A Solar Grand Plan

The January 2008 issue of Scientific American has an article titled "A Solar Grand Slam" which outlines a plan in which solar power could end U.S. dependence on foreign oil and slash greenhouse gas emissions by 2050. In a massive switch from coal, oil, natural gas and nuclear power plants to solar power plants, the U.S. could supply 69 percent of its electricity and 35 percent of its total energy by 2050. The four key elements of the plan are:

• A vast area of photovoltaic cells would have to be erected in the Southwest. Excess daytime energy would be stored as compressed air in underground caverns to be tapped during nighttime hours.
• Large solar concentrator power plants, with molten salt storage, would be built as well.
• A new direct-current power transmission backbone would deliver solar electricity across the country.
• $420 billion in subsidies from 2011 to 2050 would be required to fund the infrastructure and make it cost-competitive.

The article goes into quite a bit of detail about how the plan would be implemented and financed.

The plan also states that "If wind, biomass and geothermal sources were also developed, renewable energy could provide 100 percent of the nation’s electricity and 90 percent of its energy by 2100."

This comprehensive study is well done and well worth a read.  I disagree on their definition of what is a vast area of photovoltaic cells, which I find reasonable, especially as their estimate of the land required is very conservative compared to other studies.

I also do not see why so much power has to be provided by solar, as other, just as clean sources, could contribute considerable power, especially in the short run.

Unfortunately their study ended before two recent announcements:

1) That Nanosolar producer of thin-film CIGS solar cells, made using nanoparticle ink and roll-printing technology, has begun production of cells that will sell at $0.99 a Watt when their 430. ,000 Mw production facility in CA and a similar facility in Germany are completed. Costs are reduced because, not only by their production technology, but also because their cells and panels are the first ones to have been designed specifically for utility-scale power generation.

and 2) That Ausra which is providing a 177 Mw thermal solar facility for PG&E has begun construction on a 700 Mw production facility which is scheduled to start delivering equipment in April 2008. Ausra claims that It can generate electricity for 10 cents/kWh now and under 8 cents/kWh in 3 yrs (presumably not including storage, which would add another 2 or 3 cents). They claim that all U.S. electric power, day and night, can be generated using a land area smaller than 8,500 sq miles using their equipment.

Comments

[Clee]

Thanks for posting about the Scientific American article.

On the other stuff, I thought it was pointed out that the Nanosolar plant is 430 MW or 430,000 KW capacity.

I was also under the impression that the plant in California produces the PV cells and that the plant in Germany takes the cells from California and fabricates them into panels, and so the plants are not at all similar. But I could be mistaken in my impression.

[eric]

For those who say that this is far to much money to ever consider spending on all of this, we have to date currently spent 480$ billion on the energy policy known as the Iraq war. With no end in sight.

[Cyril R.]

This comprehensive study is well done and well worth a read. I disagree on their definition of what is a vast area of photovoltaic cells, which I find reasonable, especially as their estimate of the land required is very conservative compared to other studies.

Absolutely true. Let's take Ausra as an example: 8,500 square miles. The total US land area is 3,537,438 square miles. So: 8,500/3,537,438 = 0.24% of total US land area. Just a fraction of a percent.

The question we need to ask ourselves is:

For something so vital to modern life, to our economy, to our security, to the protection of our environment (yes!), indeed to the very continued existence of our society, why would we not be willing to allocate 0.24% of our land area to the generation of electricity? And that is assuming 90+% solar thermal but in reality we will have many clean sources.

When one realizes that the required land area is also of such a nature that it has little other economic purposes, and that solar plants do not "annihilate ecosystems" or some such unsupported nonsense, there can not be any rational reason not to do it.

You can see a pie chart of the US landuse by type here. Notice that "Federal land" takes up more than a fifth of total land, many, many times more than the land area required for solar thermal electric generation. The latter would be barely visible in the pie chart.

[PowerPointSamurai]

The biggest problem with that article is that it transitions us to one, single source of energy rather than a diverse set. This means all the energy produced by this system have the same vulnerabilities and shortcomings. The demand for implementing something like this would send materials costs up geometrically. It's easy for a physicist to say something is theoretically possible, it's an entirely different thing for engineers to make it practical and meet that vision.

I know the focus was on solar (for some reason), but I didn't see one word in there about wind power, which already is economically viable (unlike solar). They mentioned "renewable energy" could take 100% of the electricity and 90% of the energy by 2100, but no mention of other viable forms of renewable energy. Oh, and why eliminate nuclear right away (or ever)? Right in the key concepts block, they talk about a "massive switch from coal, oil, natural gas and nuclear plants"... Why? Keeping nuclear would help displace fossil fuel plants even faster. If the argument is "waste", that might be valid if a lot of "waste" didn't already exist. Moreover, that "waste" can be recycled and burned. Terrorism? I would say thousands of square miles of solar panels all in the same area and centralized production of electricity with a few grid trunks running out of it is far more vulnerable that a nuclear plant. One of the virtues of solar is that it can be DISTRIBUTED, and instead literally turned America's deserts into glass. I'd like to see the study redone with the assumption that every building in the Southwest had to replace their roofs with solar arrays--both commercial and residential. Or even a mix of that and "green roofs".

