"Combined Heat and Power" (CHP) or "cogeneration" systems for producing both heat and electric power are generally mature and really can reduce emissions of CO2 compared to other fossil-fuel technologies. But there are two problems with typical discussion of CHP:
(1) Fossil-fuel-based CHP cannot be a long-term solution on climate or energy because they still burn fossil fuels, and therefore still emit a lot of CO2. Reducing that by 20% or even 50% is not enough; we need to take steps that over the next 30-40 years will bring fossil CO2 emissions close to 0.
(2) Efficiency claims for CHP systems are frequently greatly overstated. Heat is lower-quality energy than electricity, and only at high temperatures does it become close to comparable. Efficiency claims for CHP systems that use high-temperature heat are not so far off, but CHP systems that make use of low-temperature waste heat have much lower thermodynamic efficiencies than usually claimed.
The inflated efficiency claims often lead to assertions that CHP is the "largest" or one of the largest potential solutions. But the number of applications that require high-temperature heat where CHP efficiency really is quite high are limited. And the modest efficiency gains with low-temperature waste heat use, which could be much more widely applied, don't lead to very much improvement in overall energy use. The combining of heat and power production in CHP systems can reduce our fossil CO2 emissions by a few percent, but much more than that is needed in coming decades.
Those of you reading this who are APS members should have received an email in the last few days pointing to a new "commentary" that is proposed, by the society's public affairs committee (POPA), to be attached to the 2007 climate change statement. While overall I found the commentary reasonably fair and somewhat useful as a clarifying measure, it had several embarrassing errors that I hope will be corrected before it becomes official. Below I've included my response to this commentary - it will probably be meaningful only to those who have been granted access, sorry about that...
Todd Woody at the NY Times has had a couple of stories in the last few days on The Bloom Box, or Bloom Energy Server, a solid-oxide fuel cell designed as an on-site distributed generator. Present costs are still rather pricey - $7 to $8 capital cost per watt (or $7000-$8000/kW - I had this mixed up earlier - see this analysis from Jesse Jenkins for details) plus the cost of natural gas as fuel and any operational and maintenance costs (and they're only claiming a 10-year lifetime). Efficiency is quoted at 50 to 55%. Higher efficiency and lower capital costs would be essential to making it truly useful. Still, I find this a good step forward in the technology. Why?
Science journalism is dying - but John Cook's new iPhone app on climate questions points the way to something much better: an at-your-fingertips database of accurate, up-to-date information at multiple levels of explanatory power, addressing common questions on potentially any subject. John's app has been covered in major media, on Real Climate, and on various blogs - I probably should have included his website in the basic climate references list I compiled some months back as well. Read on for why I think this new iPhone app, and the approach it embodies, is so important...
My criticism of various claims about "Combined Heat and Power" (CHP) or cogeneration systems was something I had thought I could keep brief, since the issue was intuitively clear to me. But explaining my understanding of the subject in straightforward non-scientific language has proven trickier than I'd expected. This post constitutes part 2, and will cover problems with many claims of "efficiency" in heating systems; part 3 will be more specifically focused on the several different types of CHP, what is good about them, and what is frequently over-hyped.
President Obama's new plan for NASA has been much reported on in the last few days, for example in this commentary at the Washington Post. The decision to cancel the "Constellation" program seems to have come as a surprise to many people, but it's exactly the sort of bold move that many of us have been calling for for some time now. In an era where China and Russia have national programs with successful human spaceflight behind them, while India, Japan, Europe, Brazil, some smaller nations and many private companies already have their own orbital or suborbital capabilities some of which could be extended to human spaceflight, some already announced, developing yet another rocket for travel from Earth's surface seemed stupendously pointless for a NASA that could do so much more good elsewhere.
I've discussed scientific peer review here before (one more - I really should get those category tags working!) but RealClimate's discussion of Lindzen and Choi (2009) highlights a particular example of recent peer review standards in sufficient
My youngest son (4) loves to browse the videos on the Sesame Street website. It's fun to listen in and watch once in a while, to see what amuses him. One of his favorites recently has been Cookie Monster in the Library (I hope that URL is a stable one - click through to see the video).
Michael Clarke over at Scholarly Kitchen has an interesting post today Why Hasn't Scientific Publishing Been Disrupted Already?. As he points out, the World Wide Web was invented to help scientists communicate. Shelly and I recognized this the instant we heard about WWW in late 1993 - pretty early in web history - and submitted a proposal to Physical Review Letters at the time to use web technology to put the journals online. So, all that has in fact happened, but without, for the most part, much disruption of the organizations and companies that do scientific publishing. Is it because those organizations are very smart and nimble and have been able to keep up with the times?
Discovering truths about the world is not a simple thing. Much of our understanding depends on context - what we already know. One of the central facets of human existence is our relationships with other people, and to the degree we accord others respect and trust, we also assign a higher likelihood of truth to the knowledge of the world that they share. This trust in people is not wrong or irrational - it's a perfectly valid way to economize on the time we need to spend trying to understand. Collectively we are far more intelligent then we would be if we tried to find everything out completely for ourselves. But too much trust in others is also what most frequently leads us astray. In the end, for scientific truths, the only thing that matters is the idea in itself, not the people who came up with it.
