Silicon Valley Startup Prints $1/watt Solar Panels

GWBasic writes "A Silicon Valley start-up called Nanosolar has shipped its first solar panels — priced at $1 a watt. That's the price at which solar energy gets cheaper than coal. While other companies have been focusing their efforts on increasing the efficiency of solar panels, Nanosolar took a different approach. It focused on manufacturing. 'The company [has developed] a process to print solar cells made out of CIGS, or copper indium gallium selenide, a combination of elements that many companies are pursuing as an alternative to silicon.'" The outfit also happens to be backed by Google, a fact that's getting some attention at tech media sites.

Consumer offerings?

[phrostie (121428)]

i was reading their webpage the other day and they only seemed to sell to large corporations or utilitiy companies. when will they start offering a consumer version.

Re:Consumer offerings?

[Rei (128717)]

Once their production capacity outstrips their manufacturing obligations. As per their website [nanosolar.com], which I've been following (slowly) over the past couple years, you *could* get one right now [ebay.com] off ebay -- their #2 print. However, it's being sold as a collectible item, a piece of history, with the proceeds going to charity. So, needless to say, the price is rather steep ;)

This is huge news. Punch $0.99 a watt into the calculator [daughtersoftiresias.org], and even good chunks of Alaska become economical for installations.

Re:Consumer offerings?

[smilindog2000 (907665)]

This is a huge milestone. However, the summary gets a couple things wrong: First, $1/watt panels aren't "cheaper than coal". Large coal consumers buy 2,000 pounds of coal for $50. Burn that in a crappy Bush-endorsed power station, and utilities can print money at $0.07/KWh. That's why coal is the #1 enemy in the global warming battle - not oil. The $1/watt goal makes solar utility power feasible in areas that currently have excellent sunshine (say southern CA), and expensive fuel (say natural gas). It's a huge step, but not the last step.

The second error in the summary is the current price. The company claims they could sell $1/watt panels, but with 100% of their production for 2008 already purchased, what are the odds they're selling their stuff 4X below market value? Not a chance. The revolution's happening, but it will take a while.

Re:Consumer offerings?

[Rei (128717)]

Yes, it is cheaper than coal power, almost everywhere in the US. You can run the numbers [daughtersoftiresias.org] for yourself. The problem with coal is that once you burn it, it's gone. The problem with traditional solar is that the capital costs are so high, you'll never catch up with the interest. When you cut the capital costs on solar significantly, it wins hands-down.

Re:Consumer offerings?

[smilindog2000 (907665)]

Thanks for the web site. It computes the break-even point for installing solar panels at home, and plugging in $1/watt makes it all work out quite well. I'll have to keep track of this link. However, from what I read, coal is still cheaper to burn for power in utility plants. I read that it costs utilities between $0.01 and $0.02 per KWh to produce when burning coal, even when taking the cost of the plant into account.

Re:Consumer offerings?

[mr_mischief (456295)]

I'm frankly too lazy to do the math right now, but maybe they're counting on installations closer to consumption sites with less delivery loss. The cost of generation in large centralized plants is one thing, but line attenuation and impedance loss are another.

Re:Consumer offerings?

[rcw-home (122017)]

Generation, supposedly, doesn't lose much in very large plants. That would leave distribution, which I assume means local substations and transformers on power poles.

Generation does lose a lot from any heat engine (which is currently a required step for anything that generates electricity by making something hot: coal, oil, nuclear, geothermal, biomass, and natural gas). Wikipedia's combined cycle gas turbine article [wikipedia.org] lists 59% efficiency as state of the art. The theoretical limit is not 100% efficiency - it is the Carnot Limit defined by the ratio of the high and low temperatures (natural gas burns at 1600K, the coldest you'll get the exhaust is 400K, so your absolute max is 75% efficiency).

Mechanical-electrical conversion (hydro, wind) is much more efficient. Electric generators are basically motors, and the large ones are commonly 95% efficient. The Francis turbines in use at hydro plants are upwards of 80% efficient at converting water pressure to rotor power. I don't know what the numbers are like for the wind turbines - probably much worse, since the goal isn't to make the turbine blades stop the air entirely.

