Comparison of AEO 2008 Natural Gas Price Forecast to NYMEX Futures Prices

On December 12, 2007, the reference-case projections from Annual Energy Outlook 2008 (AEO 2008) were posted on the Energy Information Administration's (EIA) web site. We at LBNL have, in the past, compared the EIA's reference-case long-term natural gas price forecasts from the AEO series to contemporaneous natural gas prices that can be locked in through the forward market, with the goal of better understanding fuel price risk and the role that renewables can play in mitigating such risk. As such, we were curious to see how the latest AEO reference-case gas price forecast compares to the NYMEX natural gas futures strip. This brief memo presents our findings. Note that this memo pertains only to natural gas fuel price risk (i.e., the risk that natural gas prices might differ over the life of a gas-fired generation asset from what was expected when the decision to build the gas-fired unit was made). We do not take into consideration any of the other distinct attributes of gas-fired and renewable generation, such as dispatchability (or lack thereof) or environmental externalities. A comprehensive comparison of different resource types--which is well beyond the scope of this memo--would need to account for differences in all such attributes, including fuel price risk. Furthermore, our analysis focuses solely on natural-gas-fired generation (as opposed to coal-fired generation, for example), for several reasons: (1) price volatility has been more of a concern for natural gas than for other fuels used to generate power; (2) for environmental and other reasons, natural gas has, in recent years, been the fuel of choice among power plant developers (though its appeal has diminished somewhat as prices have increased); and (3) natural gas-fired generators often set the market clearing price in competitive wholesale power markets throughout the United States. That said, a more-complete analysis of how renewables mitigate fuel price risk would also need to consider coal and other fuel prices. Finally, we caution readers about drawing inferences or conclusions based solely on this memo in isolation: to place the information contained herein within its proper context, we strongly encourage readers interested in this issue to read through our previous, more-detailed studies, available at http://eetd.lbl.gov/ea/EMS/reports/53587.pdf or http://eetd.lbl.gov/ea/ems/reports/54751.pdf

Structural basis of cooperative DNA recognition by the plasmid conjugation factor, TraM

The conjugative transfer of F-like plasmids such as F, R1, R100 and pED208, between bacterial cells requires TraM, a plasmid-encoded DNA-binding protein. TraM tetramers bridge the origin of transfer (oriT) to a key component of the conjugative pore, the coupling protein TraD. Here we show that TraM recognizes a high-affinity DNA-binding site, sbmA, as a cooperative dimer of tetramers. The crystal structure of the TraM–sbmA complex from the plasmid pED208 shows that binding cooperativity is mediated by DNA kinking and unwinding, without any direct contact between tetramers. Sequence-specific DNA recognition is carried out by TraM’s N-terminal ribbon–helix–helix (RHH) domains, which bind DNA in a staggered arrangement. We demonstrate that both DNA-binding specificity, as well as selective interactions between TraM and the C-terminal tail of its cognate TraD mediate conjugation specificity within the F-like family of plasmids. The ability of TraM to cooperatively bind DNA without interaction between tetramers leaves the C-terminal TraM tetramerization domains free to make multiple interactions with TraD, driving recruitment of the plasmid to the conjugative pore

Making european-style community wind power development work in the United States

Once primarily a European phenomenon, community wind power development--defined here as one or more locally owned, utility-scale wind turbines interconnected on either the customer or utility side of the meter--is gaining a foothold in an increasing number of states throughout the United States. This article describes the various policies and incentives that Minnesota, Wisconsin, Iowa, and Massachusetts are using to support community wind power development, and how state and federal support influences the types of projects and ownership structures that are being developed. Experience in these states demonstrates that, with an array of incentives and creative financing schemes targeted at community-scale projects, there are opportunities to make community wind work in the United States