It's understandable that with all the concern about climate change and talk of "peak oil" that the central issue in both cases, our use of energy, has received a lot of attention. It is also understandable that with that attention have come many instances of what may charitably be called "optimistic business plans", acclaimed for some time, even quite lengthy periods of time, as "the" solution, or a "core" solution to our energy problems. There are some real solutions out there; there is also a lot of hype and hucksterism. With this and one or two follow-on articles I hope to help people not so familiar with the underlying science get a better grasp of the distinction.
The US Office of Science and Technology Policy has been hosting a discussion on federal open-access publishing policy on their blog. A lot of interesting commentary, although a little overly dominated by Stevan Harnad up to now (but this is exactly up his alley). I think the choices that have been largely looked at though, so far, are too narrow in scope - basically doing something like a big "arxiv.org" or PubMed project on the one hand, or fostering institutional repositories on the other, or some sort of combination. What we really want is not just opening future research, but also expanding access to the vast body of existing research articles - and not just for federally funded US research, but as far as possible, for all of it.
My one or two irregular readers may have noticed a lack of recent posts. I've had rather a lot of other things to keep me busy lately, some work-related, some family, some energy/climate-hobby related, some church. One of which is our new wood stove for home heating. It's good to be off oil, but I'm starting to wonder if this was really such a good idea, with all the work it's taking to gather wood now!
Near the beginning of J. K. Rowling's 4th Harry Potter novel, Harry and friends attend an exciting international Quidditch match. In an opening ceremony, leprechauns drop heavy gold coins on the crowd. Attendees rush to gather them up, and readers only discover 20 chapters later that leprechaun gold vanishes after a few hours. It's not real gold, it just looks like the real thing for a brief time. Rowling is quite artful here in portraying a sharp distinction between appearance and reality, a common theme in the series. Much of the plot revolved around the difference between the reality the reader knew, of Harry's knowledge of the threat from his enemy Voldemort, and the appearance to the general public, or even to high authorities, that all was well. Denial of the reality of a looming threat was rampant.
I have four children. I expect to have at least that many grandchildren one day. I anticipate the world they inherit to be one filled with technical wonders, as mine has been, and also filled with the richness of life and human history. I fully expect their lives to include consumption of energy at a rate an order of magnitude or greater than mine has been; they will travel the world, and perhaps beyond this planet, with a comfort I never knew. They will build and create in both the virtual and physical worlds, they will have freedoms and capabilities beyond our current imaginations. And I know, without a doubt, that fossil fuels cannot sustain this world I envision for my grandchildren - both because the climate and other pollution implications of that level of fossil consumption would be fatal to that future world, and simply because fossil carbon represents a finite resource whose day has been wondrous, but is passing.
The Department of Energy's new "ARPA-E" program has released the list of winners of their first round of funding for advanced energy projects (note: the link goes to the ARPA-E home page and so will surely change, there doesn't seem to be a better one yet though). A version of the following comment was posted at DotEarth along with some others.
In my earlier story I recommended people write to an APS councillor to express their opinions on the matter. I slightly adapted my comments from that article and sent the following. Others should feel free to use some of this as a template if needed.
Dear Dr. XXX,
I'm hoping you'll be attending the Nov. 8 APS Council meeting, or able to forward this along to those who will be there. I'm very concerned about this proposal to "revise" the current statement on climate change. As an APS life member I absolutely support the statement as it stands - it's brief but extremely clear, and based on the science of the IPCC reports (the 2007 assessment in particular, where the analyses of the three working groups seem nicely echoed in the three paragraphs of the current APS statement).
And now for something completely different...
I started writing here in an attempt to open up things about my life that have been somewhat private, but in my own self-indulgence I've felt I ought to share a little more. It's not just thoughts on climate or physics or science that I'm trying to put out here. And the tone's been far too serious lately, so for something a bit lighter... Here's what I've been torturing my kids with the last few weeks, as I've taken up a bit more serious violin practice again, something I hadn't done quite as much of in many years.
First, apropos of some of the discussion below but more urgent than any of that, the council of the American Physical Society is considering revising its 2007 statement on climate change. If you are an APS member with an opinion on the issue, write immediately to one of the councillors; they need your input before the November 8th council meeting.
Last year (2008) we were starting to look at alternatives to our oil-fired burner for heating our house. The house is an almost rectangular 35x60 ft ranch a little over 30 years old, and came with a 1000-gallon buried oil tank, no longer allowed in town codes, so we knew we had to at least get rid of that some time. We finally got that taken care of a few weeks ago. How we're going to heat our house this winter we're still not quite sure. Anyway... one of the interesting options then (and now) was a geothermal heat pump system, and we had several contractors come in and give us quotes. Not cheap at all, mainly because we would have to switch from baseboard radiators to forced air, and putting in the ductwork and vents would take a lot of labor. But there's a 30% federal credit available so we may still go that route.