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People have tried to build prototype power stations of this kind before. One was in Cuba but was destroyed by the waves. There is a non-net-power-generating protototype in Hawaii. These things need power to to pump the water up, which must be less than the power generated. I believe it is hard to build these things because you need a very wide pipe going down to deep ocean, to minimize loss to viscosity, but the pipe also has to be strong enough to withstand storm currents. This makes the installation very expensive. I found some info in http://www.eere.energy.gov/consumer/renewable_ener gy/ocean/index.cfm/mytopic=50010 Site says: "OTEC power plants require substantial capital investment upfront. OTEC researchers believe private sector firms probably will be unwilling to make the enormous initial investment required to build large-scale plants until the price of fossil fuels increases dramatically or until national governments provide financial incentives. Another factor hindering the commercialization of OTEC is that there are only a few hundred land-based sites in the tropics where deep-ocean water is close enough to shore to make OTEC plants feasible."

Since wind turbines are expected to run for several decades, it's good to get a few years of operating experience on a new design before deploying it in quantity. It took decades to get wind turbines to where they are now. The first megawatt-sized wind turbine, in 1941, ran less than 1200 hours before experiencing a loss of blade accident. About half of the units from the 1980s failed within a few years. There are subtle issues, such as the fact that wind speeds may be different on different blades, which stresses the mounting. That doesn't happen with aircraft propellors. So aircraft hub designs don't transfer directly to wind turbine hubs.

This applies to most new energy schemes. Scaleup always brings out new problems.

All this sounds like is a more complicated version of turbocompounding.
http://www.eere.energy.gov/vehiclesandfuels/pdfs/d eer_2002/session8/2002_deer_hopmann.pdf

The short answer is that if combined with insulation and good design - YES. The cost at the moment will eb abvout $150,000 per house using data from the "solar decathalon" competition. http://www.eere.energy.gov/solar_decathlon/

I don't begin to understand how "Climate change" comes about or how the mechanisms work or if in fact it is steerable.

can we alter our environment? yes appears to be the answer every land area which isn't subject to extremes of cold or heat or dryness seems to have been modified by man.
from farming to industrial plants, we seem to have modified the planet whereever we live and that mostly is everywhere.
I am not judging the implications of these changes just stating the obvious.
Can we alter global forces, with our small contributions?

Well if you think of a car a tiny amount of input from us
to the steering wheel will alter its direction. The vast forces within the car are controlled by our small input.
we don't really put much in do we, but its undeniable the small contribution of the driver is magnified.

Look at where we are people, in a near perfect orbit of the sun closer its too hot further away its too cold. we have an abundance of water and near perfect conditions for life. We are lottery winners! It's a fluke.

The Earth is a dynamic system a lot of interactions going on we don't comprehend well enough.
So far we have been lucky the balance of forces has been in our favour making this planet habitable. nobodys at the controls steering.

I would suggest that man has been fairly ineffectual for most of our species existance. mostly we have worked alongside the natural balance and have been lucky (less of us too).

it's only in the last couple of 100 years we have harnessed energy from our environment and put it too work and made it portable.

we are now big energy consumers and the rest of the world wants to be too.

I think we are influencing the direction of the balance of forces on this planet. just like the movement of your little finger on the steering wheel of a car will change the direction of a car.

However I think that at present we are driving the car blindfolded- we don't know what the results will be.

I don't think arguing that we control this tiny % of the environmental forces so we don't have an affect is more than a comforter to a child , just makes us feel better.

The day after tomorrow is going to be outside our lifetimes (hopefully) so its not really our problem?

The balance of the worlds forces has made this planet habitable so if we minimise our influence we should be ok
it hasn't crashed yet (or has it maybe thats why the dinosaurs went extinct).
thats not a certainty either.

I think right now we are just about at a stage where investigation and modeling of the realworld is possible -certainly 50 years ago it wasn't and I think we might find answers within this century.

in the mean time can we upset the dynamic balance, its possible certainly. Should we actively be seeking to minimise our impact now and hope the natural balance keeps going till we know enough?

Seems like a plan to me.

Finally something to think about.
http://www.eere.energy.gov/femp/technologies/eep_g roundsource_heatpumps.cfm#efficiency

Heat exchangers seem to be very efficient. I have seen sites claiming over 100% efficiency that is the enegy moved to where its wanted is far greater than the energy to move it.

