Updated, 2127 EDT, 10th August 2015
The blog, Science of Doom, has taken on a new thread discussing the technical feasibilities and problems associated with building out zero Carbon energy in the context of an electric grid. As such, it provides a separate, albeit not independent look at some of the problems with such a rollout. There are
two four postings at present,
- Renewable Energy I
- Renewables II – Solar and Free Lunches
- Renewables III – US Grid Operators’ Opinions
- Renewables IV – Wind, Forecast Horizon & Backups
The second installment intermingles some interesting reports on the manufacture and efficiencies and operations of solar PV with energy required to produce them. Okay, sustainability analysis is always good and interesting, but what’s the point? Just the material in one kilometer of natural gas pipeline has an embodied energy of over 200,000 kWh. That’s assuming 15 MJ/kg for embodied energy of pipeline steel, 10 mm of pipe wall thickness, and 20 cm pipeline outside diameter, using this chart (and converting to metric). The embodied energy of such steel is a little over 4 kWh/kg. And the pipe mass is about 48 kg per meter run.
When this blog post was written, there were only two postings at Science of Doom. If I have comments, I’ll probably make them there, not here. The fourth installment looks, to me, particularly interesting, but that’s because I have a soft spot for control system-related problems.
I tried to post these comments at the site, but could not, possibly because of policy about including links in the Comments. I consider the links crucial, so I am posting here. Perhaps readers of SoD will find this. Perhaps not.
I wish SoD would not refer to these as “renewable energy”. Waste-to-energy is used a lot in Massachusetts, and it is hardly zero Carbon, something not missed at all in the recent U.S. EPA Clean Power Plan.
Anyway, it will be interesting to see where the calculations there end up. As a reference for comparison, not saying it is necessary any better or worse than SoD‘s, I offer links to the so-called “levelized cost of energy” or “LCoE” produced by the U.S. Energy Information Administration. They attempt to roll in transmission and financing factors for a head-to-head comparison of different modalities, even different kinds of, say, natural gas. Two tables for the publication from 2015 are available. As always, I wish people who produced these tables put in some kind of uncertainty bars. Maybe those clutter the table, but there’s really no excuse for leaving them out these days, at least not computationally. Nevertheless, the LCoE from EIA are interesting, and it will be good to see how SoD‘s numbers come in. EIA also updates these, roughly annually.
There is also the seemingly massive study done by Mark Jacobson and colleagues at Stanford, which seems to be at odds with the “secure supply” arguments offered at the beginning of the first SoD post. I don’t know which way it goes. I’m not yet a good enough student of the subject to be able to have a technical opinion on the matter, although readers know my enthusiasm for any engineering proposals that uses the market to move what we need to do forward, that is, mitigating climate disruption. Jacobson and company propose an enormous build-out of wind power at spatial scales on the order of the size of weather systems in order to decorrelate availability. They also insert solar, where appropriate, noting how, as is the case for California, the anti-correlation between wind power and solar.
(Click on image to see a bigger photo.)
That figure is from NERC, by the way. What’s NERC? It’s the North American electric reliability organization. They are supposed to assure for the USA and Canada that whatever is needed in terms of electricity is always there to provide it.
This has engineering implications. For if power needs to be borrowed from afar to offset local unavailability, there are transmission losses to be considered. Jacobson, et al also posit high accuracy day-before forecasting as an important component of their vision of a smart grid. I like the idea of exploiting the stochastic nature of wind and solar availability in a national energy system. I like the idea of taking advantage of the comparably dirt cheap cost of erecting land wind turbines and community solar (ocean turbines are another matter) to build a huge amount out. I’m not sure this plan, however, can cope with what I perceive to be the pervasive and deep selfishness I see in sectors of the American community. I do know that we, being some of the richest people on the planet, collectively and otherwise, there will be a price to pay if we don’t wise up.
I have heard claims from local wind and solar producers (in New England) that wind is stronger in winter, but I have not yet found data to back that up.