[Cyril R.]

And PV for 6 cents/kWh by 2020? Not as plausible as solar thermal breaking that price barrier even before that.

Cadmium telluride? Well maybe now but nano-silicon and nano-carbon are far more promising materials for PV in the future.

I don't think utility scale PV is a good idea at all. It's power is in distributed markets. If we're going to build a big HVDC network, then using the solar thermal plants for utility generation in good Mojave locations and PV for distributed markets (but grid-tied since we're going to have a HVDC grid anyway we might as well use it for distributed PV too whenever possible), makes more sense to me.

[PowerPointSamurai]

Another thing that annoyed me about the article was the assumption built into their "payoff" block that said "Global tensions eased and military costs lowered". That's not necessarily true. First of all, there is no guarantee that other nations would adopt this system if we did, and China and India's demand growth alone will more than take up our slack. Others around the world will continue to play petro-politics and we will have to be involved because disruption and instability anywhere will ultimately affect all of us.

Let's assume others DO follow us and all of the oil producing states (including Russia, #2 oil producer in the world) suddenly has a loss of income. That could cause massive instability as well.

Finally, water is emerging as the replacement for oil as the resource in conflict. Ironically, the same area this article wants to build massive solar arrays on is at the heart of it in our country, with California sucking the rest of the Southwest dry. It's much worse in many other places in the world.

[PowerPointSamurai]

eric,

As for the war in Iraq being an energy policy, as you stated, do the math. At the most, Iraq provided something like 5% of our imports. If it were about oil, Venezuela would've made a lot more sense. Or better yet, Canada. (our #1 producer)

[Cory D]

Just a quick off-the-top thought for Cyril R: He comments "there can not be any rational reason not to do it." What about this one: How do you protect a crucial infrastructure element covering 8500 square miles from terrorist attack? (These days, this is a very real issue considered with conventional power plants.) How do you distribute and modularize the generating capacity so that if one "module" is taken out, the rest is not affected? Granted, that issue already has to be taken into account with conventional plants (and arguably it is worse there, since a single conventional plant has far higher power-generation "density" - power generated per area of footprint - so a single strike takes out far more capacity). But the image of such a large area having to be protected from sabotage or outright attack makes me a bit nervous. Anyone know if studies on "reliability/robustness of distributed renewable power-generation facilities" has been carried out and published in the public domain? I would suspect not....

[PowerPointSamurai]

Cyril,

Rather than make roadrunners and other desert animals homeless, and cut down all those Saguaro cactus to build these solar arrays, why not look at another significant unused piece of land--buildings. Why not implement this as a distributed project with rooftop solar arrays on all buildings, residential and commercial, over Walmart parking lots, the whole enchilada? Covering parking lots with solar arrays would also make all those shoppers happy on those rainy days, and Walmart could provide charging for their PHEV or electric car (for a nominal fee) while they shop.

THEN they could continue to build some plants out in that so-called waste-land, which many of us actually thinks is quite beautiful as it is.

[aangel]

I love this plan as a start.

Now in revision two they need to factor in:
1) Cyril's and PowerPointSamurai's points re: distributed energy and solar thermal instead of solar cells
2) how to accomplish it while we are dealing with a worldwide oil shock

From the Hirsch report:

"...as peaking is approached, liquid fuel prices and price volatility will increase dramatically, and, without timely mitigation, the economic, social, and political costs will be unprecedented. Viable mitigation options exist on both the supply and demand sides, but to have substantial impact, they must be initiated more than a decade in advance of peaking.”
— Peaking of World Oil Production: Impacts, Mitigation and Risk Management
Department of Energy, 2005

Definitely read the Hirsch report because it is widely considered the first public acknowledgement by the U.S. government of peak oil.
www.inspiringgreenleadership.com/downloads/Hirsch-PeakingOfWorldOilProduction.pdf

Andre'
------------------------------------
Peak Oil, Climate Change and Business
Free, Bi-Weekly Executive Briefing
www.inspiringgreenleadership.com/peak-oil-climate-change-and-business

[Cyril R.]

would say thousands of square miles of solar panels all in the same area and centralized production of electricity with a few grid trunks running out of it is far more vulnerable that a nuclear plant.

You don't know what you're talking about. Even a MOAB won't damage more than one square mile and last I checked terrorists don't have MOAB's. If they do, they would probably throw it at the nuke as they would get more "bang" for the buck as we could say. Nukes are not built to withstand a direct hit from a MOAB or similar massive payload bomb. The solar thermal plants would also be distributed over the best locations in the Mojave.

Transmission vulnerability will not be an issue for this same reason: plants won't be in one location so there will be many transmission lines. Even nukes need transmission lines. What, did you think multiple GW of electric power from a nuke *magically* arrived to your home sockets? The nukes would be even more vulnarable in this regard because of larger unit sizes and because they are concentrated in one location.

