Solar Cheaper than Coal in 3-5 Years? GE and First Solar Think So

The news is carrying two stories in the last two weeks pitching solar as potentially cheaper than current electrical rates in the next 3-5 years.

First, in an interview with Bloomberg, GE’s global research director Mark M. Little said that their thin film solar PV (now at 12.8% efficiency) could be cheaper than fossil fuel and nuclear electricity in 3-5 years.

Then, yesterday, First Solar said that they believed they’d be selling solar power to CA utilities at 10-12 cents per kilowatt hour in 2014.

Both of those are well ahead of the Moore’s-Law-like exponential price decrease of solar that I’ve blogged about previously.

Could they be for real?  Possibly.  If they can keep installation costs and operating costs low enough, solar cells that are in pre-production are already at the $1 / watt manufacturing price threshold that would allow cheaper-than-fossil-fuel solar energy.

When solar is truly cheaper than fossil-fuel derived electricity, we’ll hit a new tipping point in energy.  We’ll still need some coal, natural gas, or nuclear power for night time and cloudy days, but those power usage levels are lower than the peaks on sunny afternoons in summertime.  With cheap solar PV, most of the new capacity built will make more sense as solar than anything else.

And eventually, cheap solar electricity will allow us to capture CO2 from the atmosphere and turn it into liquid fuels for storage and for transportation.  (More on that another day.)

Genetically Tweaked Microbes on 0.6% of Earth’s Land Could Replace Oil

New Scientist has an article on biotech firm Joule’s upcoming ethanol production biofuel plant.

Joule already has a pilot plant covering 0.8 hectares in Leander, Texas. On 5 May, the firm announced that it had secured 486 hectares in Lea County, New Mexico, for a plant to produce ethanol and diesel. The project may be scaled up to 2000 hectares.

With its engineered microbes, Joule claims to be able to produce ethanol at a rate of 93,000 litres per hectare per year, suggesting its New Mexico site will generate 45 million litres per year, rising to nearly 200 million litres if the site is expanded to 2000 hectares.

via Renewable oil: Ancient bacteria could fuel modern life – environment – 18 May 2011 – New Scientist.

Some quick math reveals that 93,000 litres per hectare per year is about 6.1 Watts / square meter of energy capture.   That is well beyond the < 1 Watt / m^2 of most conventional biofuels, and above even the 5 W / m^2 that is claimed for genetically engineered algae.

While that is far less than the 40 Watts / m^2 that a solar PV installation should be able to capture in New Mexico, it is not at all bad.   At 6 W/m^2, it would take on the order of 1 million square kilometers to produce as much liquid fuels to replace all of the world’s current oil production.

1 million square kilometers sounds like a large area, but it is about 0.6% of the world’s land area (148 million square kilometers), or around 2% of the land currently used for farming around the world  (around 50 million square kilometers).    Nor would biofuel production necessarily compete with agricultural land – deserts are perfect places for biofuels.

If biofuel techniques can actually produce 5-6 W / m^2 and can be scaled to large areas, then it is certainly viable on a planetary scale to gather enough energy via biofuels to replace oil.

Can We Capture All the World’s Carbon?

I originally posted this at Scientific American.  Reposting here with permission.

In 2011, the world will emit more than 35 billion tons of carbon dioxide. Every day of the year, almost a hundred million tons will be released into the atmosphere. Every second more than a thousand tons – two million pounds – of carbon dioxide is emitted from power plants, cars, trucks, ships, planes, factories, and farms around the world. The average citizen of the world will account for the release of four and a half tons – 9,000 pounds – of CO2 this year. The average American will be responsible for four times as much, almost 18 tons, or 36,000 pounds of carbon dioxide this year, roughly a hundred pounds of carbon dioxide emissions for every day of the year.

While humans emit far less carbon dioxide than nature, the amount we emit exceeds the capacity of plants and oceans to absorb on top of the amount they’re already absorbing from natural sources. As a result, most of the carbon dioxide we emit remains in the atmosphere. Year over year, the atmospheric concentration of CO2creeps up. It will rise only half a percent in 2011, a seemingly tiny change. Yet tiny changes add up. Over the 50 years since 1960, the amount of carbon dioxide in the atmosphere has risen nearly 25%. Since the start of the industrial revolution it has risen by 45%, putting it at a level not seen in millions of years.

On current course and speed, by 2050 atmospheric CO2 levels will rise by another third from their already record high levels, making CO2 twice as plentiful in the atmosphere than at any point during the lifetime of our species.

Without reversal or mitigation, the continued pumping of CO2 into our atmosphere will eventually warm the planet to the extent that catastrophic changes ensue. The only serious debate at this point is just how quickly those catastrophic changes will occur, and which regions will see them in what forms.

To avoid those changes, we need to keep the level of CO2 and other greenhouse gasses in our atmosphere at a manageable level. It’s unlikely this can be above 450 parts per million in the atmosphere. To stabilize at those levels, carbon dioxide emissions in 2050 will need to be less than half of what they are today, and less than one quarter of the levels they’re on track for if we continue with business as usual. Compare the bottom blue line in the graphic below, which depicts the necessary levels of carbon dioxide in the atmosphere and carbon emissions to achieve them, with the top red line, which depicts something close to business as usual. (Note that in the bottom graph, emissions are listed in billions of tons of carbon rather than billions of tons of CO2. Multiply tons of carbon by 3.67 to get tons of CO2.)

We hear a lot today about ways to achieve lower emissions and thus lower CO2concentrations in the atmosphere – more efficient cars, green energy sources like solar and wind, changes in lifestyle, and so on. Another option is to take specific steps to remove carbon dioxide from the atmosphere, either by removing it from the exhaust of power plants and other sources, or by scrubbing it out of the atmosphere later. Is it possible to capture enough CO2 in this way to make a difference? What would it take? Should we even pursue this path, or is it a distraction from cutting carbon dioxide emissions other ways?

