I am reading articles that accuse battery powered cars of front loading emissions in their manufacture. Somehow that sounds wrong. Any experts that can clarify how this argument is just in error?
@kalikgod - Not sure the extent to which Natural Gas pricing is based on local markets. I was a petrochem design engineer in a past life and there are plenty of LNG ships transporting NatGas around the world to/from different markets.
That is not my industry, but my understanding is that the LNG infrastructure can't handle the current supply/demand imbalance right now. I have heard there is a lot under construction, but it is not a cheap or quick endeavor. Last I heard the prices for Nat Gas was US $3 MMBtu, EU $8, and Asia $14. The imbalance wouldn't be there if there was plenty of LNG transport available.
I grew up within 7 miles of a nuke plant, so I am not a pessimist on the safety. It employed a lot of my friends parents. It was built 15 ft above sea level on a barrier island in a prime hurricane zone :-0. 40+ years old and it has be hit by two hurricanes with no issues, but if it did go bad, man what a mess. Radiation would be pumped right up the east coast via the gulf stream.
Kalikgod, government restrictions inthe form of permits and regulations are the serious things stoping LNG from the US. American corporations are going to China to help them develop fracking so they can become net exporters
most of your statements about wind and solar are inaccurate, in practice. A good e.g. is the offshore wind (massive) being built in the North Sea/Channel by Germany. Few live nearby, and the main demand is almost at the opposite diagonal corner of the country. Neither the inbetween states nor terminus states are interested in paying for or hosting the huge transmission corridors needed, so they are not built, or approved or planned. A true clusterf***.
Oxygen deprivation is not the same as breathing high CO2 levels. Get a grip.
"Forests in North America are larger than when the Pilgrims arrived. "
Outright falsehood. Yeah, there was a large area cleared for agriculture by the Iroquois and similar groups, but it doesn't compare to the amount cleared for housing + agriculture now. (There was an intervening period with fewer forests.)
As for nuclear, Chernobyl & Fukushima. We can't afford to lose lots of farmland and we can't afford to eat food with increasing amounts of radioactive heavy metal contaminants.
But it's impossible to discuss with people who make outright false claims of fact, or who blithely dismiss the problem of high-level radioactive waste with "there's plenty of room". Those two attitudes are, in technical terms, *unsustainable*.
Kalikgod makes a nice summary of the current situation.
A few comments about the near future, the next 10 years: (1) solar will continue to get cheaper and more efficient (I have inside information); (2) solar will work at night if the 'battery problem' is solved, and a solution for it is already on the drawing boards (yes, I still have inside information); (3) grid instability has been solved and the solution will be published in a few months (yes, still inside information)
I don't expect anyone to believe me. I just hope when it all happens the people who dismissed solar power as the universal solution will step back and go "hey, maybe I didn't know what the hell I was talking about and should be more humble in future".
Are we really still discussing this? John Peterson is a troll. As the saying goes... "Don't feed the trolls". I don't mind replying to John and his minions crap on Seeking Alpha... non-sense has to be countered but this is beneath a TM forum. Please stop feeding the trolls.
Chernobyl and Fukushima shouldn't be mentioned in the same breath. Chernobyl was caused easily preventable human error, probably negligent malfeasance. Fukushima was a tidal wave of unprecedented proportions. F.'s fatalities were all tidal. As for secondary nuclear contamination, none of it is dangerous except by illegitimate extrapolation of the LND (linear non-lethal dose) model which ignores threshold effects (e.g. the hormesis studies, showing benefits to the immune system's function from low to moderate exposure).
Both plants were designed about a half-century ago. As scare-monsters, they're getting very long in the tooth. But political BS-shooters love them.
I'd beg to differ on the Fukushima disaster being seperate from human error. Had the plant not gone into full shutdown but maintained enough energy to maintain it's cooling needs, meltdown would be less likley. When the eartquake hit, the reacors went into full shutdown. When the tsunami hit, the generators placed in the basement were submerged.
Classic case of a series of small design issues, (like not placing the generators on higher ground), that normaly would not be catastrophic, leading to a disaster.
I thought my post was already too long to get into the transmission issues. There are significant project underway west of the Mississippi that will tie up the biggest load centers. The East coast is a little different right now, but that is a political more than technical problem. The costs really aren't that big of a deal either, ends up being about .003 per kWh.
