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Researchers Generate Electricity Using Seawater and Sunlight
Slashdot reader sosume writes: Scientists at Osaka University have created a new method to use sunlight to turn seawater into hydrogen peroxide which can then be used in fuel cells to generate electricity. It's the first photocatalytic method of H2O2 production that achieves a high enough efficiency so that the H2O2 can be used in a fuel cell.
It's easier and safer to transport liquid H2O2, according to the article, and while its total efficiency is much lower than conventional solar cells, the researchers hope to get better results by using better materials.
It's easier and safer to transport liquid H2O2, according to the article, and while its total efficiency is much lower than conventional solar cells, the researchers hope to get better results by using better materials.
Wait, you're suggesting that something combustible can be used both to fuel engines and explosives? Perhaps someone should come up with an award to encourage people to use this knowledge for good instead of evil! Something catchy like, say, the Nobel Peace Prize.
Inheritance is the sincerest form of nepotism.
Energy efficiency and economic efficiency are totally different. Economic efficiency is "how much effort and resources do I have to expend to get this thing to work?" You can have 100% energy efficiency, but if its economic efficiency is $100 per kWh, nobody is going to use it. It is literally cheaper to build a larger system with lower energy efficiency to harvest the same amount of energy. This seawater method could have 0.1% energy efficiency, but if it economic efficiency is $0.05 per kWh it would be a tremendous breakthrough.
mdsolar doesn't care about economic efficiency, which is why his "solutions" are pointless for the real world. The reason PV solar languishes at below 1% of electrical production is not some grand conspiracy. It's because PV's wholesale production cost (after factoring in construction, financing, maintenance, lifespan) is up around $200-$300 per MWh. Coal is around $40 per MWh, around $350 per MWh if you include the environmental and health damage it causes that the IMF estimated in it's "$5.3 trillion subsidy" report. Gas around $60. Nuclear is around $60 ($90-$100 for new construction). Hydro around $30. Wind around $70-$100.
PV has dropped to about $125-$150 per MWh in the last few years, but it remains to be seen if that's real gains or due to dumping by Chinese manufacturers to try to drive other manufacturers out of business. Even if real, it still remains the most expensive source of electricity, which is why it's stuck at below 1% of production.
Unfortunately, facts, which you presented quite clearly, don't matter to many. Solar advocates will avoid talking about the real cost of energy in MWh at all costs (pun intended).
Another economic impact that gets brushed aside in national content supply and jobs. For PV, a large chunk of the initial capital cost goes straight to China or other Asian manufactures. There are some US manufacturers but they are not the biggest players. Installation jobs are low paying, and there are few ongoing maintenance jobs. Wind requires a bit more from a maintenance and on-going supply standpoint, and has pretty good local parts content.
Coal, gas, and nuclear all have high local construction content, and employ more people with higher paying jobs on an ongoing basis. In a changing world where automation is taking over and good jobs are harder to find, employment factors into the overall economic benefit. A nuclear plant, for instance, will employ hundreds of six figure salary, educated workers, and also hundreds of higher paying craft and labor jobs. Nuclear and coal also keep a large number of support companies in business. And, they pay back a lot more in taxes via property, employment, etc than they are subsidized.
It's a dumb idea- don't try this at home- but in principle there's no reason why you couldn't make an engine that runs on TNT.
TNT explosions are sooty. When TNT detonates it forms nitrogen gas and steam, but also carbon monoxide and elemental carbon which are both flammable- so you actually get more energy out of TNT if you burn it with oxygen instead of detonating it. TNT is pretty stable and was originally used as a yellow dye for years before anyone even realized it could explode (or that it was toxic). It can be melted and aerosolized like gasoline or diesel into a flammable fuel-air mixture. But since it melts at 80 degrees, it would be like making a ICE engine that runs on melted wax. It would also generate YUGE amounts of nitrogen oxides and would be much filthier than diesel. In general nitrogen is not something you want in an internal combustion engine, and there are plenty of organic molecules that don't contain nitrogen at all. From an emissions perspective, THC would be a much better fuel than TNT.
TNT also has catalytic properties (it can form charge-transfer complexes) so it might actually be useful in something like a battery.