Since cars use more energy to move than houses use for electricity a car powered by a hydrogen fuel cell that generates electricity to run an electric motor would have the capacity to supply all the power a house would need.
Another possibility that comes from such a system is the homeowner's ability to power the house from a fuel-cell vehicle. The fuel cell in a typical fuel-cell vehicle would have an output power from 25 kW to more than 100 kW. Because the average home only uses between 2 and 10 kW of electricity, it would be possible to "plug" the car into the home to provide power from the fuel cell using the hydrogen stored on the vehicle.
Of course, to make this work we first need fuel cells that are cheap enough and light and durable enough to serve as power sources for cars. But we would also need a way to store hydrogen in a dense enough form to make hydrogen a viable mobile power storage source. Even if a way to store hydrogen in a dense form in vehicles could be found we'd still face the need for a power source to use to generate the hydrogen in the first place.
In spite of these big caveats about the serious problems hydrogen faces as an energy storage form the idea that a car could generate enough power to run a few houses is a neat idea. In fact, the use of fuel cells to generate home electric power does not have to depend on hydrogen as a energy storage form. Advances in Solid Oxide Fuel Cells (also see here and here show promise for the ability to burn fossil fuels in order to generate electricity more efficiently than gas turbines can currently. If fossil fuel-burning solid oxide fuel cells become competitive for use in vehicles then the result would be that most people will come to own vehicles that can generate more electricity than they need to run their homes. Whether the burning of fuel in those vehicles (or in a smaller fuel cell attached to the house) to power a house can be done more cheaply than large centralized electric power plants remains to be seen. The potential exists for that to happen because fuel cells have the potential to convert fossil fuels to electricity more efficiently than how current large electric power plants currently do it. Plus, energy losses in electric power lines could be avoided by generating electricity much closer to where it is used. At the very least the use of fossil fuel-burning fuel cells ought to make central power outages less of a concern to anyone who outfits their house with a connector that they can plug into their car to run the house.
Update: As yet a suitable way to store hydrogen for use in cars has not been developed. Some University of Chicago researchers have just demonstrated that hydrogen can be turned into a clathrate that will remain stable at normal atmospheric pressure.
University scientists have proposed a new method for storing hydrogen fuel in a paper that appeared in the Monday, Jan. 5 to Friday, Jan. 9 online edition of the Proceedings of the National Academy of Sciences.
The lack of practical storage methods has hindered the more widespread use of hydrogen fuels, which are both renewable and environmentally clean. The most popular storage methods—liquid hydrogen and compressed hydrogen—require that the fuel be kept at extremely low temperatures or high pressures. But the University’s Wendy Mao and David Mao have formed icy materials made of molecular hydrogen that require less stringent temperature and pressure storage conditions.
“This new class of compounds offers a possible alternative route for technologically useful hydrogen storage,” said Russell Hemley, Senior Staff Scientist at the Geophysical Laboratory of the Carnegie Institution of Washington. The findings also could help explain how hydrogen becomes incorporated in growing planetary bodies, he said.
The father-daughter team synthesized compounds made of hydrogen and water, hydrogen and methane, and hydrogen and octane in a diamond-anvil cell, which researchers often use to simulate the high pressures found far beneath Earth’s surface. The hydrogen and water experiments produced the best results. “The hydrogen-water system has already yielded three compounds, with more likely to be found,” said Wendy Mao, a graduate student in Geophysical Sciences.
The compound that holds the most promise for hydrogen storage, called a hydrogen clathrate hydrate, was synthesized at pressures between 20,000 and 30,000 atmospheres and temperatures of minus 207 degrees Fahrenheit. More importantly, the compound remains stable at atmospheric pressure and a temperature of minus 320 degrees Fahrenheit, the temperature at which liquid nitrogen boils.
“We thought that would be economically very feasible. Liquid nitrogen is easy and cheap to make,” Wendy Mao said.
The hydrogen in a clathrate can be released when heated to 207 degrees Fahrenheit. The clathrate’s environmentally friendly byproduct is water.
The unanswered question here is: how much energy does it take to convert hydrogen into a clathrate? Also, if the hydrogen has to be heated to release it from the clathrate then how much energy is required to do that?
By Randall Parker at 2004 January 28 12:23 AM Energy Tech | TrackBackNot likely to work... at least from an economic standpoint. Homes and businesses almost always require continuous power for sump pumps, refrigeration systems, fire/security alarms, HVAC requirements etc. Consequently a redundant power supply on site would be required ($$$). Moreover, to avoid imposing synching, noise and power factor problems on the grid a transfer circuit is necessary to permit an isolated feed from the proposed alternative source, that's even more money. Perhaps a better use for this technology would be as an emergency backup system, but that of course incurs the aforementioned extra costs.
