Intermittency revisited

by Solarevolution March 27, 2013 14:00

A new detailed analysis has been published on the intermittency of renewables, "Household Solar Photovoltaics: Supplier of Marginal Abatement, or Primary Source of Low-Emission Power?"

Here are some observations about this article:

  • Any future scenario involving the continuing indulgence or coddling of fossil fuel interests is delusional. Catastrophic climate change is at the door. Even if our only issue were peak oil, it is already too late for a smooth "transition" or "energy conservation." We are in a state of emergency and it is time to stop kidding ourselves about our plight, especially within the well-informed but small peak oil / EROI / climate change / renewables community. More than ever, the world needs clear, honest, deep understanding. The politicians and the business community will catch on only when we get real ourselves and "tell it like it is."
  • Given the high risk of social disruption due to climate change, the only rational future for nuclear power (including nuclear weaponry) is rapid decommissioning and secure sequestration. The last thing humanity needs is coastal nuclear power plants flooded by sea level rise and on-river nuclear power plants running out of cooling water while marauders are out on the front lawns of the nuclear industry custodians. Others may be in denial about this risk, but we need not indulge their fantasies of a nuclear resurgence. 
  • That leaves us with only one sane course of action: demand destruction combined with renewables. Any challenges to high EROI renewables carry the responsibility to find high EROI solutions. If batteries don't cut the mustard, then forget batteries. If the main challenge is intermittency, then it is time for us to set the bar higher and put qualified intermittency engineers to work. Many serious developers are working on low cost, high capacity, high round-trip efficiency storage. And they aren't wasting their time on batteries. If trees can survive the night (and winter even in Alaska, Canada, Scandinavia and Siberia), then so can humans. 
    • By the way, a good peer reviewed scientific report on the costs and impacts of intermittency can be obtained from the UKERC:
      It explains the important concept of "root mean square error" and debunks a lot of the myths about intermittent generation.
  • Likewise, if we need a smarter grid to make renewables work, then we need to put more smart people to work, and pronto. One can identify the challenge and the inadequacy of efforts to date. Fine. Then what happens? (Robert Heinlein's admonition comes to mind: "Always listen to experts. They will tell you what can't be done and why. Then do it.")   
  • Residential rooftop solar has a place but it carries the challenges of high installation cost, poor orientation/shading, roof penetrations, etc. These issues stand in the way of large scale high EROI deployment. 
  • Better we look elsewhere. Stronger candidates are low profile commercial buildings, parking lots and streets (integrated with grade-separated transportation).
  • Nor does the need for scale necessarily imply huge remote solar farms out in the deserts. That's appropriate if we are up to something out there in the first place, but extensive transmission and environmental costs can be mitigated by integrating most renewables into the urban fabric.
  • Charlie Hall's claim that society's EROI has to be on the order of magnitude of 10 is similarly built upon the premise of many steps between, e.g., the well and the wheel. No wonder he's right. We fly rednecks from Houston to extract oil offshore in Angola, ship it to refineries in Rotterdam, conjure magic potions and send it off to who knows where by truck no less, and then run it through a 15% efficient engine pushing around mostly metal. What a waste! By uniting generation and application (source and sink) within a single physical structure, much of that inefficiency can be readily eliminated and the minimum EROI can get back down to a reasonable number. 
  • There is no significant future for electric cars (and thus V2G). Using the Biblical cliche, it doesn't make sense to put new wine in old wine skins. In the context of peak oil, humanity is poised to eliminate the treacherous bad engineering (misnamed "auto"-mobile / "free"-way) that willy-nilly juxtaposes children, pedestrians and bicyclists (not to mention pets, squirrels and deer) against heavy fast-moving machines on the same terrestrial plane. With grade-separated Solar Skyways, for example, we can reclaim the streets for people-not-machines and meet our energy needs as well. In the process, with a 10X improved solution, we can drastically cut the source-to-sink steps which whittle away at full EROI  / LCA / efficiency considerations.
For any new scientific inquiry, we must question the assumptions which underpin the conclusions reached. If one picks a marginal set of underlying premises, one will get marginal results.

