Slashdot Mirror
New Solar Cell Harvests Hydrogen From Water
Engadgets is reporting that researchers at Penn State have built a new kind of solar cell that can harvest hydrogen directly from water. "The folks at Penn State have now developed a process that more closely mimics the photosynthesis process in plants, and while we won't pretend to understand all the nitty gritty of dye usage and other such nonsense, we do know that such a system could eventually attain 15% or so efficiency, providing a nice and clean way to gather power for that fuel cell car of the future."
I thought that current solar cells have efficiencies of up to 40%. So how is this better?
Sigs are too short to say anything truly profound so read the above post instead.
Thermal Depolymerization can convert almost any organic substance into raw hydrocarbons. So yeah, converting humans into oil is entirely possible.
That's actually how I'd prefer my body to be disposed of when the med students are done with it. Burying corpses is so wasteful in the grand scheme of things.
=Smidge=
Perhaps, the paint on the car can be treated in some way to act as the acceptor for the sun and thus be converting water into hydrogen "on the fly"?
Beer is proof that God loves us and wants us to be happy.
there's nothing saying we couldn't use energy from nuclear plants to electrolyze water but considering the sheer amount of energy in the form of sunlight that is available, ignoring it is not an option. as you said, storing hydrogen is the problem although we have catalysts to react carbon dioxide and hydrogen to form numerous compounds, hydrocarbons, misc carbohydrates, even plastics. imagine it, using sunlight or nuclear power to reduce and remove carbon dioxide from the air while simultaneously making more plastics, the more plastic produced, the more CO2 is removed from the air- harnessing consumerism to help the environment!
Sigs are too short to say anything truly profound so read the above post instead.
Well, personally I don't care how we get H2. It's all pointless anyways. H2 will never be a common fuel for motor vehicles.
Here's why:
In regards to using liquid H2 in vehicles:
- It's too dangerous. You're driving a bomb. Every car using liquid H2 is a has-mat vehicle by legal definition. Imagine the terrorists glee where they don't have to rent a car and then build a bomb because the rental car IS a bomb.
- it must be trucked in liquid form - can't be pipelined, and therefore we'll have to deal with massive supply issues, thouands more has-mat trucks on the roads, and reduculous logistics.
- fuleing requires extensive safety measures and extremely specialized and expensive equipment
- you either have MASSIVE pressurized tanks (taking a very large portion of your vehicle space and weight) or you have to have the H2 actively cooled to extremely cold termurateres, requiring the car to be powered 100% of the time.
For metal infused H2 gas vehicles:
- well, it's much safer... but:
- maximum range uning even theoretical technologies is about 220 miles per fill up, assuming you leave enough seating room in a large SUV for 5 people and no luggage.
- the tank is huge, and weighs hundreds of pounds, eating at vehicle efficiency and space (too big for those small commuter cars in Europe)
- IT TAKES UP TO 8 HOURS TO FILL UP, and requires active cooling to prevent explosions while doing it.
H2 in general:
- it's dangerous to use a vapor gas as a fuel. Imagine auto shops all over the country having to worry about gas being spilled during repairs? Spill hydrocarbon, just avoid dropping a spark in the liquid until you soak it up with sawdust. Cause an H2 leak and you have to evacuate the building, no different than a natural gas or propane leak. Also, if liquid H2 leaks, you not only have to worry about combustion, but vapor expansion and extreme freeze issues.
- It costs 3-5 times more energy to make it that it would to simply run the car on electricity
- It's expensive. best estimates, you go the same distance on H2 for 2-4 times the cost of gasoline, and that's with all the current government funding lowering the costs.
- Where do you plan to store all the H2? Large scale containers are very difficult to make assuming you're storing it in liuquid form. We simply don't have enough room to store it in gaseous form.
- Fuel cells don't get repaired, they get replaced. The repair costs will be immense, collision insurance even worse (not to mention the danger issues insuring rolling bombs).
- burning H2 directly in ICEs is barely more efficient than burning ethanol.
- minimum car price. You can forget about those $7,000 cars. Minimum price for a fuel cell vehicle will be in the 20K range once the government subsidies stop becoming affodable.
no, we can't power every vehicle on earth on ethanol
yes, we will run out of oil, sooner than you like to admit
yes, we havre to do something, but what?
What is the answer? Super conducting electrical grids (which we can make today with existing technology at reasonable costs), fed by renewable energy in target locations around the world (wind farms where it's windy, water where there's natural falls, solar in the deserts, etc). We use all that to recharge plug-in cars using batteries from Toshiba and others companies that have already been developed which have as quick as 90 second recharge times. For those of you who say we can't do it, that we can't run recharge units all around towns for people to plug into on the run, well look at how Alaska has done it, and many other countries in the fridgid north of Europe, where cars that don't have engines running need to be plugged so their heaters can prevent fuel lines from freezing. Every parking meeter in some coutries have power cables attached. We CAN do it. It's been done before. We'll still use ethanol as a backup to the battery using ethanol in ICEs until small turbines (like BMW uses in their motercycle) become more cost effective through mass production.
There is no contest in life for which the unprepared have the advantage.
The way to deal with dents is to use lots of interconnections and make the transport system from a tube in a tube design. The outer tube contains a polymer that hardens when exposed to H2O, any dent significant enough to cause the tubing to burst seals itself and the interconnections route around the blocked tube. Think of it as a cross between internet routing and the bodies clotting system =)
There are 4 boxes to use in the defense of liberty: soap, ballot, jury, ammo. Use in that order. Starting now.
Electric heat pumps can actually get more heat in your home than they use to do it.
Heat pumps as the name implies aren't generating heat, they're moving it from one place to another and heat pumps using chemical fuels (like natural gas) also get more heat into your home than they use to do it. I doubt converting electrical energy to heat via resistive heating is any more efficient than converting a chemical to heat via combustion. (Certainly not when you consider that most of that electricity is generated using the exact same chemical combustion to produce the same heat, to produce pressure, to spin a turbine, to generate electricity, carried with transmission losses to your electric heater.)
The ONLY reason that chemical fuels seem valuable now is because we essentially get them for free. Or rather, all the work has already been done to store the energy. We just need to dig it up, refine it a bit, and get it where it is needed.
Certainly that's PART of the appeal but I think it's also significant that you can easily store chemicals but it's hard to store electricity. This is particularly relevant when what you want to do with the energy is transportation where you have to store the energy in the vehicle itself. (There are of course modes of transportation like trains which have set routes and it can be arranged that they can be plugged into the grid on those routes, but there are obvious limitations to such vehicles which vehicles that store their own energy don't face)