Noted in Passing: Solar is the Solution

The current edition of Mother Earth News has an excellent post on why Solar energy is the best solution for our energy needs.

Steve Hollerith writes:  I have been studying our energy options for more than 30 years, and I am absolutely convinced that our best and easiest option is solar energy, which is virtually inexhaustible.

Read this interesting article to see if you agree. 

Thanks to Robert Rapier of the R-Squared Energy Blog for the tip.

Comments

[eric]

The article itself is interesting enough, but the comments are even more interesting. The nay-sayers, are out in force along with the nuclear advocates.

[Al Fin]

Solar is indeed one very good answer, in this way (from the article):
# Orient buildings to maximize solar exposure and protect them from prevailing winds. Use wind breaks and berms to channel cold weather around or over buildings.
# Add insulation to hold heat in winter and exclude heat in summer.
# Use sunrooms to capture solar energy when needed and vent it when it is not.
# Take advantage of natural light by using daylighting techniques.
# Use earth-sheltered building techniques to take advantage of natural heating and cooling provided by stable underground temperatures.
# Cool homes naturally using convection loops and cooling towers to circulate air.
# Add thermal mass to buildings by using dense materials, such as brick and stone on interior walls, to maintain more constant temperatures.
# Design overhangs and plant deciduous vegetation to shade living spaces in the summer but not in the winter.

Photovoltaics, on the other hand, have been around a long time, achieving a slow incremental increase in utilisation--which is not likely to speed up soon, unless a huge breakthrough in efficiency/cost/storage takes place. Not likely.

[Mike]

"Photovoltaics, on the other hand, have been around a long time, achieving a slow incremental increase in utilisation--which is not likely to speed up soon, unless a huge breakthrough in efficiency/cost/storage takes place. Not likely."

36% increase in manufacturing capacity equals slow growth?

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

[oZ]

Solar is so clearly the solution I marvel that it is not evident to all.

Advanced third and fourth generation PV is now occuring. Nanosolar, (http://www.nanosolar.com/technology.htm) has developed a printable semiconductor and a printable conductor.

Solar printing will develop so that our giant office towers will someday be retrofitted with photon to electron surfaces that will effectively make them giant solar collectors.

Sooner than we might imagine, every suitable surface that humankind builds will be coated with these Power Inks and Power Paints.

In the meantime, we can build central station solar plants that provide long term energy at rates around 10 cents/KWH.

If advanced ultra caps are developed, we will be able to create a solid state utility (http://earthfamilyalpha.blogspot.com/2006/05/solid-state-utility.html) grid that is reliable, renewable, and affordable.

[Ken Potter]

I have one issue with the assumptions of this artical. The biofuel part did not look at the superior growth rates of proposed feed stocks, especially microalgae.

Also, it appears that many people are looking at photovoltics, when in fact direct solor thermal is well ahead in the cost/storage race.

Lastly there is no effort to identify usable land area for the direct solar estimate. Even so I think solar is the ideal choice for electric generation. I believe we will need advanced biofules for transportation uless there are very large dramatic imporovements in electric energy storage (battires or ultracaps).

[paul]

Jim, I have always been impressed with your reasonable approach to energy. But we don't have the luxery any more for incomplete analysis (read: disinformation). Even with future $/Watt improvements, solar does not have the potential to be a significant part of our near-term energy future because of the enormous area required and the cost to produce (a payback time as much as 1/2 the lifetime of a panel). Looking at the whole picture, (efficiency, $/Watt over source lifetime, polution, environmental costs, deaths per unit-energy over source lifetime) one technology stands far and above the others: NUCLEAR. In addition, when you consider that the waste reactors now produce is 96% useful energy that future reactors are being designed to use (reducing volume and radioactivity drastically), nuclear is even more attractive. I'm pro-solar (and used to be anti-nuclear), but our present crisis situation demands hard-nosed analysis and solutions. Solar simply cannot save us. Nuclear can.

[Doug]

Well. Of course solar is the ultimate source. But I don't think that's the real question at hand. Human beings haven't really been able to make solar work for us in a meaningful way.

Solar panels are a great thing - but we can't make them cheap/efficient/small enough. We should one day - just not today.

Biofuels utilize solar energy (photosynthesis). But that industry is as much a supply chain issue as it is a processing issue.

So the article was right on the spot. But in that context, it seems a bit pie-in-the-skyish. Where's the insightful solution?

[oZ]

Paul, you should consider your own disinformation. Total all of the area already commited to power plants, mines, cooling ponds, and then compare that with the 92 by 92 mile square (http://www.ausra.com/) that we need to provide all the electricity for the United States.

At my utility, I found that when you include our present nuclear facility, our 2 coal plants, and our 3 gas plants, the solar power plant footprint looks quite reasonable. (50-150 MW/section)

When we inventory the available area within the city itself, on flat roofs and over parking areas, the land issue becomes virtually inconsequential.

