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Solar Panel Breaks "Third of a Sun" Efficiency Barrier

timothy posted about 2 years ago | from the bright-idea dept.

Power 237

Zothecula writes "Embattled photovoltaic solar power manufacturer Amonix announced on Tuesday that it has broken the solar module efficiency record, becoming the first manufacturer to convert more than a third of incoming light energy into electricity – a goal once branded 'one third of a sun' in a Department of Energy initiative. The Amonix module clocked an efficiency rating of 33.5 percent."

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So confusing... (1)

Anonymous Coward | about 2 years ago | (#41867129)

This page seems to indicate that 33% is kind of weak: http://en.wikipedia.org/wiki/File:PVeff(rev100921).jpg

Maybe that's because those are still small scale in the lab and this one is in production?

Re:So confusing... (5, Informative)

Anonymous Coward | about 2 years ago | (#41867157)

From the article: "The solar module efficiency is the efficiency of the panel, and not the same as the efficiency of individual solar cells from which it's comprised. At the moment, solar cell efficiency can just exceed 43 percent for concentrated systems. It's the module efficiency, however, which reflects the amount of electricity a PV system can produce."

Re:So confusing... (1)

jmottram08 (1886654) | about 2 years ago | (#41867163)

33 ish percent is at the top of that chart...

Re:So confusing... (0)

Anonymous Coward | about 2 years ago | (#41867187)

Hmmm, I'm seeing 42.4% at the top of that wiki pic...

Re:So confusing... (1)

interval1066 (668936) | about 2 years ago | (#41867195)

I seem to recall 40% efficiency was like the brass ring as far as solar cell goals not very long ago. In that light this seems like pretty swell news.

Re:So confusing... (1)

Anonymous Coward | about 2 years ago | (#41867463)

40% is done with multijunction cells, and the expense restricts it to military/NASA use typically. I assume for this to be progress that it's regular, mass produceable cells at 30%+.

Re:So confusing... (5, Informative)

Anonymous Coward | about 2 years ago | (#41867743)

If anyone reads the article carefully...

They state in the article that individual cells can already reach 43% efficiency - which matches the top end of that chart.

The overall efficiency of the PANEL (made up of many cells) is lower though. This 33% is the record for the efficiency of the PANEL as a whole, not for the individual cells.

Re:So confusing... (0)

Anonymous Coward | about 2 years ago | (#41867199)

You didn't RTFA. Admit it.

Re:So confusing... (-1)

Anonymous Coward | about 2 years ago | (#41867397)

I admit it, I did RTFA. I can promise you, from now on, I wont.

Re:So confusing... (5, Informative)

Anonymous Coward | about 2 years ago | (#41867975)

Why not cite NREL's official and current chart? http://www.nrel.gov/ncpv/images/efficiency_chart.jpg

While they may have hit a new record for overall efficiency, any sort of concentrator photovoltaics require sun tracking, significantly increasing initial system and maintenance costs.

Margin of Error. (0)

Anonymous Coward | about 2 years ago | (#41867149)

Of course the test had a margin of error of 4%

Re:Margin of Error. (2)

PopeRatzo (965947) | about 2 years ago | (#41867181)

Of course the test had a margin of error of 4%

Does anyone have any confidence that the AC who wrote that statement knows what "margin of error" actually means?

Re:Margin of Error. (5, Funny)

NEDHead (1651195) | about 2 years ago | (#41867585)

I'd say it is 80% certain that he does not, with 2 sigma confidence

Re:Margin of Error. (1)

ILongForDarkness (1134931) | about 2 years ago | (#41867951)

Oh snap, nerd burn ! ;)

Additional Information (4, Informative)

jmottram08 (1886654) | about 2 years ago | (#41867151)

According to wiki this happened in July. Also, for info, they have received over 180 million dollars in grants from the government, and closed their las vegas plant in order to "focus on international opportunities".

**YAWN** (-1)

wiggles (30088) | about 2 years ago | (#41867153)

Call me when they get the price per KWh down to below non-renewable sources.

Re:**YAWN** (4, Insightful)

PopeRatzo (965947) | about 2 years ago | (#41867197)

Call me when they get the price per KWh down to below non-renewable sources.

If you include external costs, it's a lot closer than you think.

Re:**YAWN** (2)

NevarMore (248971) | about 2 years ago | (#41867211)

If you include external costs, it's a lot closer than you think.

Go on. Show me the mone...maths!

Re:**YAWN** (4, Interesting)

AmiMoJo (196126) | about 2 years ago | (#41867485)

For almost any new building it is worth covering the roof with solar PV. It might take 10-15 years to recover the cost, but then it is all profit. The savings are even bigger if you combine PV with solar heating. Installation is cheaper at the time of construction and the cost is a small fraction of the roof budget, let alone the cost of the whole building. If you are taking a mortgage then the cash from feed-in tariffs will more than cover the extra cost of the panels on your monthly payment.

Note: Based in building in the UK, further south it makes even more sense.