Why Capturing Carbon is a Good Idea

The best way to keep carbon dioxide levels from rising in the atmosphere would be to simply never emit carbon dioxide in the first place. An ounce of prevention is indeed more valuable than an ounce of cure. Unfortunately to completely eliminate carbon emissions we would need to go to 100% non-CO2 emitting sources of electrical power – solar, wind, hydro, and nuclear -, and simultaneously convert all transportation to either electric vehicles (powered by zero-carbon electrical sources) or entirely fueled by next generation biofuels. To understand that, let’s look at the two most plentiful sources of carbon emissions: electricity generation and transportation.

Electrical generation is the number one source of carbon emissions, making up roughly 40% of carbon dioxide emissions on the planet, most of that from the burning of coal. Most electricity on the planet is used to heat and cool buildings. Green building standards could cut electrical bills, but the lifetimes of buildings are long, and getting owners to retrofit is difficult. The other way to address carbon emissions from this sector is to switch to low-carbon ways of generating electrical power.

As I’ve posted about previously, the cost of solar power is dropping exponentially, and will cross below the price of coal-fueled electricity by 2020. Unfortunately, solar suffers from intermittent supply. At night and on cloudy days, the available electricity drops. Solar power plant manufacturers are working on solar power storage systems to offset this problem, but today the leading edge is to provide 6 hours of storage, enough to make it through the evening television hours, but not enough to provide power 24/7 or to make up for cloudy days or weeks. Energy storage also adds to the cost of electricity, since the storage systems have to be built and paid for. Wind power, far less abundant than solar and far more stagnant in price, suffers similar and even larger problems of intermittent supply. The result is that, until and unless we have breakthroughs in power storage, solar and wind will top out at between a third and a half of the planet’s electrical power needs.

Transportation is the second largest source of greenhouse gas emissions on the planet, accounting for around a third of all greenhouse gasses humans produce. Transportation can be made greener by increasing fuel efficiency of vehicles through technologies like hybrid drive systems, regenerative braking, and lighter and more aerodynamic chassis. Yet these changes affect mostly in-city passenger driving. They have far less effect on cross country transportation on trucks (where cargo makes up more of the weight and traffic patterns are less stop-and-go) and almost no impact on air travel. New aircraft design concepts could cut air travel fuel usage by half, but it will take decades to turn those concepts into production aircraft, and more decades to replace the aircraft already in use.

Electric vehicles charged with electricity from low-carbon sources would do better, but electrical vehicles suffer from the very low power densities of batteries when compared to hydrocarbon fuels (as much as a factor of ten lower) and resulting in heavy vehicles with short ranges. In addition, until night time power is low carbon, charging an electrical vehicle at night, in most places, will essentially be an exercise in burning coal. And while electric motors are more efficient than internal combustion engines, electric cars charged by coal-fueled power plants will still result in net carbon emissions.

The one major hope for transportation to become green is the development of next generation biofuels. Biofuels help with carbon emissions because growing the feed-crops for them extracts carbon dioxide from the atmosphere. While that carbon dioxide is released again when the fuel is burnt, it’s an almost net-zero cycle, unlike the burning of fossil fuels that have been in the ground for tens of millions of years.

Unfortunately, current biofuels crops including corn, switchgrass, and oil-seed rape produce less than half a watt of energy per square meter and compete with food crops. They are both too low in power density and too adverse for world food prices to be practical as large-scale replacements for petroleum products. We can effectively rule those out from having a large effect. Next generation biofuels, including genetically modified algae that can grow on salt water (and thus not compete with food crops) and capture as much as 5 watts per square meter are more promising. However, they have yet to be proven.

If we assume that automotive fleets go up in efficiency, that aircraft go up in efficiency somewhat, and that some biofuels come online, we can perhaps look forward to a reduction in transport emissions of about half over the next thirty or forty years, about the same as we see for electrical generation. That, combined with an increase in solar and wind, leaves about half of the world’s carbon emissions in 2050 still being emitted. It would effectively keep emissions steady with today. That’s insufficient. It would leaves us still walking down the path to catastrophe at today’s rate. Something more is needed.

In that context, it makes sense to talk about capturing carbon dioxide, above and beyond the proposals to reduce its emissions above, and storing it someplace safely out of the atmosphere.

How Do We Capture and Store Carbon Dioxide?

Broadly speaking, there are two types of carbon capture systems, though there are many possible ways to build systems of each type. The first sort of system is focused on capturing carbon dioxide from power plants where fuel is being turned into electricity. This is commonly referred to as Carbon Capture and Storage or CCS. In principle it could reduce the carbon emissions of coal-powered electrical plants by 90%. It cannot, however, offset the carbon emissions from transportation or other smaller sources such as farming and deforestation.

To tackle those emissions, another form of carbon capture called Carbon Dioxide Air Capture or Carbon Dioxide Removal (CDR) has been proposed. CDR devices could exist anywhere, not just near power plants, and capture carbon dioxide from the very dilute concentrations it exists in atmospherically.

Both forms of carbon capture rely on storage of the carbon dioxide. To store carbon dioxide, it must first be compressed into a liquid, then piped or shipped to an appropriate location, and finally injected into suitable geological formations kilometers below the surface of the earth. There the CO2 will remain for at least thousands of years, if not far longer.

Both forms of carbon capture require energy as well. Carbon capture at coal-powered electrical plants has the advantage of having the carbon dioxide available at extremely high densities and potentially being able to take advantage of waste heat from the plant. Even so, energy is required. At minimum, 70 kilowatt hours of energy is required to compress a ton of CO2 from a gas into a liquid. Additional energy is then required to pipe it to a suitable storage location, and then to pump it into a reservoir kilometers below the surface of the earth.

Capturing carbon dioxide away from power plants, from normal atmospheric air, requires even more energy. The basic physics tells us that at minimum an extra 130 kilowatt hours of energy is required to capture carbon dioxide from normal atmosphere, even before spending the energy to compress it into a liquid or pump it into the ground.

