This is Jim's Typepad Profile.
Join Typepad and start following Jim's activity
Join Now!
Already a member? Sign In
Jim
Recent Activity
E-P, your analysis of 6/29 is flawed. You need to account for the costs of storing your 70% electrical energy compared with a tank or compressed tank carrying some kind of fuel. It's also the capital cost of energy STORAGE. You need to consider both, especially for vehicle applications. It would be cheaper to buy and own a PHEV with 40 miles of electrical range than an EV with 250 miles of range, even if the fuel for the PHEV was entirely synthetically produced (elec.-> h2-> carbon fuel). Why? Because batteries are so expensive and fuel use on a PHEV is so low. And this doesn't even take into account the time-to-recharge problem that would plague a full EV.
If they have extra H2, they should react it with CO2 and make more methane; then they can apply the whole methane stream to the mature technology that is NG vehicles. These vehicles could also be PHEVs, so electric power could provide much of the energy needed for short drives (It's an ISLAND fercrissakes). Methane is also usable for cooking and heating, BTW. Hydrogen makes no sense because it's not as efficient as batteries and it's not as dense as methane or other fuels. And both of these alternatives have existing infrastructures to support them, even on Hawaii.
This is SO stupid. They should just use synthetic methane along with PHEVs for a place like Hawaii. They could even use wind farms to charge the PHEVs. If they really want an "integrated energy solution", then they should realize hydrogen is a crummy fuel that is 3.2X bulkier than methane. Since it is synthetic on Hawaii, either the hydrogen or the methane will be expensive. So use the denser fuel to provide range and an electric charge to lower overall fueling costs. QED
They need to compare the storage advantages of liquid fuels with the cost it takes to produce them, either from biomass (limited) or synthetically (more expensive). If they did that, they would see it's not all about storage -- it's the combination of storage along with the cost of producing a fuel from non-fossil fuel sources. If they did this, they would discover that renewable methane (from either biomass or synthetic sources) would fare pretty well. And it enjoys an extant infrastructure as well.
HarveyD, In general I agree with you. Except for CARB. They represent the (local) politicizing of technology of the worst kind. Remember these are the clowns that espoused the hydrogen economy (at the expense of BEVs) 8-10 years ago. They used their political power to advance very poor technical decisions. They've hurt the country in its effort to wean itself from fossil fuels. Stupid people in power can be very dangerous.
PBP is an uneconomical idea and I don't know why it attracts funding. Only motivation I see is to get the population on some kind of monthly fee for their cars which will be ultimately more costly to the consumer. Instead of battery swapping, just build a PHEV like the Chevy Volt. Have it run on E85 or renewable methane if you wish. PHEVs deals with the range and recharge problem in one fell swoop, needing no additional infrastructure and making use of the one we have in place now. Just to be clear, if a PHEV is configured to run perhaps 70-80% on its electric (charged) power, then the consumer could afford the 20-30% of fuel needed even if it was completely synthetic ($5-6 per gallon). This is because so little of it would be needed.
I'm sure it would be pretty bad. Assume a sortie takes about 8,000 kg of jet fuel. At 50 MJ/kg, that's 400,000 MJ or or 111,000 kW-hr-e. Assuming 50% overall efficiency (electrolysis & fuel production) you have about 200,000 kW-hr needed to make the fuel for one sortie. Nimitz class aircraft carriers have two nuclear reactors producing about 100 MW-e apiece. Assuming all that power went to fuel production, it would take about an hour to produce the fuel for one sortie. Actually not that horrible. I was expecting something worse. It looks like a Nimitz can hold about 3 million gallons of JP5 (I guess carriers use JP5 for greater safety). JP5 has a specific gravity of 0.8, so 8000 kg is about 2500 gallons. They carry enough fuel for 1200 sorties. I guess that's why they don't do this.... :) I could see commercial aircraft using LNG as the cost would be lower and the ability to developed a supported infrastructure would be more reasonable. At $3 per gallon, JP-8 is about 16MJ per dollar. LNG is about $5-10 per MMBTU or per 1000MJ. That's 100MJ-200MJ per dollar. A factor of 10 less or better!
E-P, Probably right. Long term, however, using foreign oil to power our military is probably not a solution either.
Is it just me or does sometimes the comments on GCC experience deja vu? It seems like multiple copies start appearing.
Who pays for the lost road tax revenues (from gasoline displaced by electricity)? Just wondering....
Methane can be stored 3.2 times more densely than hydrogen. That means that a FCV needs to be 3 times more efficient than a NG vehicle to have the same range. That's not feasible. Hydrogen can even be reacted with CO2 (pulled from the ambient air) to produce synthetic methane, which has no-net carbon footprint. This would be a far superior fuel for vehicles compared with hydrogen. And it enjoys an extant energy infrastructure in the form of our natural gas pipelines. By continuing to advocate FCVs, CARB is not part of the solution.
