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New Record For Solar Cell Power Efficiency

kdawson posted more than 6 years ago | from the onward-to-50% dept.

Power 351

mdsolar writes "Renewable Energy Access is reporting that a consortium led by researchers at the University of Delaware has achieved 42.8% efficiency with a silicon solar cell. The method uses lower concentration (factor of 20 magnification) than the previous record holder (40.7% efficiency) so that it may have a broader range of applications, since tolerances for pointing the device will be larger. They are now partnering with DuPont to build engineering and manufacturing prototypes. They expect to be in production in 2010. On a roof, such cells would require less than half the surface area to produce the same amount of power as today's standard solar panels, which have an efficiency of about 17%."

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351 comments

The real question.. (2, Interesting)

Enderandrew (866215) | more than 6 years ago | (#20068217)

Yes, but will it run Linux?

Actually, while I'm glad they are making a more efficient solar panel, when will they make a cost-effecient solar panel for mass-adoption?

You are a fucking asshole. (-1, Troll)

Anonymous Coward | more than 6 years ago | (#20068271)

Linux is a communist piece of shit operating system that never has any hope. Now go away, you greasey, unwashed Free Software Hacker. You make me sick to think you support Open Sores software that is destroying the United States economy by reducing our Gross Domestic Product. You are a terrorist. I should write to my favorite president George W. Bush and tell him to fix this mess with people trying to artificially lower the cost of their software to kill the competition. This is illegal!

The captcha is "vantage."

Smog (5, Funny)

Rixel (131146) | more than 6 years ago | (#20068223)

Hopefully, Solar Cell efficiency will keep ahead of smog cover in major cities.

Re:Smog (-1, Troll)

Anonymous Coward | more than 6 years ago | (#20068559)

Assuming you're serious - solar energy replaces fossil energy. More solar energy means less smog.

This is very dangerous, actually. First, less smog means the earth will receive more solar energy, so it will warm up. Secondly, the more solar energy we capture and convert into electricity, the less is radiated back into space (the earth's albedo will decrease). This warms up the earth, which means more airco's being used, need for more energy, more solar power being captured, etc..
Runaway heating - KEEP AWAY from solar energy!

Re:Smog (0)

Anonymous Coward | more than 6 years ago | (#20068801)

Assuming YOU're serious - solar energy replaces fossil energy. More solar energy means less "greenhouse gases". Lesser albedo also mean more heat radiated back into the space over night, provided we lessen greenhouse effect enough for it to break through atmosphere.

Waiting (5, Funny)

Cassius Corodes (1084513) | more than 6 years ago | (#20068229)

Im waiting for them to reach above 100% efficiency before I'll buy

You must have failed Physics class (-1, Troll)

Anonymous Coward | more than 6 years ago | (#20068289)

You can never get more energy out of something than you put in! Getting more than 100% efficiency would imply that you were. Anyone who knows the law of conservation of energy knows that is impossible! Go back to high school and pay attention in Physics class, you fucking idiot.

The captcha is "protract."

Re:You must have failed Physics class (1, Insightful)

montyzooooma (853414) | more than 6 years ago | (#20068329)

I think you failed Humor 101.

Re:You must have failed Physics class (-1, Offtopic)

Anonymous Coward | more than 6 years ago | (#20068707)

The joke wasn't funny.

feasible (2)

farkus888 (1103903) | more than 6 years ago | (#20068231)

a good grid tie system and these things will pay for themselves. I hope that panels of this efficiency are ready for public purchase when I am ready to be a homeowner. this is one of those things that makes economic and environmental sense and I hope it doesn't get stymied by people who are afraid to be "green" because they think it has to be more expensive.

Re:feasible (4, Informative)

Calinous (985536) | more than 6 years ago | (#20068273)

The most efficient use of solar power is the water heating system. Solar panels are a distant second for now - as they are very costly for the power they can produce (we assume your house needs heating or hot water). Depending on conditions, wind power might be a cheaper overall choice than solar panels.
        But in places like California, solar panels indeed pay for themselves

Re:feasible (2, Interesting)

evilviper (135110) | more than 6 years ago | (#20068465)

The most efficient use of solar power is the water heating system.

I'm not too sure about that. How about a PV panel powering a ground-source heat pump? I'm willing to bet that would give you more hot water than direct solar heating, at least in most climates.

Re:feasible (2, Informative)

Calinous (985536) | more than 6 years ago | (#20068509)

It might be so - however, I don't know the costs of a ground-source heat pump. Did any digging recently? Also, you can get hot water at a higher efficiency than electricity from solar power, and the costs of installations are lower to boot. What a solar water heating system can't give you (but a PV panel/ground pump could easily) is cooling

Not too bad (5, Informative)

Gr8Apes (679165) | more than 6 years ago | (#20069013)

I looked into this recently. Installing a ground based heat pump instead of a regular air conditioner would have been around $6K (instead of $2K for the AC). Note that this was for an old style 12 SEER AC unit that's no longer available against a 25+ SEER heat pump (get added bonus of generating heat). AC units have almost doubled in cost, and now are about $4500 installed (new US regulations require higher SEER units).

Why didn't I get the ground based system? Because when it's over 100 F and your main AC unit dies, I couldn't wait for the ground based unit installation taking over a week. I will plan for one at my next house though.

Re:feasible (2, Informative)

Smidge204 (605297) | more than 6 years ago | (#20068819)

As per the summary, solar cells are 17% efficient. The efficiency of a heat pump will vary quite a bit depending on working temperatures, but the compressor motor will doubtfully be more than about 80% efficient (electrically). So overall, at best, 14% of the sunlight makes it into the hot water.

Compare to direct solar heating, where damn near 100% of the energy you absorb gets transferred to the water. After all, the desired end product is heat, and it's trivial to convert 100% of any energy form into heat if you're patient enough.
=Smidge=

Re:feasible (1)

Smidge204 (605297) | more than 6 years ago | (#20068875)

Forgot to factor in the COP.

A decent heat pump will have a COP of around 3.5-4.0. So that 14% becomes 56%. Still losing to direct solar heat.
=Smidge=

Re:feasible (1)

dbIII (701233) | more than 6 years ago | (#20069033)

That all depends on where you are obviously. Boring deep holes is not cheap, but if you can get away with a shallow one it would be worth it.

Re:feasible (4, Informative)

knarf (34928) | more than 6 years ago | (#20068599)

That is why the two should be combined... Water-cooled Photovoltaic panels give the best of both worlds: cooler PV panels which are more effective PLUS warm/hot water for heating, hot water or - indirectly - cooling. The technology is out there. It is simple. It works. As to why is is not used that much yet? Good question.