Photovoltaic solar generation is the worst of them all. The most expensive cells that they put on space satellites are just over 40% efficient. The more cost-practical silicon-based cells are more like 12% efficient. As a result, a new development in large-scale solar is using a bunch of mirrors to focus the light into heat which can then spin a turbine (which may be 35-40% efficient).

Re:

[DaleGlass (1068434)]

I imagine though that the $1/Watt isn't a $1/Watt in the panel's lifetime, but $1 for a panel that will generate 1 Wh, when used at full capacity.

Assuming a lifetime of 20 years, a $50 panel producing 50Wh will produce 8760 kW at $.005/KWh, assuming it runs at full capacity 24/7. An actual real world figure would be several times worse, but that still comes out looking very good.

Re:Consumer offerings?

[Rei (128717)]

The calculations are a lot more complicated than that. You can check the source for the calculator (linked earlier) to get an idea of all that needs to be taken into account.

The reported wattage of a panel is typically the amount of power it will produce when given 1000W/m^2 of sunlight and with the panel maintaining a constant temperature of 25C. 1000W/m^2 is basically your best-case situation here on the surface -- bright, crystal-clear sky on a summer day with the panel facing straight at the sun. Overall, the panel will average produce far less than its rating, but the exact amount is very complex to determine and depends on where you are and what your setup is like, so panels are rated in standard terms. Beyond that, there's also the "derate factor", which is the losses in your system apart from the panels -- wiring, terminals, etc, but most importantly, the losses in your inverter. 0.77 is a good derate factor. The derate factor drops with age. Panels also produce less power with age, but this effect is often overemphasized.

Secondly, you're confusing watts and watt hours. Watts are a unit of power, while watt hours are a unit of energy (a Joule, another common unit of energy, is a watt second). If your panel is producing 1W, then it's producing 1 Wh every hour -- i.e., 8.8 kWh/year. But if it's simply a panel that's rated for 1W, and isn't on a heliostat, you'll probably get something like 0.5 to 1.5kWh/year, depending on where you are.

Re:

[dgatwood (11270)]

It's $1/Watt, not $1/Watt-hour. $1/watt is $1000/kW divided by... say 8 hours of full sun per day... time 20 years. That will get you the kWhr price, or about 1.7 cents per kWhr, a fifth the price you mention for coal. Of course, you won't always get 8 hours of full sun per day in all locations, so the numbers are highly variable by location and time of year, but if your numbers are correct, that is significantly cheaper than coal in many cases.

Re:Consumer offerings?

[bodrell (665409)]

This is a huge milestone. However, the summary gets a couple things wrong: First, $1/watt panels aren't "cheaper than coal". Large coal consumers buy 2,000 pounds of coal for $50. Burn that in a crappy Bush-endorsed power station, and utilities can print money at $0.07/KWh.

You can't compare watts to kWh. They aren't the same units. But I went ahead and did the math for you.

1 kWh = 3.61 x 10^6 J
$0.07/kWh = 14.3 kWh/$ = 51.6 x 10^6 J/$
solar panel = $1/W = $1/(J/s)
3600 s/h, 24 h/d, 365 d/year --> 31.5 x 10^6 s
51.6 x 10^6 (J/$) / 31.5 x 10^6 (J/year/$) --> 1.64 years (producing at full capacity) makes it cheaper than coal. Even if you only run at 25% capacity on average, taking into account varying daily solar intensity, the investment pays for itself in 6.5 years.

Of course, your other points are valid; burning coal is bad, at least using the current technology. And that $1/W number is still theoretical, so if they're selling at $4/W, then it would take 26 years to be as cost-effective as coal (given constant energy costs; but that time would be much shorter if we have an energy crunch and prices spike--or another Enron-style price-gouging scam, for that matter).

Re:Consumer offerings?