For example, If I simply covered just the cooling pond at our nuclear plant, I could provide all of the energy we need for the next 30 years.

[Charles Barton]

Everything is true, but big gaps are left unbridged. How is Solar energy going to be economically converted into electrical energy? How is that energy to be stored for night time use. What about cloudy days? What if you live in the arctic, where the sun does not shine several months every year. How much land would a solar power system requite? And how much is it going to cost to make all of those changes in out buildings and homes, to adapt them to solar power?

Steve Hollerith's discussion of Nuclear power is very disappointing. There are several practical solutions to the so called Nuclear waste issue. 97% of so called "spent" nuclear fuel, can be reused in reactors, and given good reactor design, all 97% can be used. Many radioactive byproducts from reactors are used in medicine, agriculture and industry. The most radioactive byproducts of of nuclear reactions, loose their radioactivity quickly.

In addition by reusing nuclear fuel, instead of regarding it as waste, we can power the earth for thousands of years. All the uses of electricity which Hollerith, mentions are possible today with nuclear power. The difference between nuclear power and solar power is both obvious and critical. We can build nuclear power plants that will 100% replace coal natural gas burning, CO2 emitting power plants. We cannot replace Coal and gas fired power plants with solar generated electricity, because they won't supply electricity at night. This is a simple problem, and it is very obvious.

I am not opposed to solar power, but I am not impressed when solar advocates start sounding like carnival barkers, rather than thinking people. Solar power might work well in areas where the sun shines reliably, at least for daytime use. It has yet to be demonstrated that solar power can be economically stored for night time use. Please Mr. Hollerith tell us the truth.

[btenney]

Several years ago I built two stand alone PV systems in a remote area of Nevada. These were security lighing and each cost about 7000 dollars each for a capacity of 1600 watts, available 16 hrs per day. Economics were not an issue since they were far from the grid.
I recently priced out a system large enough to supply 1600 watts continious summer and winter and came up at about 17,000 dollars.
Power costs would have to increase fourfold for this to pay out in anyones lifetime.

[paul]

Doug, By "hard-nosed", I mean proven. I like the Ausra technology, but it hasn't been tested at full scale yet and the energy storage technology is still in development. Also, how do you get the electricity from the deserts in SW US to the east coast? The only data from commercial solar-thermal are from the plants in CA - which have struggled to compete economically. A simple question: how so you keep the mirrors clean?

[Chan]

The solar energy is one side solution to the energy problem. PV system is "generating" energy. We need to store the energy and delivery it. Furthermore, we need energy in dark/night time while PV system can't work. We may pay more attention in battery.

[Kit P]

For more than 30 years hippies in California have been telling the same story. Oz presents an example, “For example, If I simply covered just the cooling pond at our nuclear plant, I could provide all of the energy we need for the next 30 years.”

A thermal power plant would have the same footprint for the cooling system regardless of heat source. Solar power is the hippies catch-22. The economy of scale that is need for economic viability will create water resource issue that they do not like. The million roof top theory will fail when old solar systems fail at the rate that they are replaced.

[bigTom]

Solar is probably going to be a major power source in the future, but that future in contingent on it successfully climbing quite a bit higher up the learning curve. It should not be a surprise that the first generation of solar thermal plants have struggled to be economic, hopefully we have learned enough so that the currently planned plants will ne successful.

Solar has great potential, but is not yet ready for the big time yet. Substantial research and investment is required to get it there, and there is no guarantee that it will get there. I give it 75% odds, and it will take at least 20 years.

Charles the MIT newletter had an interesting article on Thorium Power:
http://www.thoriumpower.com/

Basically with little modification to existing boiling water reacters, they beleive they can use a mixture of Thorium Rods, and standard Uranium rods. It is claimed the Thorium rods can be left in the reactor several times longer than the Uranium ones, thus reducing the waste stream considerably. Take at look at it.

[Kit P]

bigTom, 'the (nuclear) waste stream' and solar panels have something in common. Both just sit there and do nothing and are insignificant to the production of electricity. The amount of hazardous waste per MWe is about the same for nuclear and solar is about the same based LCA. However, it is a moot point because all hazardous waste is properly handled to protect the public.

[Dr Dan H.]

Surely the best answer for pushing the efficiency of solar thermal systems up is to use part of the power to pump cold deep-oceanic water up to act as a heatsink, and allow a good amount of this to evaporate in canals as it runs back to the sea.

This would boost the solar thermal plant efficiency, give a handy local source of fresh water and brine (processable into sea salt for export), and probably alter the local microclimate of the desert area it would be situated in to make it a bit wetter.

This would in turn make life a bit easier and more productive for local people due to the greater availability of water.

[Kit P]

Environmental activist often engage in circular fire squads. While they think they are shooting at nuke and coal plants, they also hit renewable energy projects that have to follow the same regulations.