That said I agree we should keep all the nukes on-line. In fact upgrade and revise them, eg with thorium capability, and make them safer. That, with regards to realism, I think is even more important than building new ones. I'd rather the subsidy money from the govt that is going to some of the new nukes went to research so we'll have better nuclear technology in the future. Heavily subsidizing new commercial reactors is just silly.

[Cyril R.]

Because they are commercial reactors, to make myself clear.

[Cyril R.]

It may be easier (but still extremely unlikely) for the terrorists to have their own bunker buster type missile and destroy a big reactor. Even the concrete reactor core won't withstand such an attack.

Such a bunker buster wouldn't do much damage in the solar thermal case. Throwing it at the solar field is relatively useless Throwing it at the turbine will only knock one medium sized plant out but it could be rebuilt fairly quickly without long lasting radiotoxic or chemical damage, and with reasonable cost. A reactor meldown however, is going to be a big mess and it will be almost impossible to finance the cleanup.

If you're really worried about terrorist (I'm not) then solar thermal is hard to beat.

[Cyril R.]

Cory D I think I just answered your question as well.

[DaveMart]

I'll reproduce a post I put in SciAm here:
A stand-alone case can be made for taxing toxic emissions from coal, and perhaps from CO2, but if they are viable at all I cannot understand why your proposals need the subsidy.
This chiefly arises from the nature of the solar resource available in the States.
Within the South-West it tracks use very well, and to the extent that it doesn't you have excellent opportunities to gradually expand storage capacity, acquiring expertise as you go.
So you don't even need initially to compete with base load, just peak use..
There is a very large market for this is the first place, and if this cannot become viable without subsidies it is certainly not viable to store the energy for base-load use or transmit it huge distances.
Subsidies also have the effect of encouraging the widespread adoption of inappropriate technologies, for instance perhaps the CAES you suggest would not be best, but hot-water storage might be, so that going firm on the first might lead to missallocation of capital.
It all depends, of course, on how great a delay would be incurred by not subsidising as you suggest.
If we were talking about 50 years, then perhaps a subsidy would be a good idea.
So, if you run the same assumptions on cost reduction as were in your model, how mush do you delay the same reduction in CO2?
Bear in mind that the alternative, perhaps with a charge for emissions, at least of the toxic variety would not involve 'picking winners', and hence would certainly be more optimised.
It is also possible that the total emissions as well as costs over, say 50 years would be less.
To give an example, your assumptions about wind power assume do not take into account proposals for harvesting wind, which if it works at all are likely to have much lower costs than anything current, have a much bigger resource base and is better geographically distributed.
Suppose that Google's efforts bear fruit, by. say, 2025 you might have subsidised a lot of unnecessary transmission lines and solar arrays.
Now I don't know if high altitude wind-power will pan out, but since we are going to get a very substantial roll-put of solar in the South-West anyway, throwing another $420billion or so at it does not seem like a good idea.
So how much do you calculate that the $420 bn you propose would speed things up?

[Cyril R.]

I will tell you now what will likely happen.

The nuclear propagandist are going to pose as concerned citizens, talking about the environmental impact of solar thermal. Like wolfs in sheeps clothing. However they will not provide credible references to support such bold claims. That is because it is a load of bullsh!t.

Then there are the enviro-wackos, arguably even worse. They will also pose as concerned citizens, this time with the hidden agenda of what some would call "enviro-irrationalism" or even "enviro-terrorism". I would give these people the choice of solar thermal plants or coal and natural gas. Rooftop PV is great, but let's not idealize the situation. PV, in it's current form and without reasonable storage, cannot yet readily replace coal, and there is no credible reason that it will in the near term. In the future, yes no doubt, but not now. It's not necessary either, PV can alleviate things like A/C needs which is great. The way it looks now is both PV and solar thermal are going to play their part. Also, not putting all our eggs in one basket would be prudent strategy.

[bigTom]

But we are an ideologically driven people. Subsidy is a four letter word. We'd rather spend trillions in a vain attempt to steal someone elses oil.

Of course distributing the generation makes the most sense. It reduces transmission costs, and reduces variablity. If PV makes it into utility scale generation, unit sizes are likely to be a few MW, and distributed relatively close to the end users. Solar thermal needs larger scale units to be competitive.

[Cyril R.]

Perhaps the biggest technical task of the government would be to provide the right context for alternative energy. That means the right, speedy siting legislation and certification, political backing but also the financing of a big part of the grid expansion costs, so private companies will build them really fast. I think direct subsidies are generally a not the best idea, but I wouldn't mind the govt spending big $ on electrical infrastructure financing together with private companies.

[Cyril R.]

Ausra claims that It can generate electricity for 10 cents/kWh now and under 8 cents/kWh in 3 yrs (presumably not including storage, which would add another 2 or 3 cents).

