Quote :

"compressed hydrogen also doesn't sound like the best idea for putting on a car, train, or plane."

I wouldn't think it would be any more dangerous than gasoline other than the fact that it burns with a clear flame and you can't tell if the car is on fire.

If the tank ruptured, it would actually rise and dissipate instead of pool on the ground like gasoline.

7/30/2010 5:46:37 PM

Quote :

"People are working on storage technologies as well from molten salt to redox batteries...which by the way actually address your second point for existing energy generation."

Storage technology will help make solar more useful, but it's not quite there yet. Even with storage technology, I think the gains from solar power would be marginal. Storage technology will be much more beneficial to wind generation, in my opinion. I think I read up that solar is only 19% efficient due to darkness, cloudy skies, etc.

7/30/2010 5:48:15 PM

Quote :

"Power costs are generally measured in cents per kilowatt hour – the cost of the electricity needed to illuminate a 1,000 watt light bulb (for example) for one hour. When the cost of a kilowatt hour (kWh) of solar power fell to 16 cents earlier this year, it “crossed over” the trend-line associated with nuclear power. (see chart below)"

Such stories never say, but when they are calculating cost, why do they always list it as price per watt? Such is useless, since the solar panel is only producing at its peak output for five hours a day, even then weather permitting. It is a lie to compare price per watt between one source that produces 23.9 hours a day and another one that produces for five hours a day. What we as engineers should demand is price per kilowatt-hour after factoring out all the subsidies.

7/30/2010 6:11:37 PM

Quote :

"Easily the dumbest fucking thing I've heard this month."

Really? Scientists have been playing with RedOx reactions for ages. They're also the volatile reactions, which may prove to be difficult to harness safely. And I believe some of the first experiments in efficiently capturing solar energy were with molten sodium in heat collection towers back in the day.

The problems with solar extend beyond simply storing the energy, as Super Dude says, atmospheric conditions can seriously hinder collection. Solar collection takes a lot of land versus a modern power station, but will be something we use in the future as it becomes more efficient in conversion.

I believe that wind turbines will pose a significant threat against all types of bird populations, especially migratory populations. Having the number of wind farms required to power the country at current consumption rates would create large "no-fly" zones for bird unless massive (and inefficient) bird guards can be constructed.

7/30/2010 6:13:30 PM

Quote :

"I believe that wind turbines will pose a significant threat against all types of bird populations, especially migratory populations. "

You are correct. I work in the cellular/broadcast tower industry, and we are always have migratory bird issues. We do everything we can to strobe light the tower, paint the tower, put other 'anti-migratory bird' measures....to little avail. We're always having schools of birds slamming into the towers.

I'd imagine wind turbines would only be worse. They're normally taller and they're actually moving
The only positive is that they're probably a bit more visible than cellular towers. Not sure if this stuff happens at night or if birds are just really really stupid


[Edited on July 30, 2010 at 6:25 PM. Reason : ]

7/30/2010 6:22:47 PM

bump

5/18/2011 2:44:51 PM

WHY? IS THERE SOME GOOD NEWS ON THE SUNPOWER FRONT?

5/18/2011 2:46:55 PM

Wake me up when they can convert more than merely IR.

5/18/2011 3:27:55 PM

I didn't request the bump but I did see this?

http://www.grist.org/list/2011-05-18-solar-breakthrough-could-lead-to-90-percent-efficient-panels-som

Quote :

"A researcher at the University of Missouri is making some eyebrow-raising claims, including that a new technology he has developed could lead to solar panels that convert 90 percent of the sun's energy to electricity. If he's even a little bit right, this would be more than amazing; it would be earth-shattering. So he's probably wrong, unfortunately. But let's suspend disbelief, shall we? The average plant converts about 1 percent of the sun's energy. That's one reason why conventional biofuels are kind of a joke. A good solar panel will convert around 20 percent of the sun's energy into electricity. The way that UM researcher Patrick Pinhero proposes to take that efficiency into the stratosphere is by capturing parts of the spectrum of light we can't even see -- like the infrared. He'll do it with these really tiny antennas carved into silicon, called nantennas. He says he can have a commercial product in 5 years, as long as he can get funding to commercialize them (hint hint). The main thing that nantennas illustrate is that unlike many other energy technologies (wind, nuclear) solar is far from "mature." It has a long, long ramp of improvements in front of it, which means that it will only become cheaper, more effective and -- in a future in which distributed power production rules -- dominant. "

5/18/2011 3:46:21 PM

The majority of the suns energy falls in the spectral sensitivity of Silicon already. Capturing the MWIR and LWIR bands will not get you a 60% jump in efficiency.