[flaming-opus (8186)]

You're forgetting two very important things. In your math you're forgetting to amortize your capital costs. Basically you're assuming that you can get a 0% loan. In reality, paying for solar up-front, instead of coal as you need it, you need to tripple the cost of the solar, because of the interest you will have to pay over the 25-year life of that "loan".

Secondly, solar provides great energy during the middle of the day. However, most residential electrical demand happens in the early evening, when people get home from work and turn everything on. Most industrial users of electricity need a constant supply, around the clock. Commercial users need electricity throughout the day, with a spike in the late afternoon as air conditioning demand increases. Solar-electricity provides for some, but not all of these needs. Storing solar energy in batteries, thermal storage systems, or mechanical storage systems doubles or tripples the cost again.

Thus, even with $1/W panels, general-purpose solar power is still 8-10X the cost of coal. I'm terribly doubtful that solar power will ever be economically competitive with coal, UNLESS you factor in the ecological costs. Unless we start taxing utilities for the carbon that they emit, we will not see solar become competitive, beyond little feel-good projects, and home-hobbyists.

Re:Consumer offerings?

[kestasjk (933987)]

It's tricky to convert between watts and kWh, they sound the same but one is a unit of power and one is a unit of energy. Power is energy per second, so it's like comparing the cost of a gallon of water with the cost of a spring.

A kWh is like a glass of water, and a watt is like a trickle of water from a leaky tap. A 1 watt panel would take 1000 hours to make one kWh.
If a panel lasts 1000 hours then you're paying $1/kWh, which doesn't compete with $0.07/kWh. If it lasts forever you're basically paying $0/kWh in the long run, so you might as well buy ~10^12 panels and forget about energy problems.
This is why hydroelectric power is appealing: Once built they stay there generating power for only the cost of maintenance, the problem is there are only so many places where a dam can be built.

In a nutshell more info is needed to know if this even counts as progress. What about the materials? Can you get lots of whatever semiconductor they're using cheaply? Does the $1/Watt panel become $1/ 0.01 Watts when it's not facing directly at the sun on a bright day in California?

I'm not looking for any "revolution" from a small start up energy company.


By the way this is an area where nuclear power could become an even better alternative: The big cost of nuclear power is building the plant and decommissioning it afterwards, the uranium is dirt cheap. The price of a kWh from a nuclear plant is made up mostly of the price of building and decommissioning the plant. If a nuclear plant's design can be made so the life is doubled the cost will halve. If a plant that lasts as long as a hydroelectric plant could be designed we could have power too cheap to meter.

Re:Consumer offerings?

[Rei (128717)]

Actually, you'd be surprised. They have a patent on their *specific* process, but they don't have a patent on CIGS cells in general, and there are quite a few companies pursuing them. I doubt anyone will be able to hit Nanosolar's price point because not only is Nanosolar ahead in terms of commercialization, but I think their tech is the most promising CIGS cell tech. Even still, the competitors should be able to at least approach Nanosolar's prices, and -- here's the big deal -- since it'd be a decade at best before Nanosolar could sate the market's demand enough to lower prices to that $1/W level, its competitors production should help the prices fall faster.

Re:Consumer offerings?

[AmericanInKiev (453362)]

I think you'll find that Clinto's administration was headed towards tighten restrictions on coal plants. There were reasonable, scheduled improvements. Bush took us off the path to improvement, so basically yes - this is all Bush's fault. remember, a stronger presidency means more blame. Clinton shared power, and thus responsibility.
AIK

Yahoo!

[by Anonymous Coward]

I don't really know whether global warming is real and dangerous. Now just maybe I don't have to care.

Can we conver Arizona with these (and use ultracapacitors for night power)? Please?

Re:Yahoo!

