This is Roger Pham's Typepad Profile.
Join Typepad and start following Roger Pham's activity
Join Now!
Already a member? Sign In
Roger Pham
Recent Activity
Too scary...Terror from you're not even safe even from inside your house. Being run-over by terrorist on a side walk is scary enough, but having something like a plane strike at any time and from everywhere from the thousands of small planes flying above you at any given time...+is really scary. If Uber, Tesla, and other autonomous driving cars can't master control in 2-dimensions, how on earth are they to be trusted operating in 3-D space with much higher risk of public harms?
Though simple, this serial hybrid setup is wearing out the battery pack much faster than Toyota's HSD hybrid. For that reason Nissan chooses to release the e-Power in Japan and not in the USA. Cars in Japan are driven 1/3rd the mileage of cars in the USA.
sd stated: "The problem I have with "clean hydrogen" is than it uses electric power that otherwise could be used more efficiently. The round trip efficiency for electrolysis, compression and back to electricity via fuel cell is 25-30% and with battery storage, it is probably around 90%, so the efficiency is about 1/3." 1) For combined power and heat or for just heating, Hydrogen's efficiency is 100%. With Electrolysis at 87% efficient on Higher Heating Basis (HHV), then we can look at a round-trip efficient of around 83%, subtracting losses during transportation and storage. Not bad! 2) A strategy for maximize efficiency would be to use battery for storage of excess Solar and Wind energy for immediate re-use (daily basis), while use Hydrogen via electrolysis when all the grid-utility batteries are all maxed out, use the Hydrogen for seasonal-scale e-storage at very low cost per kWh of energy capacity. Able to store otherwise-wasted grid-excess Solar and Wind energy will give new meaning to EFFICIENCY. Nothing can be more efficient than be able to use otherwise WASTED energy. 3) When stored in deep underground reservoirs, it only costs around $1 per kWh of Hydrogen storage capacity, vs $300 to $500 per kWh of grid-utility battery for e-storage. Do you see the whole picture now? 4) WE are NOT ruling out battery for e-storage of grid-excess RE, we are simply using Hydrogen ADDITIONALLY, to augment the capacity of the grid-utility battery. It not the question of battery VERSUS hydrogen, it is battery AND hydrogen.
Hi E-P and thanks for your feedback. What I have in mind is the following, from Wikipedia page of "Digital Protective Relay" that can be used to detect grid overload/ high-power demand situation to decide to start charging or to stop charging. Thus, a Plug-in EV can have detector of grid power situation to permit charging or stop charging. "The digital protective relay is a protective relay that uses a microprocessor to analyze power system voltages, currents or other process quantities for the purpose of detection of faults in an electric power system or industrial process system. A digital protective relay may also be called a "numeric protective relay". Input processing Low voltage and low current signals (i.e., at the secondary of a voltage transformers and current transformers) are brought into a low pass filter that removes frequency content above about 1/3 of the sampling frequency (a relay A/D converter needs to sample faster than twice per cycle of the highest frequency that it is to monitor). The AC signal is then sampled by the relay's analog to digital converter from 4 to 64 (varies by relay) samples per power system cycle. As a minimum, magnitude of the incoming quantity, commonly using Fourier transform concepts (RMS and some form of averaging) would be used in a simple relay function. More advanced analysis can be used to determine phase angles, power, reactive power, impedance, waveform distortion, and other complex quantities. Only the fundamental component is needed for most protection algorithms, unless a high speed algorithm is used that uses subcycle data to monitor for fast changing issues. The sampled data is then passed through a low pass filter that numerically removes the frequency content that is above the fundamental frequency of interest (i.e., nominal system frequency), and uses Fourier transform algorithms to extract the fundamental frequency magnitude and angle."
