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
What is Green about high-fuel-consumption supersonic jet engine?
@E-P, Hydrogen is a gas, thus it can be stored in existing natural gas reservoirs, depleted oil and gas wells, and in salt caverns wherever available. Hydrogen can be supplied to each house in existing natural gas piping. We're simply replacing natural gas with Hydrogen, that's all. Renewable-energy Methanol is also viable wherever there are no local residential gas piping, kinda like heating oil right now, but renewable-energy Hydrogen should be cheaper to produce and more efficient from source to end-user applications.
@E-P, Hydrogen is a gas, and thus can be stored in existing Natural Gas reservoirs and depleted Oil and NG wells, also in salt caverns.
sd stated: "...clean energy which is not really clean as long as you are using power that would otherwise displace electric power produced burning coal or natural gas." Grid electricity fetches much better pricing for a given amount of energy than the equivalence in fuel energy, so no one is stupid enough to use Renewable Energy to make Hydrogen when that same RE can be fed to the electric grid to fetch much higher prices. Maximum profitability would dictate the use of Grid-EXCESS RE to make Hydrogen, while feeding as much RE into the grid as the grid can handle to maximize revenue.
@sd--You can have a Tesla or a Bolt to be charged during sunlight hours, then any excess solar PV or wind electricity can be used to make Hydrogen to power FCV. With a market for grid-excess Solar and Wind electricity to make high-value H2 for transportation, this will incentivise more investment in Solar and Wind energy, and BEV enthusiasts and FCV enthusiasts will benefit. You can have it all.
You are still believing that Hydrogen from RE is uncompetitive to FF. That's the crux of the issue. Here it is again, from : "Wind's unsubsidized costs are competitive with conventional generation in certain regions of the country, ranging from $30/MWh to $60/MWh in 2017, with pricing lowest in the Interior region of the country." So, assuming an average unsubsidized wind electricity cost of 4.5 cent per kWh, we can produce bulk Hydrogen at $2.75 per kg. Adding distribution cost and profit, and $5.60 per kg at the pump is quite reasonable, while bulk purchasers like trucking companies can get H2 at $4 per kg, which is what Nikola Motor projects the price of H2 for truckers. The US Midwest Wind Belt can produce very low-cost Wind electricity, but getting this electricity to major cities requires too much investment in power transmission lines. However, producing H2 for trains and truckers to fill-up as they drive thru the Mid West AND for local farming equipment and for farming consumption will be more cost-effective. This should help reduce a lot of NG and diesel consumption, and the Energy Industry (Oil and Gas Industry) can do it! With further gain in profitability from these operations, the NG pipelines will be upgraded to handle 100% H2 to bring MidWest Wind-sourced H2 to major population centers to gradually replacing petroleum consumption, and we will see FCV's being sold everywhere. Remember that BEV's electricity is costing half as much as petroleum, yet BEV's are having hard time growing, so H2 from RE will only need to profitably match the price of petroleum cost per mile to start gaining market share. And all this will be done by the Oil and Gas industry to replace depleted oil and gas reserves. Remember that Europe and Asia are gravitating toward RE, with laws to phase out FF to comply with the Paris Accord, and so the FF industry cannot afford to lose those huge energy markets.
@sd---Nikola Motor cited 70% efficiency for their FC. The electrolyzer can use DC current straight from the PV panels from the solar farms without conversion loss nor grid's transmission loss. The best electrolyzer can be as high as 80% efficient, plus 95% efficient compression. So, 70% x 80% x 95% = 53% With catenary electrification system, you have to figure in 7% loss in DC to AC conversion from solar panels to grid, then 7% loss via grid power transmission, plus 7% loss in AC to DC conversion by the train's rectifier to be used in the. so 93% x 93% x 93% = 80% efficiency. With battery charging, you have 93% efficient, plus 85%-efficient charging efficiency, plus 93% battery efficiency = 73% efficiency. Nobody would be so dumb as to use coal-fired or natural gas power plants' electricity in electrolyzer to make hydrogen. Natural Gas, waste biomass, and Coal can be easily gasified directly into H2 at 75% efficiency, without losses in electricity generation AND in electrolyzer. The well-to-wheel efficiency from FF to BEV vs FF to FCV is quite comparable.
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.