And though one's conclusions may be valid within the present political framework and technology mindset, the science behind EROI and LCA relate first and foremost to physics, not BAU economics or political intransigence. As long as we are considering such scenarios as high residential rooftop solar deployment, it makes sense to also put forth bold scenarios with sound physics, irrespective of the political / industrial challenges we face. In the emerging milieu of severe natural consequences, bold is where the opportunities can be found.  


Transportation 100 Percent Solar Powered?

by Solarevolution June 09, 2012 06:14
At this critical juncture in history, many factors must be considered in developing new transportation infrastructure. Going up blind alleys will be very costly; every day matters in the oil depletion count-down. The electric passenger car is one of those blind alleys, for many reasons. It's time to get a 21st century transportation system off the ground. Consider this thought experiment, Solar Skyways:
  • Cost of fleet maintenance: To maintain the global fleet of nearly 1 b vehicles including trucks, fuel at $5/gallon ($210/barrel, net after refining), wild guesstimate of 10,000 miles/year/vehicle [USA is 12,000] at 25 mpg, that's 10 T VMT (vehicle miles traveled; USA has 3 T VMT) = $2 T/year. Or, 30 B barrels at $100 * 60% [IEA] used for transport = $2 T. So, ignoring all other private vehicle maintenance costs, by eliminating fuel altogether for ground vehicles we have a budget of arguably $2T/year to offset new capital costs. Can we do better than that? If we were to transition to renewables in 10 years, we could invest $2T * 10 = $20 T in renewables infrastructure. After that, energy costs (maintaining solar systems) would be a tiny fraction of what it is today. No wars over oil, for one thing.
  • How much will Solar cost? Solar PV 4 meters wide yields 1 megawatt per mile. Placed over major roads (say 4 million miles worldwide, roughly 20-30%), we achieve 4 TW electric. Can we build 4 TW of solar for under $20 T? Prices are now <$3/watt installed at MW scale. That leaves money on the table to cover much of the cost of the Skyways' construction too.
  • How many vehicle-miles will solar deliver? Average worldwide solar capacity factor is 5 kWh/kW/day, so 4 TW * 5 * 365 = 7,000 TWh. Suspended robotic electric vehicles weighing 1/4 tonne will use < 200 Wh/mi, so we can achieve 7,000 T / 200 = 35 T VMT. (Recall USA has 3 T VMT; global is on the order of 10 T VMT. Projected global travel in 2050 is less than 35 T VMT.) It appears that we will have surplus electricity by 2X to share with the folks living along the street. Or we can have the solar panels 2 meters wide.
  • Load-matching: EVs charged at night for use in the daytime is a grotesque mismatch between source and sink (engineer-speak, or "supply and demand" to the economists) which would require mountains of batteries (and mountains conquered by huge mining trucks). Solar energy, on the other hand, occurs at the same time people do most of their traveling.
    Even in winter with less sun, people travel less anyway.
  • Won't we still need storage? Yes. Using the grid for storage will be far less costly than batteries. And if deep storage isn't ready for prime time yet, in the meantime maybe you get charged more for travel at night or on cloudy days in the wintertime. Beats having somebody blow up the Middle East in a huff!
  • Single use vs multiple use: If "Detroit" manufactures a car for private use, the cost is $20,000 per driver / 2 passengers per vehicle = $10,000/pax. If we manufacture an ultralight vehicle at $10,000 that is used in public infrastructure 10X per day, 2 pax, that cost will be $500/pax. If you and I go into competition with "Detroit" in these challenging economic times, who will win more customers?
  • Safety: The automobile has been considered an improvement on the quality of life. Tell that to the families and friends of the million people who die in traffic accidents every year. What about the tens of millions seriously injured? By getting urban vehicles off the ground, the land is freed for pedestrians and bicyclists who no longer have to fear for their lives.
  • Performance: When shared by five modes (trolleys, buses, cars, bikes, pedestrians) the existing public transportation infrastructure (a.k.a. streets) cannot perform well for any one mode. Cars get congested, trolleys slow to a crawl to avoid running over pedestrians, bicyclists and pedestrians meet walls of traffic. Put all vehicles above the human realm (gravity matters, after all) and everybody gets where they want to go painlessly and rapidly.
  • What might it look like?
    Uppsala Solar Podcar
  • Visual intrusion? Fair enough. You might ask Eddie Murphy (Bowfinger) how he feels about that!