We might think that the fact that additional energy is required to capture carbon dioxide means that it’s a losing proposition. After all, that energy itself will result in more carbon emissions. Fortunately, even if we use the dirtiest fossil fuel – coal – the additional energy required emits far less new carbon dioxide than we capture. At theoretical best efficiency, capturing CO2 from coal power plants would emit less than one ton of new CO2 per ten tons captured. Capturing CO2 from thin air – and using coal to power the process – would emit a best case of two tons of CO2 for every ten tons captured. Seen another way, the best possible net capture efficiencies when the process is powered by coal are 91% and 83%, respectively.

Powering carbon capture devices by sources other than coal would be far better. CDR – capturing CO2 from normal atmospheric air – could be powered by hydro-electric, wind, or solar power, at locations and times when that power is the cheapest and most plentiful.

Capturing carbon requires more than just energy, of course. It requires investment in the physical infrastructure to capture the carbon, to compress it, to transport it to the right site, and to pump it incredibly deeply into the ground. It requires manpower to do these things, and to maintain monitoring of the sites to ensure that sequestration has been done properly and that unexpected leaks don’t arise.

All together, the pieces of carbon sequestration add up to a noticeable cost. How much cost? A recent study at Harvard’s Kennedy School of Management reviewed all previous work on cost estimation of CCS at coal power plants, and determined that the long term cost would be somewhere between $35 and $70 dollars per ton of carbon dioxide captured and stored. The costs would start much higher for the first plants, as high as $150 per ton of CO2 captured and stored, but would drop rapidly as more plants were built and the industry scaled.

Fewer cost estimates are available for carbon capture from general atmosphere, but a number of private companies are now at work in the field, and the estimates they’ve discussed fall in roughly the same range – $100 per ton of CO2 in the early stages, dropping to perhaps $30 to $50 per ton of CO2 as the technology is scaled.

If we could achieve a cost of $50 per ton of CO2, what would that do to energy prices? Every $10 per ton of CO2 increases the cost of electricity by 1 cent per kilowatt hour, and increases the cost of gasoline by 10 cents per gallon. So a $50 per ton cost to capture CO2 would, if applied back to the cost of CO2 emissions, raise electricity prices by 5 cents per kilowatt hour and raise gasoline prices by 50 cents per gallon. That is not a bad price for avoiding catastrophic changes to the planet.

Scale of the Challenges

Yet carbon capture technology is not without its problems. There are concerns that injecting high quantities of liquid CO2 near fault lines that are under tension couldtrigger earthquakes years ahead of when they would normally occur. At least one recent study has also shown that there is a risk of sequestered carbon contaminating drinking water.

The biggest technical challenge is sheer scale. Carbon dioxide compresses to a liquid about half as dense as water. A barrel of liquid CO2 weighs 70 kilograms or 160 lbs. To capture all 35 billion tons of CO2 the world will emit in 2011, we would produce nearly 470 billion barrels of liquid carbon dioxide, or roughly 67 barrels per person alive on Earth. That quantity is more than 17 times the total number of barrels of oil the petroleum industry pumps out of the ground each year.

Fortunately, while the volume is vast, geological structures exist to store this much. The Intergovernmental Panel on Climate Change estimates that geological structures away from fault lines and drinking water could store at least 1.1 trillion tons of CO2, and possibly as much as ten times that. A report by the Global Energy Technology Strategy Platform group at Batelle found geological capacity to store roughly a staggering 10 trillion tons of CO2 safely.

At the high end, that would provide storage to sequester more than 200 years worth of CO2 emissions. Even if we limit our estimates to existing oil and natural gas fields alone, structures whose capacities we’re more certain of, we could store around 900 billion tons of CO2, or enough to keep atmospheric carbon concentrations below 450ppm for the rest of this century. These fields have long term stability demonstrated by the fact that they have held oil and natural gas deposits for millions of years. The carbon they’d sop up would give us significant time to keep working on improvements to zero-carbon power and transport technologies without exacerbating climate change.

The challenge is less in the storage capacity and more in the pumping and transportation capacity. To make a significant dent with carbon capture, we would need to create a pumping and piping infrastructure with a capacity more than ten times that of the current oil industry. That is a major undertaking. It’s well within our capabilities, but not without substantial cost. At the same time, there may be no route to a climatically stable world that avoids this.

How to Make it Happen

A number of carbon capture and storage pilot programs are underway today, but the technology is very much still in an experimental phase. If concerns about drinking water and seismic activity can be addressed – which the IPCC and EPA both believe – How do we turn carbon capture from a science project into a reality?

My firm belief is that the best way to turn any dirty industry into a clean industry is to make it profitable for companies in the industry to do so. Or, to put it another way, the way to encourage change is to make it too costly to remain dirty for any company to want to do so.

This is not meant in any way to be punitive. The coal and oil industries have reached the scale they have and the emissions they have because consumers have demanded more and more energy, and because the industries have not been told to eliminate their carbon dioxide output. It makes no sense to blame industry when consumers and legislators have worked together to create a landscape in which their current actions are the most sensible ones. To change the actions of energy companies, we need to change the landscape.

The best way to go about doing this is to place a price on carbon. Pumping carbon dioxide into the atmosphere, where it causes long term damage to a planet shared by all, should be something one needs to pay for. The price paid should be at least commensurate to the cost of undoing any harm. On the flip side, efforts that remove a pollutant from the atmosphere should be rewarded at the same rate.

We’ve seen estimates of cost of mature carbon capture systems that range from $35 – $70 / ton, and of the very first systems at around $150 / ton. Where should we set the price?