There is another practical problem with solar near the ocean. The marine layer often produces a overcast that reduces the amount of solar energy reaching the panels. When Mark Twain complained that coldest winter he had experienced was a summer in San Francisco, he was demonstrating observational skills about nature often laking in the solar industry.

[Harvey D]

The comparative foot print argument is not an issue in most countries, specially in USA with enough unused space to supply at least 100x the solar energy required.

Sustainability and environment protection are much more important.

When comparing total cost, we should include the cost to fix all environmental damages caused by coal fired plants and fossil fuel plants and the total cost to adequately manage the nuclear wastes.

We all know that solar power is one of the most sustainable power source. It has been around for a few billion years and will be around for another few billion years....and it is free.

Future solar energy converters and large storage units will be cheaper and much more efficient. Cost per Kwh will match other sources within one or two decades.

Countries in polar areas will have to rely on other clean sources such as hydro, thermal, wind and up-to-date nuclear.

[DaveMart]

It seems to me that a lot of things could be done that would be a good idea from several points of view, not just dependent on the case for man-made global warming.
To be specific: a start could be made on at least specifying a DC power grid, which would be very useful almost regardless of the energy system used, and would be an enabling technology for many forms of renewable energy.
Molten salt reactors should be developed, as they are handy anyway to dispose of nuclear waste, quite apart from their energy production potential.
The biggest change though would be an energy tax on coal, which in most countries gets a bit of a free ride at the moment, which is surely equitable from just the point of view of pollutants emitted, and damage caused in extraction, without considering carbon dioxide emitted - the health costs are real anyway, it is just that they are not presently reflected in charges.
If these revenues were hypothecated then a lot could be done to improve insulation in the most energy inefficient homes, band G in the UK, 3 million of them, which has to be a good idea for the health and comfort of the people who live in them, aside from any global warming reductions.
Similarly, making the use of degraded land in the States available for the growth of prairie grass and early endeavours in biofuel and agrichar production would be good from a recreational point of view, aside from other benefits.
Adjusting planning permissions to encourage green roofs would also help with urban heat island effects, improve insulation and mitigate urban heat island effects.
Similarly solar thermal tracks well with energy use in hot regions, where it is easiest to produce.
In short, there are a lot of options available that are a good idea from many points of view.

[Stephen Boulet]

I think solar thermal is much further along than some are giving it credit for. The 354 MW of solar thermal built by Luz have been operating since the 1980s. Not a new technology, but Ausra's having gone to flat mirrors is a real improvement in manufacturing cost (more expensive to make a parabolic trough), operating cost (easier to clean a flat mirror than a trough and they are more resistant to wind damage), greater compactness (more energy per area), and simplicity.

Even the storage aspect is feasible. I am hopeful that Ausra's projections of the cost of energy production to be in the single cents per kilowatt-hour in the next few years will come true.

Getting the cost down is an engineering problem, not a physics one, and would seem to be low risk, especially compared to coal-to-liquids and carbon sequestration technology.

Combine solar thermal with the eventual construction of high voltage DC lines and greater use of plug-ins and electric vehicles, and we have a winner.

Stephen

[Ken]

Of all energy technologies Solar has the greatest potential but it doesn't exist in isolation. Wider, more efficient and responsive grids, including long distance HVDC, better storage systems as well as reduced costs will all go a long way to seeing that potential realised. How far we can reliably predict improvements is a question, however to presume that what exists now is what we will have in 10 or 20 years is surely a wrong assumption. Whether it's Ausra with reduced cost solar thermal, Nanosolar with roll printed peel and stick CIGS, Crystalline Silicon on Glass by CSG Solar AG, Origin Energy's Sliver cells etc, etc, it's clear that improvements in the solar to electricity end are occurring. Take a look at energy storage and there are technologies that are showing rapid improvement. Grid technology too is not standing still and given the ever clearer need, we will see new technology introduced on a large scale. The blanket claim that solar will not be able to make significant contributions to future energy supply the task flies in the face of the remarkable R&D successes in these areas.

[solarpowerassets]

There is no need to look for a surfeit of land in California in close proximity to grid(s) or urban/suburban locations.

If we just constructed PV and CSP istallations on the median strips of Highway 5 from Woodland thru Sacramento down to San Diego, and connected same to the grid at every city through which it passed, California wouldn't need another coal or gas powered generator...ever.

Add to this the medians of cross state highways such as 80, 50 120 etc. and we could accept the time needed to construct 3 to 4 Nuclear plants and California would be the greenest country in the world.

California could grow to its potential in population without killing the beauty and nourishing capabilities of the land.

The cost?? How much did the first trans-contenental railroad cost? What were the results?