In the case of Ausra, the opposite would be true - under the condition that their figures roughly work out in reality. In their case, thermal storage actually reduces cost per kWh. This has been explained several times in this thread. Don't you read your own blog's comments Jim? :)

[PowerPointSamurai]

Cyril,

Yes, I do know what I am talking about. A reactor containment building is designed to withstand a hit from a jet. A MOAB (if a terrorist had one) would NOT penetrate the building because it produces a low-impulse, wide area effect. I see your point about the solar array though, but I think you misunderstand what I'm saying. All of that electricity would have to be concentrated at key nodes and transmitted along main grid lines. If we really generated 100% of the US electricity from this single part of the country, it would be easy to knock out the whole country by taking out a few key nodes. Not so if this were distributed and diversified (i.e. a few wave plants along the coast, a few wind farms in the mid-west and other viable areas, etc.). I know nuclear electricity does not magically get to the socket, but those 100+ plants are also distributed widely across the country. If you look at the map from the article, it looks like Arizona would be pretty much the epicenter of our energy system.

As far as the arrays go, forget terrorists, how about vandalism? Solar panels are quite expensive and fragile. This would drive the costs way above the projections here and the only thing I see protecting them is the remoteness from bored miscreants. It's a little tougher for some idiot to mess with a wind turbine, and someone would at least have to have a boat to smack into a wave generator.

I also agree that I would like to see some Thorium nuclear plants, but I would like to see some next-gen plants for recycling the used fuel too.

[Cyril R.]

People like Powerpointsamurai should read the references I've provided about US land use. 0.24% of the US land for solar thermal plants. And that is already excluding water bodies. Even if you think solar thermal plants are ugly, and like the desert it's just 0.24% of US land, which is just a small part of the Mojave. Don't be irrational. There will be plenty of deserts left to look at.

Still think it's a bad idea? OK how do you like coal plants? Better than solar thermal plants? No? How are you going to replace coal plants with current generation rooftop PV? Are you going to pay for the expense of PV kWh's with storage? Or are you just another hypocrite? Maybe you want more nuclear power? No? What then. There are no alternatives left. Or maybe cold fusion :)

Anyone else in need of a reality check?

[Green Assassin Brigade]

I think the article is naive in several aspects.

One they discount the possibility of material shortages without showing any calculations showing there is enough of all the rare earths and such needed. (unless they make big gains in organic dye cells there will be shortages, some short term some sustained)

Two they see the U.S. project in a vacuum that does not need to deal with other countries demanding the same silicon, rare earths, technical expertise. politial tension will not just be over access to oil and water, all strategic materials will soon come into play as seen by China's recent moves to ban exports of certain materials.

While flawed I think the biggest point of this article is to show people it can be done, that we need not be dependant on the status quo for energy.

Getting it through those cement heads in Government that it is feasable, is the first and most important step.

Making a detailed plan showing several kinds of solar thermal, solar electric, geo thermal, wind/wave/current would just confuse the poor ignorant idiots. Enen just as an arguement that it can done makes this is an important study. Whether it should be done this way is irrelevant for now as long as it serves the purpose of focusing attention to the idea we have viable options.

Once there is a understanding something can be done, and gov develops the will to do something it will be much easier for a Geo thermal group as an example to say we can give you 1000MW at 2 cents cheaper than solar. Once the will to act is in place the other options will share in the boom diluting the scale of the solar component and lessening the concentration that is scaring the Terrorphobes.

[PowerPointSamurai]

Cyril,

I was a little bewildered by your last post talking about nuclear propagandists opposing solar thermal. Why would they do that? In concert with other sources it really makes sense. I'm also a little confused why you don't like rooftop PV. Yeah, it's less viable than solar thermal, but it has other virtues, like distributed production and it might get Joe Citizen more aware of his energy footprint if he had the opportunity to make his meter spin backwards. Right now dark-colored roofs do absolutely no good for anyone except the home-owners association and their concern for pretty houses.

[Brian Wang]

100GW (800 billion kwh) of nuclear power for 20% of electricity now

Thermoelectric conversion in 2010-2020 to capture 50% of the heat as electricity. (DOE freedomcar, quantum well and quantum dot 70-90% carnot thermoelectric conversion efficiency). Less efficient thermoelectric currently used for car seat warmers and beer coolers.

50% power up rate using MIT donut shaped fuel and nanoparticles

30 more reactors by 2020-2022. 9 nuclear license applications in the USA in 2007.

Almost 300 GW by 2022 (thermoelectric, new power uprate and the new reactor build from the 2005,2007 energy plan loan guarantees and other incentives.

100-200 more reactors by 2030 (assuming the likely passage of the climate change bill in 2009 to make coal a lot more expensive) (the new reactors would also have the power uprates and the increased thermoelectric efficiency

Get to 500-800GW by 2030.
Thus relatively mundane nuclear power technology can achieve the goal of displacing fossil fuels for electricity 20 years earlier. Nuclear does not have to do it all by itself. More solar, biofuels, geothermal and wind (particularly things like kitegen) can also help displace fossil fuels.