I would propose a price that starts at zero but ratchets up progressively to $100 / ton (in today’s dollars), at an automatic increment of $5 / ton each year. $100 / ton gives buffer room over the current price estimates for carbon capture and storage. This allows for some flexibility if cost estimates turn out to be too low. On the other hand, if those estimates are accurate, or if the cost of sequestering a ton of carbon turns out to be anywhere under the $100 / ton carbon price we would set, then it would be cheaper for power plants to adopt carbon capture technologies than to pay the carbon price. In the worst case, if the full carbon price is paid, the cost of coal electricity, 20 years from now, would be 10 cents higher per kilowatt hour. If capture costs end up at $50 / ton (the midpoint of estimates), then the cost of coal electricity, 20 years from now, would be 5 cents higher per kilowatt hour.

The gradual and predictable increase in the carbon price would soften the immediate economic shock of it, while giving both consumers and corporations clarity about the future and the ability to plan logically for it. A price even 20 years in the future would push utilities to start planning now for how to retrofit existing power plants and build new ones in ways that minimize carbon emissions.

Paradoxically, a carbon price would also slow the rise of oil and other fossil fuel prices, by encouraging conservation now and thus reducing demand.

A carbon price of this size would have other beneficial effects outside of carbon capture. It would make solar, wind, and nuclear power more attractive on a price basis. Over 20 years it would raise the price of gasoline by $1 / gallon, less than the difference in prices between the US and Europe, but enough to make electric cars, hybrids, and new, more fuel-efficient aircraft designs all more attractive as well.

Perhaps most importantly, a carbon price would create a gold rush of carbon harvesters working to pull carbon dioxide out of the atmosphere. Whoever could get their cost of capturing and sequestering carbon dioxide down the lowest would reap the largest profits per ton of carbon captured, driving innovation in ways to capture carbon at ever cheaper prices. A carbon price would align incentives, making it in the best interests of corporations and entrepreneurs to lower the amount of carbon in the atmosphere. That’s something we should all be excited about.

In Summary

Carbon capture and storage technology isn’t a solution to our climate problems on its own. There are unknowns and challenges of scale that need to be addressed. Possible locations for carbon sequestration aren’t infinite in size. They will eventually fill up. But carbon capture can be done, and can be done at massive scale, and at a price that would not destroy our economy. Doing so would give us more time to find ways to switch to inherently zero-carbon methods of powering our civilization and fueling our vehicles. As a complement to efficiency, green energy, and other ways to reduce our carbon emissions, capturing and storing carbon dioxide from our power plans and our atmosphere would be an extremely powerful tool. The best way to encourage carbon capture and storage turns out to be the best way to encourage efficiency, green energy, and other approaches to reducing the carbon in our atmosphere: put a price on carbon emissions.

Sources and further reading

IPCC, “IPCC Special Report on Carbon Dioxide Capture and Storage,” prepared by Working Group III of the Intergovernmental Panel on Climate Change [Metz, B., O. Davidson, H. C. de Coninck, M. Loos, and L. A. Meyer (eds.)]. Cambridge University Press, Cambridge, U.K. and New York, 442 pp., 2010.

International Energy Agency, “Carbon Capture and Storage: Progress and Next Steps,” 2010.

Global CCS Institute, “The global status of CCS: 2010“, Canberra.

Al-Juaied, Mohammed A and Whitmore, Adam, “Realistic Costs of Carbon Capture” Discussion Paper 2009-08, Cambridge, Mass.: Belfer Center for Science and International Affairs, July 2009.

JJ Dooley, RT Dahowski, CL Davidson, MA Wise, N Gupta, SH Kim, EL Malone, “Carbon Dioxide Capture and Geologic Storage“, Batelle Global Energy Technology Strategy Program, April 2006.

Capturing Carbon Dioxide From Air“, US National Energy Technology Laboratory, Klaus S. Lackner, Patrick Grimes, Hans-J. Ziock,

More Efficient Aircraft Designs

The Economist has an article on aircraft designs that could cut fuel use by 50-70%, while still working with today’s airports (a challenge for flying wing designs).  From the article:

Two groups working on the future of aircraft have come up with designs that could meet the practical needs of the industry and still cut fuel consumption by half. These researchers, at the Massachusetts Institute of Technology (MIT) and Imperial College, London, rely largely on existing technologies for many of their designs.

If a B737-800 was morphed into the shape of one of the D-series of aircraft on which Mark Drela is experimenting in MIT’s wind tunnel, then it would be about the same size, could fly the same routes and would carry a similar number of passengers. But the D8.1 version (which could be built conventionally, from aluminium) would use 49% less fuel. The D8.5 (similar, but constructed from composite materials expected to be available by 2035) would burn 71% less.

Read More:  The aircraft of the future: Plane truths | The Economist.


Key Trends of the Next 25 Years

Michell Zappa has a fascinating infographic attempting to lay out timelines for future technologies over the next 25 years. It’s an impressive job of collecting data and laying it out in a way that someone can explore. It’s worth playing with. Click through on the link and you can zoom in and drag the graphic around to see what he’s projected, based upon predictions he’s collected from a dozen or so thinkers.

I do wish the infographic were more of a starting point for exploration. I want to click on some of the circles depicting future technologies and see what he’s using as a basis for the projection.

There are some things missing from the graphic as well, and some things on there that I think are implausible.

In general, when we think about what’s going to come down the pipe in technology, it behooves us to think about economics. What are the costs and cost trends of various technologies (either in R&D or development) vs. the demand for them or their economic return?

For this reason I think his projections about space (a lunar outpost and a space elevator both around 2030, for instance) are either implausible or will happen at a small scale. True, NASA has announced plans for a lunar outpost, but it appears to be backing away from them. Such an endeavor would, after all, be incredibly expensive, and offers little in the way of economic return. A space elevator, on the other hand, would lower the cost of access to space, but its guestimated $1 Trillion cost puts it out of the range of capital outlays any country or set of countries will consider for the coming decades.

On the other hand, I think Zappa under represents the impact of biotechnology and energy efforts over the coming years. An aging population creates a nearly insatiable consumer demand for new and better medical treatments. A growing and increasingly affluent population creates a tremendous demand for more agricultural output (especially as people move increasingly to eating meat, which requires far more land per calorie) and for more energy. The combination of apparently stagnating worldwide oil output and the eventual realization by most of the planet that we need to tackle climate change will force us to make the increasing energy supply a greener one.