The solution is surprisingly simple: Use a PHEV instead of a BEV. A PHEV does not have the immediate need for charging vs a BEV, the latter must be kept at high charge level in case of emergency need for driving long distance. As such, a PHEV should be MANDATED to charge during grid's OFF-PEAK hours. An obvious advantage of a PHEV over a BEV is that a PHEV is NOT needed to be kept at high charge level all the time. Additionally, a PHEV should be MANDATED to have an ability to sense the grid's voltage level, and NOT be allowed charge when it senses high power demand from the grid.
@Yoatmon, You're obviously reading from a script and having zero experience with Hydrogen. When I was a kid, we used to play with Hydrogen balloon, since we couldn't afford Helium at the time. Hydrogen balloon behaved just like Helium balloon, and it takes days for the Hydrogen balloon to lose air when kept inside the house, the same time it took when the balloon was filled with air to gradually lose the air. Wants further proofs? Hydrogen-filled airships were crossing the Atlantic ocean for over a decade before WW2.
I would like to weigh in to this debate regarding the use of waste heat at 700 dgr C. Actually, NO waste heat would be necessary. Just feed in the electricity from Solar PV and Wind turbine to supply the initial heating to 700 dgr C. Then, with good insulation, the heating will continue, with the difference being that low-temp PEM electrolyzer is around 70%-efficient, while this SOEC may be around 95%-99% efficiency. So, we may be looking at a vast improvement in efficiency with the use of SOEC. Alternatively, Concentrated Solar thermal heat can be used to maintain 700 dgr temp, while solar PV electricity can be used in order to get well over 100% efficiency with respect to supplied electricity.
The Hydrogen component of this Catalytic Fast Hydro-Pyrolysis can come from electrolysis of water using Grid-Excess Solar and Wind electricity, thereby providing financial incentive for continual growth of Solar and Wind energy until well past 100% power grid penetration.
@sd, Pipeline system can be used to transport Hydrogen just like Natural Gas. Natural Gas reservoirs can be used to store vast quantity of Hydrogen, enough for an entire season or more. One just need to imagine replacing Nature Gas with Hydrogen and it will be very easy.
Lad stated: "I think BEVs will win the battle over FCEVs, relegating them to a niche market." The competition is NOT between BEV vs FCEV, for they both are niche-markets, catering toward different consumer preferences. 1) Those who want maximum power and performance and don't mind plugging-in will choose long-range BEV's. 2) Those who don't want to have to plug-in, or who don't have access to a plug would rather have FCEV's. The more ZEV choices we can provide the consumers with, the faster ZEV's will grow. It should be a cooperative effort between BEV supporters and FCEV supporters, NOT antagonism. An advertisement for a FCEV may get people looking at ZEV's in general and comparing different types. Many ZEV shoppers will end up buying Teslas instead of FCEV's after looking at many FCEV's on the market, and vice-versa.
Great!!! Liquid Hydrogen (LH2) used by fuel cells can overcome the weight disadvantage of battery. The ultra-light weight of LH2 can permit more payload, while the composite weight of the FC + e-motor + inverter would be comparable to the weight of a comparable aero engine. At around $4 per kg as promised by Nikola Motor in the near future, at over twice the efficiency of combustion aero engines would bring the equivalent fuel cost down to around $2 per gallon of gasoline. This, in comparison to the US national average price of Avgas at $6 per gallon in 2015. The mass production of FCV's by the automobile companies by 2015 will greatly reduce the cost of FC and e-motors and power inverters to below the current very high cost of aero engines. Welcome to the new age of electric general aviation using Liquid Hydrogen.
@SJC, Liquid H2 does not require pressurization. PEM FC has much higher power density and is much cheaper per kW. LH2 maybe cheaper thanDME.
The answer for this problem is clear: Liquid Hydrogen powering fuel cells. The locomotives already have e-motors, so this should be cost-effective.
