Valence to supply marine battery systems
June 5, 2009 at 2:39 pm #945
This is great news for me. I plan on creating a 100% electric economy on my seastead, which means even the boats would be run by fuel cell or battery tech. I’ve been watching Valence for a while, and this news about boat batteries is pretty cool. And the Siemens drives are already very cool.June 6, 2009 at 1:09 pm #6353
Electricity isn’t really a source of energy, so the expression “electric economy” probably needs some elaboration. Then there is the issue of whether the energy source sustains itself. Does a PV panel produce enough energy in its lifetime to cover the energy consumed when building it, and give back enough excess energy to be cost effective?June 6, 2009 at 3:09 pm #6354
Sorry, didn’t want to get to technical in a thread that was basically just pointing out a news item. I mean that I plan to run the entire seastead with just electricity. No biodiesel, gasoline, hydrogen for combustion, etc. Everything from the ships to the planes to the machines…everything will be run on E.
My “electric economy” is just a play on the overused “hydrogen economy” I’m always hearing and isn’t the best term, I know.June 6, 2009 at 10:27 pm #6360
The answer is ‘YES’ PV’s do produce more electricty over their life cycle than they take to produce. What’s more, properly maintained, they seem to have an indefinate ‘life cycle’…June 7, 2009 at 9:40 pm #6363
I prefer solar thermal systems myself. While the systems might be a bit more complex than PV systems (more moving parts, high temps, etc) they are much easier to fabricate…just lots of mirrors and a sterling engine. PV fabrication requires high-tech facilities and materials.June 8, 2009 at 2:58 am #6364
So… Something like this?
There is no fate but what we make for ourselves. Each to his fate.June 8, 2009 at 4:10 am #6365
I’m gonna get my tablesaw out and start cutting lenses!! Making those glass sculptures looks like fun!
Yea, something like that. I currently like the idea of using molten salts, since you can get something like 50% efficiency without even breaking the 1000 degree barrier. Ramp the pressure up in your system and you are talking like 300C which is a piece of cake. Also, the molten salts cool a lot slower than gas…so they don’t shut down as quickly as gas systems (the salts retain the heat for longer) when a cloud goes over the sun.
I’ve seen power tower designs using molten salts in the 250MW range!! The problem with these systems, as with all solar systems, is the area involved. But that’s one thing the ocean has a lot of….open space!
The pinnacle of the technology is the solar power satellite. These are large solar thermal systems floating in space, where they can collect solar energy all the time. You then beam the power back to ground stations using microwaves. Bingo, you have unlimited energy.
But you need to store that energy, so that’s why the Valence info was very nice. A123 Systems has some nice batteries too. I’ve been bouncing back and forth between batteries and ultracapacitors. The EEStor ultracap stuff is incredible, and they HAVE to have some nice stuff with all these companies pouring millions of dollars into them. But I’m still skeptical of their claims.June 9, 2009 at 4:36 pm #6388
“You then beam the power back to ground stations using microwaves.”
One must be careful with ths, of course, to not use the exact frequencies in standard microwaves… you know, the ones that are tuned to agitate hydroxic acid (aka water) and make it hotter… QA would be crucial here. If this isn’t done perfectly, then humans really will be responsible for a good chunk of the climate change in the future.
There is no fate but what we make for ourselves. Each to his fate.June 9, 2009 at 4:41 pm #6367
That was an exceptionally cool link! A good place to get Fresnel lenses for free is out of old projection screen TVs. I now have two of them and am hoping to get another one this weekend. Let me tell you, you have to be very, very careful with them out in the sun: I was just messing around going to melt a penny (zinc not copper) aimed it in the wrong direction and started a grass fire!
They are also a source of good speakers, high quality optical lenses, first surface mirrors and aluminum heat sinks…June 9, 2009 at 5:24 pm #6391
Most designs for this are based around 2.45GHz which would cause no biological or ecological effects. In addition the beam intensity is so low you could hang out in the exact center of the beam for a long time without any issues.
Of course, this requires the receiving rectenna to be quite large. But again, what we are not lacking on the sea is available surface area.
EDIT: I just went back through my old notes and found some numbers. A Japanese design calls for a maximum power density on the ground of .9mW/cm^2…that’s a bit low in my opinion. A 1980 NASA study puts the exact center of the beam at 23mW/cm^2 which is still a fraction of the power density of normal sunlight (1.4kW/m^2, which is 140mW/cm^2). So if you stand in the exact center of the beam you will be warmed up by an energy that is 1/6th as strong as what you would feel on a very sunny day.
In even the higher-power NASA study the beam intensity decreases as you move from the center. You are only getting 1mW/cm^2 at the beam edge.June 9, 2009 at 8:07 pm #6392
Could you send a link to this? It sounds quite interesting.
There is no fate but what we make for ourselves. Each to his fate.June 9, 2009 at 9:10 pm #6394
Here are some primers on SPS systems and microwave energy transmission:
1980 NASA paper (PDF)
The Discovery channel did a whole program on SPS for their Project Earth series, that’s what the press conference is about. The Discovery website sucks ass, so it’s almost impossible to find anything without just buying the DVD. But it’s mostly pretty pictures, and not much hard science, so it’s not worth much anyway.
What gets me so pissed is that the US government can come up with $150 BILLION dollars to loan AIG…a failed company that ran itself into the ground. If the US had invested just %10 of that amount in SPS then the entire US would be using cheap, pollution-free, unlimited electricity forever. What a freakin waste.June 10, 2009 at 5:53 am #6400
Why use microwaves? Wouldn’t it be a lot cheaper and easier just to put some large parabolic mirrors in space and bounce the sunlight off these down to a solar thermal generator?June 10, 2009 at 9:22 am #6402
I don’t see energy being sent via radio as a usable technology in the near future. Those heat engines with the fresnels look alot more realistic. If we’re on the water, we can constantly move the generators to avoid heavy clouds. Or set them up to do it automatically.
We set up a few huge barges with the sole intent of following the sun and producing electricity, then dock with them and take the power every few weeks.
- NickJune 10, 2009 at 3:14 pm #6409
bounce the sunlight off these down to a solar thermal generator
The issue is one of safety. When you are using microwaves the beam intensity is very low, so you don’t have to worry about frying birds or people in planes. If you were trying to focus an intense beam of sunlight onto a thermal engine, the beam intensity would have to be enormous and you would have people going crazy about this “solar death ray” that could incinerate cities.
You could get away with using mirrors to focus a less-intense beam onto PV systems, or a big solar thermal farm. You would have the benefit of not having to track the sun with your mirrors or PV arrays. But this mirror system doesn’t work on cloudy days or in bad weather. The reason for using 2.45GHz microwaves (or actually anything under 10GHz) is that clouds and water vapor have no effect on the beam strength. The beam passes right through clouds like they weren’t there so you truly have energy 24/7 (minus a few hours a year due to the sun position during the solstice).
Lasers have this same limitation, which is why all real energy beaming work since the 60s has been focused on microwaves.
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