A search on 'water cooled pv' [google.com] gives some interesting documents about experiments done with this combination. Read them and then go and build something like that. My 2 puny 11 watt panels are somewhat to small for this application but anyone who has (plans for) panels on the roof AND a need of warm water does him/herself a disservice by not looking in to this IMnsHO...

Re:feasible (1)

GreyPoopon (411036) | more than 6 years ago | (#20069103)

Depending on conditions, wind power might be a cheaper overall choice than solar panels.

The problem with wind power is that it's much more noticeable to your neighbors than solar. I live sort of at the top of a hill on 1.25 acres, and it's fairly windy. Theoretically, I could put of a few windmills and probably meet most (if not all) of my electricity needs, but my neighbors would definitely be complaining. The advantage of solar is that if you have good southern exposure and efficient panels, you can produce most of your electricity without your neighbors really even knowing that you are doing so. Windmills are a much better option when an entire neighborhood decides to use them to collectively. I think in the future we may see more of this -- new neighborhoods will be planned with open space on the high ground to install windmill farms.

Re:feasible (1)

evilviper (135110) | more than 6 years ago | (#20068495)

I hope that panels of this efficiency are ready for public purchase when I am ready to be a homeowner.

Why? You planning on putting a 50:1 solar concentrator mirror/lens in your yard?

Re:feasible (4, Informative)

liquidpele (663430) | more than 6 years ago | (#20068871)

Joking aside, the best thing you can do for the energy usage of your home is ensure it is properly insulated and buy the quality efficient heating/air units. You can take it further by buying those new florescent light bulbs that are only around 14 watts, and having your computers hibernate during the day and night when you're not using them. You could see your power bill cut in half if you do all that.

hmmm. (4, Informative)

apodyopsis (1048476) | more than 6 years ago | (#20068233)

I'm interested in solar power as a means of lowering the fossil dependency - but there are other, better means of doing so. The CE manufacturers need to meet them half way and mandate more efficient devices that consume less power and bring back the humble ON/OFF switch that actually did turn off the power. Is it that hard to walk to the TV? And, of course, wind and tidal need to be followed up.

The main problem is the general public. Everybody wants wind power (but not in their back yard) you have to actually change the law and rubbish collection to get them to recycle, and everybody needs to buy the latest and most powerful gadget on the market.

Making a more efficient solar cell is an excellent step, but I'd be more interested in a more *cheap* one so they can be taken up on a mass scale.

Re:hmmm. (3, Interesting)

NeilTheStupidHead (963719) | more than 6 years ago | (#20068347)

Everybody wants wind power (but not in their back yard)
That's one thing that I've never understood. I used to live about an hour's drive from a wind turbine and drove by it several times a day. I could never wait to drive by because I loved the sight. My new home is very windy and could benefit greatly from wind power. I simply cannot fathom the resistance to wind turbines.

One thing I have always wondered though: given the fairly large surface area of the turbine blades, would it be possible to add a photosensitive material and pull a bit of power from the sun too? Probably not terribly practical at the moment, but I seem to recall reading, probably on /., about a paint on solar panel.

Re:hmmm. (2, Interesting)

Calinous (985536) | more than 6 years ago | (#20068413)

The wind turbines convert some of the wind power in electricity, some of it goes in vortexes, and some goes into sound. A small wind turbine will spin at higher rpm in wind, and the noise might become unpleasant.
      As for solar power from blades' surface - the tower where the turbine is seated has more surface area than the blades, extra mass is not usually a problem, and you have a sun-facing side - the blades don't always have a sun-facing side (so you'll need to put panels on both sides), the shape of the blades is critical for efficiency, and mass in a fast rotating, very long blade is always a problem

Re:hmmm. (3, Informative)

hcdejong (561314) | more than 6 years ago | (#20068533)

My parents live in an area that has lots of wind turbines. A few years ago, many of these were small, high-rpm turbines that were clearly audible from hundreds of meters away. Sitting in the back yard, you always had this droning noise in the background, this could be very annoying.
Things did get better when they started replacing the small turbines with fewer, much larger ones. The turbines closest to their house were removed, and the new turbines ran at much lower rpm which means they produce less noise.

As for sticking solar panels onto the turbine blades: this would make the blades heavier and less efficient. Also, you'd have to add slip rings on the root of each blade, and on the main shaft to transfer the power.
Slip rings are expensive, heavy and they need maintenance, especially when you're transferring significant amounts of power through them.

Re:hmmm. (2, Funny)

tehcyder (746570) | more than 6 years ago | (#20069245)

I simply cannot fathom the resistance to wind turbines.
They're planning on one near where I live, and the most amusing objection/worry is that one of the blades might fly off and decapitate a swathe of children playing in their school a few hundred yeards away...

Re:hmmm. (2, Interesting)

pzs (857406) | more than 6 years ago | (#20068459)

What really depresses me is seeing the general public in interview and their complacency and dismissiveness about global climate change. People's sense of entitlement is astonishing: "I work hard so I have the right to a low-cost long-haul flight," even if we've done without that "right" for thousands of years and those flights are ultimately destroying the planet.

There is also the huge number of people who believe that the consensus of thousands of scientists on climate change is a "global conspiracy" and their fear that it may eventually mean, shock horror, more taxes. This from people who will never know hunger, get free education and health care and live in the extreme safety and tranquiltiy of a developed nation. If you think I'm making this up, try looking at the "Have Your Say" debates on the BBC News web page.

It really is enough to make me think this [vhemt.org] is a good idea.

Peter

Re:hmmm. (2, Insightful)

lauwersw (727284) | more than 6 years ago | (#20068615)

There's another idea about this gaining attention. Suppose people do care and start conserving energy. They pay less for their energy bill, so that means they own more money. What do they do with this money? Spend it on other things of course! So that means other people are earning more money, for example in other parts of the world that are currently using less energy. What will they do with this extra money? Yes, spend it and in that process use more energy than they would have before!

Net result? 0

Maybe this is just a general law in nature: a species will use up all resources it can find. The only real solution would be a real clean source of energy. Your alternative would work too, but is way less attractive ;-)

Re:hmmm. (1)

Anomolous Cowturd (190524) | more than 6 years ago | (#20068845)

Go to the brothel.

Not everything that can be bought is bad for the environment.