[J Anthony]

Solar Excesses

Solar fans may underestimate the costs that solar energy’s diffuseness impose. Following is one simple example that appears to be a show-stopper: maintenance of the mirror field of a Concentrating Solar Power (CSP) system. CSP systems have been hailed as the most likely of solar technologies to be cost-effective and dispatchable. They use a mirror fields to direct light onto central receivers; recent proposals (e.g., Ausra, eSolar, Solar Systems) have used discrete mirrors rather than troughs:

Assumed data:

- Each mirror is 4 sq m area and annually requires 6x15-min washes plus 1 hr for motor drive maintenance and angle adjustment: total 2.5 hr/y

- The station generates 1 GWe, dispatchable at 90% electrical capacity factor, via use of energy storage (e.g., Ausra’a proposed 300-m-deep underground tanks containing 50 Bar, 300 deg C water, www.ausra.com . Pumped storage, ice storage, and ultracaps have all also been proposed – at least for the future).

- Direct beam solar input is 1 kW/sq m.

- Annual average solar capacity factor is 0.25 (typical for proposed CSPs), taking night, clouds, and seasons into account.

- Solar-to-electric conversion efficiency is 0.35

- Storage in-out efficiency is 0.7; this includes any decrement from providing energy on winter nights to keep the system from freezing.

- Maintenance workers work 2000 hr/y, and their gross cost of labor (including overhead) is $60,000/person-y

Then:

Plant collector area = (1 GW/1 kW/sq m) x 1/(0.25x0.35x0.7) = 16.3 sq km

Number of mirror maintenance workers =
(16.3 sq km/4 sq m) x 2.5/2000 = 5100

Cost of workers per generated kWh =
(5100x $60,000) x 1/(10E6 kW x 0.9 x 8766 h/y)
= 4 c/kWh

5100+ ongoing maintenance workers are clearly excessive compared to a 1 GWe fossil or nuclear plant. Note that the 4 c/kWh represent a small part of what would be the total plant electricity cost: capital costs for the generation plant and a huge amount of energy storage, plus other O&M costs, must be added. By comparison, nuclear-generated electricity can apparently be had in solar California for 2.5 c/kWh all in: www.americanthinker.com/2007/07/new_nukes_for_california.html, search for “Diablo Canyon”.

[DaveMart]

Good effort to put some numbers to producing solar thermal, but I feel that only experience will give a real handle on the costs.
For a start 1.5 hours of the time you allow per mirror is in respect of cleaning - and not too many cleaners in the States cost anything like $60,000 per annum to employ.
Secondly the Ausra system means that the mirrors can be rotated to provide and effectively flat and contiguous area for cleaning, which should be easier.
The time taken for calibration is also unknown at present so far as I am aware - your figures would be very different if calibration was only needed, say, once every three years rather than one.
The nuclear power option does sound a lot cheaper, but the 2.5cents is perhaps a bit optimistic if nuclear power is to produce a very high proportion of world energy needs, as processing will certainly be needed to stretch fuel resources and this does not appear to be cheap.
Although nuclear energy is basically uninsurable as the potential losses are too catastrophic, some allowance should surely be made at least notionally for the risk taken on by the government.
Thank you for a very interesting post, which I find indicative although not fully persuasive.

[Kit P]

J Anthony you failed to take into account Harvey D offered to go work in the Mohave desert for free. However, since he does not understand the significant environmental 'foot print' of cooling water use in the desert, Harvey will not last one day.

Then solarpowerasset is a little short on brain assets. He wants to put solar collectors in one of the most dangerous places in the world. The center divide of interstates. When the brain trust at the free republic of Davis figures out how to use solar to make more electricity than press releases, let me know.

[Clee]

15 minutes to wash 4 square meters seems quite excessive. But on the other hand, they wash the mirrors more than 6 times a year. You can play all sorts of games with assumptions.

I prefer data from existing plants. This IEA/NEA study
http://www.iea.org/Textbase/publications/free_new_Desc.asp?PUBS_ID=1472
includes data from a roughly 100MW solar thermal plant in the US (I suspect Harper Lake). It has an annual O&M cost of $50/kWe, and a capacity factor of 0.28.

So each KWe rated capacity produces 0.28 x 24h/day x 365 day/year = 2452 kWh per year. Divide that $50/yr by the 2452kWh/yr gives an O&M cost of 2 cents/kWh, and that's all of the O&M costs, not just washing mirrors.

[DaveMart]

Thanks for the figures - that is a great resource.
A decent DC grid would seem to me critical to a lot of power technologies.
For Europe and North Africa the cost of such a grid has been estimated at around £40bn - not a huge amount of money over say, 10 years.
If you take that as a ball-park figure for the States, then solar thermal looks a lot more attractive, and you could have higher penetration rates.
Not that you would need that initially, as solar is available at peak times of use, so the economics should really be judged against the rates for peak rate electricity, not base load.
If you accept the desirabililty of reducing carbon emissions one plan for California might be to use nuclear for base-load and solar thermal for peak electricity.