New reactors like Molten salt and uranium hydride can also increase the percentage of uranium and plutonium that is burned. Reducing the amount of existing and future unburned fuel (what is called nuclear waste)

[PowerPointSamurai]

Cyril,

You say it's a small amount of land, but it does not include the road infrastructure, temporary (and permanent) support and living facilities during construction and operation, etc. I've also been out to that area and it's not a pool-table flat idealized landscape either, so your available land shrinks some more.

As for alternatives, I gave you several in previous posts. Nuclear (esp. Thorium and fast-reactors to burn used fuel), wind, rooftop PV, wave, etc. Oh, *AND* solar thermal! So I'm a little confused why you seem to feel the need to get hostile about this.

[BH]

Solar power may perhaps be effective for this situation, but it is obviously rather pricey. However wind power may be a better solution for lessening our dependence on oil. Of all the alternative energy available, wind power is perhaps one of the most practical and effective solutions. Wind power provides clean and consistent energy for those who choose to work with their environment. Not only is wind energy effective, it is affordable too for personal uses. Investing in switching to wind power is one that pays for itself over time due to the lowered energy costs if provides for the user. There is a variety of ways to work with the ecosystem with alternative energy like wind power. Visit www.windpowersavings.com to see how you can help the environment and effective lower energy costs, as well help the environment.

[David]

Making the perfect the enemy of the good is no way to make anything happen. Lets get started!

[Marcus]

DC power transmission lines seems to be a common element for integrating intermittent renewable energy across large areas. The question seems to me to be whether the American government is capable and willing to help organize such a feat together with the states. Could this become an election issue? Can we MAKE it an election issue?

[Paul H.]

This discussion reminds me of a couple of years ago in an emergency teachers meeting that I was called into. Later in the month, the teachers were going to be forced by the administration to have 2 hours of their day taken for some parent/teacher conference. They spent 2 1/2 hours arguing with each other about how they should vote. Do we want to spend the 2 hours?? What!?

When there exists a path to zero emissions for our country, we should take it, even if it is a less than ideal path. But unfortunately, our country will probably still be arguing about which is the most optimized form of energy independence path long after our planet has gone to heck in a hand basket.

[Ike Solem]

As far as distributed vs. centralized solar power generation, it's really not an either-or situation. Household rooftops are great sites for power generation, and that becomes even more feasible with the new solar PV-integrated building materials. Solar thermal plants of various kinds, however, are ideal for large-scale plants in high sunlight regions (The equatorial regions in particular).

Wind turbines are another good intermittent power source - particularly the very large ones. Again, both solar and wind have to be stored and distributed - but you can use an on-demand power source (existing nuclear or biomass plants) at night, and turn it off during the day. There are many technologies for energy storage, ranging from the simple (pumping water up a hill) to the complex (hydrogen fuel cell/electrolyzer systems).

As far as the economics go, solar is economically viable - especially if the artificial government subsidies for fossil fuels are removed. Nuclear, on the other hand, is definitely not. There is the accident potential, the terrorism potential, the waste disposal problem, and the high cost of construction.

For example, for $1 billion you could probably build about ten solar PV manufacturing facilities, or one GW nuclear power plant. Over twenty years (assuming a solar PV production of 50 MW per year per plant) those PV factories would have produced 5 GW of power generation equipment - while the nuclear power plant would need to be refurbished. The only reason anyone is talking about nuclear is because of the $50 billion in nuclear loan guarantees offered by the U.S. government, as well as the nuclear liability indemnity under the Price-Anderson Act.

[Mike]

I would second the comment "making the perfect the enemy of the good"...waiting around for the "right" technology when workable ones are already around is a mistake. If you do not shut your mind to innovation, the newer better products can be added in later revisions to the initial plan.

I thought the SciAm authors were somewhat more favorable to utility scale PV than warranted. I think PV has a promising role to shave peak power and more efficient and cheaper modules are going to do a lot to remove or shave the midday and early afternoon peaks in power usage.

On the other hand, they glossed over some of the difficulties associated with CAES: the fact that you need natural gas or (even more complicatedly) biogas or a synthetic biogas to reheat the air upon re-expansion. CAES ends up being a "supercharger" for a natural gas or biosyngas power plant.

Thermal storage has a great deal more promise than CAES from what I have seen and is carbon neutral. Utility scale CSP requires no revolutions to generate baseline power while PVs with CAES or some new undiscovered cheap mass battery storage do require some major technological advances to be both carbon neutral and firm round-the-clock sources of power.

I think it is recipe for passivity and no progress at all NOT to take steps right now with current technology AND to research newer technology but not PREDICATE plans on a particular innovation.

[Paul F. Dietz]

On the other hand, they glossed over some of the difficulties associated with CAES: the fact that you need natural gas or (even more complicatedly) biogas or a synthetic biogas to reheat the air upon re-expansion. CAES ends up being a "supercharger" for a natural gas or biosyngas power plant.