[explosivejared (1186049)]

You sir are a genius. No really I mean it. I wish there were more people like you that put the ad nauseum hashed debate about warming or climate change or whatever to the side. There is a legitimate argument for a lot of different viewpoints about the climate. The area where there is no room for different viewpoints is on the limited nature of fossil energy resources. Whether or not you buy into anthropogenic climate change or not, you should support more efficient non-fossil fuel energy sources. Diversity is the key. For two long we've all of our eggs in one basket, and it hasn't been until recently that we've realized that come back and bite us. Cheap solar like this could go a long way to broadening available energy as we start to see the real issue with energy arise, namely how do we support a rapidly industrializing third world and a world population that will reach nine billion in fifty years. Quantity is a real problem. We've built our economies on cheap energy, and now we're gonna have to work to keep that going.

Re:Yahoo!

[Rei (128717)]

Quite a few problems with that. :)

For one, I can't picture production capacity catching up with demand enough to lower prices to that level for at least a decade, and even that would take a trenemdous expansion rate. There's no way Nanosolar is going to *sell* at $0.99/W when the current market price if $5.80/W and they don't have enough production capacity to meet supply. They stated that they can *turn a profit* selling at $0.99/W. They'll sell for $5.70/W, $5.60/W, or whatnot -- whatever's the most they can charge and move all their capacity. They're not idiots. They're going to earn every last dollar they can, and pump it into new production facilities. Only as the market becomes saturated will prices drop.

Secondly, global warming is going to happen even if all killed ourselves today. There's too much inertia behind the problem. What we effect today is what things are going to be like in 2050, 2100, not the next decade or two.

Third, this doesn't address vehicles. Still have to take care of that gorilla in the corner. It also doesn't address industry CO2 pollution unrelated to power demand, such as steel production. Still, it's a great start.

Fourth, you don't need to cover a big expanse of desert at all. There's more than enough rooftop space in the world to meet demand. Example: China has 32521 square kilometers [peopledaily.com.cn] of urban area. Assuming 11% efficiency on these cells and 25% of that urban area being able to be coated in cells, and assuming an average insolation of 200W/m^2, we get a total power production of about 180 terrawatts. Current *world* demand is only 10 terrawatts. See where I'm going with this?

Fifth, ultracapacitors are too expensive for power storage currently. We're still going to need baseload power production until a cheaper method of storing power can be found. One concept that I find interesting relates to electric cars. To charge a car quickly in your garage, you're going to need a home charging unit. Your house just can't deliver power nearly fast enough for a five to ten minute charge. The idea I read is to use those for power balancing: have them charge themselves when there's a glut of electricity and discharge into the grid when there's a shortage. In exchange, utilities would give consumers a significant discount on their power bill.

Re:Yahoo!

[Rei (128717)]

You're right. All of the world's climate scientists are idiots, and didn't figure out this obvious thing which you did. Right? Because that's the implications of what you're saying: you think essentially all of the world's climate scientists are complete and utter idiots.

Of course, what you said is completely untrue [realclimate.org], but hey, who cares? Like most anti-global warming arguments, they sound good to someone who knows absolutely nothing about the subject.

What's in your stocking?

[by Anonymous Coward]

Of course coal also works at night.

Re:What's in your stocking?

[sm62704 (957197)]

So do rechargeable batteries.

This makes me think once again that the 20th century was an abberation.

Before the 20th century if you wanted to know what time it was you pulled a clock out of your pocket. In the 20th century you looked at the clock on your wrist. After the 20th century you pulled your phone out of your pocket.

Before the 20th century musicians made their money by performing. During the 20th century many musicians made their money by recording music. After the advent of the internet musicians will once again make their money by performing and use their recordings as advertising (as everybody but the RIAA bands do now).

Before the 20th century there were few wires. During the 20th century wires were everywhere - strung from poles, on your phone, TV, computer eqiopment, everything that used electrity. After the 20th century everything is wireless.

-mcgrew

Re:

[Slugster (635830)]

This is true.

There's only three problems with solar power installations: the cost of solar cells, the cost of inverters, and the cost of storage batteries.

Solar cells without storage batteries is only helpful for things that you only need to run during peak daylight hours--or if you live in an area that doesn't have enough power capability for peak-load use times (such as California, with its regular rolling blackouts in certain areas during the summer).