Re:**YAWN** (2)

Newtonian_p (412461) | about 2 years ago | (#41867571)

What is the "life expectancy" of PVs?

Re:**YAWN** (4, Informative)

starworks5 (139327) | about 2 years ago | (#41867681)

typically 30 years with 80-90% of the original efficiency, less if you live in a hurricane / tornado prone region.

Re:**YAWN** (1)

symbolset (646467) | about 2 years ago | (#41867893)

Also shorter lifespan for the roof of a professional sports venue.

Re:**YAWN** (3, Informative)

AmiMoJo (196126) | about 2 years ago | (#41867779)

25 years for reasonable ones. Of course by the time they wear out you will be able to replace them cheaply as you already have the mounting hardware and electrical infrastructure.

Re:**YAWN** (4, Interesting)

tsotha (720379) | about 2 years ago | (#41867833)

Concentrated cells tend to wear out much more quickly. They get much hotter, and junction heat is what determines the life of any semiconductor.

Re:**YAWN** (4, Informative)

rs79 (71822) | about 2 years ago | (#41867875)

Solar cells and silicone sealant share the same property: we have no idea how long they're good for.

Originally silicone cement had a 3 year warranty. Then none failed and they made it 10. Now it's 30. I have aquariums that are forty years old that have just a microscopically thin lawyer of silicone holding hundreds of gallons of water in a glass box. We have no idea how long the stuff will last, it could be a hundred years or more for all we know.

Solar panels started being deployed in the 70s. They all still work and were expected to give 10 years service. To be sure, efficiency diminishes over time, but that's a secondary consideration to the fact newer panels are much more efficient. Somebody can use those old panels though.

Re:**YAWN** (1)

AK Marc (707885) | about 2 years ago | (#41868259)

There's no upper bound. Many have warranties above 20 years, and those that made it to 20 years, on older, less stable configurations, are still going strong. Sure, you lose about 1% efficiency per year, but that that's more a financial issue than anything else.

Re:**YAWN** (0)

Anonymous Coward | about 2 years ago | (#41868397)

For almost any new building it is worth covering the roof with solar PV

For a lot of places it would be worth covering the roof with dummy PV panels. The shading would reduce your need to run the air conditioner. I prefer deciduous trees for that though. The trouble with the trees is that you have to be careful about roots, foundations, water and sewer lines. You also have to maintain them and they don't provide much power (very few BTUs from firewood over the life of a tree compared to panels).

Re:**YAWN** (-1)

Anonymous Coward | about 2 years ago | (#41867223)

It already is. YAWN.

Re:**YAWN** (1)

Seeteufel (1736784) | about 2 years ago | (#41867231)

That is just a matter of time. That is what the Chinese say but the Germans are most advanced.

Re:**YAWN** - 2nded eff does nothing for economics (0)

Anonymous Coward | about 2 years ago | (#41867247)

Agreed.

Efficiency per unit area does not matter much at all, for almost all uses (residential, light commercial) roof area is not really an issue.

Cost / watt is what matters, and durability long term matters.

If you make the 33% efficient panel cost 50% more per watt the economics of using the more efficient panels goes out the window, and the economics are barely there....If I self build a system (my own labor) and I am in an area with $0.1/kwh (and rising) with the 30% government subsidy it still takes around 10 years to pay out ignoring the cost value of money.

Re:**YAWN** - 2nded eff does nothing for economics (1)

K. S. Kyosuke (729550) | about 2 years ago | (#41867775)

More efficient cells are usually used with concentrators, aren't they? I'd think that changes the game a little bit.

Re:**YAWN** (1, Interesting)

ThatsMyNick (2004126) | about 2 years ago | (#41867417)

It already is. Once you set up the panels, the price per watt is 0 (which is less than non-renewable sources, and as low as it will ever get)

Re:**YAWN** (-1)

sribe (304414) | about 2 years ago | (#41867459)

It already is. Once you set up the panels, the price per watt is 0 (which is less than non-renewable sources, and as low as it will ever get)

Stupidest. Comment. Ever?

Re:**YAWN** (1)

ThatsMyNick (2004126) | about 2 years ago | (#41867467)

Oh, did that fly over your head? Did it make a Woooosh when it flew over?

Re:**YAWN** (3, Interesting)

realityimpaired (1668397) | about 2 years ago | (#41868187)

Not really... the point he was making is that the energy is there to be collected, and once the system is installed the maintenance costs are negligible. Many solar installations don't need any maintenance at all beyond keeping the panels clean.

The initial installation costs a lot of money (which is becoming less and less every year), but you can sell any extra electricity you produce back into the grid, and the reduction in your monthly electric bill should be significant enough to make it worth considering. In most cases, the reduction in your bill will be more than enough to cover the cost of the loan to have the panels installed in the first place, and in some cases you'll find yourself in a position where the power company is paying you each month.

Re:**YAWN** (0)

Anonymous Coward | about 2 years ago | (#41867549)

Call me when you can fly a 747 or F-15 on electricity.