Zappa covers Green Energy in the chart a bit, but it doesn’t quite convey that solar photovoltaic electricity, for example, will likely drop below the cost of coal electricity by 2020 (if not earlier), or the likely importance of biofuels created by genetically engineered organisms as ‘drop-in’ replacements for gasoline and kerosene. These are both quite near term impacts that will have a larger impact on the planet than space technologies, robotics, or artificial intelligence.

Zappa has a “Biotech” node which includes both a bit of medicine and a bit of food, but again I would have loved to see a more quantitative approach. Between now and 2050, population will rise by 35% and food demand will rise by 70-100%. Arable land, on the other hand, will not increase. One of the prime applications of biotech (in a broad sense) will have to be the increase of food yields per acre to meet that increased demand. Similarly, as the population ages, there will be more and more demand for therapies against the indignities of age. Stem cell treatments are a fantastic advance, but the major killers will remain heart disease and cancer. And the elderly will pump more and more dollars into products that allow them to age more gracefully, helping them look, act, and feel younger.

I very much applaud Zappa for attempting to lay out such a broad view of the future in a single place. It’s a challenging task that required synthesis of information from a number of sources.

Some things, though, are best looked at quantitatively. I would suggest we all think of the future trajectories of technology as being driven by the intersection of consumer demand (how much money are consumers willing to pump into something) and underlying cost trajectories (is the cost of something dropping or rising, and if so how fast?).

In that vein, here are what I see as the biggest trends going forward (with apologies for placing this only in text).


1. Health & Longevity:

Worldwide healthcare spending is almost $4 Trillion, or around 10% of the GDP of developed countries, and is growing faster than any other category. Today there are less than 1 Billion people on the planet aged 60 or over. By 2050 there will be 2 Billion.

That doubling of elderly populations in OECD countries and China will place increasing demand for therapies that either slow aging (best case and not guaranteed) or which address the illnesses and loss of function, vitality, and appearance with aging. All up, healthcare will likely more than quadruple in total spending and double as a fraction of worldwide GDP by 2050, to more than 25% of the economies of developed countries and as high as 40% in some.

For instance, the US Council of Economic Advisors predicts that, on current trend, by 2040, healthcare spending will consume 35% of the economy of the United States.

That projected level of spending is more or less untenable. The aging population and rising health care costs will create enormous pressures for new technologies that can address medical needs at lower costs. That is one almost certain prediction.

2. Food:

Worldwide food spending is around $3 Trillion. While worldwide population will increase only by 35% by 2050, growing affluence will lead to a growing demand for less efficient meat and dairy foods.

As a result, total demand for grain (which is needed in large quantities to produce meat) is expected to nearly double by 2050.

Source: Bruce Babcock, Charting Growth in Food Demand

At the same time, there is virtually no additional arable land to expand farming into. For farmers to keep up with demand, yields per acre will need to nearly double in the next few decades. At the same time, overpumping of aquifers, debates about pesticides and GMOs, and the energy inputs required in modern agriculture all serve as brakes on productivity gains.

3. Energy & Climate:

Worldwide energy demand is at $4 Trillion today and will roughly double by 2050. At the same time, populations and governments will come around to the need to virtually reduce net carbon emissions. That will place tremendous demand on both low-carbon energy sources and technologies to capture and sequester CO2 and other greenhouse gasses from the atmosphere.

Here is the US Energy Information Administration’s projections for world energy consumption through 2035.

Source: International Energy Outlook 2010, EIA


4. Information Technology:

Information technology (including telecoms, computing hardware, software, and online services) is over $3 Trillion today and is growing at roughly 6% per year. Because it is so useful in so many different arenas of life, demand for it will continue to grow. While demand growth will likely slow over time, it could easily be three times as large in 2050, growing past all sectors except Health Care (which will almost certainly be the largest economic sector on the planet by a healthy margin).



Weighed against these consumer demands we have the underlying price and productivity trends.

1. Moore’s Law

Moore’s Law and its analogues for storage and bandwidth will, if they remain on their current paths, reduce the cost of a unit of computation, data storage, and data transmission by an estimated 100 million times by 2050. It remains to be seen whether these trends actually continue. Both physical challenges and potential saturation of consumer demand loom in the decades ahead. If they do continue, for many current applications, storage, bandwidth, and computation will be effectively free. (There will be exceptions for truly massive scale problems in physics, chemistry, biology, neuroscience, and artificial intelligence, where systems are incredibly complex and problems often scale extremely sub-linearly. These areas may be the prime economic drivers of continued improvement of IT power / $$ by mid century.)

2. The Dropping Cost of Genetic Information Processing

..will have a profound effect on biotechnology and medicine. We are much farther from personalized medicine than Zappa’s graphic would lead one to believe. But the Moore’s Law-like exponential drop in the cost of gene sequencing and gene printing will reduce the cost of sequencing a whole human genome to $5 by 2020 and pennies in 2030. In fact, the price of sequencing genes and of printing gene sequences has been dropping far faster than Moore’s Law:

The resulting flood of data, combined with the continued exponential rise in computing power, will start to make possible the large scale data mining necessary to truly extract valuable medical insights from the genome. Cheaper gene printing, cheaper proteomics, and cheaper experimentation systems based on similar trends will start to make an impact on delivering therapeutics, and also in turning manufacturing via synthetic biology into reality.

3. The Exponential Drop in Green Energy Price/Performance and Density

…if it continues, will herald a green energy revolution. Humanity’s energy use, from all sources, is roughly 1 / 6000th the amount of energy that the sun delivers to the planet. It is a huge and largely untapped resource with practically no greenhouse gas emissions. Solar power up until now has been uneconomical due to low efficiencies and high manufacturing costs of solar technologies. But over the last 30 years, solar photovoltaic cells have increased in energy returned per dollar of manufacturing cost by around 7.5% per year. On current pace, they will cross the price of coal-powered electricity between 2015 and 2020, and be half the price of coal around 2025-2030.