Perhaps they were assuming the use of an adiabatic CAES system, as the europeans have been studying. Such systems would require little or no additional energy for reheat, since they store and reuse the heat produced during adiabatic compression.

[bigTom]

Mike,Mike,Mike:
very good points.
As per CAES. Only adiabatic CAES will have low energy loss. It sounds like you are familar with nonadiabatic storage, which uses FF to recover the
energy lost as heat in the compression (or storage) process. Of course adiabatic means the temperature of the compressed air must be higher than adiabatic (the amount being given by ratio of pressures, and the gas law), and conductive loses from the storage tank/cavern need to be minimized. So does it look like most proposals for CAES are for nonadiabatic?

[robert anselmi]

Why not set the photovoltaic cells on roof tops? That area is already set aside and for the most part worthless for anything else.

[Carl Hage]

I don't believe the authors intended to exclude other technologies-- it's just a scenario showing centralized solar is a feasable path to solving greenhouse gas and imported fossil energy problems. It's intent seems to be to answer questions specifically about solar technology in the context of our existing centrally managed energy infrastructure-- not to provide a most likely scenario. The latter has already been done-- and the complexity makes it easy to ignore.

Independent of which renewable or distributed generation technology, we will need new transmission and storage inftastructure. We developed the interstate highway as a public works project that yielded great benefit (from most people's perspective). The same can solve the curent chicken-and-egg problem with transmission lines and remote windy areas.

I don't think we have put enough research resources into energy storage. I don't believe the stories of using fuel-cell cars or batteries as grid energy-- if this were true, it would be cheaper for the utilities to build H2 electrolyzers and fuel cells (not practical) or batteries (could become cost effective).

I liked the article and agree with the scenario as being practical and possible, but realistically, desert land will be just a player. Consider the 6% of developed land in the pie chart (that includes roofs and parking lots). When I plug in the correct solar radiation and land use measurements in N. California, covering 50% of commercial and industrial area alone could generate all electric consumption. That would be viable, but unrealistic, since PV power would come from home roofs, commercial industrial roofs, farms, roadsides, and dedicated land in the desert or whatever. And Solar would only be a part of the mix with wind and other technology.

I agree that taxing bad things like pollution and wasteful consumption and giving us refunds is better than taxing work and subsidizing selected technologies. Conservation/efficiency-improvement still has the biggest opportunity to free up energy, yet is left out of the subsidies or cap-and-trade schemes.

[PowerPointSamurai]

Ike,

I don't know where you get your figures for nuclear, but they now produce electricity at 2 cents per kWh. Another flaw with your logic is that while you might build a nice solar plant or two, you totally neglect the energy costs of running that plant, refining the silicon, the toxic waste disposal, etc. Your implication about nuclear plant maintenance is also off the mark, because they really only need to be off-line periodically for refueling, and the "overhauls" are years (nearly decades) in between. The "loan-guarantees" you mention have far more to do with the ridiculous licensing fees and process, and the up-front capital costs of building a nuclear plant (vs. RUNNING a nuclear plant). I wouldn't get too cocky about those loans, because that's almost exactly the situation most renewables are in as well--high up-front costs with virtually free running costs. People are talking nuclear not because of loan guarantees, but because it makes economic sense, and because of the emissions savings. As far as terrorism is concerned, please tell me you are not serious. Please tell me how a terrorist could do anything significant to a nuclear power plant. That argument is a total red-herring. As for the "waste", let me reprocess it and I'll give you back 95% of the fuel you didn't burn, and the rest will only be around for 300 years (and serve good uses to boot--example: Xenon).

I think nuclear is a very important piece of our energy future, as part of a suite of tools, such as solar, wind, wave, bio (anaerobic digesters, bio-diesel). Someone mentioned squabbling getting in the way of progress, to which I say a diversity of sources and a combination of centralized and distributed sources are critical. If nukes and renewable advocates start fragging each other, the only win will be for the status quo and the fossil industry.

[Arthur Friesland]

The stated goal is to solve the fossil fuel problem by 2050. That is forty-three years away. Who believes that the planet can sustain another four decades of abuse. All of the politicians and bureaucrats are talking as if we have years to burn. How bad do you think it will be in another ten years, let alone forty? If Khosla's scheme works, he should be canonized.

[STEmagic]

It is interesting that distributed solar generation seems synonymous with PV. There are viable distributed solar alternatives.

I can provide a Solar Thermo Electric (STE) distributed solution with the following merits. E.g., 10 kW peak electric output. (Other systems are possible, e.g., 3 kW or smaller).

- Comparable additional energy output as heat (for water heating, space heating, desalination, any process that requires heat)

- can be placed on a roof, or "small" piece of vacant land

For 10 kWp electric + 10 kWp heat system:

- installed cost of ~ 9000 USD

- 20 year lifetime

- cost of installed equipment translates to about 2.8 cents/kWhr over 20 years usage (without Federal or State incentives, without carbon credits)

- incentives and carbon credits will at conservatively reduce cost to 1.5 cents/kWhr.