Re:hmmm. (2, Funny)

Anonymous Coward | more than 6 years ago | (#20068903)

The hooker herself can be inherently bad for the environment unless you find an off-the-grid vegan hooker. But by that point, she's so skinny and annoyingly opinionated that you really wouldn't want to touch her with a 20 foot pole. Besides, those emo frame glasses were made from petroleum.

Re:hmmm. (5, Interesting)

pjabardo (977600) | more than 6 years ago | (#20069185)

These are *VERY* wise words!

Instead of making more money, people could work less. Instead of buying all sorts of shit, people could do much cleaner things such as talking, writing, riding a bike, going to a brothel, taking a walk, singing, playing a part on a play, painting, fighting (if not pushed too far it is not necessarily bad for some people...).

It is way too simplistic to say that there is a law of nature that says we will end up using every resource available. We are supposed to be rational beings even if we often do stupid things. One of the things of being rational (or partly rational) is that we can choose what we do. We don't simply answer any call of the wild (even if there is such a thing).

We are changing from a production society to a consumer one. We are becoming a bunch of morons that just sit and receive stuff. Not very different from the Eloi in H. G. Wells' The Time Machine. I don't think just consuming is satisfying enough. It is much easier (and faster) just to watch a movie than it is to tell a story and we end up watching 10 movies. Maybe a little boredom is good for creativity. It certainly is much cleaner than riding a car 100 km to do anything "new".

Re:hmmm. (2, Funny)

russ1337 (938915) | more than 6 years ago | (#20068847)

They pay less for their energy bill, so that means they own more money....Spend it on other things and in that process use more energy than they would have before....Net result? 0
I didn't realize my energy company was denying me spendable income with the intention of saving the planet. Here I thought they were just squeezing every cent from their customers for profits!

Re:hmmm. (4, Insightful)

JaredOfEuropa (526365) | more than 6 years ago | (#20068689)

There is also the huge number of people who believe that the consensus of thousands of scientists on climate change is a "global conspiracy" and their fear that it may eventually mean, shock horror, more taxes.
This believe is partly justified. The conspiracy isn't by the scientists, and isn't a global conspiracy either, but the climate scare has given the meddlers of any political stripe the perfect pretext to push their own agendas. The climate debate has been thoroughly politicised, at the expense of proper science. That does not mean that all conclusions are incorrect or made up, but very often peer reviews are sorely lacking, and many reports have had chapters and sections stricken in the final draft, because those sections could cast doubt on the severity or existence of human impact on the climate. In many cases scientists voicing such doubts have not been gainsaid, but fired from "scientific" institutions. Because a widespread doubt in our impact on the climate would spoil the party for the meddlesome politicians. The political stakes are huge, perhaps the largest of any issue in our history.

Why are long term trends not taken into account in these reports, for example. It is rubbish to say that we cannot accurately predict climate that far into the future because our short-term predictions are not very good. After all, we cannot predict the little ups & downs in next month's weather, but we can predict that winter will follow summer and autumn, and we know what the trends are in each of those seasons. The long-term trends in global weather can be predicted as well.

On a geological timescale, we are in high summer. Winter is coming, and in 10.000 years we'll be in an ice age. The start of the downward trend in average temperatures is imminent (which means anywhere between now and 1.000 years)... Perhaps that is why the IPCC report does not look any further than the year 2100, the scary hockeystick curve will flatten out after that year, and if you look even further it will drop. Our distant descendants (if any) may even be grateful for the extra CO2 we have released, since it might make the next ice age a little less severe.

But with all that said, conservation and reducing our dependancy on a limited resource is a good thing. But I refuse to join in the mindless panic.

Re:hmmm. (2, Interesting)

monk.e.boy (1077985) | more than 6 years ago | (#20068573)

My friend lives about a mile away from a small wind farm. I is very noisy, it sounds like cars on a freeway, but far too regular. Almost like a loud heart beat. And when the sun catches the blades you get a nice strobe effect which sends you fucking crazy after an hour or so.

My friend is selling up.

I can't wait, we never visit him any more. His house sucks.

Wind farms are ok - so long as they aren't in your back yard. Solar and Nuke is the real future.

monk.e.boy

PS check my .sig for Open Source Flash Charts (bar, line, area and pie)

Spot on. (3, Informative)

ushering05401 (1086795) | more than 6 years ago | (#20068627)

"The CE manufacturers need to meet them half way and mandate more efficient devices that consume less power and bring back the humble ON/OFF switch that actually did turn off the power."

I recently had a new lady move in with me... and she insisted on actually unplugging things like my stereo when we were not using it. I was skeptical about the benefits of this tactic to save electricity, but being a curious person I was willing to humor her.

By unplugging all of my electronic devices (there are many of them) when not in use we saved around $30 U.S. a month. Where was all that energy going? Not sure.

If you are the type of person that has electronics in every room give it a try for yourself. Even if you don't care about being 'green' you will likely see a difference in your energy bill. Either way you win.

Regards.

Re:Spot on. (4, Informative)

JaredOfEuropa (526365) | more than 6 years ago | (#20069085)

By unplugging all of my electronic devices (there are many of them) when not in use we saved around $30 U.S. a month. Where was all that energy going? Not sure.
It goes to heat production, mostly. However I prefer a step forward rather than taking a step back by having to turn everything off. It is possible to make equipment have a minimal power consumption on standby, by only running a small circuit that looks for the "On" button being pressed on the device. A lot depend on how you power this circuit... a transformer is a notoriously bad way of doing it.
Some equipment behaves nicely on standby. Use a Wattmeter to check how much your stuff actually consumes in standby mode; you'd be surprised how little some things consume when idle, and there is little use in unplugging these completely. You might also be surprised at the large amount of power drawn by plug in transformers (The "wall warts"). Removing these when you are not using them saves a lot.

Another good way to save without sacrificing convenience, is to use a "master-slave" power block with your computer. I have a lot of inefficient transformer power supplies next to the computer, for printers, routers, LCDs, speakers, etc. I installed a "master-slave" system, that will automatically switch off all this rubbish when the computer is switched off. The power draw of this system when idle is minimal compared to those transformers, and you don't have to switch off every individual piece of equipment either,

Re:hmmm. (1)

Eisenstein (643326) | more than 6 years ago | (#20068743)

half way and mandate more efficient devices that consume less power and bring back the humble ON/OFF switch that actually did turn off the power.

Oh, yes. I bought several of those multi-outlet things with their own ON/OFF-switch for everything I don't need to run while I'm not actively using it. Saves money and temperature down.