Re:**YAWN** (1)

mosb1000 (710161) | about 2 years ago | (#41867777)

That would be trivial, if you could find a way to plug it in.

Re:**YAWN** (0)

Anonymous Coward | about 2 years ago | (#41868129)

That would be trivial, if you could find a way to plug it in.

Also trivial. Just need a really long extension cord.

Re:**YAWN** (1)

Anonymous Coward | about 2 years ago | (#41867791)

Providing you use them for over a decade, it is already cheaper in the long term. They just cost a lot more initially.

I have a whole array of panels. Not only have I not paid a penny for electricity for over 8 years, but I actually sell surplus power back to the grid - amounting to an income of almost £1000 a year. Which actually means the panels will soon have paid for themselves.

Great! (0)

Anonymous Coward | about 2 years ago | (#41867191)

Now slap 4 of them on every mcmansion in the country and hook them to the grid.
Bonus: That'll keep a bunch of people employed forever.

What? No? Expensive? Not gonna do it?
Ok... well.. you kids enjoy the world we're leaving you.

Repost? (-1)

Anonymous Coward | about 2 years ago | (#41867207)

Seems like we get one of these stories every six months or so. New solar panel efficiency record.

Do we ever see these in the real world, nope. Call me when you start selling these.

Send it into space! (1)

StripedCow (776465) | about 2 years ago | (#41867217)

If you move the panel closer to the Sun, you'll need quadratically less area for the same amount of energy.

Of course, you'll need a parallel laser beam to send the energy to Earth, and a receptor, etc. but those are left as an exercise for the reader.

Re:Send it into space! (0)

Anonymous Coward | about 2 years ago | (#41867291)

Honestly, it'd probably be much easier just making a HUGE ass magnifying glass in space that sends it to a solar panel in space, then beam it back down to surface in the most efficient non-interacting beam. (or deadly high energy beam and just put up a no-fly zone)

The problem would be cooling because space is inert, you'd need to have a huge cooling station behind it that is kept in constant shadow to dissipate heat quick enough for such a huge industrial-scale design like that.

But, it is entirely doable with the right funding and people behind it.
There are a few space solar projects going right now. Varying distances along their project timeline.
There is still time for us to be space truckers. Soon. Soon.

Space based energy collection (0)

fox171171 (1425329) | about 2 years ago | (#41867377)

If you take solar energy from space that was not falling on Earth, and sending that energy to Earth, then you're still contributing to global warming.

Re:Space based energy collection (1)

amorsen (7485) | about 2 years ago | (#41868383)

Stefan–Boltzmann says that the radiation from a black body is proportional to the fourth power of its temperature. You would have to add a lot of energy to make any significant difference to temperature.

Re:Send it into space! (2)

K. S. Kyosuke (729550) | about 2 years ago | (#41867793)

Honestly, it'd probably be much easier just making a HUGE ass magnifying glass in space

Magnifying glass? Are you insane? A thin silver-covered mylar mirror is much lighter than that.

Go ahead, build and sell it without subsidy (4, Insightful)

tp1024 (2409684) | about 2 years ago | (#41867219)

That's just about where the miracles stop reliably. You may or may not find some special cases in which those actually make sense (given that we're talking about concentrated solar and 2-axis drives are mandatory, those cases become even more special), but at large scale it's just not worth it - even without considering the need to store the energy, so you have it when you need it.

yet another solar tech not available to the public (4, Insightful)

SuperBanana (662181) | about 2 years ago | (#41867251)

Every 6 months on Slashdot we read about higher efficiency solar panels. Virtually none of them are available on the market, and if they are, they're only available to large-scale commercial installations. Right now, the best you can do retail is about 20%; some panels are barely 10%.

A condition for any prize should be "available in half-dozen quantities to individual purchasers."

The best return on investment remains solar hot water - we're talking an order of magnitude in efficiency per area between common solar panels and evacuated-tube hot water collectors. We waste enormous amounts of energy heating hot water and heating homes...

We'd also save billions of dollars if we stopped selling clothes dryers that are hideously inefficiency; elsewhere in the world condensing dryers are the norm and in some cases dry clothes faster.

Re:yet another solar tech not available to the pub (2)

Yoda222 (943886) | about 2 years ago | (#41867337)

Nuclear power plant are also difficult to build from stuff that you can find on the market, and they are only available to large-scale commercial installations.

Re:yet another solar tech not available to the pub (3, Interesting)

Trepidity (597) | about 2 years ago | (#41867347)

We'd also save billions of dollars if we stopped selling clothes dryers that are hideously inefficiency; elsewhere in the world condensing dryers are the norm and in some cases dry clothes faster.

I think the prevalence of gas-powered dryers is a reason the U.S. still uses more inefficient dryers, because the fuel (natural gas) is fairly cheap, and much cheaper than with the electric-powered dryers that are prevalent in parts of Europe. So there's less economic incentive to improve efficiency.

