Limitless solar?

One of the things I have been almost continuously talking about in the realm of renewable energy is the need to diversify our sources of energy. Another is the need to beware of people who preach that there is One True Solution. It was thus with great interest that I read about an upcoming paper in the Proceedings of the IEEE.

In this paper, Derek Abbott of the University of Adelaide argues that solar, and in particular, solar thermal, is the Ultimate Answer to the world’s energy problems.  In fact, according to Physorg, he claims that solar thermal can last us for “the next billion years.”

Despite this claim, the quoted numbers in the article and the conclusions are actually pretty reasonable in general. Solar thermal is the most cost-efficient (although certainly not the most space efficient) renewable technology in terms of energy yield.  However, stating that solar thermal by itself is sufficient for the next “billion” years is rather unreasonable.

Either Abbott presumes that the rate of growth of energy usage on the planet will slow down to nearly nothing or that we will eventually fill near-Earth space with solar collectors and ship either hydrogen or microwaves back down to Earth. No other possibility can justify his statement. As I calculated some time back, at modest growth rates, there is a much-closer horizon of about 500 years before we start running up against the limits of solar power.

There are also other issues in the article that should be addressed. The first is the cost, both capital and variable, of transmission lines in his scenario. If, as he suggests, we convert 8% of the desert land in the world to energy production, we are faced with the challenge of either building transmission lines to the hinterlands, which are on average about 30% efficient, or according to his scenario, generating hydrogen, liquefying it, and shipping it. I don’t know the efficiencies of electrolysis of water, or of hydrogen liquefaction, but in any case, there are three lossy steps here, before that hydrogen is either burned or passed through a fuel cell to make electricity.

Don’t get me wrong: in large part I agree with Dr. Abbott. Both my numbers and his point to the same conclusion – that solar must be a part of any renewable future. My primary concern about this article and others like it is that they will serve to skew the funding and research environment in renewable energy the same way that the biofuel craze has. We have a good way to go before we can replace fossil fuels in their entirety and it seems clear to me that as we transition away from a fossil fuel energy monoculture, we would do well to avoid another one.

Notes from my Renewable Energy talk

As promised, you can click through here and get a list of resources that I used in putting together my talk and that you might find helpful in general. I appreciate the great audience that I had – everyone was really engaged in the subject and I’m glad that so many of you got a lot out of it.

There are a couple of points I want to reiterate. First is that I think that true wealth can only be measured in Joules, the unit of energy, and that access to energy is a key human rights issue. I also think that the current and coming energy crisis can be solved by breaking both design and technology constraints on our production and use of energy. Of these, I think that the design constraints are going to be hardest to solve.

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Renewable Energy 101

This Friday, I’m going to be speaking at Asheville Green Drinks about renewable energy. The event starts at 6 pm and I’ll start talking at around 6:30. The blurb about my talk is up on the AGD website already, but I wanted to write a little bit about why I’m giving this presentation.

Talking to lots of people has made me realize that it is easy to be overwhelmed by the quantity of information out there about renewable energy.   Energy production and consumption is a complex topic and it is made more complex by those who have the most financial interest in the field tossing out truths and truthiness, often out of context, in order to solidify their position. And without some kind of base level of knowledge, its impossible to think critically about the news and propaganda that’s flying around in the media.

What I want to do is to give a quick overview of the state of the art in renewable energy – pros, cons, myths, and challenges. In addition, I’m going to talk about the size and scope of the “energy problem” that the world is facing and why its of utmost importance that we solve it, rather than deferring it or succumbing to it. I’m going to talk about why energy is the only true measure of wealth and how access to energy is a human rights issue. And, I’m going to end up by giving my perspective on what the ultimate solution will look like.

Its shaping up to be an exciting presentation.


Robert Rapier at the R-squared Energy Blog has written a very good analysis of how ethanol may be more efficient a transport fuel than gasoline, despite the fact that ethanol contains fewer BTUs per gallon than gasoline. The upshot of it is that because of ethanol’s incredibly high octane rating (over 100!), it is possible to run an engine on ethanol at a much higher compression ratio than one could with gasoline. This would allow you to extract more work from the ethanol than can be extracted from the gasoline.

(note: Robert works for Accoya, one of the most interesting green materials companies out there. I currently have a sample of their product and if I order from them for a project I’m working on, I’ll blog about it here.)

Investment in R&D for sustainable technology

I just finished Common Wealth, by Jeffrey Sachs. The book is a fairly dry layout of why we aren’t meeting the UN’s Millennium Development Goals and what the consequences of that failure may be. I can’t recommend the book to the casual reader, because of its incredible denseness, but it does contain a fair amount of useful data for those of us who are thinking in the Bright Green mode.