Are fossil fuels superior to renewables?

by Solarevolution February 15, 2012 00:46
I read this on The Oil Drum.
"... fossil fuels are qualitatively superior on the matrix categories..."
It all depends on what qualities one cherishes. I cherish clean, quiet, powerful. My matrix I suppose would differ from the Oil Drum author's. In fact, I set forth such a matrix years ago: Scoreboard.

One day, the notion of burning fuels to move things will seem as primitive as cooking a meal in Manhattan at a campfire on the floor in the kitchen. Yes, fossil fuels are compact, but not as compact as electricity delivered by wire. Fuels are explosive too, whether fossil or bio, and it is absurd to have these dangerous substances held in conveyances being hurdled along at highway speed. Now please don't be confused; I'm not advocating EVs with batteries – yet another primitive notion for the urban landscape.

Teams around the world are designing transportation systems based on solar energy, with PV panels directly overhead to meet 100% of the systems' energy demand (on average, net-metered). Teams are designing these systems to place small, on-demand vehicles above the street, where they won't run into people, pets or deer. This is not a pipe dream

"... and that transportation without fossil fuels will be hard..."

Maybe that's true in the USA, but not in Europe. Really, how hard can it get?! When was the last time you looked at a freeway cloverleaf? That's what's hard: accommodating a free-wheelin' half-drunk cowboy in a 3-ton behemoth with a wide margin for error – 12' per lane?! – plus a shoulder or barricade. Tons of steel and concrete can be eliminated by greatly streamlining the urban transit system using this emerging technology, with 200 kg podcars on switched computerized networks above the streets. One day we will be jackhammering the streets to turn them into parks where kids can play again, in their village, without getting run over by the above-mentioned cowboy or a choo-choo train cleaving the community in half.

We can do better. Come on, it's time to roll up our sleeves and stop kicking the can down the road for our children's children to figure out what to do. It is obvious: the age of fossil fuels is moribund, and it's time we stopped killing over a million people a year (globally in traffic) with a transport system design that's completely out of step with peak oil realities – and the reality of 21st century technology that is 10X better in so many dimensions: 10X less weight, 10X less energy, 10X greater safety.

 Join the solarevolution!

What are we shoveling with shovel ready solutions?

by Solarevolution September 09, 2011 08:29

I learned a new phrase a few days ago, "drop-in fuels." Leave the fuel-hogging devices all the same -- ask no questions about efficiency -- and concoct a new fuel to keep feeding the hogs. (On small islands in ancient Polynesia, it was discovered that hogs were competing for the same food as humans, and they were exterminated. Oh, that we could learn such lessons from our ancestors.)

The military is looking for a way to fuel jets, tanks, personnel carriers, etc., without oil, and the politicians are providing the rhetoric to suspend the laws of physics until they get re-elected.

Just as with the flawed notion of "shovel ready," we have institutionalized business-as-usual (BAU) remedies which have no future. Rebuilding America, fixing our infrastructure, etc., is all about constructing stranded assets -- artifacts of the age of oil which will last 50-100-200 years longer than the fuel that is needed to operate them. Pity. 

What is the alternative?

  • Simultaneously with putting solar panels on our roofs, we must swap out our incandescent bulbs and put in LEDs that use 10% as much energy. The same goes for the efficiency of refrigerators and washing machines. We can do better.
  • In the haste to convert our cars to electric propulsion...
    • Did anyone notice that the car itself is only about 1% efficient? (Most of the fuel is used to move metal. We use a ton of metal to move a person!)
    • With help from other 2 & 4 wheeled contraptions, the car kills a million people worldwide every year and maimes countless others.
    • The electric vehicle uses as much in materials as a conventional car -- or more. There are no savings in materials.
    We did not speed up the horse by feeding it on the newly discovered fuel, kerosene. We created the horseless carriage. As the horseless carriage scaled up, we didn't notice its limitations. We now know how to achieve mobility without oil, and we can solve the other flaws of our transportation system at the same time. Getting off oil is liberating, not confining.