Re:yet another solar tech not available to the pub (5, Informative)

Anonymous Coward | about 2 years ago | (#41867849)

http://ths.gardenweb.com/faq/lists/laundry/2004120958010854.html

"All else being equal (i.e. not including household heating/cooling issues), condenser dryers are slightly less efficient than their vented counterparts, typically on the order of ~15%. The real design intent of condenser dryers isn't improved efficiency, but the simple fact that they don't require a vent duct, permitting easy installation most anywhere (ideal for apartment dwellers, etc). "

A gas dryer is going to be much more energy efficient than an electric dryer considering that ALL the heat generated from the flame enters the tumbler. Typical power plants can only transmit up to ~40%% of the heat from their power source to the dryer heater coils.

Min energy eff electric: 3.01 lb/kWh
Min energy eff gas: 2.67 lb/kWh

Electric is 12% more efficient at point of use

Total heat efficiency including power generation:
3.01 * 40% = 1.2
2.67 * 100% = 2.67

most efficient setup would be an external venting gas dryer in a unheated space like a basement or garage since you would not be adding load to an HVAC system.

Re:yet another solar tech not available to the pub (2)

amorsen (7485) | about 2 years ago | (#41868417)

You are at least 5 years out of date with that information. Traditional condensing dryers are obsolete, modern ones use heat pumps and are vastly more efficient than vented dryers.

Re:yet another solar tech not available to the pub (1)

Anonymous Coward | about 2 years ago | (#41867445)

We'd also save billions of dollars if we stopped selling clothes dryers that are hideously inefficiency; elsewhere in the world condensing dryers are the norm and in some cases dry clothes faster.

"...All else being equal (i.e. not including household heating/cooling issues), condenser dryers are slightly less efficient than their vented counterparts, typically on the order of ~15%. The real design intent of condenser dryers isn't improved efficiency, but the simple fact that they don't require a vent duct, permitting easy installation most anywhere (ideal for apartment dwellers, etc)..."

"...There IS in fact a true heat pump dryer - the AEG Lavatherm WP - which is very energy-efficient, but it's not available in North America, and is extremely expensive (probably so much so that it wouldn't pay for itself in energy terms)...."

Source: http://ths.gardenweb.com/faq/lists/laundry/2004120958010854.html

Re:yet another solar tech not available to the pub (2)

AmiMoJo (196126) | about 2 years ago | (#41867455)

At this stage cost a more important factor than efficiency. We have vast amounts of unused space that could be covered in solar PV panels, but the fact that it takes years to recover the investment of thousands of Euros/Dollars is holding back adoption.

Re:yet another solar tech not available to the pub (0)

Anonymous Coward | about 2 years ago | (#41867481)

Really? You're getting 200% efficiency off your solar water heater?

Re:yet another solar tech not available to the pub (1)

khallow (566160) | about 2 years ago | (#41867887)

Well, if it's a heat exchange system, you can get higher efficiencies than 100%, because the energy is expended in transferring a greater amount of heat from a heat source (usually the outdoors) to the water.

Re:yet another solar tech not available to the pub (1)

AK Marc (707885) | about 2 years ago | (#41868343)

No, getting 10% efficiency from a solar system is still better than a 100% efficient electric one run off a coal-fired plant. The "efficiency" is in economic terms, not thermodynamic terms. I put in "no" heat and get back more than I put in. Or the natural gas ones where it's 75-85% efficient and still cheaper than the electric version at 100% efficiency because of the cost of energy, so people call the natural gas one "more efficient".

Re:yet another solar tech not available to the pub (1)

Gothmolly (148874) | about 2 years ago | (#41867515)

Why troll about how the rest of the world is better than the US?

Re:yet another solar tech not available to the pub (5, Informative)

Annirak (181684) | about 2 years ago | (#41867531)

It looks like I can buy solar modules for a minimum cost of $1/Watt.

Assume an energy cost of $0.1/kWh. Assume an average of 12 hours of sunlight per day and a 50% of maximum average intensity.
$0.1/kWh * 1 year / 12 * 50% * 12 hours/24 hours = $0.01826

The monthly value that a solar cell generates is $0.01826/watt month.

Assume a yearly interest rate of 5% (monthly is 0.4074%)

Since the cost of a solar cell is $1/watt, work out the number of months that a 1W solar cell must run for to generate $1.
PV = A/i (1-1/(1+i)^n)
PV = $1, A = $0.01826, i = 0.004074

n = 62 months = 5.17 years

The warranty on the reference cell is 10 years product workmanship, 25 years linear power.

So the value of the cell over its 25-year life span is $3.15/watt, with a cost of $1/watt.

This all neglects installation and grid-tie costs, but 50% average illumination per daylight-hour is conservative in most areas. Solar cells ARE worthwhile TODAY and WITHOUT government subsidies.