Seems like this could be a great way to have our energy and reduce our enviromental impact.

The exhaust from combustion of hydrogen is water vapor. If this is a more serious greenhouse gas than originally thought, can hydrogen really be considered an eco-friendly fuel?

This is a general misconception, that hydrogen fuel cells will produce significantly more water vapor than fossile fuel cars already do. I found this explanation useful, from this web site (I have lost the exact page). Essentially it says (based on some assumptions) that a gasoline internal combustion engine vehicle puts out 0.14 kg water/mile and a hydrogen fuel cell vehichle 0.15 kg water/mile.

However, if you produce the hydrogen using an energy source which is polluting, then you haven't gained anything.

There are several hard problems in wind turbine design. One is that, for large wind machines, wind speed may vary considerably across different parts of the blade area. This produces huge stresses in the blade system. Aircraft propellers and hubs don't have that problem, so technology borrowed from aircraft props didn't quite work. That's been solved, but it took years to get past it.

A basic problem, one which this new design doesn't solve, is overspeed protection. Wind turbines above toy size must be able to deal with high wind conditions safely. Some turn sideways; some turn upwards; some feather the props. Brakes aren't enough. There's no way to feather or turn this new design. Even small turbines need, and have, overspeed protection.

There are lots of wind machine designs that more or less work in a small size, but don't scale up to the point where they're worth building. There's a square law; double the blade length and get four times the energy out. So big turbines beat out little ones, once ths scaling problems are solved. Wind turbine size has been creeping up since the 1970s, from about 50KW to a few megawatts.

A 1.5 MW unit was built in the 1940s, but it suffered a bearing failure within a year, then a loss of blade accident which threw a blade 700 feet. Only in the past decade have reliable wind machines in that size range been produced in quantity. With 2800 of their 1.5MW units installed, General Electric can be said to have solved that scaling problem.

The big machines aren't simple. They have active yaw control, active pitch control, hydraulic brakes, AC to DC to AC variable frequency conversion, and lightning protection. But, at last, they work.

So these guys are going to beat that with a little tin model that looks like something used to spin a sign in a used car lot. Right.

First there is a huge infrastructure to deliver gaseous fuels to the home. Ever hear of Natural Gas?

Second, hydrogen gas can be stored in other forms, metal hydrides and ammonia come immediately to mind. Ammonia, NH3, is 18% hydrogen by mass and can be easily liquified by storing at moderate pressures (60atm or 882psi) will keep ammonia liquid to 210F (9atm or 133psi to 80F). The problem is that it is an irritant and pungent. It requires about 8 liters to hold 1Kg of hydrogen (5.5Kg NH3).

Third, the infrastructure needs are being planned: http://www.eere.energy.gov/hydrogenandfuelcells/in dex_html.html

Fourth, there is an easier way to deliver electric power for running a car, the Aluminum Air battery. It converts Aluminum to Aluminum Oxide and electric power. It gets about 8.7KWH/Kg. Gasoline is about 12.3KWH/Kg. See http://www.exo.net/~pauld/activities/AlAirBattery/ alairbattery.html for a simple version. You would still have the cost of getting spent batteries out of the car and reinserting fresh ones. plus the costs of extracting the Aluminum from the oxide and remanufacturing the battery. Although a little water is used as the electrolyte, you don't have to create a complicated hydrogen group of devices. The Aluminum infrastructue is highly developed, smelter->foil->truck->store->user->car->recycler-> smelter.

I can see it now, cars that run on aluminum foil. Get 30 miles per 1 pound roll. Dump white powder residue (aluminum oxide) into recylcer who pays you 10 cents per pound. Trouble is they forget how much it costs for a pound of aluminum foil.

I have been impressed with the LED lights over florescent or incandescent. The subdued lighting is fine with me and the energy consumption / bulb longevity is the best part. When my wife and I move (build a house), we will go 100% LED.

Currently I use CFLs, Compact Fluorescent Lights, 12 and 15 watt bulbs that produce as much light as 60 and 75 watt incandecent or "regular" bulbs and last up to several tymes longer. But LED lights bulbs I found out about a few months back use much less energy and last a lot longer than even CFLs. I'd like to, and am working on plans to, build my own home and when I do I want to be off the grid, probably powered by solarand wind genies. Or maybe fuel cells. So I'll be using LED lights myself.

A little known fact is that it takes more energy to manufacture a turbine...

It's little-known because it's NOT a fact. Got a source? Here's what you're looking for. For every $1 you spend building and installing a wind turbine, you'll get $6-$80 worth of energy out of it over a lifetime. Compare that to $7-$29 for coal, $11-$60 for nuclear, and, contrary to popular myth, $4-$12 for solar. Then there's the fact that the Dutch found it economical to build turbines for centuries, long before the massive increases in efficiency we've seen in the past 20 years. Also, have a look at the graph on page 18 of the August, 2005 issue of National Geographic...

Really?

So what's the impact (no pun intended) if a tank of hydrogen explodes?

Here's an old (from 2001) doc: http://www.eere.energy.gov/hydrogenandfuelcells/pd fs/30535be.pdf

You might also check here: http://www.hydrogenandfuelcellsafety.info/index.as p

The pressure IS high, but I think that the risk is still ~ the same as a gasoline tank.

It that is the case, you would be more intrested in this contest:
http://www.eere.energy.gov/solar_decathlon/

It is the Solar Decathlon. Teams have to build a small house (400 sq ft or so) that can run on solar power. The house also has to be energy efficant, and be able to do things that are considered normal everyday stuff.

This constest does more to show the public about using solar and being able to sell it back to the grid.

The actual contest starts this week.

The last nuclear plants to come on line in the US generated power at 10-15 cents/kWh - and that is not including all of the external costs the industry leaves up to the government to cover

PV, wind, and other renewable are growing 6 times faster in the market compared to nuclear. Twice as much wind capacity is being added every year than nuclear has added in the last 10.

With all of nuclear problems: cost, waste, terrorism, insurance subsidies, security, proliferation, centralization, long construction (read IRR profits)- why bother?

There are cheaper, better, decentrialized, safer solutions. Even photovoltaics generates power as economically, and its cost has been coming down exponentially, even without the trillion dollars in subsidies enjoyed by the nuclear industry over the last 50 years!

Transmission losses
A reasonable argument, though H2 can be produced on location and piplined. But going with your argument, your efficiency number is off. Average losses are only 7.2%.

Wind power price
I went off memory here, and I was off only slightly. Long-term wind contracts can be had for 3.5 cents/kWh. So hydrogen can be produced for $1.50 a gallon gas equiv - with retail wind power. If a wind company wanted to product H2 directly, it would be even lower.

IC engine Efficiency If you look in the fuel cell article, it clearly says that IC engine efficiency is 12% in a typical driving cycle. The problem isn't that IC engines can't be more efficient at the peak point, but that cars are driven in the real world all over the RPM spectrum, bringing the efficiency down substantally. Here is another link that claims a marginally higher 16% (depends on the car/driving cycle you use).

Crude oil to gasoline
As in the privious link, the Energy return of investment for US oil is 11, the EROI for gas is 4.4. Divide the two and you get 40% efficiency.

End result
Adding the trasmission losses to the mix, and taking the optpmistic view on average IC engine efficiency you still get 3 Times better with H2.

The adsorption/desorption of gas into solid materials is often exo/endothermic and by controlling the temperature you can add or release hydrogen and other gases.

The basic technology of adsorbing certain gas species onto high specific surface area substrates (pellets and powders) has been around for a long time. The DoE uses this technology to separate deuterium and tritium from hydrogen gas (they have different desorption rates from hydride powders). I think that this paper was written by Westinghouse SRS and talks about the subject:

http://www.eere.energy.gov/hydrogenandfuelcells/pd fs/review04/st_p4_ritter.pdf

Also refer to 'Hydride' on Wikipedia:

http://en.wikipedia.org/wiki/Hydride

Metal hydride powder, as well as zeolite and amine powder, is used in the aerospace industry for adsorbing particular gases. They used to use amine powders to take the co2 out of the air in submarines by throwing it on the floor (a long, long time ago) and they still use amine reactor beds to scrub the atmosphere in the space shuttle.

Looks like pellets for hydrogen exists from several different companies.

This article: http://www.eere.energy.gov/consumerinfo/factsheets /a109.html

"A company in Utah, Power Ball Technologies, has developed a process in which sodium metal is pelletized and encapsulated with polyethylene plastic. The pellets can then be containerized, transported, and then opened in a patented hydrogen generator to produce hydrogen gas. According to the company, each gallon of these pellets is capable of producing 1,307 gallons of hydrogen gas, which is an equivalent hydrogen storage density more than 7 times greater by volume than a compressed hydrogen tank storing hydrogen at 3,000 psi."

I found another aritcle where pellets go through a chemical reaction to release hydrogen.

http://www.redherring.com/Article.aspx?a=13355&hed =New+Hydrogen-Making+Method

Not sure if these methods are related to the article above, but may lead to more information

You won't find a government of any significant size willing to promote such technology due to such business relationships between politicians and energy interests.

I guess you don't consider the US government to be of "significant size?"

At least spend one minute using Google before you make such ridiculous comments.

Read.

French Fries to Fuel
Clark County School District, Nevada

The Clark County School District operates almost all its 1,186 buses on B20, which is a cost-effective way to improve the safety of its 246,000 students, according to district vehicle maintenance coordinator Frank Giordano. "It was our obligation to explore alternatives that would help clean up the exhaust from our diesel engines," says Giordano. "We worked with the engine manufacturer to include its new generation of cleaner burning diesel engines, and got its consent to run them on biodiesel."

Because the local area lacks a supply of soybeans, the traditional biodiesel feedstock, suppliers turned to one of the area's plentiful resources: cooking grease from restaurants and casinos. Clark County restaurants produce twice the national average of three gallons of grease per resident per year. A joint venture between Nevada-based Haycock Petroleum and Biodiesel Industries supplies the grease-based biodiesel to the school district.

http://www.eere.energy.gov/solar/clean_energy_payb ack.html

But what would they know?

I wasn't aware that silicon crystal solar panels were disposal problems. A quick web search turns up sites like this which seems to downplay the problems, but they are clearly larger than just disposing of silicon dioxide.

wikipedia doesn't say anything about either payback times or disposal issues.

BTW, the DOE page that your worldwatch page points to indicates that lighting accounts for only about 3.3% of energy use in homes! A far cry from 34%! Maybe someone lost a decimal somewhere.

"Biodiesel" is more competitive than you think in many regions. In Europe, many cars work with it (link is German, but list of brands should be comprehensible :)
In rural areas, farming equipment is routinely powered by it (German again)

Current R&D by the US on hydrogen and Fuel Cells: http://www.eere.energy.gov/hydrogenandfuelcells/in dex_html.html

You will notice that one of the storage methods is chemical hydrides. One such is NaBH4 (Sodium Borohydride). It is made in a plant and then distributed to a local "gas" station. It is filled into a tank in the car. To release the hydrogen and thus propel the car, water is added to the sodium borohydride which is then converted to sodium borohydrate. This then is dumped from the tank at the gas station and returned to the plant to be recycled back into sodium borohydride.

It releases 5% of its mass as hydrogen. Thus 100Kg of NaBH4 holds 5Kg of hydrogen which has the same energy as 5 gallons of gasoline. Using a fuel cell like PEM, alkaline, MCFC or SOFC, 5Kg of hydrogen yields driving ranges like 15-25 gallons of gasoline in current vehicles (300-500 miles).

As for production, modular VHTGCRs using either sulfur hybrid or sulfur iodine processes can produce hydrogen for $1.27 to $1.54 per Kg (about equal to 1 gal of gasoline) at the pump. This is quite favorable compared to current gasoline prices of $1.69 (wholesale price not including delivery to the pump) to $1.96 (current local price sans fuel taxes at the pump) a gallon. To make it even cheaper, the VHTGCRs could generate electricity during the day (peak hours) and hydrogen at night. 2000 1GWe VHTGCRs could produce enough hydrogen to replace all of the energy used by this country which can be fueled by domestic uranium deposits for the next 400 years.

The problem is overhyped fears with anything having nuclear in the title (even NMRs were renamed MRIs bvecause of the taint) even against the demonstrated lethality of "fossil" fuels. Remember that fatal propane explosion a few days back? Or the leaking gasoline detonation in the sewers in Mexico? Fatalities are so common with the extraction, refining, distribution and use of fossil fuels that we neglect them when comparing to other technologies. No one has been killed due to this country's commercial nuclear power generation over its lifetime. Then why are people here so afraid of the word nuclear?

The natural gas supply system can be easily converted to a hydrogen/NG mix for early distribution of the hydrogen converting to just hydrogen in the long term. Hydrides or the other storage technologies are only needed for cars, trucks and other mobile applications. Those however are the high impact uses which replace a lot of imported oil with far lower quanities of hydrogen.

Point condeded. :)

You are correct in stating that the Prius, and other gas/electric hybrids, are not "alternative fuel vehicles" -- This page lists the various tax deductions for hybrids and other alternative fuel vehicles currently in effect in the US, and it does say that "hybrids are not eligible for the electric vehicle tax credit".

I have apparently made a bad assumption, for which I humbly apologize. -_-

I love when people talk out of their ass...

Most power for the creation of hydrogen in the US will probably come most directly from Coal (which is burned to make electricity, which can be used to perform electrolysis on water, which gives us Hydrogen).

The US has a shitload of coal. We are the Saudi Arabia of coal. If we switched entirely to coal power (we're already ~70% of the way there), we could go for another century, quite possibly two without importing any more. And the other ingredient for electrolysis, water...well, we have a fair bit of that too.

So, a better name for the "Hydrogen Economy" might be the "Coal Economy", but it really does have a chance to seriously reduce US dependence on foreign oil. Coal is, of course, a notoriously dirty power generation method, but there have been serious efforts recently to clean it up a bit. The real future may be something like FutureGen (warning: may contain DOE propaganda :) where a single plant produces electricty for homes and hydrogen for fuel cell cars and the like, ostensibly with no emissions. Plus, if we switch all our vehicles to hydrogen now, we can use some other power source for electrolysis (wind, solar, fusion, geothermal, whatever) later on.

I think it comes down to who you believe. The AC who started this line of discussion, or the two studies that have been cited.

I guess I'm inclined to believe the panels pay themselves off eventually (the web sites say 2 years, our contractor says 12). I'm also inclined to believe that before the panels die their net environmental impact would be positive.

But from what others are saying, it looks like solar water, new appliances, and home insulation should take precedence.

This is a myth. After two to four years, there is a net gain. (It also fails the sniff test: if the myth were true, they would have to sell them for less than it costs to make them.)

--MarkusQ

Methane (Biogas) from Anaerobic Digesters

Methane is a gas that contains molecules of methane with one atom of carbon and four atoms of hydrogen (CH4 ). It is the major component of the "natural" gas used in many homes for cooking and heating. It is odorless, colorless, and yields about 1,000 British Thermal Units (Btu) [252 kilocalories (kcal)] of heat energy per cubic foot (0.028 cubic meters) when burned. Natural gas is a fossil fuel that was created eons ago by the anaerobic decomposition of organic materials. It is often found in association with oil and coal.

The same types of anaerobic bacteria that produced natural gas also produce methane today. Anaerobic bacteria are some of the oldest forms of life on earth. They evolved before the photosynthesis of green plants released large quantities of oxygen into the atmosphere. Anaerobic bacteria break down or "digest" organic material in the absence of oxygen and produce "biogas" as a waste product. (Aerobic decomposition, or composting, requires large amounts of oxygen and produces heat.) Anaerobic decomposition occurs naturally in swamps, water-logged soils and rice fields, deep bodies of water, and in the digestive systems of termites and large animals. Anaerobic processes can be managed in a "digester" (an airtight tank) or a covered lagoon (a pond used to store manure) for waste treatment. The primary benefits of anaerobic digestion are nutrient recycling, waste treatment, and odor control. Except in very large systems, biogas production is a highly useful but secondary benefit.

Good source to understand organisms and methane.

but since they're sparsely populated, their votes are worth 3 of mine (in Georgia).

Considering Georgia is 21st nationally in corn production, and that agriculture makes up 18-percent of its GDP, I'd say Georgia is a corn growing state and that your fellow Georgians, at least, do give a shit about corn.

This link is kind of old, but several years ago Georgia was looking into building an ethanol production plant, so your state by now might be part of the problem corn growing states after all.

Ok, all these experts say we'll run out of fossil fuels in about 50 years at our current consumption.

Ok, all these experts say we'll run out of fossil fuels in about 50 years at our current consumption.

Here are a few links to muddy your perception of events:


http://www.energy.gov/engine/content.do?PUBLIC_ID= 16141&BT_CODE=PR_PRESSRELEASES&TT_CODE=PRESSRELEAS E

http://www.wjla.com/news/stories/0604/152311.html

http://www.cnn.com/2003/WORLD/meast/06/25/sprj.irq .centrifuge/

http://www.guardian.co.uk/Iraq/Story/0,2763,894550 ,00.html


It's all a matter of how deep you're willing to dig for the information. You won't see this stuff repeated on the news... because it might just make the War in Iraq justified. Can't have that now, can we?