There's little getting around the fact that because of engineering scale effects power produced at central facilities and in large quantities will be distributed to most consumers more reliably and at a significantly lower cost than distributed power schemes. There is a place of course for the alternatives in peak demand situations and where homes and businesses are remote from the distribution systems. But in the long run the economic viability of such systems as the one proposed will be determined by value engineering considerations not wishful thinking.
I was hit by the blackout of August 14, and I have been struck by the irony of cars with 60-150 KW engines sitting out of fuel while thousands of gallons of fuel lay in tanks just a few feet away, unable to be pumped for lack of a few KW to run the gas station. Just one Honda Insight with the appropriate control and inverter hardware could have made the difference.
That said, I believe that the concept of using vehicles as the power supplies for buildings is backwards, an example of thinking stuck inside the box. For instance, suppose that batteries are 90% efficient and you have prime movers (engines, fuel cells - doesn't matter) which are 60% efficient. If you put the only prime mover on the vehicle, you can harvest 60% of the input energy split however you want it. But if you put a prime mover on the building, you can harvest potentially 100% of the energy split between electricity and heat; sending 60% to batteries on the vehicle leaves 54% returnable, plus the 40% heat released at the building totalling 94%. The only way that the model of vehicle as powerplant can equal cogeneration for total efficiency is if there is zero demand for heat. Heat can even power refrigeration systems (look at any propane-powered RV), so there are usually ways to do better.
It's true that the typical prime mover on a vehicle will need to be 20 horsepower or more (15+ KW) to keep the typical car at highway speed, and the typical house requires but a small fraction of this on average. It might look attractive to put the prime mover on the car just to avoid redundancy. But given that fuel cells will be expensive for some time, the fuel cell for a home is bound to be much cheaper than for a vehicle. It can also be run on fuels which are too difficult to store for vehicles, and it is free from considerations of weight, bulk, shock resistance and packaging which drive choices for vehicles. On top of this, the hypothetical fuel-cell vehicle is going to require batteries for surge power in any case. The batteries do not care if the energy charging them comes from on-board or off.
Such a system of fuel-cell-powered buildings running electricity to plugged-in cars has advantages: people are going to plug in much more often, which means the batteries on the cars can be used as surge capacity for the grid. A cursory examination of the power fluxes in play on 8/14 ( a few gigawatts) versus the hypothetical power capacities available from the millions of cars and light trucks in nothern Ohio and SE Michigan (over 3 million for the latter alone; at a mere 2 KW apiece the figure tops 6 GW) shows that the proper control of the fraction of the resource likely to be connected would have been more than sufficient to damp the transients and prevent the outage completely.
For more information on the concepts, check the acpropulsion.com web site. Look for "vehicle-to-grid".
E-P, For most the year I have no need for heat. Ditto for lots of others in So Cal, Florida, and other warm places. But that is a minor nit.
The point of my post is that if and when fuel cells become the preferred way to power cars then at that point central power plants run by huge electric power utilities really go down the tubes one way or another.
As for how long fuel cells will remain expensive: 5 years? 10 years? 20 years? But won't they be cheap some day?
Randall,
To pick a nit with your nit-picking, you live in a tiny microclimate that seldom requires heating or cooling compared to the vast bulk of North America, which generally needs one or the other. E-P already mentioned the heat could operate your refrigerator, and it could heat the water for your shower.
How many of your neighbors have heated pools? I wonder if you could sell excess heat? Heck, with a heat sink and a thermocouple, you could even capture excess heat to generate additional electric potential.
Randall wrote:
The point of my post is that if and when fuel cells become the preferred way to power cars then at that point central power plants run by huge electric power utilities really go down the tubes one way or another.True, true. Distributed generation has the further advantage of eliminating much of the losses and capital expenditures for long-distance transmission. (You'll have to make the investment anyway if you want to take advantage of the best wind-power sites.) But this does not change the salient facts:
As for how long fuel cells will remain expensive: 5 years? 10 years? 20 years? But won't they be cheap some day?When they are cheap enough, we'll move to them. This is not an argument for waiting that long, and I'm really surprised that you would buy into it. It is the same argument Bush is making for hydrogen cars in the misty future, instead of the 80 MPG PNGV cars that we could be building today. Regardless of what we'll be using 10 years from now, we have no time to waste. We need to start making a difference immediately.