If we do all these things and more, we won't be needing the over-powered military machinery which is being used mostly to protect our sources of oil. 

We have a unique opportunity in the context of peak oil to redesign our infrastructure, to transform personal transport to 100% renewables -- and while we are at it, eliminate the fundamental flaws in our present system.

First principles:

  • grade separation (put fast-moving vehicles above pedestrians and bicyclists with podcars or below with subways),
  • automated on fixed guideways,
  • dispatchable at will, not scheduled,
  • solar powered,
  • light weight, aerodynamic,
  • consuming less than 100 watt-hours per vehicle-km.

You don't know how to do that? If you jettison the oil, you will be able to figure it out. Don't leave it to future generations to struggle in an oil-depleted world. It is time for our generation to become responsible. Let's not kick the can down the road to the next generation.

Noche Triste for Black Gold

by Solarevolution June 20, 2011 14:29
A reader recently commented...
Consumers and businesses will not abandon $30 trillion in rolling stock and infrastructure tied to petroleum/liquid fuels that provide the energy for 97% of transportation worldwide. How could they?

Hold that thought...

In his stunning, brilliant chronicle of the conquest of Mexico by Cortés, William Prescott tells of the "Noche Triste" (Sad/Melancholy Night) when the Spaniards and their native allies escaped the Aztec palace shortly after the death of Montezuma.

Montezuma had been mortally wounded by his own people who were disgusted by his traitorous complicity with the Spanish enemy. His death undid the cover provided by a political hostage, and a hasty retreat was staged at midnight on June 30, 1520. Scrambling to prepare their escape, Cortés offered treasures to his men, many of whom stuffed their pockets with gold and jewels to improve their lot when they returned to Spain.

 Built on an island in the middle of the grand shallow lake where Mexico City now stands, the palace was connected to the shore by eight causeways, the favored of which had three breaches to cross (where bridges had been destroyed by the Aztecs). Deciding to reuse only one portable bridge for these three crossings proved to be a tragic mistake when, after the army had crossed it, the bridge could not be dislodged from its first moorings. Prescott describes the struggle to cross the third and last breach as the army was beset by those defending their homeland:

"Those fared best, as the general had predicted, who travelled lightest; and many were the unfortunate wretches, who, weighted down by the fatal gold which they loved so well, were buried with it in the salt flats of the lake."

... and now, let's get back to the question at hand...

My reader may be right, that many people won't be able to abandon their black gold. If that's so, then one's point of view may make all the difference between thriving and despair.

Peak oil is a juggernaut that answers to no one. The desires and opinions of consumers and businesses will have no weight when the oil is gone. They will be forced to abandon that $30 trillion of then worthless rolling stock and infrastructure if they wait till Mother Nature shuts down the gas pumps.

When they are heading for the rocks, sailors jettison their cargo -- simply to survive. As the oil economy declines, those who would cling to their black gold may be pulled down with it. Those who jettison the tempting shiny substance in favor of living lightly on the earth with the new artifacts of the solar age will be free to move forward without impediment.

It seems like an easy choice for those who have shifted their point of view from fear (holding onto what we already have for dear life) to hope, investing in solar technology that will survive the decline of oil.

Trying to preserve the automobile with its freeways and fuel tanks will inadvertently hasten our economy's decline. In the next few years we will either spend another $30 trillion more just to operate and maintain our ill-fated oil-based monstrosity -- most of it leaving our economy to support unfriendly regimes -- or we will spend a "mere" $10 trillion building a post-automobile transportation system -- boosting our own economy -- designed to operate henceforth sustainably with solar energy already bought and paid for, without fuel, for the long term.

Hybrid vehicles won't get us there. Electric vehicles won't get us there. Flex fuels won't get us there. Grasping at straws (biofuels) won't get us there.

We still has the opportunity to encourage innovation and call upon American ingenuity to meet new standards of excellence: Energy Return On Energy Invested (EROEI, say, higher than 10) and performance standards (for example, "more than 150 miles per gallon equivalent"). Those who read the writing on the wall and work together to find new approaches still have a fighting chance!