But since these stories don't fit the party line that's been coming from the press... I guess they're lies. I'm not saying this is definitive evidence, but these stories show at least a plausible explanation for invasion, not to mention shooting holes in the "cut and dried" we shouldn't have gone to war, camp. And it has CERTAINLY shot down the "full compliance with UN resolutions" camp that has popped up lately. Compliance? If you mean kicking out inspectors so he can hide his banned equipment, then... yes. :)

Not to mention Jan. 27th 2003, Hans "I never said that" Blix told the UN that Iraq had shown "NO EVIDENCE of FULL compliance" with disarmament. (And we all know, the Security council authorization for retaliation as a result of non-compliance was not more sanctions... but then again, who listens to the UN?)

He later recanted, denied, claimed he was misquoted, when it was impacting his book sales.... but that's another story.

Given that a fiscally conservative governemnt should, by nature, intervene in or assist with the population's energy needs, our government is taking a proactive stance to reduce dependence on expensive foreign energy.

Bush announced [http://www.eere.energy.gov/hydrogenandfuelcells/] $1.2 billion in federal grants to fuel cell programs in his 2003 SOTU Address so that we could lessen our dependence on foreign oil. According to http://costofwar.com/, we Americans have supported Bush in spending $163.9 billion to destroy and rebuild Iraq since 2003.

That is, if anyone's interested in giving less money to people who have been granted the rights to profits from Earth's natural resources. Whether 2020 is a conservative estimate or not, anyone even contemplating further industrialization should recognize that we're treating oil like diamonds: overvalued for lack of an equally well marketed alternative.

If you want to control each light then here is a 1-wire ballast controller which should cost about $1 per controller. This would be great as you could add it to each individual bulb and get total control, but I can't find anyone that sells it. I want to light my entire apartment using LEDs, and am thinking of using this 8-channel PWM module as a dimmer. It's centrally controlled though and rapidly gets expensive if you want to control too many lights individually (with RBG you need three channels per light).

There are PICs with PWM output and CAN/RS485 built in. I'm amazed no-one is prepared to sell a micro-PWM dimmer for a couple of bucks each. Maybe someone can help this guy out?

Phillip.

Wood: 6,800 Btu/pound
Coal: 12,000 Btu/pound
Oil/gas: 20,000 Btu/pound

Last I checked, it was not limited to coal burning but is largely dominated by it currently.

Electricity source %
Coal__ __Nuclear_ _Gas__ __Hydro_ __Oil_ _Other
51___ ___20____ ___17___ __7___ ____3__ __3

Electricity info:
http://www.eia.doe.gov/neic/quickfacts/quickelectr ic.htm

Some Coal info:
http://www.energy.gov/engine/content.do?BT_CODE=CO AL

I am all for preparing for the future, but my point is that currently this is the situation and although everybody is working hard at producing technology to cleanly and sustainably produce eletricity, it is naive to think that switching to electricity is any real solution now or will be any time soon.

A variety of advanced approaches to solar cells are under investigation. Dye-sensitized solar cells use a dye-impregnated layer of titanium dioxide to generate a voltage, rather than the semiconducting materials used in most solar cells. Because titanium dioxide is relatively inexpensive, they offer the potential to significantly cut the cost of solar cells. Other advanced approaches include polymer (or plastic) solar cells (which may include large carbon molecules called fullerenes) and photoelectrochemical cells, which produce hydrogen directly from water in the presence of sunlight.

But this Department of Energy page does. They say such systems are currently at 9-12 cents/kWh, but expect 4-5 cents/kWh in a few decades. Which is certainly competitive.

Cheap fusion already exists, and the fuel supply is expected to last millenia.

It just happens to be 93 million miles away.

Photovoltaics aren't sufficiently efficient yet to remove significant amounts of demand from the electrical grid, but PV isn't the only type of solar energy. Personally, I'd like to see a scaled-down version of Solar Two. I mean, think about a couple 3-meter heliostats (the same size as the older analog satellite TV dishes) sitting on top of your garage (or on top of a shed in the back yard; as long as it gets plenty of sunlight), focusing on some small collector on the top of the house.