Bob wrote:
Heck, with a heat sink and a thermocouple, you could even capture excess heat to generate additional electric potential.Thermocouples are extremely inefficient. There is some work going on concepts to use molten-carbonate fuel cells as the topping cycle for a gas turbine. Given that MCFCs can hit 60%, I'd guess that a total efficiency of 70% could be achieved in that section. Further recovery via steam cycle or just use of heat for industrial or district heat could push the total utilization much higher. Unfortunately, the scale of any such machine would be too big for domestic use. The smallest you could make a 2-stage machine like that would be sized about right for an apartment building.
E-P, To get started doing what? Generating electricity in each home? I do not understand what you are proposing.
80 MPG PNGV cars: They are what exactly? NG for Natural Gas?
PNGV = Partnership for a New Generation of Vehicles, a Clinton-era program to develop an 80-MPG full-size sedan. And they were just about done (save for the EPA's new NOx regulations putting the kibosh on the diesels they intended to use) when Bush cancelled the program.
To get started doing what? Generating electricity in each home?Get started on a conversion of vehicles from petroleum-only to partially electric. Generating electricity at home (heating season only) is a possible outcome of higher natural gas prices independent of such vehicles; the greater overall efficiency will pay off.
If 2/3 of your driving consists of the first 20 miles after a charge and is therefore all-electric, and the car gets 50% better economy due to hybrid efficiency, fuel usage falls by 7/9. You do not need great technology to make huge differences, and the establishment of a market for traction batteries, electric drive systems and such will attract R&D money; at that point the development will feed on itself without further intervention.
I fail to see why a car that has 50% better fuel efficiency can have its fuel usage fall by 7/9ths.
Market for batteries: There has been a huge market for lead acid batteries for decades and they cost too much and weigh too much for hybrids. NiMH batteries similarly cost too much.
PNGV: If the development of the vehicles was just about done and the results looked like the cars were going to be appealing enough to the car buyers to justify production costs then I think the car companies would have finished the development with their own money (they spend tens of billions per year in car development) gone into production with them. My guess is that they cost too much to build for all the familiar reasons: batteries cost too much. The need for a regular engine plus the electric engine cost more too.
Hybrids continue to be held back from mass acceptance by batteries that cost too much and weigh too much. Get the cost and weight down and the car companies will embrace them.
I fail to see why a car that has 50% better fuel efficiency can have its fuel usage fall by 7/9ths.I stated this very plainly in the response immediately before:
Note that this is NOT a net energy saving, it is a saving of petroleum-derived motor fuel - a crucial distinction.
There has been a huge market for lead acid batteries for decades and they cost too much and weigh too much for hybrids.How can you say that when I just quoted you retail prices for single units [1] that are downright inexpensive? Note that this does not include the bulk discounts one would expect for large numbers of identical units. As for "too heavy", I have weighed one 105-AH unit at 65 pounds. Sixteen of them would weigh 1040 pounds, some of which would be made up by a lighter engine in the car. I don't think that an extra 700 pounds would make a car excessively heavy; on the contrary, given the current mentality that "weight=safety" I think it might become a selling point. Weight does make a car feel smoother, a feature of luxury vehicles.
NiMH batteries similarly cost too much.I don't think that NiMH is the gold standard here. The killer technology is lithium-ion ("As a complete car, the Li-ion tzero has higher specific energy, in Wh/kg, than the [NiMH] RAV4 EV battery pack alone.", www.acpropulsion.com - your HTML censor mangled my link and deleted the address completely), and with oceans full of lithium I don't see materials being a large part of the cost for some time. The rest is design and fabrication, which always falls with experience. Until Li-ion hits the right price point, lead-acid is capable of doing the job at a very affordable price.
Hybrids continue to be held back from mass acceptance by batteries that cost too much and weigh too much.Actually they're held back by the subsidy of petroleum costs through such routes as the US defense budget, some half of which went to defend Persian Gulf supplies even before the current War on Terrorism and overthrow of the Hussein regime in Iraq. If the USA consumes 100 billion gallons of gasoline and another 50 billion gallons of light fuel oil per year, those defense costs are more than equal to the pump price. If people were paying the true cost of the fuel that comes to the pump, they'd happily pay for the hybrid technology needed to minimize it.
[1] http://www.futurepundit.com/mt/mt-comments.cgi?entry_id=1911 - your link-mangler deleted the URL there too.
7/9ths: But, again, what is the point of decreasing petroleum consumption when the result, most likely, will be to increase natural gas consumption as much or even more?