Standby vs. remote power-on (1)

CarpetShark (865376) | more than 6 years ago | (#20068761)

I don't really see the problem with leaving devices on "standby". I'm not an electronics type, but it can't take that much power for a small IR receiver circuit to flick the power on for the main circuitry. The only problem with that is that governments allow people to sell goods where "standby" means "don't show a picture until they press a button". Other (PC-like) devices are starting to have extended startup times, and so standby is starting to mean "keep memory running, but don't show a picture...". Maybe what we need is to differentiate between "sleep" mode and "remote power-on" mode.

Solar cell? Pfftt..... (4, Funny)

ihaveamo (989662) | more than 6 years ago | (#20068241)

I'm working on a lunar cell at the moment... the other 50% of a day is totally untapped!!

Lunar power (1)

CarpetShark (865376) | more than 6 years ago | (#20068773)

There was talk a while back of beaming microwave energy to earth from solar-power-collecting satellites, since they're outside the atmosphere, and in the sun at times when other spots on earth aren't. The moon might also fit into that satellite model, except that it's further away.

Re:Lunar power (1)

mooingyak (720677) | more than 6 years ago | (#20069129)

IIRC a satellite in a geosynch orbit is in sunlight for all but something like 10 minutes or so of a day.

Can't find a reference at the moment though.

What a pointless comparison (2, Interesting)

suv4x4 (956391) | more than 6 years ago | (#20068245)

On a roof, such cells would require less than half the surface area to produce the same amount of power as today's standard solar panels, which have an efficiency of about 17%.

Let me guess: you'll leave how your roof empty to produce the same electricity, or take the whole roof to produce more than twice the electricity. Hard dilemma...

At this point solar energy seems inevitable in our future. Not long from now we'll have more efficient electric motors and even more efficient solar cells, so that would make it a viable backup to a car battery charge and mean you can drive for days and days at long distance without recharging.

The big money now will go to those people who manage to best make use of our existing infrastructure and our new technologies (stellar examples include Toyota's hybrids... imagine if that electric motor they use also has few solar panels to help it in the next models).

Re:What a pointless comparison (1)

Calinous (985536) | more than 6 years ago | (#20068317)

Some cars already have a small solar panel in order to cope with the parasitic loads when the car is shut off (alarm, remote key, and other things). However, the solar power you could produce from the surface of a car is not enough to give you mobility. Look at the solar races, they reach maybe 100km/h during the day, using lots of solar panels, on a car that's worth hundred of thousands of dollars. And no air conditioning, it seems.

Re:What a pointless comparison (1, Insightful)

suv4x4 (956391) | more than 6 years ago | (#20068393)

However, the solar power you could produce from the surface of a car is not enough to give you mobility.

They use conventional panels (17%). This one is 42%. Also I'm suggesting they won't run on pure solar, but support the electric motor in the same way the electric motor supports the diesel one in hybrids nowadays.

It may drop your fuel consumption 15%, using "free" solar energy, still worth it.

Re:What a pointless comparison (4, Informative)

Calinous (985536) | more than 6 years ago | (#20068503)

Assuming your car has 20 square meters of surface, all of it oriented towards the sun. In Ecuador. With 100% efficient solar panels.
      You can get at most 20 HP of power from that. In your real situation, with maybe 5 square meters of surface available in the morning, and lower solar power, and the 40% efficiency solar cells, you get 2HP (or 1.5KW). Does it help? A bit, yes. If your car can load itself all day with energy, and know when she will reach destination, she could bleed the electricity storage battery (and reload it later). This way, you could get 10 square meters of max power, 8 hours a day, and with perfect efficiency in rest (charge, discharge, motor) you get 80 HP hours - or two hours at 40HP. Good enough for a commute... but...
      Now, you could buy solar panels at $5000 per kW (and 20 pounds). Assuming double efficiency is treble the price - you need $15,000 per square meter, so you'll pay $150,000 for solar on your car. Is it worth to drop your fuel consumption 50%? Or completely?

Re:What a pointless comparison (2, Informative)

TheRaven64 (641858) | more than 6 years ago | (#20068741)

Seeing a car's power rated in terms of horsepower has always seemed somewhat excessive to me. For a long time, people used a single horse[1] to get around. They were quite slow for long distances, but could achieve something close to the legal speed limit for built-up areas. Since we're playing with absolutely ideal numbers, let's try another one; the car has zero mass.

According to Wikipedia, the Sun produces approximately 1KW of energy per square metre. Your 20 square metre car then has a 20kW energy output (around 27hp). How fast can this accelerate a human? Assume for now that a human weighs around 100Kg (most people weigh less, so this includes a small luggage allowance as well). One Watt is one Newton per second, and one Newton is the amount of energy required to accelerate one kilogram at one metre per second per second. Your 20 kW car can accelerate a 100kg person at 20,000 / 100 = 200 meters per second, per second. Since this is roughly 20g, you would probably not want to do that very often.

Now we have some absolute upper bounds on optimality, let's stray back slightly towards feasibility. At 40% efficiency, you get 80m/s/s. Still not bad. For reference, 0-60mph in five seconds requires just over five meters per second per second of acceleration. Of course, we're still assuming equatorial sunlight. Dropping the solar energy down to a more reasonable 50% gives us 40m/s/s. Our car still weighs nothing, however, so let's run this the other way; if we want 0-60 in 5 seconds, how much can our car weigh? The answer comes out at 700kg (800kg including passenger), which is not too bad; a quick google indicates that this is about half the mass of an average car.

It seems that a totally solar car is not completely beyond the realms of feasibility with current technology, but it will probably not be commercially viable for some time. For one thing, you're going to need a battery for when it's cloudy or night, which will drive up the mass very quickly.


[1] The original definition of a horsepower was for mine ponies, so a cart horse probably provided a few horsepower.

Re:What a pointless comparison (2, Informative)

Calinous (985536) | more than 6 years ago | (#20068833)

Let's see what is possible now:
http://www.greencarcongress.com/2006/06/2006_solar _drag.html [greencarcongress.com]

      Solar drag racing (without batteries) can run the 1/4 kilometer (800 feet) in 57 seconds (using no batteries).
Well, the new record is 30 seconds for 820 feet, and 50 mph on finish - see http://users.applecapital.net/~jim/solardragrace.h tm [applecapital.net]

      And the future is shiny:
"As the race develops over time, solar dragsters may eventually exceed two horsepower"

Re:What a pointless comparison (1)

dbIII (701233) | more than 6 years ago | (#20069149)

Think lightweight golf buggy instead of SUV - it's not quite so stupid then. The better answer is of course public transport giving you an economy of scale where you can use it - a low powered electric vehicle to get you a short distance to the train makes more sense than a long slow trip into town.