@Henrik, Please kindly do the math for the Boeing 777 and 787 when converted to LH2 to see how it would work. The Tu-155 is a very old and inefficient plane using very-low-bypass hence inefficient engines, with less-efficient aerodynamics. Modern Boeing 777, 787, and Airbus A380 are far more efficient and consume far less energy per passenger-mile, hence making LH2 feasible. The topic of this article is about electric small planes aka general aviation. In this regard, a LH2-FC propulsion system will prove to be far more efficient with regard to range and payload. An H2-FC powered quadcopter can fly 2-4 times longer than a battered-powered quad-copter, and ditto for H2-FC powered industrial forklifts, and the industry is gravitating toward H2-FC-powered large equipment for the same reason. Nikola Motor is choosing LH2-FC for propulsion of its electric semitruck, even though the truck also sport a humongous 320-kWh battery pack as power buffer. Please regard battery as being analogous to RAM in a PC while H2 is the Hard Drive Memory that is much cheaper and can be packed in much large amount. For commercial aviation, why not aim higher and work on Hypersonic planes, Powered by LH2 and ScramJet engine that can travel from NY to Tokyo in 2 hours? The LH2 will be circulating through the skin surface of the place to absorb heat before being burned off in the ScramJet engine. Everything else will be obsolete. For shorter range, there will be Fast Electric trains and Hyperloop. Please kindly forget about Li-ion battery for aviation and kindly regard LH2 as the new fuel for the dawn of Renewable-Energy and Zero-Emission Aviation. The ultra-lightweight of LH2 is the biggest asset that any aerospace engineer would kill to obtain. Tremendous weight reduction will lead to unprecedented level of efficiency. The LH2-FC can be regarded as a much, much lighter battery and much higher energy density than Li-ion can ever attain.
>>>>>>>>>"@Roger you can’t retrofit a hydrogen powered aircraft from an existing aircraft. " Yes, you can. I've done all the calculations, taking into account the volume of LH2 required and the volume under the seating floor of an airliner. It is entirely possible without any loss of passenger space nor cargo space. You can try to do it yourself if you care to. However, to really save more fuel and save energy and save internal space by reducing the volume of LH2 fuel, a re-design will be necessary to incorporate smaller wings, smaller tails, smaller engines, and smaller wheels and landing about 60% the size of the kerosene-powered aircraft to adjust to the much lighter weight of the LH2. Only the fuselage will need to remain the same. With this type of re-design, it only takes 30% of LH2 fuel energy to fly a long-range aircraft for a given cargo weight as compared to using much heavier kerosene. On a long-range flight, 66% of the useful load weight is fuel weight when using kerosene. Using LH2 on an aircraft optimized for LH2, the proportion of fuel weight WRT useful load is only about 30%.
@Dr.Strange Love, Apparently, the lifespan of the LH2 tank should be good enough for Nikola Motor to consider the use of LH2 in semi-trucks. Furthermore, the LH2 tank can be designed to be easily removed and replaced at regular intervals to ensure safety. Having a thin aluminum inner layer and polyurethane foam outer layer should be cheap enough and light enough. Boil-off rate is insignificant at the size of LH2 tank required for an airliner. The APU (auxillary power unit) (which could use a fuel cell) can use the H2 evaporating to make electricity and have a plug-out to power the airport and the city as well, while the plane is parked, until the next flight. NASA study showed that a LH2 spherical tank a foot in diameter with 1" foam insulation takes about 6-8 hrs for complete boil off. If you triple the insulation thickness,it would take a whole day for boil off, and with ten-fold volume to surface ratio, it would take 10 days for complete boil off. @Henrik, Please read my reply to Dr. SL above for concern about LH2 tank durability and boil-off. Just use the LH2 in existing jetplanes would be the cheapest option. Designing new airliners takes $10 Billions, like the Boeing 777, that use conventional turbofan tech. Designing a completely novel and unconventional system may cost a lot more than that. Due to the much lower loaded weight of a LH2 jetplane, the wings, the tails, the landing gears, and the engines can all be around 60% the weight of previous sizes, causing even further reduction in airplane gross weight and hence even lower fuel consumption...probably 30% the fuel consumption per mile in comparison to a kerosene powered plane for a given payload weight, so you can actually save on fuel cost...You pay double for fuel cost per energy unit but your plane only consumes 30% of the energy per mile. @Harvey, LH2 seems to be the best option for both small aircraft as well as for the largest airliners. At the end of a flight, any LH2 remaining in a small aircraft can be pumped out, and the plane can taxi back to the hangar using battery power. Of course, electric trains will save more energy than jetplanes, but we're discussing air travel here.