Lead acid batteries: Hybrid cars costs thousands more. Are you saying the hybrid car makers are overcharging?
Heaviness: Make the car carry a heavier load and it then needs heavier springs, heavier shocks, etc.
NiMH: But I used that example intentionally since Honda is using them and Toyota may be as well. Hence my choice. Li Ion: I agree it costs too much. But how can we know that it is going to become cheaper to make? Maybe the smarter way forward is to develop lithium polymer. Donald Sadoway of MIT says that is the better way to go.
US defense budget: Well I agree and have repeatedly poster that part of our cost of oil doesn't show up in its price. But the public really doesn't want a tax on their oil price to embody that cost. Also, part of the cost comes to us because other countries send cash to the Persian Gulf that gets used in ways hostile to our national security.
We need technological advances that will lead to the displacement of oil usage throughout the world. Nothing short of that will solve the problem.
Mangled links: I don't filter out HTML tags. I have no HTML censor software. Other people post links in posts all the time. I don't know what you are doing that is causing problems. I'd like to figure it out. BTW, In one of your posts you actually put an "a" tag but forgot to include the "href". I fixed that though since I knew where you were trying to point to.
But, again, what is the point of decreasing petroleum consumption when the result, most likely, will be to increase natural gas consumption as much or even more?The efficiency of cogeneration + wires + batteries is far higher than the Otto-cycle engine, and there are technologies already in use which can make up for the natural gas with e.g. coal. See my February 6, 2004 07:02 PM comment here; it looks like the job could be done without any additional fuel of any kind, just by fixing inefficiencies in our current methods.
Lead acid batteries: Hybrid cars costs thousands more. Are you saying the hybrid car makers are overcharging?No. First, these are low-production models with powertrains that are not shared by anything else; you expect them to cost more per unit. Next, with the exception of the Honda Insight, those cars are pressing existing platforms into hybrid service (the old Prius is an Echo save for the battery in back and what's under the hood). The engineering constraints of bulk and weight force the use of smaller, lighter and more expensive battery technologies than you would probably use if you started with a clean-sheet design.
Li Ion: I agree it costs too much. But how can we know that it is going to become cheaper to make? Maybe the smarter way forward is to develop lithium polymer.You can follow the price curve of Li-ion over time and see that it's falling fairly rapidly. I know of someone who is putting a string of 90 AH Li-ion cells into a Corbin Sparrow; he got them at $1/ampere-hour. Lithium-polymer is just a variant of lithium-ion; it's possible that some other variant, like lithium-iron phosphate, may win that contest and get rid of thermal-runaway problems.
I believe that if the potential sales volume is there, we will see a lot of research and engineering thrown at the problem with the result of rapid advances. A big market for CalCar-style hybrids would offer such volume.
We need technological advances that will lead to the displacement of oil usage throughout the world. Nothing short of that will solve the problem.Once the USA has removed its dependence on imports, it would be a simple matter to embargo the exporters of terrorism and prevent them from making any money while simultaneously punishing those nations which had failed to remove their dependence; even the threat of such an embargo would probably lead to a stampede toward oil-displacing technologies. It would be poetic justice (my speciality) for the phrase "arab oil embargo" to reverse its meaning over 40 years.
The link-mangler is alive and well; the contents of my link above were supposed to be "<a href=http://www.futurepundit.com/mt/mt-comments.cgi?entry_id=1911>", but it was reduced to "<a>" when I previewed. I will paste it in one more time and see if it endures the attempt to actually post it.
Check into the liquid nitrogen research being done for energy storage. Reported results are storage of 482 KJ/Kg without isothermal expansion and 769 with. Think this is mostly theory. Can anyone compare this with battery storage abilities?
Re my earlier comment on LN2 energy storage. Have a stationary fuel cell or co-generation in the house, refuel the vehicle with stored LN2. Stationary is easier than mobile for high efficiency production. What is needed is inexpensive high efficiency storage. BTW, anyone interested in low cost building conditioning should check out www.annualizedgeosolar.com.
DDHv
Great ! I need some more.
Annualized geo solar is a variant of ground-based heat storage, aka underground heat storage. They use insulation and thermal movement time delays to isolate the ground under and around a building, then use summer heat to warm said dirt. Get 500 tons of dirt to 80 or 90 degrees, it doesn't cool off quickly. I've been using summer heat to warm my basement (fans) for several years, with a good change in my heat bill, but didn't notice the need for the wing insulation. Which is being installed now in my spare time. The LN2 is promising, but needs research.