The huge costs of residential whole-house sola

Re:

[Red Flayer (890720)]

I think we'll see studies as soon as we have the capacity for economically feasible distributed energy production (such as the solar cells mentioned here ramped up in scale). I think feasibility studies will be happening in the next fifty years. Decentralized power production is really what the power companies fear.

Eventually.

[xlsior (524145)]

From the article: Roscheisen said the manufacturing process the company has developed will enable it to eventually deliver solar electricity for less than a dollar per watt

Hopefully this will just be the start...

[tinrobot (314936)]

Once they get their manufacturing up to speed, prices will most likely get even lower.

Too bad they're already sold out for the first 18 months of production, because at those prices, you could make a typical house solar for about $1500-2000 for the panels, plus another few grand for installation and hookup. At that price, it makes a lot of sense.

Re:Hopefully this will just be the start...

[Rei (128717)]

How do you explain the cooling trend in the 70s? You guys are the same tossers who were out there in the 70s claiming the Ice Age was coming,

Not [realclimate.org] really [realclimate.org].

the same alarmists who were warning that everyone would soon burn up because of the ozone hole (which is now smaller, but the hole has always been there) in the 80s

Not [realclimate.org] really [realclimate.org].

But, hey:

Don't try to educate me on the science

Finding the sand comfortable around your head, eh?

Inaccurate summary

[Chainsaw Karate (869210)]

From the article: "Roscheisen said the manufacturing process the company has developed will enable it to eventually deliver solar electricity for less than a dollar per watt"

Nowhere in the article does it mention the price of the first run of panels. I'd imagine they are much more expensive than $1/watt.

Units Please! What's the cost per watt hour

[Overzeetop (214511)]

It's not just the cost of the panel that matters, but the anticipated life of the panel. Traditionally, it has taken more energy to make a panel than that panel will return to the grid. That's not as big a deal if you're truly off grid - say in the boonies, or in space - but it matters if you want to make it viable in a business sense. And it can't just be equal, it's got to be a significantly low fraction. Otherwise you're creating an energy storage medium (and a very limited one in the case of a solar panel) instead of a power generator.

Re:Units Please! What's the cost per watt hour

[Alioth (221270)]

The current generation solar panels have an energy payback time of 6 years in the real world, and typically last for at least 25 years.

Presumably, what makes this technology potentially less expensive is it requires less resources to make than silicon solar cells, so it's fairly likely that they have a faster energy payback than silicon cells.

Re:

[matt_martin (159394)]

For sure, usable life is an important part of the cost/benefit and energy balance calculation.

However, I've seen energy payback quoted anywhere from 1-3 years for conventional silicon photo-voltaic solar panels including the glass and metal packaging. As they are supposed to have a life > 20 years I'm not sure your second statement is correct. Do you have a source ?

Re:

[blind biker (1066130)]

Traditionally, it has taken more energy to make a panel than that panel will return to the grid.

That's actually incorrect. The average till a couple of years ago used to be 1:4, that is, the total production energy was about 1/4 of the energy the panels would generate in their lifetime.

But I guess mods can't be bothered to check facts.

Re:

[steveha (103154)]

Traditionally, it has taken more energy to make a panel than that panel will return

However, that is no longer the case. I quote Wikipedia:

In the 1990s, when silicon cells were twice as thick, efficiencies 30% lower than today and lifetimes shorter, it may well have cost more energy to make a cell than it could generate in a lifetime. The energy payback time of a modern photovoltaic module is anywhere from 1 to 20 years (usually under five)[12] depending on the type and where it is used (see net energy gain

Indium

[RikF (864471)]

This stuff is already hard to come by. We won't all be covering our houses in this stuff!

Re:

[Bryansix (761547)]

"It is estimated that, at current consumption rates, there is only 13 years' supply of indium left."

This according to New Scientist which is quoted in the Wikipedia Article [wikipedia.org] on Indium.

Consumer use?

[Dan East (318230)]

Since they are focusing on cheap manufacturing instead of light conversion efficiency, these things may not produce much output per unit of area.