Efficiencies in solar cells are irrelevant. The only thing that matters is the $/Watt.
Reference Solar Cell: http://www.affordable-solar.com/store/solar-panels/CSI-CS6P-245P-245W-Solar-Panel-STD-Frame

Re:yet another solar tech not available to the pub (1)

gfxguy (98788) | about 2 years ago | (#41867917)

I agree with you, and would love to use as much renewable energy as possible and save money in the long run, but I think the problem is that most people in the U.S. do not actually live in their homes for a long enough time. I've been here 13 years, but I've been looking to move for the past five or so (but haven't been able to for various economic reasons). Before the housing market crash, I read the average duration in any one home had shrunk to only about 7 years, so it's not just me. I'd actually love to buy a brand new home that I've had input on - solar, on-demand hot water (if not solar heated), maybe even geo-thermal... but that only works if I plan to stay there for a LONG time.

Re:yet another solar tech not available to the pub (2)

Annirak (181684) | about 2 years ago | (#41867981)

It actually continues to work for you even after you leave. Adding renewable energy generation and high efficiency heating/cooling (geothermal) to your home increases your property value, which gives you the option to do the same again, or buy one with the work already done.

Re:yet another solar tech not available to the pub (2)

Solandri (704621) | about 2 years ago | (#41868395)

but I think the problem is that most people in the U.S. do not actually live in their homes for a long enough time. I've been here 13 years, but I've been looking to move for the past five or so

This shouldn't really matter, as any unrealized value of the PV panels would presumably be recouped by increased resale price of the house.

The hang-up is up-front costs. The average home in the U.S. uses 11,500 kWh [eia.gov] in a year. So at a constant power draw that's 1311 Watts. Factor in PV solar's average capacity factor o 0.145 and that means you need 9050 Watts of nameplate capacity installed to (on average) zero out your electricity bill (in reality it's a bit less because peak electric prices are during the middle of the day when nobody's home but the panels are generating the most).

If panels are $1/Watt, that's a $9k up-front cost the homeowner has to pay, plus several thousand more for installation, mounting, inverters and regulation, etc. That's simply out of the reach of most homeowners unless they can somehow roll it in with their mortgage.

Re:yet another solar tech not available to the pub (3, Informative)

Solandri (704621) | about 2 years ago | (#41868285)

Assume an energy cost of $0.1/kWh. Assume an average of 12 hours of sunlight per day and a 50% of maximum average intensity.
$0.1/kWh * 1 year / 12 * 50% * 12 hours/24 hours = $0.01826
The monthly value that a solar cell generates is $0.01826/watt month.

Average capacity factor for solar in the U.S. is about 0.145. That is, a 100 Watt nominal panel will on average generate 14.5 Watts throughout the year after factoring in everything - night, weather, angle of the sun, etc. In the desert Southwest it's about 0.18 (0.195 in extreme desert regions), but for the country overall it's about 0.145. The NREL assumes a capacity factor of 0.17 [nrel.gov] for PV installations in the U.S., which are predominantly in the desert Southwest.

Your quick "12 hours a day, 50% max average" assumes a capacity factor of 0.25. Almost twice the actual value.

Correct for this in the rest of your math and you get n = 120, or 10 years payback. That sounds about right as the test cases I've calculated usually wind up between 7 and 15 years.

Re:yet another solar tech not available to the pub (1)

ljw1004 (764174) | about 2 years ago | (#41868363)

So the value of the cell over its 25-year life span is $3.15/watt, with a cost of $1/watt... Solar cells ARE worthwhile TODAY and WITHOUT government subsidies. Efficiencies in solar cells are irrelevant. The only thing that matters is the $/Watt.

That's interesting. Please also compare:

* If you invested $1 in the stock market, and see how much it grew in 25 years, minus the cost of the energy you'd need to buy.

(I suspect that 315% over 25-years is much smaller return than what you'd get from stock market growth).

Re:yet another solar tech not available to the pub (0)

Anonymous Coward | about 2 years ago | (#41867785)

A condensing dryer isn't a slam dunk in efficiency gains. What you need is to have the closed loop, with an available vent, hooked into the rest of the house's HVAC system. Then, the dryer can elect to vent or not, based on what temperature you want inside, and what temperature is available outside.

Re:yet another solar tech not available to the pub (1)

AK Marc (707885) | about 2 years ago | (#41868355)

That's a bad idea. Maybe with a heat exchanger, but most homes are already too damp, so adding moisture is worse than any thermal gains you get.

Re:yet another solar tech not available to the pub (0)

Anonymous Coward | about 2 years ago | (#41867923)

Don't forget every time we see a new solar panel discovery, the big question never comes up: How many watts does it take to fab the silicon, add the secret herbs and spices, stuff the silicon in a panel with a cover, and ship it out.

All this takes energy, and so far, there has been NO solar panel ever made, that has gotten back the energy it takes to produce it. Solar panels need to be compared to alkaline batteries where they do have energy, but nobody ever thinks they are an energy *collection* device.

Lets be real, solar does not give us energy. That is what dino cake (coal) and dino juice do. All it does it allow stuff like an electric fence zapper that is not on the grid to have electric power, or play the game of creative green accounting which is so popular with our politicos.