I don't know what all of this antenna business is, but it sounds like a stupid research project.

5/18/2011 4:12:28 PM

Quote :

"he's probably wrong"

Deals with nano though. I, for one, am going to peruse the NC State libraries for shit about him.

Theory and manufacturing processes of solar nanoantenna electromagnetic collectors
Kotter, D.K.1; Novack, S.D.1; Slafer, W.D.2; Pinhero, P.J.3 Source: Journal of Solar Energy Engineering, v 132, n 1, 011014 (9 pp.), Feb. 2010; ISSN: 0199-6231; DOI: 10.1115/1.4000577; Publisher: ASME, USA

Author affiliation:
1 Idaho Nat. Lab., Idaho Falls, ID, USA
2 MicroContinuum, Inc., Cambridge, MA, USA
3 Dept. of Chem. Eng., Univ. of Missouri, Columbia, MO, USA

Abstract: The research described in this paper explores a new and efficient approach for producing electricity from the abundant energy of the sun, using nanoantenna (nantenna) electromagnetic collectors (NECs). NEC devices target midinfrared wavelengths, where conventional photovoltaic (PV) solar cells are inefficient and where there is an abundance of solar energy. The initial concept of designing NECs was based on scaling of radio frequency antenna theory to the infrared and visible regions. This approach initially proved unsuccessful because the optical behavior of materials in the terahertz (THz) region was overlooked and, in addition, economical nanofabrication methods were not previously available to produce the optical antenna elements. This paper demonstrates progress in addressing significant technological barriers including: (1) development of frequency-dependent modeling of double-feedpoint square spiral nantenna elements, (2) selection of materials with proper THz properties, and (3) development of novel manufacturing methods that could potentially enable economical large-scale manufacturing. We have shown that nantennas can collect infrared energy and induce THz currents and we have also developed cost-effective proof-of-concept fabrication techniques for the large-scale manufacture of simple square-loop nantenna arrays. Future work is planned to embed rectifiers into the double-feedpoint antenna structures. This work represents an important first step toward the ultimate realization of a low-cost device that will collect as well as convert this radiation into electricity. This could lead to a broadband, high conversion efficiency low-cost solution to complement conventional PV devices. (21 refs.)

Downloaded the article. Pretty cool stuff.

[Edited on May 18, 2011 at 4:26 PM. Reason : lkj]

[Edited on May 18, 2011 at 4:27 PM. Reason : removed irrelevant conference source]

5/18/2011 4:13:57 PM

There's still some decent intensity from the infrared range, but the highest intensity of light can be found in the visible region of the solar spectrum




but by merely 'expanding' the range in which light can be absorbed doesn't necessarily mean an increase in efficiency, if we're speaking in terms of ([energy out] / [photons in]) *100

also, by developing solid materials that have bandgaps low enough to absorb such low frequency photons you are also going to run into electron-hole recombination issues, which is already a tough area to tackle with current solar technology.


best of luck to him though, i hope he gets his funding and everything works exactly as described

5/18/2011 5:35:51 PM

Quote :

"Yup, it's only a matter of a decade or so before places like Saudi Arabia and Yemen are back to a point when rugs are their primary export to the US. It's appalled me for quite some time that we still burn coal and oil for electricity when there are better, cleaner, and smarter ways to do it"

those countries don't produce coal and also are solar radiation hotbeds.

5/19/2011 8:09:59 AM

Quote :

"yay a power source that wont power your lights when you need them"

Household lights account for a very small amount of energy use.

Imagine your AC running wide open in the summer and not having to cringe at how much its gonna cost. I would put everything in my house on a timer to not run at night.

Hot tub. No Heat at night unless manually over rode.

Water Heater. Same thing, shuts off at dusk, if someone is gonna take a late shower gotta turn it on in advance.

Clothes Dryer, only use during the day.

Dish washer, only use during daylight.

Not sure if anything can be done with the fridge. Maybe have it run to a colder temp in the afternoon to coast through the night, but that might not be good for your food.

If you could also address "phantom" energy use like all the things around your house that are drawing current when not being used then you could have virtually no usage at night in the summer.

In the winter it would still suck, but only if you have electric heat.

5/19/2011 10:12:35 AM

Quote :

"Household lights account for a very small amount of energy use. "

Especially as LEDs move into the home. One of my friend's parents have a sailboat/yacht that they recently converted to 100% solar and replacing every traditional bulb with LED lighting was a big part of the conversion. They installed a desalination machine and they are going to be living on it full time at the start of next year.