So it may be one of those scenarios where you would have to cover your entire roof, as well as those of your two nearest neighbors, to generate enough power for a single house. In other words, they may be intending this for use in solar farms out in rural areas, where real-estate is not a concern.

Dan East

Some calculations

[SamP2 (1097897)]

In hotter climates people use solar roofings already, especially for electric water boilers. But with sufficiently cheap and available coating, people could make entire roofs covered with solar panels. You'd also of course have to think about things like durability and waterproofing.

(Up front, I apologize to all the yanks for being an insensitive clod that doesn't use imperial measurements).

Earth's surface is absorbing ~90 petawatts of electricity any give time (Wikipedia), and with 510 million square kilometers of surface area, an incredibly rough generalized calculation says that each square meter absorbs 175 watts (this is a 24-hour average, even though obviously it's all absorbed during daytime). Of course, not all or even most of it can be converted to electricity, but still, that's a huge resource tap. I'd estimate an average home to have a roof surface area of about 50 square meters, which means that on average the sun sends 8kW on your roof. Next, the average American household uses 8900 kWh/year, which produces, again, an average usage of about 1 kilowatt per household. If you tile your entire roof with solar panels, you'd need to be able to convert 12% of heat/light energy to electricity in order to be fully self-sufficient.

An extra bonus is that the more you absorb the sun's energy as electricity, the less of it is converted to heat which dissipates around the planet, and that in and of itself reduces the effect global warming. So you are being twice as productive - not rely on heat-trapping coal, and reduce the amount of heat that saturates on the planet in the first place.

Of course, this would have to be done on a truly massive scale to have any effect, but every bit helps, and if the industry can make it profitable to the consumer (and of course overcome the interests of evil megalomaniac neofascistliberal Big Oil corporations, as any /. troll will point out), it'll grow on its own.

Re:

[ZorinLynx (31751)]

>the less of it is converted to heat which dissipates around the planet, and that in and of itself reduces the effect global warming.

Allow me to teach you about the laws of thermodynamics.

You may be converting the sunlight into electricity instead of heat directly, but unfortunately when that electricity is used, it eventually will become heat.

It doesn't matter what you use the power for. Run a fan? The moving air will eventually slow down via friction and turn into heat. Run a light bulb? The light is e

CdTe vs CIGS

[savuporo (658486)]

Anyone followed First Solar ( FSLR ) IPO ?
They were the first to bring CdTe cells to market, and guess what happened [google.com] ..

Now, several companies have been working furiously to get the competing CIGS cells going. Miasole, Nanosolar, HelioVolt, just to name a few. FSLR of course beat them to market, and is already a winner, but i am waiting for IPOs for the CIGS companies too ..
Anything that doesnt use crystalline silicon is going to be huge, and in some instances, already is.

Honda

[Ogive17 (691899)]

Honda has been develloping CIGS technology for a few years now. I believe they are already selling these type of solar panels in Japan. http://world.honda.com/news/2005/c051219.html [honda.com]

Corrections

[abramsh (102178)]

• They are not selling at $1/watt, that is their goal. They would be selling at $2.12/watt, but they are sold out for the next 18 months.
  
• They are not backed by Google, they are partially backed by some of the Google founders.
  

Watt, Watt Hour?

[WPIDalamar (122110)]

I'm confused by the $1 per watt and "cheaper than coal"...

Please correct me if I'm wrong here, but I thought a watt was a measure of capacity whereas a watt-hour was what we actually paid for from our electric company as a measure of (what? power? energy?)... So a watt-hour is something like "continuously using one watt for one hour".

For solar, there's no fuel cost. So the $1 gets you a "perpetual" 1 watt. If it lasted forever (which it won't), that'd be an infinite amount of watt-hours.

But coal plants have a fuel cost. So $1 only gets them so much coal, and only so many watt-hours.

Or is that comparing the cost of building a coal plant to building solar panels? Or is it some kind of TCO figure?

Re:How practical

[tinrobot (314936)]

They have a 25 year warranty, so hopefully they'll last at least that long.