- larger systems will benefit from economies of scale

I can have the first systems ready within 2 years from raising 6 M USD.

Just need to find the money now:)

STEmagic

[Paul H.]

I think we need leadership to force a zero emissions manhattan project since average joe's only care about sitting on their fat butts and watching t.v.

[Mike]

Tom,
Re: CAES
I'm not an expert in this but you lose a lot of your stored energy when you use adiabatic expansion...it has to happen more slowly. Yes, there might be a way to store the heat of compression and use it during expansion but it is my understanding that you want rapid expansion to capture the kinetic energy of the expanding air at the turbines and only the high heat of burning a combustible gas is going to provide you with the rapid, high, heat flux to keep the turbines and expanders from freezing up.

It is kind of disappointing re: CAES...I wish there were a way to make it efficient and carbon-neutral. You would have to collocate a biogas or biomass gasification facility with sufficient output with the CAES. Then the question comes where do you get the biomass and was it raised sustainably.

I have seen no plans for adiabatic CAES...the new plant in Iowa will use natural gas. Please post links if you have seen concrete plans.

[STEmagic]

Funny.

My post appears as
Posted by: Arthur Friesland | December 31, 2007 at 05:27 PM

And the next post (not mine) appears as
Posted by: STEmagic | December 31, 2007 at 08:50 PM

I think we need leadership to force a zero emissions manhattan project since average joe's only care about sitting on their fat butts and watching t.v.
-----

Moderator, web admin, please take note.

STEmagic

[Paul F. Dietz]

Of course adiabatic means the temperature of the compressed air must be higher than [non-]adiabatic (the amount being given by ratio of pressures, and the gas law),

The heat in the compressed air is transfered to a thermal storage medium before the air is delivered to the storage cavity, and returned to the air as it is extracted from the cavity. If countercurrent heat exchange is used then the fraction of heat so transfered can be quite high. So it is not the case you have to store hot compressed air and, indeed, your system uses the storage cavity more effectively if the air there is cool.

[Danzig]

STEmagic: Each post is followed by a horizontal line, which is then followed by the poster's ID. Site is working as it always has.

[STEmagic]

Thank you, Danzig (NOT Paul). I apologize for the confusion.

I made the (natural?) mistake of assuming that all material enclosed within solid lines belongs to the same post. Sorry.

On an other note, any ideas of where I can raise 6 M USD?;)

STEmagic

[Ike Solem]

The practical question is this: where do you want to put your limited resources in order to get maximum return on investment - either in terms of energy of economics?

Right now, solar is taking off, and companies that supply equipment for solar PV plants are going to be doing very well.

There are a lot of options - the CIGS panels look pretty good at 12-15% efficiency (lifetime?), but finding a cheap way to manufacture the high-efficiency satellite PV systems would double those numbers.

The thing about solar vs. nuclear is that nuclear fission generates a steady stream of extremely dangerous waste, for which there are still no good disposal options - major nuclear power plants have hundreds of thousands of spent fuel rods lying around under pools of water. Expensive and dangerous. Solar PV, once manufactured, generates energy from sunlight with no waste products. They don't discharge hundreds of hot fuel rods every five years. Furthermore, the solar PV manufacturing waste is pretty minimal as far as industrial processes go. (CdSe panels are not a very good idea in that regard).

Any sane investor or financier who wanted to get involved in energy would do well to focus on solar, wind and various biomass conversion schemes - and as someone else said, the government's job should be to ensure that the transmission grid - the highway for energy delivery - is as efficient and reliable as possible. That doesn't mean we should shut down existing nuclear power plants (unless their lifetime is up and they've become decrepit) - it just means that new investments in nuclear are not a good idea.

The fact is, building new energy infrastructure is expensive, and there are limited resources to do so - integrated solar, wind and biomass systems are the best place to put those resources.

[bigTom]

Paul, I'm a bit confused by your response. I can certainly imagine a multistage compression decompression strategy, where the heat is removed/added at each step. That would reduce the entropy increase, but requires significant thermal storage at each stage, this would mean we need storage for both high pressure gas, and heat. If the cavern were sufficiently insulated the most efficient method would be hot air storage. That is essentially what happens with a sound wave, the air adiabatically compresses/expands, and the loss rate is quite small.

[Cyril R.]

Rather than make roadrunners and other desert animals homeless, and cut down all those Saguaro cactus to build these solar arrays, why not look at another significant unused piece of land--buildings

Why not try the solve the problem first rather than dismissing solar thermal out of hand altogether? Replant the cacti and move the animals to another area. The arrays will only occupy a part of the Mojave, environmentally sensitive areas will be excluded as potential array sites, and the arrays will be smaller sizes so there will be plenty of space left for ecology and people to admire the scenery.