Solar Price / Watt is on an exponential decline and will drop below coal around 2019.

Solar does not solve all problems, of course. Intermittent power supplies (due to nights and cloudy days) make it an imperfect solution, but advances in energy storage will allow solar stations or home solar systems to store up energy during sunny periods and return it during the rest. By the 2030s solar should be fully competitive with coal (the cheapest fossil fuel energy source) for most of the world.


The predictions above could be wrong, of course. The world is full of surprises. Trends in consumer demand sometimes change. Exponential trends in technology are even more suspect and more likely to eventually flatten out. But whether these projections are right or wrong, if we want to have a rigorous look at the future, we should attempt to do so quantitatively, putting together our best data on what people want, on what’s possible, and on the trajectories of both.

As for how to sum this up in a single wonderful graphic, I leave that to someone else today. Perhaps Michell Zappa will take a shot. 🙂

Is Moore’s Law Really a Fair Comparison for Solar?

[This is an update of a post I first wrote in March of 2011, responding to criticism of the analogy of Moore’s Law for solar power. Updating in April 2015, on the 50th Anniversary of Moore’s Law, in light of renewed conversation on this topic.

tl;dr: Moore’s Law is an analogy. As an analogy, it works. And progress is happening far faster than I projected in my ‘solar Moore’s Law’ piece of 2011.]

In March of 2011, as I was researching the book that would become The Infinite Resource, I plotted out the price of solar modules and found an exponential decline. Researching this, I found that nearly every other observer that had plotted the data had found the same. I wrote a guest blog post for Scientific American titled Smaller, Faster, Cheaper: Does Moore’s Law Apply to Solar Cells? In that post, I projected the future cost of solar power if the cost trajectory of solar modules continued, and other costs shrank in the same proportion. And crucially I found that new solar would be cheaper than new coal electricity across most of the US by 2020, and in the sunniest parts of the US by 2015 or 2016.

Paul Krugman linked to this post in his Sunday column Here Comes the Sun some months later. I wasn’t the first to observe the exponential decline in solar module costs or the first to analogize it to Moore’s Law. I just boosted signal, and getting picked up by Krugman boosted the signal even further. In retrospect, there’s much I’d change about the piece: Differentiating retail vs. wholesale prices, talking more about the need for storage, talking about whole system cost reductions, talking more about how subsidies function, talking more about peak-of-day prices vs baseload prices, and more. But overall, it stands the test of time fairly well.

Yesterday, CFR published a post titled Why Moore’s Law Doesn’t Apply to Clean TechnologiesIt’s thoughtful and nuanced. But I think I’ve already responded to most of the points in it, in this piece below.

Before returning to the original piece, I’d note that actual progress in solar power module prices has been dramatically faster than I projected.

In the 2011 piece, the graphs project that in 2015, solar modules would cost just under $2 / watt. We’d reach 50 cents per watt in module price around 2030.

We have 50 cent per watt solar module prices today. Solar module prices are 15 years ahead of where those (at the time, optimistic) projections in 2011 placed them.

Say what you will about the analogy of Solar Moore’s Law – the numerical projections of price that I presented in 2011 were too conservative. Price reduction has happened far faster than the historical norm.


One weakness of the original piece is the assumption that whole system cost would drop at the same pace as module price. Because modules have plunged in price so fast, whole system cost hasn’t quite kept pace (though it’s done surprisingly well, driving by market forces). Another weakness is that the price line to beat is really wholesale electricity prices, around 6-7 cents per kwh, not the 12 cents per kwh I presented in the SciAm.

Even so, the projection of grid parity in the sunniest parts of the United States by 2015 or 2016 appears to have been correct. UBS is informing clients that earlier this year, NextEra, a subsidiary of Xcel energy, submitted bids for new solar projects in New Mexico at a cost of 4.2 cents per KWh. Even after backing out the 30% solar Investment Tax Credit that may soon expire, that would be a cost of 6 cents per kwh, lower than EIA’s estimate of 6.6 cents per KWh for new natural gas. This bid has not yet hit the media. I’ll link to it when it does.

Finally, the original piece didn’t mention energy storage. Storage matters tremendously. And energy storage is also seeing an exponential decline in prices and surging demand driven by real market needs. Battery prices have been on an exponential trend of price reduction for roughly 25 years, and as a recent piece in Nature Climate Change documented, prices are now below what was projected for 2020. Here’s more on the rapid innovation in energy storage.

Now, here’s the original post from 2011, with a few small edits:

A reader at Scientific American comments on my post making an analogy of Moore’s Law to the price trend of solar power raises some healthy skepticism about whether or not the exponential trend in solar watts / dollar can continue.

This is a fine thing to be skeptical about.  As I mentioned in the original post, we shouldn’t expect exponential trends to continue for ever.  Most run up against external limitations at some point and level out or reverse.

It’s also worth noting that the solar gains are far slower than gains in computing.   Computing gains have been roughly 60% in circuit density per year, and more or less the same in the annual gain of computing per dollar.   Solar gains are much more modest, at roughly 7.5% gain per year.   While computing performance per dollar seems to double roughly every 18 months, solar power per dollar doubles every 9 years. [Update: The solar pace over the last 37 years is now 14% improvement for year, or a doubling in watts / $ every ~4 years.] Moore’s Law and the price performance improvement of solar are both exponential trends (at least so far), but they have different slopes. Moore’s Law is clearly faster.

That said, the comparison between the gains in solar watts / dollar and the Moore’s Law increase of transistors per area (or the later morphing of this to computations / dollar) is fairly apt.