Re:What a pointless comparison (3, Insightful)

Rocketship Underpant (804162) | more than 6 years ago | (#20069293)

"Now, you could buy solar panels at $5000 per kW (and 20 pounds). Assuming double efficiency is treble the price - you need $15,000 per square meter, so you'll pay $150,000 for solar on your car. Is it worth to drop your fuel consumption 50%? Or completely?"

This is the point where the central market planners jump in and shout that we should subsidize solar panels. But why does that solar panel cost $15,000 per square metre? Because of all the resources, energy, and labour consumed in producing it. Chances are those more than offset the gas you're not burning.

When the manufacturer can make panels efficiently enough to be more affordable than gasoline, it'll be because they're finally less wasteful and polluting overall.

A similar principle holds with recycling, by the way. In the instances where recycling actually saves on energy and raw materials, there is a cost savings as well, and the recycler will pay *you* for your bottles and cans. If the government has to make you do it, it's because the process is not cost-effective overall, and more waste is taking place in the recycling process than the recycling itself saves.

Re:What a pointless comparison (2, Insightful)

tekrat (242117) | more than 6 years ago | (#20068653)

So, run this by me again;...

Consider that, aside from police cars and taxis, most cars spend most of the time PARKED, either in a parking lot at work, or a driveway at home. The average car's lifespan is mostly spent at rest, with about a 1/2 hr drive to work and a 1/2 hr drive home.

Why is it NOT prudent to build a solar panel into the roof and/or engine hood to help recharge the batteries while the damn thing spends 8 hrs per day parked in the sunshine?

Hell, if we could take the heat that builds up inside the car on a hot summer day and convert that into electricity, I bet I could drive home just on that!

TTYL
Brian C.

Re:What a pointless comparison (1)

gonk (20202) | more than 6 years ago | (#20068781)

I don't know about the rest of you, but I leave my car parked in a parking garage. I don't want it baking in the sun all day...

robert

pfft... (1)

djupedal (584558) | more than 6 years ago | (#20068555)

"At this point solar energy seems inevitable in our future. Not long from now we'll have more efficient electric motors and even more efficient solar cells, so that would make it a viable backup to a car battery charge and mean you can drive for days and days at long distance without recharging."

It was more than 15 years ago when similar comments were being tossed about, as the Japanese Govt. began pumping money into solar as a technology. The prediction then was that within the decade, solar energy would be a thriving industry and a large scale, reliable alternative power source for the masses.

At this rate, with not much having changed, it would seem a safe bet that 15 years hence we will still be hearing how solar energy as a commodity is 'just around the corner...'

Re:What a pointless comparison (1)

inflex (123318) | more than 6 years ago | (#20068831)


> Not long from now we'll have more efficient electric motors

Currently, brushless (3 phase) digitally controlled motors are already in the high 95~98%+ level at 'optimal' RPM, dropping into the 80% area when running at less than optimal RPM. Incremental gains from improved stator materials, smoother bearings/sleeves, more efficient drivers (MOSFET/IGBT) will come but for the most part you're already looking at technology that is extremely efficient.

Some things I'd really like to see are;

  1. a good energy storage system (4~10x the energy density of lithium polymer would be nice)
  2. replacing linear voltage regulators with switchmode regulators (linear regulators burn off excess voltage as heat, horribly wasteful, switchmode is 95%+ efficient)
  3. low cost microturbines (1m dia or less) to fit onto households. ....mmm... looks like I've got myself some projects this weekend ;) :D

Equation? (1)

marcovje (205102) | more than 6 years ago | (#20068249)


I'm not a solar panel expert, but the statement

"On a roof, such cells would require less than half the surface area to produce the same amount of power as today's standard solar panels, which have an efficiency of about 17%."

purely based on efficiency is dangerous. A lot of solar cells require a certain minimal light threshold before they start producing energy, and for reallife application, a lower threshold matters more than a few percent more of peak efficiency.

IOW efficiency is a function of among others light intensity

How much power? (3, Interesting)

DoofusOfDeath (636671) | more than 6 years ago | (#20068261)

On a roof, such cells would require less than half the surface area to produce the same amount of power as today's standard solar panels, which have an efficiency of about 17%."

OK, but how much of a typical house's power would that supply? (I realize this depends on location and time of year.)

Or how many panels would it take to give you a daily, full recharge of a plug-in hybrid in, say, Los Angeles? (Imagine that that would do for LA's smog.)

Re:How much power? (1)

Alkonaut (604183) | more than 6 years ago | (#20068365)

Found this at wikipedia. http://en.wikipedia.org/wiki/Solar_cells#Energy_co nversion_efficiency [wikipedia.org] Efficiency seems to be how much of the energy is converted, at a standard point (equator, noon, equinox) the irradiation is 1000W, so 42.8% would mean 428W of power.

At that efficiency I think you could easily supply a house entirely, at least in those sunny regions. The problem is if course the price per kWh and not the efficiency only. As for the hybrid, you could even imagine that covering the hybrid itself with cells would be sufficient to recharge it (if it normally charges at 1-2kW or something?). In that case, you can drive your hybrid to where the sun don't shine (and from there on it's gas...)!

Re:How much power? (3, Informative)

Calinous (985536) | more than 6 years ago | (#20068377)

Peak solar power is around 750W per square meter of installation. With those new panels, you could get - let's say - 1000W per 4 square meters (40 square feet).
      Assuming you are going at work using 10kW (14 HP) average for two hours (both ways), and assuming 6 hours a day peak power, and your losses are zero, you need less than 15 square meters (160 square feet).
      Now, if you add 50% losses in the recharge system (car and house), you need to double that - 30 square meters, or some 300+ square feet of solar installation, inclined to an angle equal to your location's latitude (equator- flat roof top, Alaska - sharp roof)

Re:How much power? (1)

constantnormal (512494) | more than 6 years ago | (#20069231)

Instead of putting solar cells on the roof of a car, why not cover the south side of the garage roof with them, sell it to the electric utility during peak rates, and recharge an electric hybrid at night (when the utility rates are cheaper)? Seems like that would be a better way to power an electric vehicle, and generate a little cash to improve the household budget as well.

In my case, I have at least 400 sq ft of south-facing garage roof (at a 12-12 pitch) and about twice as much on the house. Last month's electric bill showed 1105 kWh of power consumed. Depending on how much a photovoltaic panel installation would cost, it would seem to be a practical thing to do even now, with AC units and furnaces having useful lifetimes of about a decade, the payback time for solar panels would seem to be less than that, depending on the cost.