Re:yet another solar tech not available to the pub (1)

AK Marc (707885) | about 2 years ago | (#41868369)

If grid power wasn't subsidized, then the price of the panel includes all the energy required to make it, and it is a net win today. So they must make more than they take to make them, or the government is heavily subsidizing electrical generation.

Re:yet another solar tech not available to the pub (1)

Anonymous Coward | about 2 years ago | (#41867933)

YES! If you can, put up a clothes line. It can make a huge dent in the amount of energy you use.

I know not everyone lives someplace were they can line dry clothes, but even hanging out clothes for a bit and finishing them in a dryer can make a difference.

Re:yet another solar tech not available to the pub (1)

Anne Thwacks (531696) | about 2 years ago | (#41868023)

OR you can hang the wet clothes in the server closet - helping keep the humidity up and cooling the servers as well as drying the clothes!

PLUS: you get double points on your geek card!

Re:yet another solar tech not available to the pub (1)

slashmydots (2189826) | about 2 years ago | (#41868073)

We'd also save billions of dollars if we stopped selling clothes dryers that are hideously inefficiency; elsewhere in the world condensing dryers are the norm and in some cases dry clothes faster.

You're wrong. If everyone drove half, used 2x efficient appliances, etc it would work until the population doubles. Then we're right back where we started. If they start creating energy from "nothing" like sunlight, we can use all the energy we want at any rate at any population level.

Re:yet another solar tech not available to the pub (0)

Anonymous Coward | about 2 years ago | (#41868219)

I'm suprised no one has mentioned patent trolls.

I know for a fact Siemens have trolled the hydrogen fuel cell market buying up and researching succesful tech that would put big oil out of commision. But I heard 2cnd hand from a researcher who presented a solution to a board at Siemens they (the board) refused to sell the product because it would hurt "their portfolio's". Their stocks in oil are appearently more important to them then their companies success and dominance or the well being of the earth and you at home.

AHWESOME (0)

noobermin (1950642) | about 2 years ago | (#41867285)

This is pretty good. We have a humongous energy radiating source that sends us rays everyday but we've yet to use it properly. Hopefully, more strides in this area can be made...

Re:AHWESOME (5, Funny)

NEDHead (1651195) | about 2 years ago | (#41867653)

I am concerned about the long term effects of taking all that power from the Sun. How long before it starts to shine less, or doesn't keep us in orbit anymore. The whole idea of endangering the longevity of the Sun gives me shivers. Think of our children!

OMFG (1)

noobermin (1950642) | about 2 years ago | (#41867813)

OMFG if you weren't replying to me I'd mod you to high heavens. I even have mod points now...disappointing :(

Re:AHWESOME (0)

Anonymous Coward | about 2 years ago | (#41868055)

Glad you told me that. I have a Sydney harbour bridge for sale for $50m ... If you wanna buy, contact me at bridge4sale@hotmail.com - only genuine buyers please.

Re:AHWESOME (0)

Son of Byrne (1458629) | about 2 years ago | (#41868097)

umm, what?

Your comment being modded as insightful made me re-read it about 3 times. I'd say more but I'm too busy scratching my head and looking incredulous at the same time.

Re:AHWESOME (5, Funny)

edxwelch (600979) | about 2 years ago | (#41868165)

This is true. They've used too much solar power and now in some parts of northern scandinavia there is darkness for 3 months of the year.

Re:AHWESOME (1)

Turminder Xuss (2726733) | about 2 years ago | (#41868365)

AND it goes away every night. Who's to say it won't come back again one day if we keep sucking up all the light ?

Concentrated solar is less efficient (4, Informative)

ChumpusRex2003 (726306) | about 2 years ago | (#41867317)

Unfortunately, this is a concentrated light solution. This means that the figures quoted for efficiency are in the presence of direct sunlight. However, this is only a proportion of energy generated from PV modules, hence the "efficacy" and therefore, total energy production, of concentrated solar solutions is less good than unconcentrated modules.

The reason comes from diffuse sunlight - light that has been diffused by the atmosphere or by clouds. This typically accounts for 10% of module illumination in direct sunlight, and much higher in the presence of atmospheric haze/cloud; even in lightly overcast conditions, you can expect unconcentrated PV to yield approx 10-15% of direct illumination yield because of the diffuse illuminance.

Diffuse light cannot be concentrated by optics, thus concentrated solar PV modules cannot utilise the diffuse light (more precisely, they can utilise it, but not concentrate it - thus if the system uses a 10:1 concentration, then the energy yield from diffuse illumination falls from 10-15% to 1-1.5%).

A boost from 30 to 33% efficiency by switching to concentrating modules could be completely wiped out by the loss of diffuse yield, even in direct sunlight. In non-direct sunlight, hazy or cloudy conditions, the yield can be reduced much more severely; resulting in a net reduction in productivity, despite the higher nameplate efficiency.

This technology is most suited to areas with the most intense direct illumination; e.g. dry areas, at low latitudes (where the role of diffuse light is diminished in proportion).