They are printed on aluminum instead of glass so yes, they are flexible.

Are they fire resistant? Toxic when burning?

[AHumbleOpinion (546848)]

Will they last, are they durable, is it flexible or rigid? Lot of questions left to answer on the solar front. However, if I can shingle my roof with these things, all the better!

If you are going to shingle your roof then "are they fire resistant" and "do they release toxic fumes when burning" should be two more explicit first questions.

Re:

[rucs_hack (784150)]

sooo.

I can has my tin foil hat and be environmentally friendly at the same time?

Re:Seems good.

[Rei (128717)]

It is a rather safe formulation. That's one of the reasons why it's more popular among new companies than cadmium telluride cells.

Nobody can "put their money where their mouth is" and "snatch these up", because all of their capacity is currently being eaten up by a 1MW german PV installation. And, one correction to the article: they're not being sold for $0.99. The company has stated that they can turn a profit on them selling them at $0.99. But as long as there's a glut of demand and shortage of cells, it seems unlikely that they'll hit that price. What it *does* mean is that Nanosolar never has to worry about money again. Venture capitalists will be throwing money at them if only Nanosolar lets them. They'll have no problem scaling up production; we just need to be patient.

Re:

[Tiroth (95112)]

You were right the first time: 220V * 100A = 22000W = $22000 @ $1/W.

Of course, most designs would require a much smaller up-front investment, because you'll run off the grid when you are using the dryer/stove/ironing/AC, but take advantage of cheaper power for the base load (lights, computer, fridge).

Re:DOH!

[ivan256 (17499)]

You have to clear the snow off of it, it only works when the sun is out so you need a crap-load of batteries or $15-20k worth of automated switching equipment which allows you to be simultaneously connected to the grid without electrocuting the lineman who is working on your pole and thinks the power is off, you probably need to multiply your number by at least 4, because you need to generate power for the 75% of the time you're not getting good sun in the 25% of the time that you are, and you need some pricey inverters if you want to run devices designed for 110V AC...

Additionally, they're not actually $1/watt. That's the theoretical cost if they are able to ramp up production as planned. If you had $1 for every startup that failed in that phase, you wouldn't care how much your solar panels cost.

Re:

[hypnagogue (700024)]

So I could power my whole house for a one time investment of less than $2k? Sounds too good to be true. What's the catch?

Depends on what your expectations are. Were you planning on actually having power during the other 20 hours of the day? If so, then you'll need to have a very large battery array, and about 6 times the solar capacity you've calculated in order to fully charge the batteries during the relatively brief peak hours. Add in a massive charge controller and inverter, and you are pretty clos

Re:Cost per watt is based on what time frame?

[DragonWriter (970822)]

When companies report that their solar solution costs $X a watt, is this figure a steady watt/hour figure (e.g 1000W = 1kw/h) during which time the sun is shining on the pannels, or watts generated per hour of direct sunlight, 8 hrs of direct sunlight, every odd Tuesday, what?

Watt is a unit of power, not energy. So its watts (presumably, in some specified lighting conditions), not "watt/hour".

I always assumed it's a steady watt/hour figure but in this case $1000 would give you 1KWH while they were running, which gives you (assuming you have a battery storage solution) a production of 180KW/H a month (assuming 6hrs of "good" sunlight a day for 30 days.)

Assuming it was average output per 6 hours of usable time a day (which its probably not, its more likely the peak at the best conditions), and presuming also that surface area limits are not an issue (which they may well be), and that $1/watt was the current cost, rather than an estimate of what the technology would eventually provide, yes, $1000 would get you panels that would produce ~$180 kW-h (not kW/h) per month.

Re:

[giafly (926567)]

Even if you covered the whole earth with solar panels, it would not supply the power that is currently used.

Yes it would, 1000 times over. There is plenty of renewable energy, the issue is cost, which is where these cells come in. "The total solar energy available to the earth is approximately 3850 zettajoules (ZJ) per year ... Worldwide energy consumption was 0.471 ZJ in 2004." - Solar Energy [wikipedia.org]