JP8 has an energy density of 33-36 MJ/liter. Liquid methane would be about 25 MJ/liter. It is lighter, though (55 MJ/kg vs. 42-45 MJ/kg for JP8). I'd think weight is just as important as density for aircraft, if not more so. Tanks to hold liquefied methane would be a pain, though. But not impossible. Maybe the cold fuel could help with the intercooler, not sure.
I wonder why the Navy hasn't considered synthesizing fuel from the nuclear power on aircraft carriers. They probably could get something to fly using liquid methane. 50-55 MJ/kg. Better than JP8.
Aromatics all have rings in them. Like benzene. I guess the ring is what makes them smell good, hence the name.
It's not completely useless if the overhead can be lowered. As it stands now, it takes about 60 kW-hrs of electricity to synthesis 1 kg of H2 by electrolyzing water. This is to produce a barely storable gas containing 39 kW-hrs (HHV) of energy. Can we do better? What about the overhead of converting H2 to something more useful like methane, methanol, or heptane? What about the COST of the conversion equipment such that if it sits idle sometimes (due to intermittent renewable energy sources) then it's not a big deal? Still lots of stuff to do, even if we don't have free energy lying around.
It's fair to be critical of my criticisms! :) In many ways, the concept is very appealing to me. But the energy industry is a very old and mature one, and it's hard to stomach "feel good" ideas that are problematic economically. Mom and Pop markets are "feel good" places too, but that didn't keep the mass consumer from abandoning them for Wal-Mart. In addition to the battery packs of limited utility, the systems will also need to have their own grid connects. And a pair of DC-AC and AC-DC inverters. All that stuff is expensive! It's hard to rationalize them for a system under 10KW or so. The good news about all of this is that realized cost of gasoline used (assuming 20% overall efficiency and $2.50 per gallon) is about 35 cents per kW-hr. That's very high -- so even solar PV would be a cheaper method of fueling a car than gasoline, provided we can get our infrastructure ducks in a row. We don't need stunts to accomplish that, especially stunts that raise costs even further.
I haven't heard much from these guys lately: http://www.hydrogensolar.com/ My concern about the direct sunlight connection is that it results in the physical plant (whatever it may be) being unused much of the time. Something with direct electric input could also benefit from wind or nuclear power, which are also currently less expensive than PV. Any direct solar system will have to provide clean water and CO2 to the light source, and draw the product back. That's a lot of pipes! I don't see the economics working out anytime soon.
Will S. sez: "So having the battery helps from a disaster recover perspective." So does having batteries in PHEVs. For free.
So they want to spend millions of dollars on something that only works 12 hours per day and less well in the winter? I don't get the necessity of the direct sunlight to fuel linkage.
On further thought, this is a REALLY stupid idea. Adding an additional battery to charge other batteries on a vehicle? Simply crazy and stupid!! There is a non-trivial efficiency loss in doing that, not to mention an unnecessary added cost. Look at it this way. During the day, when the panels are working, one of three things could be occurring. 1) There is no car present, in which case you sell the power to the grid during peak usage time (that is, a good price). 2) There is a car that needs charging, in which case, you charge it. 3) There is a car there that does not need charging, in which case you sell to the grid, and maybe even the some of the car's storage too, if desired. At night, you can charge the car from the grid at lower rates. I think Toyota has become somewhat brain-dead w.r.t. the whole concept of PHEVs. Kinda weird.
Looks good, but pretty stupid. The energy source does not need to be proximal to the charging station. They have amazing technology to handle this. They are called 'wires'.
Let's see CNG at 3600 psi means about 198 grams per liter. That means: 25% hydrogen by weight (CH4 is 25% hydrogen) 49.5 grams (hydrogen) per liter
I'm going to public where my stupid hat for a minute. I thought turbines were generally more efficient than IC engines. Is that not true? Maybe they need tighter machining ($$$) to be efficient? I know Capstone turbines last forever, but are quite expensive, and (I thought) fairly heavy. I'm old enough and local enough to know a little bit about Chrysler's efforts at turbines engines in the 60's. I think their main advantage was that they could use basically any fuel; the president of Mexico even ran one on Tequila! It also had fewer moving parts, so conceptually it would have been a much less expensive engine. I think many of the Chrysler turbine problems related its power curve not matching driving needs very well. I'd think a linkage of the system to an electric motors (with u-caps and maybe some batteries) would probably address most of those concerns today.
IMO, the main mis-design with the Volt was the serial hybridization. This was done (again, IMO) because of their hydrogen fuel cell mindset; you can't drop-in a fuel cell with a parallel hybrid architecture. I think they were anticipating a hydrogen-powered Volt sometime in the future. Reasonable minds can argue the pros and cons of parallel (like the Prius) vs. serial hybridization. But letting the hydrogen hype drift into the Volt design mindset will prove costly to them in the long run. They are building an inefficient design.
The headline is misleading and inappropriate. This is more of a pure science discovery. I think the 41,000 atm. (= 615,000 psi) is also a bit of a deal-breaker as well.