[bigTom]

Some interesting ystem level data from the following report:
http://www.americanscientist.org/template/AssetDetail/assetid/56471

Some highlights:
Current (peak) PV capacity 6GW.
Growth rate 36% per annum.
Payback time of polysilicon PV panels 2.9 years.
That pretty much means that at the current growth rate PV is enenrgy neutral, i.e. we are consuming
as much energy manufacturing panels as they produce. This doesn't mean that is a bad thing, but if the only energy was from PV, and it was all used to build more PV capacity we could just sustain the current solar buildout.

Now 3year energy payback isn't cast in stone, and newer production methods, and products can do better.

KitP had expressed the opinion to my Thorium power comment, that Nuke waste disposal isn't a real problem, but a psyhcological/political issue. I agree completely with that statement. But getting past the psychological/political roadblocks is a serious issue. Reducing the rad waste stream would IMO substantially help in changing the politics. And changing to a more sustainable (by an order of magnitude or more) Nuclear fuel cycle should be encouraged even if it isn't the cheapest near-term solution.

[Charles Barton]

Solar in the intermediate future has potential to provide day time peak power in the southwest. Further out, maybe in a few hundred years the technology may be there to get all of our electrical energy from solar sources. We are not there now. Our society faces a major crisis. We need to eliminate fossil fuel power plants, and switch as much of our transportation from fossil fuels to carbon-free electricity. The only proven technology which will allow us to do that is nuclear.

W need to stop our day dreaming about how solar power will save us, and focus on how we can stop emitting CO2 as we generate electricity.

[DaveMart]

'A few hundred years?'
Not on any conceivable extrapolation of technology trends - progress in decreasing costs and increasing yields is huge for many renewable technologies, and what is a proven technology is improving the grid to carry power far beyond the South-West US.
Not that I have anything against nuclear - it is a very good technology for base-load power and getting better.
To say that nuclear is proven technology though for power generation in the quantities we need is stretching it, as the fuel cycle needs drastically changing to stretch resources to have a major impact at world levels.
The same consideration applies to coal with sequestration.
I have no serious doubt that either can be done, but we don't know all the details and importantly we don't know costs.
In fact, if you want to reduce greenhouse gasses there is a pretty level playing field between renewables and nuclear and clean coal and so on.
The reason I have far more doubts than I used to about nuclear is simply economic.
Maybe it is foolish, but the political reality is that it takes a long time to get planning permission for a nuclear plant.
This is serious if you are talking about capital expenditure of several billions per unit, with associated interest on capital.
The scalability of most renewable resources is a major advantage in those terms, although as others have said environmental impacts of technologies like solar thermal need careful attention.
I would certainly like to see further development of nuclear options though, especially pebble bed reactors, thorium cycle and molten salt reactors.

[BILL HANNAHAN]

It is amazing how many grand solar solutions come without a cost estimate to replace one coal or nuclear plant.

My estimate is that to achieve an average 900 MW with 15% average solar cell output and 0.95 inverter efficiency we would need an array with 6,170 MW peak output (900 MW / 0.15 / 0.95). At $2.93 per watt the array will cost $18.1 billion.

In cold climates peak demand occurs in winter when days are short, sun angles are low and long periods of bad weather are common, a much bigger array would be required.

We will need batteries to store excess power for night and periods of bad weather. Let’s assume the customers are willing to tolerate three blackouts a year, and an analysis of meteorological records shows that a two day supply of electricity will meet this criterion. We will need to store 63 million kilowatt hours of energy.

At $136 per KWh the battery costs $8.6 Billion. We need a 5,000 MW battery charger, at 20 cents per watt that is $1 Billion. We will need a 1,000 MW inverter, at 80 cents per watt that is $800 Million.

Add to this the cost of land (24,500 acres), construction, maintenance facilities, instrumentation and control systems, wiring, switchgear, administrative and engineering facilities, insurance, and the interest on the loan to build the plant, the total cost will be around $29 Billion.

For detailed calculations and references download the spreadsheet.

http://www.nuclearcoal.com/energy_facts.htm

Click on ENERGY CALCS REV 7.xls

The calculations start on line 237

[Aaron]

Bill Hannahan,

I followed the link and your site builds a very good case for continuing to develop nuclear power. Although it's a bit of a pain to read because of the site's gigantic width. I've noticed that most people who shoot down wind and solar solutions tend to be big nuc advocates.

[Ken]

It's not simply a matter of faith to foresee further significant cost reductions for solar and for related technologies - there's a strong, consistent trend that will continue because of the remarkable variety of successful developments already in the pipeline. These are being achieved with relatively small R&D budgets. Any projections based on a presumption of future pricing being much like current pricing are wrong. Solar Thermal can come in well under the solar price provided by nuclear advocates such as BH -projected costs for Cloncurry solar thermal power station in Australia are under US$1 per kWh. An ongoing investment in R&D ensures relative costs aren't going to stay the same.

[Kit P.]

Clee, according to FPL the largest plant near Harper Lake is 80 MWe and co-fueled with natural gas. That would explain the higher than expected capacity factor.

My problem with solar is not cost. Solar is not environmentally friendly. I used Google Earth to find the solar thermal plant west of Barstow. With the scale that filled the screen or the solar collectors of one of the 80 MWe, I went looking for 1000 MWe nuke and coal plants. Tiny little things in comparison. I did find the strip mine feeding the coal plant for 30 years. About the same size as the solar field.

[Kit P.]

Aaron, I am an advocate of renewable energy and

Nukes

And

Coal.

When I say solar is not a very good way to make electricity it is a statement of fact. This is not to say that we should not utilize solar. I see no problem with California using lots of solar as long as I do not have to pay for it.

[DaveMart]

Bill, I liked your site a lot, and essentially go along with most of the argumentation there.
Unfortunately it seems unlikely to me that the investment in R & D that you advocate there of around 5% of gross in the electricity industry will happen, and a lot of exciting alternatives will not consequently be explored.
Both nuclear and renewables can most fairly be regarded as a sheaf of technology rather than one particular technology - I believe that there are something like 900 different designs for nuclear reactors, and the safety of operation varies from the disastrous Russians, to the secretive and inept British, to the excellent record of the French - as a Brit seeing how incompetent the government is in looking after data, sticking records of 25million people in the public post, I would not trust them with a tricycle, let alone a nuclear reactor. Similar considerations apply to renewables, with a vast variety of designs and costs, such that it is difficult to be too specific about characteristics.
In general though, as you say solar, or more specifically PV power is certainly too expensive for base load at the moment, although thermal solar would do better than you have indicated and a decent grid would obviate many of the storage concerns you mention.
Environmental concerns with solar are certainly not negligible as many here have said, although again it is really too early to be very specific.
Sensitive spacing of even large thermal installations, with adequate distances between mirrors, would reduce impact, and for some designs might even produce some welcome shade in very hot environments, whilst designs like inflatable solar collectors would be high enough and widely enough spaced to cause relatively little concern:
http://www.treehugger.com/files/2007/12/inflatable_solar.php
I always felt that the way to go was nuclear, but I have been impressed with the rate of price decrease of some renewables and if carbon dioxide release is a concern it is difficult to see nuclear providing other than base load power, so coal and natural gas would make up peaking power.
In areas where solar incidence is high it seems to me that this is the section which solar power, possibly thermal, might address.

[bigTom]

DaveMart.

I don't know if the inflatable concentrator technology will work out, but it is one of the more innovative ideas out there. And they are only a half mile away from where I work. I guess I should pay them a visit.

[DaveMart]

bigTom:
I guess you should! :-)
-Not that I have the slightest idea whether that particular idea will pan out - but I have an inherent bias towards technologies where the resource base is widely distributed and the costs (if it works) are low! - that's why I am keen on the various high altitude wind proposals - if we can't make one of them work, we are too dumb to deserve to not get boiled by global warming!

[bigTom]

Dave:
I think we think alike. (Darn it is considered to be bad literary form to use the same word twice in a sentence!).
I'm pretty skeptical about about the kites. Lots of tricky issues. Such as reserving airspace, avoiding accidents -or keeping the loses rare enough.
Maybe I'll learn enough about inflatable CPV to be able to write about? I do like a couple of things about it though:
(1) Low capital cost.
(2) Should be compatible with argricultural use of the land. I suspect we have a lot of cultivatable land for which the yield is determined by the water supply not the available sunshine. Their system might be able to increase farm revenue without hurting agricultural output.

Of course keeping the darned things aligned, especially in wind might not be so easy. And if the cooling system fails for even a second, you've just fried an expensive multijunction cell.

Do you have anything to do with the google funded kite power program?

[DaveMart]

I'll look forward to reading your account, if they give you any access.
I'm no pro in any of the energy fields, just a guy who got interested back in '73.
If we have energy at reasonable cost, most of the other issues like feeding people and dealing with pollution get a lot easier.
One of the first books I tackled was Fred Hoyle's 'Energy or Extinction' - he was very keen on Candu type reactors, and dismissive of wind.
Some of the powergrid ideas though seem to push a lot of the distributed ideas closer to viability.
100meter towers to harness the wind have always struck me as clumsy though - replacing them with a cable is much more elegant, and much, much cheaper.
The issues you mention seem to be fairly well tackled.
Automated control systems seem to have been more or less solved by these guys:
http://skysails.info/index.php?L=1
the video of a ship being pulled by a kite and the kite system deploying and being retracted is awesome, if you don't happen to have caught it before! - they are putting it into a 400foot ship this month, too.
As for the hazard to aircraft, you get pretty constant winds and a heck of a lot more power at anywhere above 800meters, way below cruising height.
These guys reckon you could generate are 1GW of power from an airspace not much bigger than the restricted zone over a nuclear plant anyway:
http://www.kitegen.com/
I would have thought the control system for what they are suggesting with multiple kites might be difficult though.
Makani, if they are following Peter Lynne's ideas, seem to be going for a generator/propeller built into the kite, which raises weight issues but should be simpler to control:
http://groups.google.com/group/sci.energy/browse_thread/thread/7e4fdb0421d2afb0/882c3b4181aa1b4d
Anyway, high altitude wind and paint-on solar cells look to be the only technologies with the possibility of producing power a lot cheaper than at present.
Hot dry rock geothermal and thermal solar whilst excellent widely distributed resources would have their work cut out to come in at present costs for energy.
Anyways, enough rambling! - I certainly hope that you get to see the boys building the inflatable solar cells, and look forward to your account.

[bigTom]

I'll have to look into your kitepower links.

One thing that has been bouncing around in mind mind this morning. Lets say we find a source of power which is both very cheap, but also highly variable and not too predictable. Not very usable for directly powering the grid. What sort of products which embody lots of electrical energy, but can be created economically with low capital expenditure and little or oncall type manpower? A few things come to mind as being perhaps useful sinks for such power:
Pumping water.
Heat pumps to create either cold (ice) or warm for space-cooling/heating apps.
Waste disposal or Enhanced Oil recovery, which needs a great deal of power to work...
Electricity to fuel.
Perhaps readers have some good markets?

[DaveMart]

Compressed air storage is another technology - currently being installed in an Iowa park:
http://www.isepa.com/about_isep.asp
You can also of course build containers.
I am not a fan of the hydrogen economy, but electricity to liquid fuel of one type or another is a different thing:
http://www.technologyreview.com/Energy/18582/page1/
Sounds a pretty neat way of utilising carbon dioxide! - perhaps produced with direct carbon fuel cells:
http://thefraserdomain.typepad.com/energy/2005/12/direct_carbon_f.html
Maybe using carbon from plant matter.
If you can get the basic cost of producing electricity low enough, the rest falls into place.

[BILL HANNAHAN]

Although it's a bit of a pain to read because of the site's gigantic width. I've noticed that most people who shoot down wind and solar solutions tend to be big nuc advocates.

Sorry, you can download the Word file for easier reading.

Windmills are a mature technology, and they have no chance of keeping up with improvements in other energy sources. Windmills are a fad like hula hoops and they will go away.

Solar has the potential for substantial breakthroughs that will likely make it an important player. Solar thermal might become competitive in suitable locations, but I think bio-engineering will produce the biggest breakthroughs in the long run. I would put some of that R&D money in bioengineering focused on energy problems. Imagine a bio energy pond that cranks out diesel fuel that can be skimmed off right into the tank. The solar CO generator also looks very interesting.

Germany has put up a huge subsidy for solar, it will be interesting to see what happens, my bet is that in a few years it will push them into the lead of the race for worlds most expensive electricity. Germans pay 21 cents/kWh, behind Denmark 29.5 cents/kWh, and Netherlands 25.8 cents/kWh, due to their huge wind subsidies.

http://www.eia.doe.gov/emeu/international/elecprih.html

Our energy policy must include a rock solid foundation of proven technology that can meet our needs. Only fission satisfies that requirement. Using sea water uranium, first and second generation reactors can meet the world’s energy needs for a few hundred years, advanced reactors can stretch that to over 30,000 years. If breakthroughs in other technologies come, things will only get better, if they do not, we will be OK.

…it is difficult to see nuclear providing other than base load power, so coal and natural gas would make up peaking power.
In areas where solar incidence is high it seems to me that this is the section which solar power, possibly thermal, might address.

The reason coal and nuc plants are used for baseload is that their fuel costs are so low.

GAS 5.2 CENTS / KWH
COAL 2.3 CENTS / KWH
NUCLEAR 0.49 CENTS / KWH

http://www.eia.doe.gov/cneaf/electricity/epa/epat8p2.html

Fuel costs for wind and solar are 0.0 CENTS / KWH, so we would run them at maximum possible output whenever solar or wind energy is available. They should be classified as intermittent baseload power. The utility must have 100% backup power for these sources, usually gas turbines, so the real break even price for intermittent sources is the cost of the fuel they save. That is why intermittent baseload sources have a tough time competing with nuclear.

If electric vehicles become practical and popular, nighttime load will grow dramatically, flattening the power swings from day to night. That means more need for baseload capacity, peaking energy will be less as a percentage of the total energy consumption.

If floating nuclear power plants are mass produced, the cost could drop to the point that they could sometimes operate at less then 100% without driving the cost per kWh up much, further reducing the need for peaking capacity.

It is true that solar costs have the potential drop quite a bit, but so does the cost and time to build a nuclear power plant.

[bigTom]

Bill,
It seems to me that the possibility of very cheap, but very intermittient sources of power might be available. Two high risk, but potentially cheap resources could be: kite based wind power, and inflatable concentrating solar. For the sake of discussion lets pretend we get some source of cheaper than FF or Nuclear, but whose availability is variable. Using it for baseline -or even grid power may not ne economic. Can we build industrial processes onsite/nearby which can benefit from cheap but unreliable electricty. Rejecting certain forms of supply due to reliability issues may not be the best course of action. Learning to live with variability should be some part of the solution.

I'd like to see advanced nuclear as much as you. I think the psychological and political barriers will likely preclude us from embracing this source in a timely enough fashion. We need to hedge our energy bets by funding many different potential methods.

[Harvey D]

Bill;

I like your evaluation of peak load vs base load based on availability and fuel cost.

Your forgot to mention another perfect combination such as Hydro (yes, as peak load) + Wind (as main/primary load). I propose intermittant wind power for main primary load to avoid/reduce energy storage cost. Hydro power output can easily be adjusted for peak loads and even turn down (off) during off-peaks without wasting power. The huge water reservoirs will store the energy. By letting the water resevoirs level rise during high wind conditions you effectively increase (maximize) the hydro power generation potential.

Both, water and wind, are free and produce less GHG.

[DaveMart]

I don't think it is the case that wind power needs 100% backup:
http://www.sciencedaily.com/releases/2007/12/071207000819.htm
With the right grid you can also balance things out quite a lot:
http://www.spectrum.ieee.org/jun06/3544
I am not sure that all of the difference in price of electricity between the US and most places in Europe is due to the support of wind power - the UK is not (yet) heavily committed, but prices have risen a heck of a lot from the tables with rising general energy costs.
having said that I am not a big fan of windmills - I am just even less of a fan of coal.
Unfortunately, I don't fancy algae as a solution either:
http://www.theoildrum.com/node/2531
I pretty much agree with you about the desirability of a nuclear solution, short of solar thermal, geothermal or advanced wind or PV, and none of them are readily available, so nuclear it is.
Except I don't think it will happen - in the developed world because of safety concerns, and in the developing world because of capital costs, which at the moment are a lot higher for nuclear than coal.
So I am afraid that what we are likely to end up with is lots of expensive pork-barrelling ethanol, windmills and so on, and the real production being in dirty, carbon heavy coal.
Not an attractive prospect.

[Cyril R.]

I agree with bigTom. Nuclear fission is good to have as proven and reliable energy generation - at least in some places. But promoting nuclear by using rather dubious (unscientific) arguments against wind (or any other form of power generation for that matter) should not be necessary.

If you're shooting for US presidency, do you bring down the other candidates and their arguments or do you advertise with the strengths and merits of your own plans?

Seems like the latter strategy would be more productive and constructive in general.

[BILL HANNAHAN]

Cyril R. the Energy Blog agrees with you, my response was rejected as spam.

[DaveMart]

If you support nuclear power it is perhaps fair enough to have reservations about wind power and to express them.
Basically the two sources aren't a very good fit in the grid.
Nuclear's strength is as base load capacity, and wind is variable not very dispatchable.
Both need coal or gas to deal with peaks with current technology, although future technologies like very wide grids or the production of liquid fuels or V2G hybrids might reduce the problem.
At the moment here in the UK we are supposed to be going for 33GW of off-shore wind, as a head-line figure, generating perhaps 10GW annually.
To do that we are also going to have to upgrade our grid considerably, as the power comes from remote locations.
All this costs money, and personally I would prefer that we were going for 10GW of nuclear, or hopefully more since you could certainly use 30GW of baseload here in the UK - easily achievable with nuclear, but not so easy to hit the 90GW or so needed in headline capacity for wind.
One way or the other, if we are to take global warming seriously, coal has to go.

[Ender]

Bill - "The reason coal and nuc plants are used for baseload is that their fuel costs are so low.

GAS 5.2 CENTS / KWH
COAL 2.3 CENTS / KWH
NUCLEAR 0.49 CENTS / KWH "

However you should add "at the moment". Here's a scenerio for you. Our (Australian) recently elected Labor Government next July has a Senate that has the Greens with the balance of power (which looks like is what is going to happen). As a compromise to pass other legislation the Greens demand that we only sell uranium to countries that do not have nuclear weapons and the Government agrees.

So at a stroke you in the US do not have access to 40% or 50% of the world's current high grade uranium. This would cause your buy price to skyrocket as you will run out of re-cycled warheads sooner or later and your other suppliers will take the chance to scalp you by tripling their prices because they know you cannot get it anywhere else.

How does solar thermal sound in this scenerio? At least you will not be at the mercy of foreign governments.