One tidbit that I found interesting was Sachs’ estimation of the required investment in research and development in sustainable technology in order to address the issues in climate change, water and food security, disease, et al. that the book covered. This required investment was set at 0.2% of GNP of the developed world. By his calculations, which were likely made in 2007, this amount is equal to 70 billion dollars. While his estimation methodology was unfortunately not clearly disclosed, lets run with it for the time being.

By comparison, the 2007 NSF budget was 5.9 G$ (source:, the NIH budget was 29 G$ (source:, and the Department of Defense research budget was 72 G$ (source: Defenselink). Exclusive of other smaller research programs, such as the Department of Energy research programs and NASA, this represents around 107 G$ in funded research. By comparison, the 2007 cost of the Iraq War (specifically excluding Afghanistan and other “War on Terror” expenditures) was 123 G$ (source: CBO)

The implication of these numbers is that it appears to be quite feasible to fund the required research and development in sustainable technology, perhaps even unilaterally. Further, investing that 70 G$ above and beyond current research funding would at least partially address the “green jobs” development that President-elect Obama has been advocating. While some portion of this money would go to academic grants, some non-trivial portion of the funding should be made available in a SBIR/STTR program. Additionally, some technology-driven small business development funds, something like an angel investment fund for sustainable technology, would encourage green job growth while meeting these sustainable technology R&D goals.

It also seems reasonable that such an initiative would incentivize growth in the science and engineering fields. Despite a lot of ado about the need to train more scientists and engineers, many technical fields are and have been producing a glut of students with advanced degrees (as Daniel Greenberg and various industry publications, such as Physics Today and C&E News, have pointed out.) It also goes without saying that once a technical professional transitions from science and engineering to business or law, they do not return – the disparity in pay scales is generally insurmountable, at least in my experience. Driving the demand for technical professionals with these R&D incentives could absorb at least part of this glut, preventing the loss of the most talented individuals from the technical fields.

Above all, the goal of this funding is worthwhile: many of the challenges facing the world have solutions that are either in whole or in part technological. While I am always skeptical of throwing money at problems, I find a world of difference between things like funding direct food aid to developing countries and funding research in drylands agriculture and permaculture in order to improve cropland yields while reversing soil degradation. The former is simply spreading the wealth while the latter so very clearly creating new wealth for the entire world. When these Millennium goals are met, political scientists and economists argue that conflicts over scarce resources in the developing world will dwindle. It seems reasonable , then, that the best investment in foreign aid and development should start here. Hopefully, President-elect Obama’s advisors will encourage him to champion this opportunity to make such an investment in sustainable technology.

Genius Grants

I make it a point to read up on each year’s MacArthur Fellows. These MacArthur “Genius Grants” are unlike Nobel Prizes in that they are more often awarded on the strength of what the recipient will accomplish in the future than on the strength of what the recipient did years ago. More importantly, I’ve found at least one Fellow every year whose work has been so inspiring to me that I’ve continued to follow it over the years. The first of these was Dr. Angela Belcher, a professor of Materials Science at MIT. I’ve also been pleased when I see folks whose work I’ve admired recieve the award, such as Saul Griffith, the founder of Squid Labs and David Macauley, the incredible illustrator of “The Way Things Work.”

This year, one of the most inspiring recipients of the MacArthur Fellowship is an agriculturalist named Will Allen. His non-profit, Growing Power, maintains an urban farm in Milwaukee, providing fresh vegetables to the residents of the distressed inner city there. Regular readers here will note that I have a strong interest in urban agriculture and small-lot permaculture, so it is especially rewarding to see the MacArthur Foundation take interest in the kind of project that Will Allen is leading.

The New York Times published a great article about a month back on Will Allen and Growing Power and MAKE magazine has the video of an interview with him.

Worldchanging on Walkscore

The folks at Worldchanging point out the critical flaws in Walkscore. I had a similar take on the site about a year ago, though one that was a lot less in depth. Check out the Worldchanging article for a very insightful take on why WalkScore’s approach is outdated (terrible business model), as well as some commentary on the Second Life tool called Carbon Goggles.

My take on Carbon Goggles is something between “obvious” and “pointless.” Second Life has utterly failed to impress me in the suspension-of-disbelief department, thus I’m much more likely to be moved by data on carbon impact than on something that gimmicky. I suspect that while such gimmicks do tend to be effective in getting points across to folks who are not intimately familiar with the subject at hand, the Second Life audience is one that is not ill-educated on climate change.