Re:Concentrated solar is less efficient (4, Insightful)

BlackPignouf (1017012) | about 2 years ago | (#41867733)

However, this is only a proportion of energy generated from PV modules, hence the "efficacy" and therefore, total energy production, of concentrated solar solutions is less good than unconcentrated modules.

No. A 2-axis tracked CPV system with multi-junction cells will produce more with beam radiation than a 2-axis tracked monocrystalline PV system with global radiation, at least in the regions where CPV is installed (Spain, Israel, Arizona, ...).
Sure, it won't work well in Norway.

The reason comes from diffuse sunlight - light that has been diffused by the atmosphere or by clouds. This typically accounts for 10% of module illumination in direct sunlight, and much higher in the presence of atmospheric haze/cloud;

Diffuse fraction never falls below 16%. Even a clear, deep blue sky still emits diffuse radiation.

Diffuse light cannot be concentrated by optics, thus concentrated solar PV modules cannot utilise the diffuse light (more precisely, they can utilise it, but not concentrate it - thus if the system uses a 10:1 concentration, then the energy yield from diffuse illumination falls from 10-15% to 1-1.5%).

True, but we're probably talking 500:1 concentration, here.

A boost from 30 to 33% efficiency by switching to concentrating modules could be completely wiped out by the loss of diffuse yield, even in direct sunlight. In non-direct sunlight, hazy or cloudy conditions, the yield can be reduced much more severely; resulting in a net reduction in productivity, despite the higher nameplate efficiency.

33% has been measured under 850W/m2 direct radiation (nominal operating conditions). Compared to 1000W/m2 global radiation (STC), you get 15% less.
That's still about 28% of module efficiency. How many single-junction PV modules are there that deliver that much, even in laboratory? None.

This technology is most suited to areas with the most intense direct illumination; e.g. dry areas, at low latitudes (where the role of diffuse light is diminished in proportion).

You meant "high altitudes", right?

Re:Concentrated solar is less efficient (0)

Anonymous Coward | about 2 years ago | (#41867741)

tl:dr the grandparent is a babbling moron

wake me up when they beat 100% (0)

Anonymous Coward | about 2 years ago | (#41867409)

wake me up when they beat 100%

I'd do it tomorrow (5, Interesting)

rueger (210566) | about 2 years ago | (#41867413)

I never seriously looked at solar and other "off the grid" options until investigating a house on an island off Vancouver.

It was new, purpose built, so had some obvious advantages, but what I took away from it was:
  • All electricity was from solar panels on the roof, with a small generator for backup when running things like power tools.
  • All water was from captured and filter/UVed rainwater.
  • Cooking and refrigeration was propane powered.
  • Woodstove for heating.

Obviously location and climate matter, but at the end of the day it was a viable and practical option, and one that made economic sense as well.

Sooner or later some bright government will figure out that by heavily subsidizing the installation of solar in homes they'll a) Develop a very viable industry b) drop solar costs due to volume c) get relected because everyone's electric bills will drop d) boost the economy because the money that was going to the electric company can be spent elsewhere. Now, I'm still a fan of hydroelectricity - if you need to generate electrical without generating CO2 and pollution, and without the no-nukes crowd at your door, there isn't a better way to go.

Re:I'd do it tomorrow (3, Insightful)

sribe (304414) | about 2 years ago | (#41867487)

Sooner or later some bright government will figure out that by heavily subsidizing the installation of solar in homes...

That's already being done all over the US--has been for years. Yet solar PV is still barely viable economically, even when the government pays 30-60% of the cost.

Re:I'd do it tomorrow (2)

drinkypoo (153816) | about 2 years ago | (#41867993)

Sooner or later some bright government will figure out that by heavily subsidizing the installation of solar in homes...

That's already being done all over the US--has been for years. Yet solar PV is still barely viable economically, even when the government pays 30-60% of the cost.

No, heavily subsidizing. Let's see if I've got the correct question. Where is Germany. That is correct, let's see how much they wagered. Germany leads in solar because they lead in subsidies. I have my own issues with subsidies but it seems to have worked in this case. In the US there's too many places and cases where you can't get the subsidy, many of which coincide with some of the best places for solar installations, almost like they intended it.

Re:I'd do it tomorrow (1)

floodo1 (246910) | about 2 years ago | (#41868253)

Barely viable economically? You might want to look at how many houses are getting solar added every year. From experience I can tell you that it's thousands of homes per month and the pace is steadily increasing. When you consider solar on your home compared to the utility in your area over the next 20 years PV does a lot better than "barely viable economically". (Yes what I'm talking about is happening because of government subsidies, but those subsidies are HIGHLY effective, and within not too many years won't be necessary.)

Re:I'd do it tomorrow (1)

im_thatoneguy (819432) | about 2 years ago | (#41867503)

I hate to be *that guy* but in the interest of fairness, while hydroelectric doesn't emit CO2 it does apparently emit a good bit of Methane from algae/sediment. I don't know however whether that's methane emission that is due to hydroelectric or no net increase in Methane from redistribution of methane that would have been released somewhere anyway. But it's something to consider.