ERCOT is an excellent example of successful wind integration. About 8.5% wind last year and likely to break the 10% mark this year. And that is in one of the most energy hungry markets in the country.
Let's not mix offshore wind into this, it makes no sense in the US, there is plenty of onshore resource. Nobody in the US is willing to pay 25 cents per kWh like EU. You can point the offshore wind push directly back to the political issues.
Just because this thread started as a result of a Peterson article doesn't mean we can't have a good discussion about related topics. We're pretty much not talking about him or his article anymore.
Human error (or, at least, a bad assessment of seismic risks) did indeed contribute to the Fukushima plant incident. But neither that, nor Chernobyl, nor any other anecdote proves that nuclear plants can't be designed and operated safely. Only that some have not been.
The fact is that there are a vast number of places where spent fuel could be stored which would meet any rational requirements for safety of the public. The problem is that public fear makes the requirements irrational and impossible to meet.
And I've never said that any of the problems with wind, solar, etc. that I've pointed out can't ever be overcome. I'm always open to the possibility that I could be wrong, as well as the fact that the state of technology is ever-changing. In fact, I've learned some stuff on this forum that leaves me more open to solar/wind than I was before.
If you're saying it's "impossible to discuss" the issue with anyone who disagrees with you, maybe you're actually looking for an echo chamber rather than a discussion. But in my experience there is not a whole lot of opportunity for learning in environments where everyone just reinforces everyone else's beliefs. Dissent can be annoying, but a complete absence of dissent is usually bad.
@tesla.mrspaghet... I don't agree that there is anywhere acceptable to store nuclear waste. It needs to be contained for thousands of years, and not leak. Even synrock isn't good enough.
That is why most of the waste is still at the plant that created it.
The closest to acceptable was in Sweden, but even there they had to revise the standard when they discovered that there were cracks I the rocks that were supposed to be solid.
Remember that the pyramids were built about 5000 years old. You are talking about keeping dangerous waste contained for much longer.
You are confirming my point that those opposed to nuclear power cannot be satisfied no matter what steps are taken. In my opinion you are being completely unreasonable.
"Oxygen deprivation is not the same as breathing high CO2 levels."
High CO2 levels are still detrimental to your health, even deadly. The CO2 concentration in the blood stream regulates breathing, among other things.
Remember Apollo 13? Plenty of O2, but too much CO2 in the cabin, astronauts getting dizzy, CO2 scrubbing needed to be jury rigged.
The plants scrub the CO2 from Earth's atmosphere. With a lot of the rainforest cleared, and a lot of human-made CO2 emissions, we are bound to become a global Apollo 13. How do we jury-rig this?
@Brian H, I closely follow LPP and focus fusion, after learning about them from you. Their advances are promising, although some of their collaborations are miffing, at the least?
@tesla.mrspaghet.. I'm wiling to look at any new technology that can make storage of highly dangerous radioactive materials safe for thousands of years. The closest that I've seen is synrock, - which seals the waste to try and stop it leaching out of the containers over time.
Unfortunately there is the additional problem of where to put it. It has to be geologically stable, able to be secured and monitored continuously for both leaks and break-ins.
The overall cost of doing this - effectively for ever - should also be factored into the cost for Nuclear power. Currently this cost is conveniently avoided - as is the cost of decommissioning the old power stations.
The potential for 'unlimited' power from Nuclear (fission) looked great 50 years ago, but now you'd have to wonder if its worth the future investment considering the developing alternatives and hidden costs.
As for safety, a single accident can wipe out any cost advantage that Nuclear appears to have. I wonder how much the 80km radius of land around every potential power station is worth, considering an accident can make it uninhabitable for decades or centuries. The damage to the Japanese economy is enormous, including the food production from a huge area.
I'd rather see development in the storage of electricity - better batteries in effect - as this makes intermittent renewable supply much more reliable. It would also have the benefit of making our portable technology (laptops, cars, phones etc) much more useful.
10 years ago an electric car with 85kWh costing $80k was unthinkable. With battery technology improving at even 7% p.a. an 85kWh battery becomes 167kWh in 10 years.
Nuclear "waste" is ultimately unused fuel. Numerous designs exist to use it, virtually completely. If anyone gets around to building truly modern reactors, the world's "waste" becomes a valuable resource.