Maybe in a few years, as the cost declines and experience improves the reliability, I'll open the wallet for a set of solar panels. Don't want to buy the version 1.0 model (or worse yet, the beta product).

Re:How much power? (1)

ari_j (90255) | more than 6 years ago | (#20068685)

What bothers me is that the blurb (RTFA? never!) doesn't tell us exactly how loose the tolerances for aiming this one are. I don't care that it's more efficient if it requires me to put my house on a turntable and add a tilting roof.

Significant indeed (1)

Calinous (985536) | more than 6 years ago | (#20068267)

It seems the cells uses three different solar receptors (low, mid and high energy light), and doesn't need precise tracking devices.
      A satellite-based solar panel could easily have the solar tracking device - however, tracking devices are expensive, could be affected by strong winds (for big installations), and use some power by themselves. Such a kit could bring higher efficiency in stationary panels, or (as suggested in article) could be used by the army as recharge packs for and instead of batteries.

someone convince my local government (5, Interesting)

Shivetya (243324) | more than 6 years ago | (#20068281)

that renewable sources of energy are a good thing.

why?

because my HOA (home owners association) does not permit them. As such it would take State or local laws to override the HOA; because in many States the HOA rules have strong legal backing at the State level.

This is akin to the problems satellite TV faced in many locales. There were numerous ordinaces, both at the HOA and local level which blocked satellite dishes. Even the small ones we are accustomed to today were blocked. It took a Federal Law to end that restriction. Unfortunately its going to take another such law to allow many of us to use renewable energy. Hell, I cannot even get rain barrels approved even though they would not be visible from the street.

Re:someone convince my local government (1)

Alioth (221270) | more than 6 years ago | (#20068481)

If it's not visible from the street...well, it's better to ask for forgiveness than for permission. Just install the rain barrels, chances are no one will notice them.

Re:someone convince my local government (1, Informative)

Anonymous Coward | more than 6 years ago | (#20068727)

This is exactly how I treat my HOA. I do what ever I want and let them come and fine me for it latter. Really, my HOA is just a way for some Assholes with too much time on there hands to make money off everyone else. hmm, remind you of anyone?? Like they required that I have my house painted by company X, well, I went with company Y, payed a fine for it but still saved my money, they did a better job then my neighbors got plus I feel better not hiring a company that gives kickbacks to my HOA.

Re:someone convince my local government (0)

Anonymous Coward | more than 6 years ago | (#20068557)

Too bad you bought a McMansion and not a real house, hoss.

Re:someone convince my local government (0)

Anonymous Coward | more than 6 years ago | (#20068699)

#1: Why don't you convince them, if you're seriously wanting them?

#2: Install them anyways. What are they going to do, sue you for saving money and the environment?

#3: Sue them instead. Lawsuits like this get settled quick and fast because once the media gets hold of them, they blow up into huge, national spectacles, like the people suing McDonalds for their own stupidity. Even if they don't let you install them, you will have made a few bucks after lawyer's fees, and probably more than enough to sell your current house, move to a municipality that will allow you to install the panels, and get the panels on the Home Owner's Association's tab. Sounds like a win to me.

Re:someone convince my local government (0)

Anonymous Coward | more than 6 years ago | (#20068749)

Florida already has state laws preventing HOA nonsense. It covers any renewable energy device which means solar down to clotheslines (remember them?).

Re:someone convince my local government (0)

Anonymous Coward | more than 6 years ago | (#20068803)

This is a perfect example of why I would never buy a house restricted by a "homeowner's association". The myriad of rules (not to mention outrageous property taxes) forced on me by local government is MORE than enough.

When you come right down to it, what does it really mean when somebody else can legally tell you what you can and can't do to your house? It means you aren't the ultimate owner of your house. If I can't be the ultimate owner of my house, then why not just rent?

Re:someone convince my local government (-1)

Anonymous Coward | more than 6 years ago | (#20069079)

In Soviet Russia, rain barrels hide you!

Re:someone convince my local government (1)

tpconcannon (619066) | more than 6 years ago | (#20069173)

All you have to do is convince the HOArseholes that by implimenting certain green features like rain barrels, solar hot water, solar power, and composting that they could get LEED certification. I have found that the ignorant people whom run HOAs will instantly bend over if they get a little piece of paper with a shiny foil star on it.

Efficiency is less important... (5, Insightful)

Anonymous Coward | more than 6 years ago | (#20068321)

...than price per watt. We got plenty of space we can cover with solar cells so it's not important that they are extremely efficient, just cheap enough so it doesn't cost much to cover large areas.

Re:Efficiency is less important... (1)

Overzeetop (214511) | more than 6 years ago | (#20069427)

Actually, price per watt is probably just below price per lifetime watt-hour. If it costs more to buy than the cells will produce, it's just an off-grid luxury item.

Another kind of efficiency (3, Interesting)

fringd (120235) | more than 6 years ago | (#20068325)

The real problem with solar power is not getting more watts per square inch; it's getting more watts per dollar. From what I hear, high grade silicon is prohibitively expensive. It takes more than 3 years to pay back your monetary investment. This information is probably based upon old panels though.

These new panels may produce twice the energy, but is there any chance that they cost less than twice the dollars? What is the limiting factor in solar panel costs?

I've heard that some people are working on polymer solar panels, this would seem to deal with the dependence on expensive silicon...

Re:Another kind of efficiency (1)

farkus888 (1103903) | more than 6 years ago | (#20068363)

3 years to pay for themselves is not a big deal in the long term, most of the current panels that are the grade you would use to panel your roof are warrantied for 10 times that long last I checked. you also have to think that this is something you put on the roof of your house, until recently people would only buy one house and spend their entire lives in it. 3 years is nothing in those terms. I just recently bought a brand new toyota, cost a lot more than a used ford pinto would have up front, but I plan to keep it a long time and it should be cheaper in the end because a used pinto will cost a lot more to maintain. the same math applies here, suck up the initial cost, its cheaper in the long run.

About payback times (3, Informative)

Anonymous Coward | more than 6 years ago | (#20068531)

It probably takes a lot more than three years to pay back the investment. A three year payback would be astounding. If that were the case, you could shut down all the existing power plants and run the country just on solar. OK, that's a bit exagerated because solar doesn't make power all the time. Even so, a three year payback would see a dramatic increase in solar use.