Slam on the Brakes

by Solarevolution June 20, 2011 09:15

Reading all these price predictions by peaksters, I’m reminded of the Austrian economist Murray Rothbard who said, “The only function of economic forecasting is to make astrology look respectable.”

We know that the media (government / business / religious leaders) are giving very little attention to Peak Oil, but I would like us to consider what we, the Peak Oil community, are not talking about.

We’re not talking about slamming the brakes on fossil fuels.

Even as our contribution to creating Peak Oil awareness begins to see a little light (at least in some circles), I am concerned that we will be so worried about saving our own bacon or appearing to be rational that we will fail to take posterity into account. If we are to save just a little oil for our children, we need to just plain stop using oil (gas, coal).

“Conservation” doesn’t capture the urgency of our existential moment in history. In fact, conservation is like a salve to assuage the conscience of well-meaning people who are stuck in “business as usual.” We can be conned into thinking that we are doing our part by swapping out incandescent light bulbs.

Why can’t we just use less oil? If you are drowning, drowning slower isn’t going to save your life.

If you are in the know (Peak Oil), it’s not about telling others to slow down. We have to abandon the artifacts of the oil-based economy and retool.

It requires a fundamental shift. It’s about transforming society from oil to ingenuity. We must slam on the brakes and turn about-face.

Nuclear power swirled down into the ocean in March and humanity’s perceived energy options narrowed sharply. We are back to where our great-grandparents were their whole lives: figuring out from-one-day-to-the-next how to live within a solar budget. They did it (or we wouldn’t be here having this conversation). We can do it too. But we have to shift gears.

We are sliding down the back side of the peak, and just like with most mountains, the dark side is steeper than the sunny side. Will it be a soft or hard landing? Well… it depends:

If we have already used up too much of our natural resources, it will be a hard landing. (Time will tell.)

If we “conserve,” I don’t see how we can avoid a hard landing. Going slower sliding off the cliff is still sliding off the cliff.

We are aiming at the tail feathers of the goose that passed by here already a while ago. We need a word somewhere between conservation (voluntary) and deprivation (involuntary, Mother Nature’s decision) – something to make it obvious that we aren’t stuck promoting the same old baggage. The ship is going down. I repeat: we must jettison the artifacts of oil. If we hang onto them, they will sink us for good. (Some of Cortez’ men loaded their pockets with gold as they were escaping the Aztecs. When a causeway collapsed, many of them sank like stones and drowned.)

What legacy are we leaving for our children? What robust assets will they have at their disposal to climb back out of the hole we put them into? Why are we postponing this radical change? By waiting even one day, we are willy nilly leaving the solution up to our children. But what advantage are we giving them by drilling for more oil, mining more coal, fracking more gas? We are handing them a polluted world, a mountain of debt, hobbled with depleted resource deposits, and blindfolding them – all the while talking seriously about the price of oil for the next year.

We aren’t calling enough attention to carbon-based boondoggles (“shovel-ready” projects). Anyone who designs a system or artifact (highway, bridge, tunnel, airport, automobile, bus) that depends on imported oil is a traitor. After all, eight presidents in a row have proclaimed that imported oil is a threat to national security. Promoting a construction project to convey vehicles operating on mostly imported oil is now an act of treason.

I hear the question, “What percentage of our energy demand can be replaced by renewables?” There are two unchallenged assumptions that frame this question and illuminate our fossil-fuel mindset.

1. One good answer is none. “Replacement” suggests doing things the same way. We can’t “replace” oil with sunshine any more than we were able to “replace” horses with high-speed 4-legged robots shaped like horses. We jettisoned horses and made devices with engines and wheels.

Now we must jettison devices with engines and wheels that are 1% efficient, that weigh 2 tonnes to move 100 kg.