Note the % of air symptom-diagram. You have to get up to 3% (30,000 ppm) before you see anything beyond some dizziness (80-100x current atmospheric levels. Burning every gram of known fossil fuels would barely double them.) A "global Apollo 13" is such a ridiculous scare-mongering comparison I will spare you my opinion of it.
About focus fusion, not sure what you mean by "miffing"...?? ;) They are pushing the limits of switching and plasma tech in some areas, and are having to hand-rig innovations, plus push machinist and supplier shops to their limits. A side-benefit is that they are filing patents on many of their "secondary" advances. Progress would be much faster with even a reasonable trickle of research funding, though. Far less promising projects are rolling in it, by comparison.
Got to weigh in here, thorium LFTR are probably the most promising for us in the medium term not a panacea by any stretch but appears very promising. I must confess it is my second obscene after Tesla of course.http://www.thoriumenergyalliance.com/
I think you meant to write "obsession" - at least, I hope so! Lol
Glad you're keeping an open mind. You are correct that fission power has hidden costs, as does every other method of power generation. The hidden costs of all the others may just be more hidden, not necessarily less costly.
Anyway, it would be great if our previous poster who claimed to have inside knowledge were correct, and we could soon have a source of abundant power with no pollution at a price that compares well with fossil fuels. I'll believe it when I see it though.
@Brian H - as many of your opinions are commendable, you are wrong (or manipulative) here:
"As the concentration of carbon dioxide in the air approaches 1,000 parts per million, some classic symptoms of CO2 poisoning begin to occur."
That is 0.1%.
On Focus Fusion: I agree, they advance and have good results despite poor funding. They even rely on donated equipment! I have high hopes. What I was referring to is their collaboration with an Iranian Islamic university... that one left me miffed...?
If the device/generator works, the install and output will be well below 1/10 of current costs (pre-taxes, etc.) . Not "portable and pourable", of course, but "distributed and dispatchable", which is almost as good. ;)
Here in Seattle, solar doesn't work so well. On the other hand, most new residential construction incorporates downspout turbines. We do get a lot of flack from animal rights advocates, however, because they tend to be hard on small animals.
@ Brian: "Nuclear "waste" is ultimately unused fuel. Numerous designs exist to use it, virtually completely. If anyone gets around to building truly modern reactors, the world's "waste" becomes a valuable resource."
Wrong. *Some* of the waste products from Nuclear Fission can be reprocessed into fuel. *Some* newer designs of reactors produce less waste than others.
However. There is also tons of waste generated in the normal operation, and decommissioning of the plant. Lots of the fission byproducts are not suitable as fuel at all, yet are highly unstable, dangerous substances with half lives in thousands of years.
For those who don't understand, the half life of a radioactive substance means that half of it still exists. The other half has decayed to be something else - most likely also radioactive and dangerous, but not the original substance.
This means that if you start with 1kg of waste with a half life of 10 years (keeping the maths simple as an example), then after 10 years you have 500g of the original substance and 500g of something else which is also dangerous and needs to be stored safely. If the secondary half life is also conveniently 10 years then after 20 years you have 250g of the original substance, 500g of the secondary and 250g of the tertiary substance. **you still have 1kg of dangerous substances that need storage **
Unfortunately, some half lives are in hundreds of thousands of years.
The waste products from nuclear fuel reprocessing (including the safe storage of decommissioned plant) is an enormous, yet often glossed over cost of running the nuclear cycle. Further, reprocessing of spent fuel is generally considered 'not economically viable' when uranium prices are relatively cheap.
The Nuclear industry is very good at avoiding troubling conversations like this and pushing the true costs further and further out - which is why, as I stated previously, the bulk of the waste is still sitting in the cooling ponds at the plant where it was created.
Oh, and the time that it takes to decommission an old plant is decades - it takes that long for things to cool down. Even 'spent' fuel rods need to be constantly cooled to avoid them overheating and being even more dangerous.
Why would you spend billions on this kind of risk when we get around 1kW per square metre of solar energy for free? Covering the roofs of factories and cities with solar panels can produce all of the energy we need, if we could just store it better. Wind, tidal, geothermal and solar thermal offer better alternatives at less risk environmentally and financially than last century technologies like nuclear fission.
Half life is half life. It is constant for given isotope and doesn't change. There is no "secondary half life" unless you are talking about element the original changed to which can have half-life of its own (which can be a lot faster, like milliseconds, or it doesn't have half-life IOW it is stable isotope. Anything between those).