The calculation that produces a three year period says that you start saving money after three years. It assumes that you borrow money to buy the panels. After three years, the money you save on electricity is greater than the loan payments. The link below has a graph. You will notice that the savings take a big jump after twenty years. That's when the loan is paid back and you aren't making payments any more. So, using the link's assumptions, the payback on the investment is about twenty years.

http://www.ongrid.net/PVPayback.html [ongrid.net]

The point of the link is that, even if it takes a long time to pay for the system, you can still save money by going solar.

Re:About payback times (1)

olman (127310) | more than 6 years ago | (#20069365)

The point of the link is that, even if it takes a long time to pay for the system, you can still save money by going solar.

Assuming maintenance free operation for 20 years, of course. No panel breakage or degradation, equipment failures, need to replace batteries..

Re:Another kind of efficiency (4, Insightful)

dwandy (907337) | more than 6 years ago | (#20068577)

It takes more than 3 years to pay back your monetary investment.
"Three years" should not be a 'too long' perdiod to re-coup your investment.
  • That's less than 4% of an average lifetime.
  • I'd take an investment that was guaranteed to pay back 100% every three years.

I don't see energy getting any cheaper on this planet, and I don't see energy consumption decreasing.

The problem is it's not just the solar panels: it's the batteries and other infrastructure (and then maintenance!), and the last time I looked at it, it was closer to 20-yrs to pay back a whole system, and the system had a 20-yr life expectancy. That's break-even assuming it makes it to life expectancy.

What I am interested in is directly attaching an AC unit to a solar panel. Where I live it's generally only hot when it's sunny, so the AC would run for free.
Since the AC is one of the most expensive things to run it's win-win-win-win:

  • I can run it guilt-free
  • It runs whenever it's hot
  • I don't need the other infrastructure
  • I will still pay for the panel in a relatively short time.

Re:Another kind of efficiency (1)

AnObfuscator (812343) | more than 6 years ago | (#20068881)

The problem is it's not just the solar panels: it's the batteries and other infrastructure (and then maintenance!), and the last time I looked at it, it was closer to 20-yrs to pay back a whole system, and the system had a 20-yr life expectancy. That's break-even assuming it makes it to life expectancy.

Exactly. Also, the life expectancy of a solar roof is even worse if you live in a high-risk area, such as Florida. How well does a solar roof hold up to a hurricane? How much will it cost to repair?

How well would a solar roof hold up to, say, 1 foot of snow cover? Or a hailstorm?

What I am interested in is directly attaching an AC unit to a solar panel.

Yeah, that is the real application of solar power that I see -- auxiliary power. It's already common for swimming pools to be heated with solar panels. This is a nice new step.

Note also that the creators of this panel developed it for the US military, with the specific application of powering the field equipment of soldiers. They see it as a possible secondary power source for cell phones, laptops, etc. I think this is the right track; if these solar panels are being manufactured in large quantities for smaller goods, it can bring down the cost of the tech enough for applications like yours to be feasible.

Re:Another kind of efficiency (1)

Thing 1 (178996) | more than 6 years ago | (#20069055)

It's already common for swimming pools to be heated with solar panels. This is a nice new step.

Rude awakening when we moved to Florida: "solar heated pool" means "it's heated by the sun." :(

why don't they... (1)

salec (791463) | more than 6 years ago | (#20068449)

...cover the front of solar cell with deep, open, honeycomb-shaped, reflective walls (e.g. Aluminum or silver) grid? That would effectively act as a light trap, making solar panel more "absolutely black body"-like. Or, even better, make open "boxes" with walls covered in solar cells. Photon should have very little chance to escape after multiple reflections...

Re:why don't they... (1)

Calinous (985536) | more than 6 years ago | (#20068537)

Some of the energy is "lost" as light reflection, while some is lost as heat. Anyway, once a photon starts to go away from the cell, the reflective walls will direct it outwards

Re:why don't they... (2, Insightful)

zqwerty (686798) | more than 6 years ago | (#20069203)

Its 20 years since I looked into solar cells in my engineering job, but the figure quoted above must be close to theoretical maximum because solar cells amount to a forward biased diode and can never get to 50% efficiency, they also have poor temperature performance which falls off rapidly as they get hotter, so enclosing them and reflecting more sunlight onto them is exactly the wrong thing to do, they run most efficiently when cool. As said in this thread the big problem is cost and having to store the electricity when the sun is not around at night.

Getting sick of this. (0)

Anonymous Coward | more than 6 years ago | (#20068527)

Although these much-hyped "breakthroughs which are in fact so far from any kind of practical application that they are completely and utterly useless. Instead it just encourages expectations which cannot be satisfied.

Unless you have plenty of money, photovoltaics isn't practical for any but those with no alternatives. Even then people in that situation tend to have systems which provide nothing but the very basics. (Maybe run a light or two, and a radio.)

If you have plenty of money to spend on PV it's still not really practical from a purely financial perspective: the cost of the system will take many years to recoup. You'll save some money if you're grid-tied but average household electricity usage generally far exceeds that supplied from all but the biggest, most expensive installation.

You'll pay no electric bills at all if you're not grid-tied, but unless you have the hell expensive system (with its related ongoing maintenance costs) don't expect to be running the washer-dryer too often, or do anything like welding.

I'm all for PV and rely on it for my power needs. My site is too remote for AC Mains. But I can't afford a hypersystem to meet the kind of needs the average household expects to have on tap, therefore I live frugally. And these bullshit claims being plastered all over Slashdot every damn day about breakthroughs-which-aren't are really starting to piss me off.

Now get the fuck off my lawn.

Re:Getting sick of this. (1)

Calinous (985536) | more than 6 years ago | (#20068611)

Even if your solar system doesn't generate more energy than what you consume, you might sell it at a far higher "day tariff" in some places. But the electricity company won't give you money back

So maybe there is an upside... (1)

tgatliff (311583) | more than 6 years ago | (#20068563)

To me spending $3 per gallon of gas. Now maybe they can manufacture these solar cells cheaper than the power company can make them. Personally, I think it is only a matter of time until we see either solar cells or a solar collecting stirling engines on each home to offset peak power usage...

Massive scale solar farming (2, Interesting)

Linker3000 (626634) | more than 6 years ago | (#20068629)

The development of solar power will go a good way to lowering our dependency on fossil fuels, but to be practical we need to deploy the cells in a massive scale - I'm thinking thousands of square miles of solar farms - so what we really need is a relatively flat landscape in a location with significant sunshine levels. It would also be ideal if the region could provide the raw materials for the manufacture of the cells to save in transportation costs, but to be perfect the region would also have an abundant supply of fossil fuels to power the manufacturing plants until such time as construction was complete.