Personally I'm a big fan of the Nukes.

Re:I'd do it tomorrow (2)

gman003 (1693318) | about 2 years ago | (#41867589)

But in the further interests of fairness, this is more a feature of the reservoir than the hydro plant itself. So even non-power-producing reservoirs emit methane.

Also, the methane emissions can be greatly reduced by clearing the area of trees and plant life before filling the reservoir. This brings it down to roughly the level of a natural lake.

Re:I'd do it tomorrow (0)

Anonymous Coward | about 2 years ago | (#41867635)

Sooner or later some bright government will figure out that by heavily subsidizing the installation of solar in homes they'll a) Develop a very viable industry b) drop solar costs due to volume c) get relected because everyone's electric bills will drop d) boost the economy because the money that was going to the electric company can be spent elsewhere.

Now, I'm still a fan of hydroelectricity - if you need to generate electrical without generating CO2 and pollution, and without the no-nukes crowd at your door, there isn't a better way to go.

a) Develop a very viable industry in China
b) Keep solar costs high because it's a subsidized market
c) Get ousted because everyone's taxes will go up
d) Destroy the economy because the money that was being spent in accordance with individuals' wishes is now being taxed and spent on something nobody wants.

Re:I'd do it tomorrow (1)

Anonymous Coward | about 2 years ago | (#41867647)

No, stop the subsidies! It's backwards and causes market distortions -- that is why we in the US have corn-ethanol in our gasolene: a monstronsity that should never have existed. Sure, I'm in favor of government grants for research (universities) to help develop the new technologies -- but am against any subsidies for consumer purchases.

Anyhow, if there were any real market for alternative energy (especially Solar, as I live in the middle of Texas), my electric co-operative power company would already be using it.

wiggles above said it best: "Call me when they get the price per KWh down to below non-renewable sources."

Yeah for research dollars, nay for consumer sibsidies (price controls). If you want, consumption/sales tax the heck out of natural-gas and other fossil fuels if you want to shift costs around (argument for making fossil fuel's external costs into an internal cost) -- that is a better way to make the 'free-market' adapt.

Re:I'd do it tomorrow (4, Interesting)

AK Marc (707885) | about 2 years ago | (#41868433)

Anyhow, if there were any real market for alternative energy (especially Solar, as I live in the middle of Texas), my electric co-operative power company would already be using it.

What if electric was a net gain (returns 5% on investment) but doesn't meet the minimum 10% ROI for the coop to implement it? What if the issue is that, if land and backhaul were free, it would be marketable, but a power company building a solar plant doesn't get free land and free infrastructure? You do. You've already bought the land your house is on, and paid for the infrastructure to that house, so the land and infrastructure are free. Just because someone can't make a profit on selling it doesn't mean it isn't worth doing. If every home in the US had panels on the roof, that would eliminate the peak summer loads, and would supply a surplus so that storage, rather than peak generation, would be the next problem to tackle. And the industrial sites would always use more than they can generate, so we'd end up where industrial sites would pay the power company, and the power company would pay millions of home owners.

Re:I'd do it tomorrow (0)

Anonymous Coward | about 2 years ago | (#41868213)

That's seems like a nice house, but wait - what about internet? It seems like whoever built that house wanted to live off the grind, but who wants to have to use satellite/mobile internet rather than good old landline cable/fiber?

Re:I'd do it tomorrow (0)

Anonymous Coward | about 2 years ago | (#41868235)

Sorry, meant grid, not grind.

33.5% of nothing (1)

Anonyme Connard (218057) | about 2 years ago | (#41867535)

What is the use in increasing the percentage of a free energy source converted into electricity?

The factor that matters is the panel production price, in watts per dollar. Along with life duration, total pollution during production, etc. But not watts per candela!

Re:33.5% of nothing (1)

Anonymous Coward | about 2 years ago | (#41867765)

You also have to factor in the cost of real estate.

Cheap (per unit area) but inefficient solar cells may be viable if you're building a large-scale plant in the middle of a desert, but not if you want solar on the roof of the house. Paying 100x more for 2x efficiency may still be cheaper than buying the neighbour's house just so that you have a second roof to mount solar cells on.

Re:33.5% of nothing (2)

slashmydots (2189826) | about 2 years ago | (#41868079)

I believe they're referring to total energy of the sunlight itself. I think sunlight is an average of like 2000W per square meter or something.

Re:33.5% of nothing (2)

Turminder Xuss (2726733) | about 2 years ago | (#41868405)

Most PV installations have some space restriction. A collector that harvests more energy per area will produce more watts per $ provided that the cost of manufacture doesn't rise by more than the increase in efficiency. Prototypes don't have that constraint. Moving from prototype to mass production deserves a prize of its own; fortunately the Phonecians invented just such a prize many years ago.

101%? (1)

pbjones (315127) | about 2 years ago | (#41867591)

So if we get past 100%would that create a black hole that sucks in energy for everything around it and ultimately would destroy the earth? Just askin'

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