Half-life is purely statistical phenomenon. You can't predict when certain atom changes to something else, but given big enough amount of those atoms you see that this process is quite predictable. It's like throwing a dice, you don't know when you get six, but given trillion throws (with ideal dices) you see that it comes roughly one time in six.
Very long half-life usually means that radiation is very low, and radiation itself might not be all that harmful if the dosage is low.
It also depends which sort of radiation we are talking about, is it alpha and beta radiation are weakest and easiest to contain (also quite short range), neutron, gamma and x-ray are more dangerous.
IMO "radioactive" has come a monster in peoples minds. Fear of unknown. Ordinary household radon (which can be surprisingly high concentration in the air) is way more dangerous than nuclear waste from nuclear power plants unless you practically stand right next to it. http://en.wikipedia.org/wiki/Radon
First of all, many radioactive elements decay to non-radioactive ones. Second, if you're storing it all anyway what's the difference what the particular composition of the waste is after x number of years? It's irrelevant whether the waste is composed of 100% the original waste material or some "other dangerous materials [AAAAHHHH!!!!]" at some point down the road, although I realize it makes for good scary prose.
Why would you spend billions on this kind of risk when we get around 1kW per square metre of solar energy for free?
If it were economically feasible, people would have already done it, don't you think? It's not quite free - people still have to build the solar panels, ship them to their final destination, install them on the roof and wire them up. And then they utilize a relatively small percentage of sunlight to produce relatively little electricity for the resources used to build, ship, install and wire them.
You have a point when you say there are hidden costs to fission, and it's true that advocates of nuclear power tend to gloss over them. But it appears you're doing the same thing.
Why would you spend billions on this kind of risk when we get around 1kW per square metre of solar energy for free?
That's more like 100W/m^2 (20% conversion, half a day you don't get anything at all).
@tesla.m oh my yes "obsession" thank you (last time I try and post using my IPhone;) surprised @Brian H didn't get there first
No inside information about thorium and LFTR, the subject just caught my eye a month or so ago and have been reading about it ever since. Now I will have something to do/read after my Model S finally arrives.
@Timo: Agreed - I use the 10 year figure as an indication of how the process works - not as the real world. Different isotopes decay at different rates. You'd be surprised that many people think that it means that after the half life half of the isotope is now safe - when it often isn't. Alpha radiation is sometimes dismissed as 'safe' as it cannot even penetrate skin. While this is true it's not so safe if you inhale or ingest an alpha radioactive isotope.
Yes the conversion factor is currently around 20%, and they don't operate in darkness. Its a numbers game. In Sydney you get, on average, with today's technology, around 4kWh for each 1kWh of PV installed. That means that to completely power my house I'd need a 6-8kW system and battery storage.
Current panels readily available are 250W in 1.6m2.
@tesla.mrsphaghet... Yes, some elements/isotopes decay into non-radioactive ones, and given long enough they can all be non-radioactive. This may take millennia though.
10 years ago the price for solar PV was dramatically higher than today, the costs are rapidly coming down and the efficiency coming up. The advantage of renewables is that once installed they cost of keeping them going is generally low - current PV recoups the embedded energy (that used to construct it) in around 12-18 months. They then continue to run for 20-25 years.
Once again, I'm not saying that PV is the ultimate solution for everything, just that it makes more sense to invest in technology research that harnesses the enormous energy that is renewable rather than concentrating on technology where you go and dig something up, burn it to create heat for steam to turn a turbine and create electricity. Coal, Gas and Nuclear are all essentially doing the same thing - except that the nuclear combustion process is different.
The subsidies that support the current 'fuel' industries would be better directed into renewable R&D and rollout - including improved battery storage to smooth out the peak and trough generation characteristics and our usage.
"Why would you spend billions on this kind of risk when we get around 1kW per square metre of solar energy for free?
That's more like 100W/m^2 (20% conversion, half a day you don't get anything at all)."
Timo, the average solar insolation in the US is 5kwh/M2/day, Marks 1kwh per square meter of solar panels already took both the day night cycle and the 20% solar efficiency into account, your trying to double account for them.http://www.nrel.gov/gis/solar.html
The natural decay products of waste are not the whole story; the recycling and (e.g.) thorium designs accelerate and alter the decay paths to enhance output.
As far as projecting consequences hundreds, thousands, or hundreds of thousands of years into the future, it is to laugh. Already the science and tech to readily cope with the issues is in sight or in hand, and its users will smile condescendingly at current efforts to "save" them.
What stands between us and thorium reactors generating our electricity and in fact powering our Teslas? Sounds like only politics.
For those of us in Washington State we've had a story this week about one of the Hanford storage tanks leaking.
Don't worry about the water or soil because it's waste from plutonium the consistency of catsup. I guess it pours slow like Heinz. It's apparently escaped the inner tank and is now between the tank and the outer wall. One million galons of radioactive catsup. Those tanks were designed for 20 years. The older ones are 44 years old now. The glassification process ten years ago had already had three failed starts. And back in 2001 they were projecting processing 10% by 2018. At that time 30% of the tanks, some built in 1944 were already leaking. So you pump the stuff from new to old tank and now you still have the waste, but a bunch of contaminated soil, pumps, machinery, and underground tanks to dispose of.
We were spending a couple billion a year on it even 10 years ago. Today? Still no glassification plan working, so we are well out past 2038 for the Hanford cleanup and need a second newer plant built to hit even that target.
It is not to laugh. Science and tech in sight? If you say so. That's great. We've been hearing that for decades with this project and Yucca mountain. Anything get delivered? No.
So, we've had some experience with this since 1944, and the promise of technology on the horizon makes me smile condescending. Seen that movie a few times already.
FYI - I'm pro nuclear.
I'll add a couple more comments here...
As far as comparing the collection of solar energy, the usual measuring stick is to generate enough to power the home under the roof. I don't think this is a good point of reference. Homes only use about 1/3 of all electric power (http://www.eia.gov/energyexplained/index.cfm?page=electricity_use) and are the most energy efficient per square foot compared to commercial and industrial. This is what I mean when I say solar has a difficult time scaling up. You can line a factory roof with solar panels and power it.
Regarding nuclear, it is frustrating that nuclear hasn't proved more successful with the investments that have been made over the last 70 years. The nuclear industry has three $5 billion laboratories dedicated to supporting the industry (shared with weapons). In contrast, wind energy has a federal research budget of a paltry $90 million a year (roughly 1/5 of the solar funding). If there was $15 billion a year in wind energy research, it would be by far the cheapest energy in the world. Take that with a grain of salt though, I am bias ;)
Kalikgod, homes might only use about 1/3 of the power, but coal only generates one third of the US electrical supply as well, therefore even if we could only displace residential power with solar that seems like a pretty good start. The reality is even though a solar array on an industrial roof might not supply all the power needs of whatever industrial activity goes on beneath it can make a hell of a dent, at the same time many industrial processes are particularly suitable for demand response, for example industrial refrigerators can be cycled off during times of low solar output or high grid demand without any noticeable impacts. The combination of diverse renewable sources (wind, solar, tidal, wave etc) diverse geographical distribution of the renewable generating capacity, demand response measures and a bit of storage abolishes all of the issues with renewable intermittency.
I agree distributed renewable generation statistically takes out the variation assuming the grid connections are there and the grid operators will "play nice".
The real issue comes down to cost of energy. You can find my absurdly long post earlier in this thread. Most industrial operations couldn't afford to pay double for the (unsubsidized) solar on their roof compared to just buying grid power. Until renewables are the cheapest forms of energy (which will happen) the ideal scenario we agree on above just can't economically happen.
P.S. if you have time, read the report I linked to in my other post to find out how far away tidal and wave really are. Wind is really close to grid parity (< 5 years), solar is probably not far behind (10 - 15 years), the rest are really non factors for decades.
Mark E used kW, not kWh. 1000kW during full day would give you a lot more than 1kWh. Power vs energy.
...and now I made a mistake. "1000kW 1kW during full day..."
@Timo - yep, I used kW. I know that you don't get all of it, however in Australia solar radiation hitting the ground is close to 1kW per m2. Current panel efficiency is around 20%. My house has 150m2 of roof area. Factories etc are much bigger and often not shaded by trees.
With all of this I'm talking about the potential opportunity to harvest free power - not what we are getting today. In 10 years with some reasonable funding we may either have really cheap solar PV panels or much higher efficiency. I've seen dye based PV solutions that are painted onto metal roofs and even on glass - transparent.
Not very efficient, but dramatically cheaper and work in the shade.
Today's tech gives 4kWh per day for each 1kW of system. If solar panels were cheap enough, then my house alone could generate around 400kWh per day. With a battery to smooth it out - I'd have more power than I'd ever need. That's with 150m2 of PV array - expensive today, but in the future?
Solar can be cheap. There are methods that are basically sprayed in paper in a machine that looks like ink jet printer which give you approx 10% conversion ratio with price that is only slightly higher than paper it was printed on. Other assorted things like wiring, electronics, weatherproofing etc. are what costs in them, not the panel itself.
Using those, giving enough space and good enough place, solar can be cheaper than coal. Only major problem with solar is that it depends on weather and time of the day.
Geothermal could provide to be the best solution for "green" energy unless fusion breakthrough comes soon.
Hydro is always good choice if a place allows it.
Ocean waves can be used to generate electricity
Obviously nothing prevents using them all.
As I said some time ago in thread similar to this, there is energy everywhere, we just need to tap into it. Rooftop solar & small and silent wind turbine to common household could provide all of its energy need without conserving much. Add in smarter building to conserve energy (passive gravity-based AC, good insulation, heat pumps instead of normal batteries etc.) and there is excess of energy without nuclear/coal/oil/natural gas. If we were just smarter with our energy usage we could manage with a lot less energy production. I think main problem is that people don't do things in long term benefits in mind. It is cheaper to build crappy things which gives result now, but that crappy thing costs you in long term.
Same thing with BEV. Initial cost is higher, but it pays the difference back in long term.
the word is "biased".
And in macro (large economic) applications, it wouldn't matter if the panels were free. Real estate, maintenance, and coping with non-dispatchable power unsuited to base load would make it a net negative, worse than worthless.
In 10 years with some reasonable funding we may either have really cheap solar PV panels or much higher efficiency.
That would be great, but I've been hearing that for decades. I've also read a lot of optimistic articles about various designs for fusion that predicted breakthroughs just around the corner. Eventually I hope the breakthroughs come, but I have learned to ignore predictions and just wait for someone to actually do it.
In the meantime, we have to have power that we can afford. So that's mostly fossil fuel, like it or not.
How much do you pay for electricity? I pay 4 cents per kwh using my residential solar installation(that is the unsubsidized rate, its about 2c per kWh if I count the rebates and incentives). The cheapest I can get it from Southern California Edison is 14 cents per hour. I'm looking at rates around the country and I don't see many actually buying for less that that regardless of whether it is dirty coal or gas. From my experience solar is already at grid parity.
Solar sounds like a great deal to me and a no-brainer. Why not take advantage of it?
Was the installation free? And I realize it may have been at no up-front cost to you, but I assure you someone paid for it. And there were undoubtedly subsidies, tax-breaks/incentives involved.
Solar is not even close to price parity with fossil fuel power when you take all the costs into account (including the ones that don't come directly out of your pocket).
I looked into solar panels for my business in the Midwest. The ROI was about 20 years, even considering the state and federal incentives. I just couldn't justify the cost. Of course the numbers work out better in FL, AZ, etc. but it seems we still need a technological breakthrough to get widespread adoption. If the payback could get down to 5-7 years I would jump on it, and I think many other business owners would also.
This discussion kind of sidetracked a while ago. I am a concerned environmentalist, but I think we should be realistic. I think the frontloading question is valid, however minor. This is the first real car powered by batteries. Can we expect a perfect solution for all things right away? No.
Getting amped, I'd encourage to recheck on solar regularly, depending on when you last looked into it you may be stunned to see the current state of play. In the last 12 months the cost of solar has fallen >50% and about 70% in 18 months, so where paybacks may have been 20 years a few years ago they are now around 7 years.
@reitmanr +1 a.k.a misinformation
So you folks think Elon is full of it when he says "Drive for free, forever, on pure sunlight"?
@Docrob, I have a Sunpower solar array, and I'm not seeing 5 kWh/m^2/day by any stretch. My data:
Area: 21.15 m^2
Days running: 49.5 (small sample size in the autumn, I know)
Total output: 660 kWh
Location: Minneapolis, MN
That gives me 0.63 kWh/m^2/day. Yes, the season and location has something to do with it, but I have a hard time imagining that would account for a factor of 8.
The link you provided was to the national solar resource, which is the amount of sunlight energy. Timo wasn't double counting the efficiency losses. Take into account the 20% efficiency, and we're talking 1 kWh/m^2/day, which is a reasonable result given what I'm personally seeing.