A reactor containment building is designed to withstand a hit from a jet. A MOAB (if a terrorist had one) would NOT penetrate the building because it produces a low-impulse, wide area effect.

I do not believe what you are claiming here. Could you provide a reference? I don't think nukes have been tested in realility to withstand such an attack. There's a BIG difference between a commercial airliner and a MOAB. I'd reckon the shockwave alone would be more than enough to destroy vital reactor parts.

All of that electricity would have to be concentrated at key nodes and transmitted along main grid lines.

Why? I'm thinking more about a larger number of smaller lines and junctions. As long as there are enough of them, this will not be a greater problem than for nukes. Which are inherently concentrated and thus also have concentrated key nodes.

As far as the arrays go, forget terrorists, how about vandalism? Solar panels are quite expensive and fragile

That's crazy. Do you have any idea how long it will take to destroy a square mile of steel backed mirrors, concrete and metal pipes? With what, crowbars and sticks? Even with a large group, it would take a long time. And then there will be thousands of square miles and not even in one location anyway. They'd be apprehended before they could knock down serious amounts. (There are several military bases in and around the Mojave).

And if by solar panels you mean PV, then they would be distributed so much that it wouldn't be a problem unless there is a (civil) war going on. If that were the case I'd be worrying about other matters than the reliability of my electricity!

[Cyril R.]

I was a little bewildered by your last post talking about nuclear propagandists opposing solar thermal. Why would they do that? In concert with other sources it really makes sense.

Perhaps it's just me, but I've been hearing some very silly arguments against solar and wind etc lately. It appeared to me an act of propaganda to bring down others in favour of nuclear power. Which I don't get, the case for nuclear fission is quite clear to me. But it is like you say, a combination of power sources that will be the best strategy for now.

I'm also a little confused why you don't like rooftop PV.

I absolutely love PV! It has great potential. But I just don't see a significant reason not to combine it with solar thermal. I think that PV and solar thermal could actually help each other in the grid.

You say it's a small amount of land, but it does not include the road infrastructure, temporary (and permanent) support and living facilities during construction and operation, etc.

Airfields also take up a lot of land. So should we just shut them down then and stop flying airplaines? Roads are all over the US, even in environmentally sensitive areas. And they are rather wouldn't you say? So dig them up and stop driving cars? It's just so deconstructive, the way you talk about solar thermal.

I've also been out to that area and it's not a pool-table flat idealized landscape either, so your available land shrinks some more.

Already taken into account. Using GIS analysis. Only low slopes, no areas with other economic uses, no sensitive areas etc. Still over 7,000 GWp. That's not even assuming the CLFR which is more compact. So probably close to 14,000 GWp. As a rule of thumb, divide by 3 to get load following plants. So no resource problem there.

As for alternatives, I gave you several in previous posts. Nuclear (esp. Thorium and fast-reactors to burn used fuel), wind, rooftop PV, wave, etc. Oh, *AND* solar thermal! So I'm a little confused why you seem to feel the need to get hostile about this.

Now we're talking! Seems like we agree after all. That's what I've been asserting, but you were actually disagreeing with it if you recall. And most of this stuff has been dealt with in the posts in the recent Ausra thread, so I got a bit annoyed to hear the same arguments over and over. I'm sorry if that was a bit too hostile. Perhaps you just meant not building that high a percentage of solar thermal, and I must agree. A clever combination will do fine. A one system approach is just too risky anyway.

[Cyril R.]

The stated goal is to solve the fossil fuel problem by 2050. That is forty-three years away.

Forty-two :) Happy Newyear everyone!

[Charles Barton]

The most curious thing about the Ken Zweibel, James Mason and Vasilis Fthenakis speculation is their underestimation of demand for electrical energy in 2050. If we are to bring down CO2 generation by 80%, the substitutes for fossil fuels in transportation and industry must be found. The most promising sector for electrification is technology, and transportation consumes 20% of the energy used by our society. The Ken Zweibel, James Mason and Vasilis Fthenakis scheme leaves us without a clue where the electricity that will be used to power surface transportation will come from.

There are other energy demand sectors for which eletrical energy is the best candidate for the replacement of fossil fuels. For example commercial and residential space heating can be electrified. Electricity can also provide heat for industrial processes.

So we have a plan that fails to deal with where up to 56% of the electricity used in the United States is going to come from. A plan to provide 44% of American electrical demand is not comprehensive.

There more than a few conceptual gaps in the Zweibel, Mason and Fthenakis scheme. For example they assume storage of energy for night time electrical power is possible at a reasonable cost. They propose the notion that there are a large number of leak proof caverns in the Southwest, ready to be tapped for compressed air storage. This has yet to be demonstrated. They assume that there will be no shortages of critical materials needed to build the truly massive solar farms. They also appear to believe that a HVDC grid would be sufficiently reliable that we can put all our eggs in a basket involving that scheme.

Well I can go on. In the next issue Scientific American should tell us how to re-electrify the country by running gerbils in exercise wheels that have been hooked up to generators. Now that is a real plan.