener1, for their phosphate-based Lithium ion batteries. Valence Technologies Inc., based in Austin, TX, is working with a small company, Energy Control Systems Engineering (EnergyCS), a privately held company based in Monrovia, California, to produce an Electric Vehicle. EdriveSystems, part of EnergyCS, makes PHEV conversion kits for Toyota Prius’ using Valence’s batteries. Hymotion, whose parent company is A123 Systems, also makes PHEV conversion kits.

Conclusion

In summary, PHEV’s are a new generation of vehicles which could be available to the consumer as near as the year 2010. While they promise reduced emissions and increased fuel savings, their success, however, depends heavily on the mass manufacture of safe, inexpensive lithium batteries. Start-ups and established companies, alike, seem confident that the safety issue can be addressed, especially, with different, inherently safer cathode chemistries. Additionally, battery companies are relying on the mass production to significantly bring prices down under $500/kilowatt-hour, but details as to how and to what extent remain sketchy. If successful, however, the car might go through a change not experienced since the first model-T came off the assembly line.

by Seth Hollar

March 20, 2008