In summary, the ideal location would have:

Sun
Sand
Oil

You see what I did there!?

fail (4, Funny)

jovius (974690) | more than 6 years ago | (#20068705)

Yes, this is great, but solar power will eventually fail completely, and there are no guarantees for long-term investments beyond five billion years from now.

Economically feasible? (3, Interesting)

Anonymous Coward | more than 6 years ago | (#20068765)

What matters to me: Do those new cells finally "produce" more energy during their life than they required during manufactoring?

Re:Economically feasible? (1)

zero_Bytes_free (964407) | more than 6 years ago | (#20069247)

This question needs to be asked more often. It's all about the energy used from the beginning of the product to the end of life.

Concentration Is Good (3, Insightful)

Doc Ruby (173196) | more than 6 years ago | (#20068893)

Concentration of a larger solar input area onto a smaller solar cell is nearly always better than straight 1:1 reception. The efficiency goes up with these materials, which of course is good.

But also the concentrators are a lot cheaper than the cells. The concentrator is usually a cheap (compared to the cell) lens or mirror. So a 20x concentrator gets 20x the input energy, but for a much lower cost than 20 cells. And that cell is operating at higher efficiency, on 20x the input. So a $10 cell fed by 20 $5 concentrators costs only $110 instead of $200. 5% more efficiency in the cell is applied to all 20 concentrators, not just the 1 cell, for 200% efficiency. So it's double the efficiency at 55% the price, or over 3.6x the $:energy efficiency. In reality, the concentrators are better than 5x cheaper, and the efficiency gains can go higher than 5% greater.

And then there's all the savings from cheaper replacement concentrators, which could even last longer than the cells (though the cells typically last >30 years), and dropping all the other HW from the 19 (or however many) extra cells in favor of "dumb" concentrators. In fact, since concentrators are so cheap, the cells might not require HW to track the Sun for maximum absorbtion, but just array the concentrators in an arc (or bubble) that always leaves an array of concentrators facing the Sun (and the rest off-axis), without consuming energy to move. Or extra parts, or computing, and saving all the maintenance costs, too.

So the more concentration, the better. After all, that's how the engineers thought up this stuff.

What I'll never understand... (1)

rAiNsT0rm (877553) | more than 6 years ago | (#20069075)

Is why every building/house isn't required to have at least one solar panel on the roof. I could care less about their efficiency, or the ability to run my whole house on them, but the relative low cost and huge amount of energy would benefit everyone. Give people a tax break like they do for weatherproofing your home and make it mandatory.

Full systems to run a home only cost $10k-15k, and single fairly large panels and the needed wiring are ~$1k without batteries or other complexity.

It would also bring down the costs and fund better efficiency and research due to the increased demand. Then some people would be more likely to add a few more or go fully solar, while others don't have to do anything more. It's a win-win. And yes, $1k is a lot for some, but I'd rather see energy co's and the government spending here than in forcing and subsidizing grandparents to get digital TV converters.

Impossible economics, take 761, action! (1)

Ancient_Hacker (751168) | more than 6 years ago | (#20069093)

I wish at least someone would run the numbers on these things once and for all.

  • Solar collectors are expensive.
  • You need a mirror, a support, maybe a steering system, periodic cleaning and maintenance.
  • If the support is going to last more than one year, it needs to be rather sturdy in order to survive wind, rain, maybe snow and hail.
  • So we're talking an installed cost of lets say $500 per square meter, more if it's steerable. Plus yearly cleaning and maintenance.
  • Now a square meter of sunlight is about 1 kilowatt of light.
  • Going into a 17% efficient solar cell, allowing for clouds and "night", is going to average about 60 watts of DC.
  • At electricity going for the wholesale rate of 3 cents a KwH, which is, that's .2 cents per hour.
  • But wait, this is undependable power, going away at every passing cloud, so it either is going to have to go into a storage device, (more $$$, more losses), or the utility is not going to pay you the going rate for dependable power, instead maybe half that at best, if they'll take it at all (you see to take it they'll have to build more gas-turbine peaking plants to make up for the cloudy times).
  • So taking that into account, it nets out to about $9 per year. Probably closer to $7 if you include time down for maintenance and cleaning.
  • For an investment of $500.
  • So you can't even pay the cost of interest on the loan, much less the cost of cleaning and maintenance, much less making any headway on the principal.

Re:Impossible economics, take 761, action! (1)

burgundy (53979) | more than 6 years ago | (#20069385)

3 cents per kWh? Sign me up. Electricity in NY is several times more expensive than that.

Here's a page that runs the numbers for a solar PV system on Long Island, NY:

http://www.majesticsonli.com/7.html [majesticsonli.com]

After taking into account all the tax breaks and kickbacks from the local utility, it's about a 10-12 year payback period. I think that length of time is right at the limit of what people in the US might consider.

So, how's UV solar coming along? (1)

jollyreaper (513215) | more than 6 years ago | (#20069373)

I remember reading that there was a research program trying to make solar cells work with UV as well as visible spectrum light. That way, you can still make use of the UV part of the spectrum even on cloudy days.

Speaking of solar power, have we yet come up with a way of capturing ambient heat and doing something with it? When I look at my car in the midday sun, I'm reminded of Texas prison movies with prisoners getting put in "the box." Sheesh! Can't somebody do something with all that heat just sitting around, doing nothing?

In the past, most of the ginchy-keen ideas for alternative fuels always got shot down because fossil fuels were cheaper. You aren't going to get anyone to pay a cent more per kilowatt-hour than they have to. "For the environment?" you suggest. "Die, hippie fag," they reply. But the moment fossil fuels become more expensive, they'll be coming right back all like "Hey, buddy, what was that you were talking about, a hemp-powered car? Did I mention I like the Dead?" I saw some great work being done with solar ovens for third world nations lacking a dependable supply of cheap cooking fuel. These ovens were just shiny sheet metal bent into focusing mirrors. Sure, that's not as advantageous for us westerners, especially when we want to toast up some leftover pizza at night. For people whose choices are solar oven or nothing, a little something looks a whole lot better.

Or look at housing. I live in Florida. Before the advent of the AC, a premium was placed on intelligent housing design to make things livable. The old-style Florida houses were designed for passive cooling and proper airflow through the structure. Once AC's came around, shit, who opens their windows these days? Build everything in blocks and use active cooling, elecricity is cheap. Well, now it ain't.
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