Quote :

"Water Heater. Same thing, shuts off at dusk, if someone is gonna take a late shower gotta turn it on in advance. "

The good thing is that if you had a traditional tank water heater it would store the water at a warm enough temp all night. A whole family might not be able to shower off it, but a couple could probably make it work just fine. Not going to work with a tankless setup, but most of those are gas so electricity wouldn't really affect them other than a tiny amount for the electronic controls.

[Edited on May 19, 2011 at 10:28 AM. Reason : s]

5/19/2011 10:27:14 AM

You're overthinking this; energy is still cheapest at night. If you're going to isntall solar panels, then switch to TOU metering and adjust all of your appliances to run at night as much as possible.

5/19/2011 11:16:34 AM

Mine is not, its the same rate at all times.

There is no peak/off peak rates on my bill.

5/19/2011 11:52:59 AM

it's still cheaper for the utility to generate at night, and you're going to see mandatory TOU metering in the next few years. Maryland is pushing for it hard right now. Why not go ahead and take advantage of the optional enrollment TOU systems offered by most utilities?

5/19/2011 12:00:24 PM

^^ only because of the default pay structure you are opted in to. I think most major utilities these days have TOU options.

5/19/2011 12:02:18 PM

^^ Misleading. It is not "cheaper" to produce electricity at night, there is just less demand and therefore a buyers market.

5/19/2011 4:15:02 PM

^it IS cheaper because they don't have to run at full capacity.

[Edited on May 19, 2011 at 5:00 PM. Reason : ]

5/19/2011 4:59:44 PM

No, it is cheaper because they don't want to shut down.

Throttling back a nuclear reactor or Coal plant makes them work less efficiently, and shutting them down at night wastes everything (fuel, labor, capital, etc). As such, they cut the price of power at night to boost demand and keep the plants throttled up.

[Edited on May 19, 2011 at 5:23 PM. Reason : .,.]

5/19/2011 5:22:13 PM

Federal law prohibits throttling back nuclear plants, so that's not even an option. regardless, our peaking plants are mostly gas turbine units that are much more expensive to run than steam plants. For that reason, generation is cheaper at night than it is during the day because we can use cheaper plants. You also have to consider wheeling charges on transmission lines, which is what caused the blackouts in California years back. Generation isn't always the driving factor.

There are a slew of other reasons to make electricity cheaper at night. the grid becomes unstable under extremely low load, nukes can't be throttled back, and coal plants are costly to shut down.

5/19/2011 5:44:08 PM

Quote :

"regardless, our peaking plants are mostly gas turbine units that are much more expensive to run than steam plants."

Quite right, which has nothing to do with the day/night divide. After-all, peaking plants must be run at night, too, since the big plants cannot throttle very well. What you meant to mention were day-run plants which come on in the morning and run all day shutting down at night. At least some peaking plants run 24-hours, throttling to keep grid production matched to grid consumption.

Also, while gas turbine plants do exist, they are usually only for emergencies. Day-run gas plants usually use steam, peaking plants are usually gas-piston engines, and gas turbines are only used for emergencies such as the warmest summer day.

5/20/2011 12:32:47 AM

nope, peaking plants are typically run only during the daytime in months when air-conditioning loads are high. You're trying to describe a load follower plant, which typically is a combined cycle plant if it was built in the last 20 or so years. Even the load-following plants are more expensive to run than our base load coal plants, so my statement about electricity being cheaper to generate at night still holds true.


Outside of peak shaving duties for a few municipals and generation on a few islands, I've never seen piston engines used for any grid generation purpose. They typically don't get big enough to generate anything worthwhile. IIRC, a 20MW diesel generator costs more initially than a 60MW gas turbine with diesel run capability, and the maintenance and downtime on the diesel is higher.

5/20/2011 7:51:13 AM

Solar/fuel cell combos would be great for distributed generation... there is a lot of research* going on with different catalysts to make splitting water into hydrogen and oxygen more efficient. This way a home's power could come from a fuel cell using hydrogen produced by electricity from the solar cells during the day.

* http://www.sciencedaily.com/releases/2011/05/110516102331.htm (for example)

5/20/2011 8:22:05 AM

PGN uses gas turbines for load followers and peak demand generation. Obviously, the cost per kWh to generate on coal and nuclear is considerably less than the cost to run on gas. Since regulated utilities can only charge a fixed rate and you pay the same thing no matter how much they pay to generate it, the less they rely on the gas turbines, the higher their margin. They cut you a deal on TOU plans so that you use your power when they have the greatest profit margin.

5/20/2011 9:02:12 AM

How about something like this for emergencies?

http://mysolarbackup.com/


Disregard the Alex Jones comments. Focus on the device.

5/20/2011 12:09:28 PM