A 3 meter diameter dish has about about 7 square meters of aperature. If your heliostats are about 85% efficient (you can get reflective films which do this), and the main collector/generator is 33% efficient, that's about 2 kW for each heliostat (7 sq meters * 1 kW solar energy / sq meter * 0.85 * 0.33). That's about 28% efficiency, from the surface of the heliostat to the final output. Considering the fact that most PV's (and all consumer-priced PV) are <20% efficient, that's not too bad. If your generator consists of a steam engine (Rankine or Kalina cycle) or Stirling engine, these typically product AC to begin with, so you don't have to worry about an inverter (which you will probably need with your PV, since they only produce DC).

If you use the molten salts Solar Two used, you could still get power after the sun sets (their research showed this was >95% efficient in terms of energy in vs. energy out). Alternately, you could just do net metering and knock your electric bill down.

Also, if you use the waste heat from the system to provide household heat or hot water, you get an even higher total efficiency. That aspect of it could reduce the amount of electricity you need, as well (if you have electric heat or an electric hot water heater).

Why are you maliciously spreading lies, or are you just stupid?

"Studies have shown that, depending on the type of PV technology, the clean energy payback of a PV system ranges from one to four years. With life expectancies of 30 years, 87% to 97% of the energy produced by PV systems will be free of pollution and greenhouse gas emissions. For more information, see the NREL report, "Energy Payback: Clean Energy from PV""

The one picture that site has is linked to a AOL user's web site? Ok.. Anyway, more information about solar technology and a picture of a light tube!

The one picture that site has is linked to a AOL user's web site? Ok.. Anyway, more information about solar technology and a picture of a light tube!

I seem to be the only one who found this FAQ

Yes, it's thick fibre optics. That's not new, as many comments have pointed out.

The novel trick here is that they're splitting the solar light into visible and non-visible spectrums. The visible is routed to the "hybrid" fixture that also has a light bulb in it and a light sensor to make sure the hybrid fixture is putting out enough light. The non-visible portion of the solar light is used to GENERATE ELECTRICITY with Photovoltaic cells that are specialized to work with infrared.

The prevailing opinion here seems to be that this is a stupid story, because light pipes are old news. Two people have even been moderated up to +5 for posting links to light pipe vendors.

Light pipes are NOT the story here. Hybrid lighting is a NEW lighting system which separates the visible and IR components of sunlight, directing the visible components to room lighting and the IR components to thermo-voltaic generator, which stores electrical energy to light the room after the sun has gone down. Ordinary light pipes do not do that.

From the U.S. Department of Energy Solar FAQ:

Q:How does a hybrid solar lighting (HSL) system work?

A:Imagine being able to light your home or office most of the day, and on most days, with sunlight, but not the kind that comes through the windows. That's what hybrid solar lighting (or HSL) systems are being developed to do. Prototype HSL systems are made up of roof-mounted concentrators that collect and separate the visible and infrared portions of sunlight. The visible portion of the light is distributed through large-diameter optical fibers to hybrid luminaires. (Hybrid luminaires are lighting fixtures that contain both electric lamps and fiber optics to distribute sunlight directly.) Unlike conventional electric lamps, the solar component of HSL produces little heat.

The remaining "invisible" energy in the sunlight, mostly infrared radiation, is directed to a concentrating thermo-photovoltaic (solar) cell that very efficiently converts infrared radiation into electricity. The resulting electric power can be directed to other uses in a building. When sunlight is plentiful, the fiber optics in the luminaires can provide all or most of the light needed in a particular area. But when there is little or no sunlight, sensor-controlled electric lamps turn on to maintain the desired illumination level.

Independent cost and performance models suggest the overall affordability of solar energy could be doubled or tripled by using this new hybrid approach. The multidisciplinary R&D effort involved in developing HSL includes several industrial and university partners. Other Resources:

Actually, this is different than simple redirected light. Check out this link for more information. Basically, it runs the sunlight through fiberoptic cables to light fixtures that work much like our current light bulbs. These means that you won't have to have serious architectural redesigns of buildings to get the same effect. It also will generate electricity that can be used for other applications (powering computers?). It is basically a hybrid approach to lighting.

The Department of Energy has some information on solar lighting available here.

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Because you can't absorb it all at once. Check how eyes try to catch as many of the fotons flying around as they can. For the same reason chlorophyl in plants has an 'antenna complex'.

Bad luck you cannot patent this idea as it is already in use, see for instance this paragrpah on reflection , describing such an efficiency increasing trick.