In both cases, they’re driven by three factors:

1. Nearly insatiable consumer demand for more of the resource (computing and energy, respectively)

2. Industry expectations.  Any company working on a new microprocessor has to expect that their competition is going to be improving at a rate around that dictated by Moore’s Law (roughly, a doubling of transistors on the same size chip every 18 month).  That gives companies working on new microprocessors a goal post to aim for. If they don’t hit that post, they can expect to be behind their competition.  Similar factors apply in memory, in storage, and in bandwidth, each of which have their industry-noted exponential trends.The same dynamics work in solar photovoltaic power. Solar PV manufacturers have observed the same trend discussed here. As I noted in the original article, the trend is now 31 years old.  Whether or not it will continue for 31 more years, any PV manufacturer has to expect that it will continue for at least the next few. That gives PV manufacturers their own goal posts to shoot for. And the PV market is crowded.  Wikipedia lists more than 50 notable solar PV manufacturers.

UPDATE: In energy storage, where another exponential trend in price reduction exists, industry expectation is also a clear factor. Talk to any energy storage company in the world. They’re all watching this trendline and aiming to beat it.

3. Progress Made by Reducing Materials Per Output. The final factor is the one that makes the gains physically possible.   In both computing and in solar, the gains being made in performance per dollar are being made by reducing the amount of material required to achieve each unit of output.  By etching thinner lines, the semiconductor industry crams more transistors onto the same amount of silicon.  They’re using less silicon per transistor. The solar PV industry, similarly, is using less silicon per watt and less manufacturing energy per watt. Solar manufacturers are doing this by reducing the thickness of solar cells, reducing losses in manufacturing, using more efficient ovens,(slowly) increasing the efficiency of solar cells, and increasingly by looking at techniques that use materials other than silicon. For a look at how industry thinks about this, here is a graph of silicon per watt that Sun Power presented at the SEMICON West Conference in 2007. And here’s a chart of decreasing silicon wafer thicknesses out to 2012 from an article by researchers at Applied Materials Switzerland, specifically focused on reducing silicon grams / watt.

4. Update: Total Cost of Ownership Matters – If there’s one more similarity I’d add between IT and solar (and batteries), it’s this: It’s not just technology cost that matters. It’s the total cost. Corporate buyers of computers long ago realized that the purchase of a computer was only a fraction of what they paid. The majority of the cost is really in the installation, deployment, and management of those systems.

In a sense, solar is no different, and storage will eventually be no different. The cost of the technology is plunging. But the total cost of the system is now more than twice the cost of the technology. To continue the true downward trend in the cost of energy from solar (or solar + storage), the total cost, including deployment, ancillary hardware, and maintenance has to be continually brought down. Arguably, this is now more important than module costs.

The similarity of the three factors tells me that the analogy is an apt one.  That does not guarantee that it will continue forever.  We will eventually hit the limit of what can be physically done to reduce materials needed for solar cells.  But that looks likely to happen significantly after solar PV becomes less expensive than building new coal or natural gas electricity in most of the world. That is, indeed, transformative.

There’s more about the exponential pace of innovation in both storage and renewables in my book on innovating to beat climate change and resource scarcity and continue economic growth:The Infinite Resource: The Power of Ideas on a Finite Planet

The Exponential Gains in Solar Power per Dollar

My post on the Moore’s Law-like exponential gains in solar power per dollar went up at Scientific American yesterday.  Reprinting here with permission.

The sun strikes every square meter of our planet with more than 1,360 watts of power.  Half of that energy is absorbed by the atmosphere or reflected back into space.  700 watts of power, on average, reaches Earth’s surface.  Summed across the half of the Earth that the sun is shining on, that is 89 petawatts of power.  By comparison, all of human civilization uses around 15 terrawatts of power, or one six-thousandth as much.  In 14 and a half seconds, the sun provides as much energy to Earth as humanity uses in a day.

The numbers are staggering and surprising.  In 88 minutes, the sun provides 470 exajoules of energy, as much energy as humanity consumes in a year.  In 112 hours – less than five days – it provides 36 zettajoules of energy – as much energy as is contained in all proven reserves of oil, coal, and natural gas on this planet.

If humanity could capture one tenth of one percent of the solar energy striking the earth –  one part in one thousand –  we would have access to six times as much energy as we consume in all forms today, with almost no greenhouse gas emissions.  At the current rate of energy consumption increase – about 1 percent per year – we will not be using that much energy for another 180 years.

It’s small wonder, then, that scientists and entrepreneurs alike are investing in solar energy technologies to capture some of the abundant power around us.  Yet solar power is still a miniscule fraction of all power generation capacity on the planet.  There is at most 30 gigawatts of solar generating capacity deployed today, or about 0.2 percent of all energy production.  Up until now, while solar energy has been abundant, the systems to capture it have been expensive and inefficient.

That is changing.  Over the last 30 years, researchers have watched as the price of capturing solar energy has dropped exponentially.  There’s now frequent talk of a “Moore’s law” in solar energy.  In computing, Moore’s law dictates that the number of components that can be placed on a chip doubles every 18 months.  More practically speaking, the amount of computing power you can buy for a dollar has roughly doubled every 18 months, for decades.  That’s the reason that the phone in your pocket has thousands of times as much memory and ten times as much processing power as a famed Cray 1 supercomputer, while weighing ounces compared to the Cray’s 10,000 lb bulk, fitting in your pocket rather than a large room, and costing tens or hundreds of dollars rather than tens of millions.

If similar dynamics worked in solar power technology, then we would eventually have the solar equivalent of an iPhone – incredibly cheap, mass distributed energy technology that was many times more effective than the giant and centralized technologies it was born from.

So is there such a phenomenon?  The National Renewable Energy Laboratory of the U.S. Department of Energy has watched solar photovoltaic price trends since 1980.  They’ve seen the price per Watt of solar modules (not counting installation) drop from $22 dollars in 1980 down to under $3 today.


Is this really an exponential curve?  And is it continuing to drop at the same rate, or is it leveling off in recent years?  To know if a process is exponential, we plot it on a log scale.