@Henrik, Dr. Strange Love must have referred the 115:1 energy:weight ratio as between Liquid Hydrogen (LH2) vs Li-ion battery at 400 Wh/kg, though getting 40 kWh per kg HHV of H2 divided by 0.4 kWh/kg of Li-ion would only give 100:1 ratio. But please know that LH2 is the future of aviation, due to the extreme weight advantage of LH2 vs kerosene jet fuel, of 3:1. Foam insulated container for LH2 is very light, as used in NASA's rocket. The reduction in fuel weight itself will double the payload:fuel for airliners and airtransport planes. The H2 can simply be burned in current jet engines with some modification, at around 50% thermal efficiency, which is comparable to the efficiency of the latest large-size turbofans. With LH2 costing $4 per kg and JP4 costing around $2 per gallon, the fuel cost per lb of payload is comparable. @ECI, Look to LH2-FC electric power as a way to significant boost payload capacity of General Aviation aircraft. Imagine carrying 1/5 the fuel weight for comparable range, for example, 500 lbs of AVgas fuel can be reduced down to 100 lbs of LH2 to travel 1,000 miles in LH2-FC electric aircraft! How is that doing for your payload capacity, eh? Your 2-occupant aircraft at full fuel load now can carry 4 adult occupants with luggage to travel 1,000 miles. NASA is paying about $4 per kg of LH2. So, you can carry twice as much payload while paying 1/2 for fuel cost, or FOUR-fold payload to fuel cost ratio.
@ECI, It only takes about 1,000 H2 stations for the entire USA to ensure a median driving distance of 4 miles from home to the nearest H2 station in urban and suburban areas. At the latest cost of $1 Million per station as mass-produced by Nel Hydrogen in factory, the price tag of the initial H2 station network will be only $1 Billion. If each of the 5 automakers who are making FCV's or planning to make FCV's would share this cost, each will only have to fork out $200 Million. There is no need to have 120,000 H2 stations in the USA to make FCV practical for urban and suburban dwellers. Only 1,000 initial H2 stations costing $1 Billion would suffice.
@msevior, You do have a good point, however, the cost of H2 won't double as you projected. Here's why: 1) The capacity factor of wind in the USA is around 34%. New wind turbines with much bigger blades can produce power with less wind, hence can have capacity factor around 40-50%. 2) Combined solar and wind will raise the capacity factor, especially if half of the solar power can be fed to the grid during peak grid demand during the day, leaving the most of night-time wind for the electrolyzer. So, you would build out twice the solar capacity of the grid daytime demand, and on sunny day, use half of the solar PV power to make H2. On cloudy days, all of the solar PV output can be devoted to the grid. The combination of solar and wind can raise the capacity factor to above 50%, which is quite close to the 70% utilization factor in the cost calculation. 3) The H2-production facility includes power-handler, electrolyzer, purifier, low-pressure storage facility, H2 compressor and high-pressure H2 storage, and necessary piping. Assuming 50% combined wind and solar capacity factor, then the power handler and the electrolyzer will be used only 50% of the time, but the rest of the facility can be sized so that they can be utilized nearly 100% of the time. For example, inexpensive low-pressure H2 storage can store intermittent H2 production to be fed to the H2 purifier and H2 compressor and H2 dispenser that can be sized so that they can be utilized nearly 100% of the time. When considering all the above factors, the cost of H2 facility will not exceed much of the cost calculation using 70% utilization factor in the H2 cost estimate by ITM Power, even when using RE with combined capacity factor of around 50%.
@msevior, ITM Power reported Hydrogen cost of £2.69/kg (US$4.13/kg)... after capital amortization, at 70% utilization, with electricity cost of 5c/kWh and 55 kWh per kg. With the new-low electricity cost of 3 cents per kWh, we can expect a cost reduction of $1.10 per kg, thus only $3.03 per kg. Within a 10-year capital amortization period, £4.19/kg (US$6.44/kg) with electricity cost of 5c / kWh. With electricity cost down to 3 cents per kWh, the H2 cost will go down to $5.34. If we assume that the electrolyzer will continue to last for 10 years more after the 10-year amortization period, then the H2 cost will be the average of the $5.34 and the $3.03 = $4.18 per kg. To be cost-competitive with gasoline in the USA, the H2 can be priced at the pump at $6.8 per kg, so that will give a profit margin of about $2 after a $0.50 of fuel tax. Conclusion: Retail price of H2 for FCV at the pump made from the new-low costs of solar and wind electricity will soon be cost-competitive with gasoline on per-mile basis.
The good news now is that Solar and Wind (S&W) electricity is coming down on par with the prices of Fossil Fuel (FF) power plants. However, intermittency and non-dispatchability of S&W render new S&W unable to substitute for new FF power plants, unless e-storage or natural gas backup power plants are also built. The problem with energy-storage systems is that they will double or triple the cost of Solar and Wind (S&W) electricity when energy-storage is employed in conjunction in order to make S&W reliable 24/7 source. Even worst, battery and pumped hydrostatic storage have very limited capacity that will be depleted after more than one or two days of dark clouds and little wind. For this reason, Solar and Wind must cost-effectively depend on stand-by natural gas power plants that are already paid for. This will significantly affect the growth potential of S&W. For example, if a community will need 300 MW of new generation capacity, that community cannot depend on S&W alone, but must build out additional ~250MW of natural gas power plant for use when combined S&W is very weak. This will significantly increase the cost of new S&W capacity and will make S&W much less competitive. However, if we now shift strategy and employ Solar and Wind (S&W) to make high-value transportation fuel instead, then perhaps the economics may look more compelling. At 3 cents per kWh and 55 kWh per kg of H2 at the pump, the raw energy cost will be only $1.65. Adding $2 to cover the cost of H2 production facility, distribution cost and operational cost, then 1 kg of H2 at the pump can have a pre-tax-and-profit cost of $3.65 per kg. Adding profit and tax to this to price this S&W H2 to $6.8 per kg at the pump, and this will still be cost-competitive with gasoline car with 25 mpg and gasoline at $2.5 per gallon, when used in the Honda FCX Clarity at 68 MPGe, when both will have a fuel cost per mile of 10 cents. Subtracting $3.65 from $6.8 = $3.15, and assuming 50 cents tax per kg of H2, will give a profit of $2.65 per kg of H2. Dividing this $2.65 to $6.2 pre-tax price = 43% profit potential. This is very good, considering profit margin for the major oil companies to be around 23%.
Sorry, Harvey, but the Least Significant cars will be the FCEV's, while the PHEV's will be the most significant cars, according to a Twitter survey by GCR.
Ok, geniuses, this is how one can take advantage of this wonderful discovery: Expose the chemical to sunlight together with electron donor source, pump away those exposed chemical, then separate out the radicalized molecules in the dark and generate hydrogen and then pump out those de-radicalized molecules again to the light. What the above has accomplished is the elimination of solar PV AND of electrolyzer which are both costly, and replace with just translucent tubing running on top of any roof to circulate the chemical while being exposed to sunlight. A potential to eliminate H2 storage tank and the H2 compressor, if the sun-exposed radicalized molecule collected during the day can be turned directly into H2 on-demand later for used in home-based fuel cells that can generate both power and heat. Power to run the house lights and appliances, while the waste heat from the FC unit can make hot water for bathing, laundry and dishwashing. Since it is easier to store liquids at ambient pressure than to store H2 at high pressures, this can replace the Tesla Powerwall for daily storage of solar energy to be used later in the evening.
With new stuffs, you sometimes have to give 'em away to get people to get hooked to 'em. And get hooked, they will.