For example, what about biodiesel? Consider this thought exercise. Define inefficient = stupid. A car engine is 13% efficient (per RMI); the average car weighs about 4000 lbs (per DOE, DOT) and carries an average of less than 200 lbs; that’s 5% efficient. So 13% (engine) * 5% (mass) = 0.65% < 1% efficient = stupid. Now how do we get biodiesel? Photosynthesis can convert 3-6% of sunshine into soybean plants. Then we take the oily portion of the plant (you can’t make oil out of the stems) so even assuming that it takes zero energy to harvest and process that plant material into oil, your net efficiency is <<1% = stupid. (Using 100 gal/acre/year, I estimated that 0.05% of the sun’s energy is converted to soy biodiesel. I’ve heard of yields as high as 600 gal/acre/year for “next-generation” biofuels. Give them the benefit of the doubt, and we’re at 0.3% efficient, still <<1%. Correct me if I’m wrong.)

Now put that <<1% efficient biodiesel (stupid) into a car that is <1% efficient (stupid) and you get << 0.01% efficient. The result? Compound stupid.”

2. Another answer is 100%. Built into the question (remember the question, “percentage of energy … replaced by renewables”) is the curious assumption that we have a choice. We don’t.

Most of humanity lived within a solar budget until World War II. As near as I can tell, we have no option but to return to 100% renewables, whatever that may look like. (I’m all ears if you think you have found something else.) With the incredible amount of knowledge and skills we have gained during the fossil fuel era, we are much more capable than our grandparents to take on the task. If we are to avoid becoming a dead branch on the evolutionary tree, we will switch to renewables now so we can leave something for our children to work with.

It’s not “practical.” We will face skepticism and ridicule. But those who embrace renewables now will be the sellers in the post-oil economy, and there will be plenty of buyers who postponed the inevitable shift.

Slam on the brakes! Save the oil!

Also posted at

Will China opt for Oil? Will India invoke Ingenuity?

by Solarevolution July 07, 2009 01:29
I'm in the middle of what seems an interminable debate with a few friends who can't handle the idea of anthropogenic climate change. As I look at the various scenarios, I realize that China and India are just about as locked into the fossil fuel future as Americans are. And thus we face a stupidity end game ... in which all the major countries say, well, we can't change because it would screw up our own economy. We'd have to retool and that's expensive.

But China seems to have more money than India to go out and secure oil for their own future, as they are out-bidding just about everyone else (example). So if India wants to move out in front to power its economy, especially transport, then ingenuity (as opposed to business-as-usual, BAU) has to play at least some role.

Germany did this with renewables (solar, wind) and guess what harm came to them? They developed the most powerful solar industry in the world, with only half the daily sunlight of southern California. They are treating the USA like a third world country -- exporting complete solutions to the USA, buying USA solar manufacturing companies, enticing USA companies to relocate in Germany, etc.... A clean sweep!

You say that you will start doing solar in earnest when it can compete without subsidies. Germany didn't keep on looking; their champion Herman Scheer proposed a different point of departure.
Fossil energy not only threatens massive environmental and social disruption through global warming but, at present rates of consumption, it will run out within decades, causing huge industrial dislocation. Even before then, the conflicts and imbalances it causes in the Middle East and elsewhere in the world's economy will be frighteningly exacerbated.

But let's say I buy your argument -- that we should wait until it competes. Then I would suggest looking for the solar "killer ap" which works today without subsidy.

How about this, then? A solar system with a 4 year payback, without subsidy:

It is the solar highway: a continuous solar system 2 meters wide = 300 kW/km = 500 kW/mile. Not on roofs, which are often shaded by trees and cluttered with HVAC equipment, but alongside existing roadways. A solar system providing power for a transportation system which is 10X better along at least a half dozen metrics compared to the automobile ... and even 10X better than public rail transit along several of those metrics. I presented a paper on this in Stockholm at the end of 2007. The calcs are here, assuming Sweden's lower level of solar but higher price of fuel. (You can change the assumptions for India. It will only get better than the 3.8 year payback I calculated for Sweden.)

Development of this technology is ramping up in Sweden, the UK (an installation is nearly complete at Heathrow Airport), and elsewhere.

China is buying oil rights and building cars. India is too. Utter insanity.

Which shall it be: engineers or soldiers?

Which countries will be the first to move beyond oil

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