And indeed, it follows a nearly straight line on a log scale.  Some years the price changes more than others.  Averaged over 30 years, the trend is for an annual 7 percent reduction in the dollars per watt of solar photovoltaic cells.  While in the earlier part of this decade prices flattened for a few years, the sharp decline in 2009 made up for that and put the price reduction back on track.  Data from 2010 (not included above) shows at least a 30 percent further price reduction, putting solar prices ahead of this trend.

If we look at this another way, in terms of the amount of power we can get for $100, we see a continual rise on a log scale.


What’s driving these changes?  There are two factors.  First, solar cell manufacturers are learning – much as computer chip manufacturers keep learning – how to reduce the cost to fabricate solar.

Second, the efficiency of solar cells – the fraction of the sun’s energy that strikes them that they capture – is continually improving.  In the lab, researchers have achieved solar efficiencies of as high as 41 percent, an unheard of efficiency 30 years ago.  Inexpensive thin-film methods have achieved laboratory efficiencies as high as 20 percent, still twice as high as most of the solar systems in deployment today.


What do these trends mean for the future?  If the 7 percent decline in costs continues (and 2010 and 2011 both look likely to beat that number), then in 20 years the cost per watt of PV cells will be just over 50 cents.


Indications are that the projections above are actually too conservative.  First Solar corporation has announced internal production costs (though not consumer prices) of 75 cents per watt, and expects to hit 50 cents per watt in production cost in 2016.  If they hit their estimates, they’ll be beating the trend above by a considerable margin.

What does the continual reduction in solar price per watt mean for electricity prices and carbon emissions?  Historically, the cost of PV modules (what we’ve been using above) is about half the total installed cost of systems. The rest of the cost is installation.  Fortunately, installation costs have also dropped at a similar pace to module costs.  If we look at the price of electricity from solar systems in the U.S. and scale it for reductions in module cost, we get this:


The cost of solar, in the average location in the U.S., will cross the current average retail electricity price of 12 cents per kilowatt hour in around 2020, or 9 years from now.  In fact, given that retail electricity prices are currently rising by a few percent per year, prices will probably cross earlier, around 2018 for the country as a whole, and as early as 2015 for the sunniest parts of America.

10 years later, in 2030, solar electricity is likely to cost half what coal electricity does today.  Solar capacity is being built out at an exponential pace already.  When the prices become so much more favorable than those of alternate energy sources, that pace will only accelerate.

We should always be careful of extrapolating trends out, of course.  Natural processes have limits.  Phenomena that look exponential eventually level off or become linear at a certain point.  Yet physicists and engineers in the solar world are optimistic about their roadmaps for the coming decade.  The cheapest solar modules, not yet on the market, have manufacturing costs under $1 per watt, making them contenders – when they reach the market – for breaking the 12 cents per Kwh mark.

The exponential trend in solar watts per dollar has been going on for at least 31 years now.  If it continues for another 8-10, which looks extremely likely, we’ll have a power source which is as cheap as coal for electricity, with virtually no carbon emissions.  If it continues for 20 years, which is also well within the realm of scientific and technical possibility, then we’ll have a green power source which is half the price of coal for electricity.

That’s good news for the world.

For an update on these trends, see here.

You can also read about how battery prices are dropping exponentially too.

I write much more about solar, wind, energy storage, and why the pace of innovation in them is critical – and hopeful – for both fighting climate change and for long term economic growth in the book I originally did this research for, The Infinite Resouce: The Power of Ideas on a Finite Planet 

Sources and Further Reading:

Key World Energy Statistics 2010, International Energy Agency

Tracking the Sun III: The Installed Cost of Photovoltaics in the U.S. from 1998-2009, Barbose, G., N. Darghouth, R. Wiser.,  LBNL-4121E, December 2010

2008 Solar Technologies Market Report: January 2010, (2010). 131 pp. NREL Report TP-6A2-46025; DOE/GO-102010-2867

Singularity Summit Talk: The Digital Biome – Re-Engineering Life on Earth to Survive and Thrive in the 21st Century

This weekend I was at the Singularity Summit in San Francisco.   On Sunday I gave a talk called The Digital Biome – Re-Engineering Life on Earth to Survive and Thrive in the 21st Century.  (Follow the link to see the slides on SlideShare.)

The basic thrust of the talk is that we’re facing very real and pressing threats to the environment and human civilization – Climate Change, Peak Oil, Ocean Acidification, Species Loss, Fresh Water Depletion, etc…
…and that at the same time, the exponential progress in biology gives us the potential capability to take advantage of capabilities of nature – in some cases re-engineering nature – to overcome those problems.
It’s a fine line to walk sort of talk.  I wanted to get across to the crowd at the Singularity Summit (some of whom are tremendously more optimistic than even I am) that we have real problems.  But I also see a tremendous potential in biotechnology to address these problems, and the fundamental limits of growth on the planet are still orders of magnitude beyond where we’re at.
It seems to have gone well.  A number of people came up to tell me they really liked it, and more than one person called it the best talk of the summit.
Take a look and tell me what you think.

Solar Prices Drop Exponentially for 30 Years

>FuturePundit blogs about projections for $2 a watt photovoltaics by 2010, which would be a reduction in cost of about half from today’s prices.

The interesting thing in this post for me is a link to an Earth Policy Institute page which shows an exponential decline in photovoltaic prices over the last 33 years, from $100 per watt in 1975 to $4 a watt today.

That’s a highly encouraging long term trend. It reflects a “cut the price in half” time of about 5 years, which bodes very well in the long term.

Lots more stats available at the Earth Policy Institute Solar Power Indicators page.


A Solar Grand Plan

>The cover story of this month’s Scientific American is a proposal to build out solar power in the US to supply 70% of the country’s electrical needs by 2050. It looks like a pretty doable plan, actually, requiring no technological advances in solar power beyond what’s projected between here and 2020. The price tag the authors estimate is $420 Billion, which works out to $10B a year, or about ½ of 1% of the US federal budget.


Sidebar with a quick summary of the plan: