Most fuel cells designed for use in vehicles produce less than 1.16 volts of electricity-far from enough to power a vehicle. Therefore, multiple cells must be assembled into a fuel cell stack. The potential power generated by a fuel cell stack depends on the number and size of the individual fuel cells that comprise the stack and the surface area of the PEM.
Before FCVs make it to your local auto dealer, significant research and development is required to reduce cost and improve performance. We must also find effective and efficient ways to produce and store hydrogen and other fuels.
Automakers, fuel cell developers, component suppliers, government agencies, and others are working hard to accelerate the introduction of FCVs. Partnerships such as the DOE-led FreedomCAR initiative and the California Fuel Cell Partnership have been formed to encourage private companies and government agencies to work together to move these vehicles toward commercialization.
FreedomCAR
FreedomCAR is a new cooperative research effort between the DOE and the U.S. Council for Automotive Research (Ford, General Motors, and DaimlerChrysler) formed to promote research into advanced automotive technologies, such as FCVs, that may dramatically reduce oil consumption and environmental impacts. FreedomCAR's goal is the development of cars and trucks that are:
California Fuel Cell Partnership (CaFCP)
The California Fuel Cell Partnership is a collaboration of auto companies, fuel providers, fuel cell technology companies, and government agencies demonstrating fuel cell electric vehicles in California under day-to-day driving conditions. The goals of the partnership are to test and demonstrate the viability of FCVs and related technology under real-world conditions, move them toward commercialization, and increase public awareness. The Partnership expects to place about 60 FCVs and fuel cell buses on the road by 2003.In the archetypal hydrogen–oxygen proton exchange membrane fuel cell (PEMFC) design, a proton-conducting polymer membrane, (the electrolyte), separates the anode and cathode sides. This was called a "solid polymer electrolyte fuel cell" (SPEFC) in the early 1970s, before the proton exchange mechanism was well-understood. (Notice that "polymer electrolyte membrane" and "proton exchange membrane" result in the same acronym.)
On the anode side, hydrogen diffuses to the anode catalyst where it later dissociates into protons and electrons. These protons often react with oxidants causing them to become what is commonly reffered to as multi-facilitated proton membranes (MFPM). The protons are conducted through the membrane to the cathode, but the electrons are forced to travel in an external circuit (supplying power) because the membrane is electrically insulating. On the cathode catalyst, oxygen molecules react with the electrons (which have traveled through the external circuit) and protons to form water — in this example, the only waste product, either liquid or vapor.
In addition to this pure hydrogen type, there are hydrocarbon fuels for fuel cells, including diesel, methanol (see: direct-methanol fuel cells) and chemical hydrides. The waste products with these types of fuel are carbon dioxide and water.
The materials used in fuel cells differ by type. The electrode–bipolar plates are usually made of metal, nickel or carbon nanotubes, and are coated with a catalyst (like platinum, nano iron powders or palladium) for higher efficiency. Carbon paper separates them from the electrolyte. The electrolyte could be ceramic or a membrane.
A typical PEM fuel cell produces a voltage from 0.6 V to 0.7 V at full rated load. Voltage decreases as current increases, due to several factors:
To deliver the desired amount of energy, the fuel cells can be combined in series and parallel circuits, where series yield higher voltage, and parallel allows a stronger current to be drawn. Such a design is called a fuel cell stack. Further, the cell surface area can be increased, to allow stronger current from each cell.
http://en.wikipedia.org/wiki/Fuel_cellThis emerging technology has the potential to significantly reduce energy use and harmful emissions, as well as our dependence on foreign oil. FCVs will have other benefits as well.
A Radical Departure
FCVs represent a radical departure from vehicles with conventional internal combustion engines. Like battery-electric vehicles, FCVs are propelled by electric motors. But while battery electric vehicles use electricity from an external source (and store it in a battery), FCVs create their own electricity. Fuel cells onboard the vehicle create electricity through a chemical process using hydrogen fuel and oxygen from the air.
FCVs can be fueled with pure hydrogen gas stored onboard in high-pressure tanks. They also can be fueled with hydrogen-rich fuels; such as methanol, natural gas, or even gasoline; but these fuels must first be converted into hydrogen gas by an onboard device called a "reformer."
FCVs fueled with pure hydrogen emit no pollutants; only water and heat; while those using hydrogen-rich fuels and a reformer produce only small amounts of air pollutants. In addition, FCVs can be twice as efficient as similarly sized conventional vehicles and may also incorporate other advanced technologies to increase efficiency.
A fuel cell is an electrochemical energy conversion device. It produces electricity from various external quantities of fuel (on the anode side) and oxidant (on the cathode side). These react in the presence of an electrolyte. Generally, the reactants flow in and reaction products flow out while the electrolyte remains in the cell. Fuel cells can operate virtually continuously as long as the necessary flows are maintained.
Fuel cells are different from batteries in that they consume reactant, which must be replenished, while batteries store electrical energy chemically in a closed system. Additionally, while the electrodes within a battery react and change as a battery is charged or discharged, a fuel cell's electrodes are catalytic and relatively stable.
Many combinations of fuel and oxidant are possible. A hydrogen cell uses hydrogen as fuel and oxygen as oxidant. Other fuels include hydrocarbons and alcohols. Other oxidants include air, chlorine and chlorine dioxide.
Stationary
More than 2500 fuel cell systems have been installed all over the world — in hospitals, nursing homes, hotels, office buildings, schools, utility power plants - either connected to the electric grid to provide supplemental power and backup assurance for critical areas, or installed as a grid-independent generator for on-site service in areas that are inaccessible by power lines.
Fuel cell power generation systems in operation today achieve 40 percent fuel-to-electricity efficiency utilizing hydrocarbon fuels. Since fuel cells operate silently, they reduce noise pollution as well as air pollution and when the fuel cell is sited near the point of use, its waste heat can be captured for beneficial purposes (cogeneration). In large-scale building systems, these fuel cell cogeneration systems can reduce facility energy service costs by 20% to 40% over conventional energy service and increase efficiency to 85 percent. Check out our database of worldwide stationary fuel cell installations.
Telecommunications - With the use of computers, the Internet, and communication networks steadily increasing, there comes a need for more reliable power than is available on the current electrical grid, and fuel cells have proven to be up to 99.999% (five nines) reliable. Fuel cells can replace batteries to provide power for 1kW to 5kW telecom sites without noise or emissions, and are durable, providing power in sites that are either hard to access or are subject to inclement weather. Such systems would be used to provide primary or backup power for telecom switch nodes, cell towers, and other electronic systems that would benefit from on-site, direct DC power supply.
Landfills/Wastewater Treatment Plants/Breweries - Fuel cells currently operate at landfills and wastewater treatment plants across the country, proving themselves as a valid technology for reducing emissions and generating power from the methane gas they produce. They are also installed at several breweries - Sierra Nevada, Kirin, Asahi and Sapporo. Untreated brewery effluent can undergo anaerobic digestion, which breaks down organic compounds to generate methane, a hydrogen rich fuel.
Transportation
Cars - All the major automotive manufacturers have a fuel cell vehicle either in development or in testing right now, and several have begun leasing and testing in larger quantities. Commercialization is a little further down the line (some automakers say 2012, others later), but every demonstration helps bring that date closer. Check out our page on Benefits for Transportation and for a comprehensive chart showcasing all the fuel cell vehicles ever demonstrated, visit our Charts page.
Buses - Over the last four years, more than 50 fuel cell buses have been demonstrated in North and South America, Europe, Asia and Australia. Fuel cells are highly efficient, so even if the hydrogen is produced from fossil fuels, fuel cell buses can reduce transit agencies’ CO2 emissions. And emissions are truly zero if the hydrogen is produced from renewable electricity, which greatly improves local air quality. Because the fuel cell system is so much quieter than a diesel engine, fuel cell buses significantly reduce noise pollution as well. For a comprehensive chart on fuel cell buses, click here.
Scooters - In spite of their small size, many scooters are pollution powerhouses. Gas-powered scooters, especially those with two-stroke engines, produce tailpipe emissions at a rate disproportionate to their small size. These two-stroke scooters produce almost as much particulate matter and significantly more hydrocarbons and carbon monoxide as a heavy diesel truck. Fuel cell scooters running on hydrogen will eliminate emissions - in India and Asia where many of the population use them - this is a great application for fuel cells.
Forklifts/Materials Handling - Besides reducing emissions, fuel cell forklifts have potential to effectively lower total logistics cost since they require minimal refilling and significantly less maintenance than electric forklifts, whose batteries must be periodically charged, refilled with water, and replaced. Due to the frequent starting and stopping during use, electric forklifts also experience numerous interruptions in current input and output - fuel cells ensure constant power delivery and performance, eliminating the reduction in voltage output that occurs as batteries discharge.
Auxiliary Power Units (APUs) - Today’s heavy-duty trucks are equipped with a large number of electrical appliances–from heaters and air conditioners to computers, televisions, stereos, even refrigerators and microwaves. To power these devices while the truck is parked, drivers often must idle the engine. The Department of Energy (DOE) has estimated the annual fuel and maintenance costs of idling a heavy-duty truck at over $1,800 and that using fuel cell APUs in Class 8 trucks would save 670 million gallons of diesel fuel per year and 4.64 million tons of CO2 per year.
Trains - Fuel cells are being developed for mining locomotives since they produce no emissions. An international consortium is developing the world’s largest fuel cell vehicle, a 109 metric-ton, 1 MW locomotive for military and commercial railway applications.
Planes - Fuel cells are an attractive option for aviation since they produce zero or low emissions and make barely any noise. The military is especially interested in this application because of the low noise, low thermal signature and ability to attain high altitude. Companies like Boeing are heavily involved in developing a fuel cell plane.
Boats - For each liter of fuel consumed, the average outboard motor produces 140 times the hydrocarbonss produced by the average modern car. Fuel cell engines have higher energy efficiencies than combustion engines, and therefore offer better range and significantly reduced emissions. Iceland has committed to converting its vast fishing fleet to use fuel cells to provide auxiliary power by 2015 and, eventually, to provide primary power in its boats.
Portable Power
Fuel cells can provide power where no electric grid is available, plus they are quiet, so using one instead of a loud, polluting generator at a campsite would not only save emissions, but it won't disturb nature, or your camping neighbors. Portable fuel cells are also being used in emergency backup power situations and military applications. They are much lighter than batteries and last a lot longer, especially imporant to soldiers carrying heavy equipment in the field.
Micro Power
Consumer Electronics- Fuel cells will change the telecommuting world, powering cellular phones, laptops and palm pilots hours longer than batteries. Companies have already demonstrated fuel cells that can power cell phones for 30 days with out recharging and laptops for 20 hours. Other applications for micro fuel cells include pagers, video recorders, portable power tools, and low power remote devices such as hearing aids, smoke detectors, burglar alarms, hotel locks and meter readers. These miniature fuel cells generally run on methanol, an inexpensive wood alcohol also used in windshield wiper fluid.
A fuel cell is an electrochemical device that combines hydrogen and oxygen to produce electricity, with water and heat as its by-product. As long as fuel is supplied, the fuel cell will continue to generate power. Since the conversion of the fuel to energy takes place via an electrochemical process, not combustion, the process is clean, quiet and highly efficient – two to three times more efficient than fuel burning.
No other energy generation technology offers the combination of benefits that fuel cells do. In addition to low or zero emissions, benefits include high efficiency and reliability, multi-fuel capability, siting flexibility, durability, scalability and ease of maintenance. Fuel cells operate silently, so they reduce noise pollution as well as air pollution and the waste heat from a fuel cell can be used to provide hot water or space heating for a home or office.
Selected BRAVIA TV models offer important benefits.
Standard on BRAVIA X series models and the BRAVIA D3000 model, Motionflow +100Hz technology has a really important job. It captures all the detail and drama of fast-moving action scenes, such as sports, and makes them ultra smooth.
Motionflow works by doubling up the number of frames you see on screen. New ones are inserted into fast-moving sequences, like the flight of a ball for instance, to smooth out the motion.
Based on information it gets from the before and after frames in every sequence, Motionflow cleverly creates brand new pictures to do this. So existing frames aren’t just copied and doubled up.
To display the film, they have to double the original number of frames by duplicating existing ones and speeding the film up, which noticeably distorts synchronisation. They even raise the pitch of the actors’ voices.
24p True Cinema matches the original speed to capture the power and quality of the studio recording.
The 24p format is detected by your Blu-ray Disc player or PLAYSTATION®3 and outputted directly to the TV in 24 frames per second. What you see is exactly how it was originally recorded.
Design
The KDL-40D3500 is the embodiment of Sony's design philosophy with a chic matte black understated presence that simply oozes class. Build quality is back to its very best with the Sony looking like it could have been sculpted from a solid block of metal.
Features
A change in model number from 3000 to 3500 would suggest that the KDL-40D3500 represented a relatively minor upgrade from its predecessor the KDL-40D3000. However, the changes in specification are more wide ranging than you would imagine.
Screen: 40in 16:9 Tuner: Digital Sound System: Nicam Resolution: 1920 x 1080 Contrast Ratio: 1800:1 (16,000 dynamic) Brightness: 450cd/m2 Other Features: Bravia Picture Processing Engine, Live Colour Creation, 24p True Cinema. Sockets: 2 HDMI, 2 SCART, Component Video, Composite Video, PC input.
To begin with, the 40D3500 gains a Full HD (1920 x 1080) resolution which can potentially give a marked improvement in the display of sources such as Sky Tv (1080i). The 1080 lines of resolution match the resolution of the screen negating the need for any picture scaling to fit. If you have a device which outputs pictures in the superior 1080p (e.g. Sony's PlayStation 3) the 3500 can accept those pictures in their full glory.
'Motionflow +100Hz' technology (featured on the 40D3000) which doubles the number of frames shown from 50 to 100 by interpolating an extra frame in between each source frame does not feature on the 40D3500.
With 2 HDMI inputs, the 3500 has one less than the 3000 model. Otherwise, the specification of both screens are largely similar.
The Sony 40D3500 is equipped with '24p True Cinema' which enables the panel to display films at their intended 24fps (frames per second).
Alongside 24p True Cinema is Sony's 'Theatre Mode' technology which adjusts colour, contrast and brightness settings to makes movies look as authentic as the original.
It is worth mentioning that the 24p mode comes into its own with High Definition (Blu-ray or HD DVD) players which allow you to play movies at their original speed. The original 'cine' film is generally recorded at 24 frames per second, which in the absence of '24p True Cinema' is speeded up to 25 (standard for most TV's) frames per second with an accompanying increase in audio pitch.
Colour reproduction on the KDL40D3500 should offer smoother transitions than previous Sony LCD's with a new 10-bit panel offering 1024 shades of gradation.
Theatre Sync, which is Sony's name for CEC (Consumer Electronic Control), is a control standard that functions over HDMI 1.3. The technology facilitates one-touch control over compatible devices and in practice means that if you fire up your compatible DVD player, the all connected devices such as your LCD TV will also spring into life.
Sonically, the KDL-40D3500 comes equipped with Sony's S-Force Front Surround which is their latest virtual surround sound technology.
Performance
Although specification has changed considerably between the 3500 and 3000 models, performance comparisons reveal a not so dramatically differing performance.
As with the previous model, High Definition (HD) is where the Sony KDL-40D3500 excels. Hook up a 1080p capable source however, and you have even more pristine pictures. The KDL-40D3500 displays a clarity and sharpness that make you want to reach out and touch objects or people as they glide across the screen. Colours are wonderfully vibrant and reach a level of authentic realism to match any LCD.
Although black levels are still behind the best that plasma can offer, the KDL-40D3500 has made great strides in this area from previous Sony's. Shadow detailing now takes on a subtlety which is a match for any 40in LCD currently out there.
Again, Standard Definition (SD) performance suffers to a degree from some of the inconsistencies that creep into a picture as a result of the conversion of a 576p source to an HD ready screen configuration.
The effectiveness of Sony's Motionflow +100Hz has always been open to question, and the fact that the 40D3500 does not seem to suffer too much from its departure suggests that this technology is not quite the complete article as yet. There was some evidence of a little more motion blur and shimmering than on the 3000, and the picture did appear to be very slightly 'grainy', but not to any great degree. The picture quality is still pretty good, but you'll have a hard time shifting down from HD because the picture is so outstanding in this respect.
Finally, if there is a 40in LCD TV out there with a richer or more precise colour palette, we have yet to see it. The range, depth and subtlety in this respect is simply outstanding. The most intricate of detailing such as skin tone is realised with class leading performance.
Conclusion
The Sony KDL-40D3500 is a highly accomplished performer when it comes to High Definition material. However, if SD viewing is just as important there are better performers out there.
| 40in LCD | |||||||||||
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| Peerless HD performance tempered by slightly disappointing SD pictures. | |||||||||||
| HD Ready: | yes | ||||||||||
| Resolution: | 1920 x 1080 | ||||||||||
| Rating: | 89% | ||||||||||
