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Report from U of M Renewable Energy Workshop Oct. 12

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I attended the Renewable Energy Workshop today sponsored by the U of MN Electrical Engineering Department. As expected, it was largely technology-focused, with some general discussions of the challenges facing renewable energy here and elsewhere. (And a good buffet style lunch). Here a few salient points of the talks I attended.

A Power Grid for the Hydrogen Economy - Thomas Overbye, U of Illinois

The speaker talked about his research into superconducting transmission lines. The idea behind the project is to supplement our existing grid with a network of underground high voltage DC transmission lines made with superconducting material. The benefit of using superconductors is that the current density can be much higher, so fewer transmission lines have to be built. Line losses would also be minimized.

Each line would consist of a superconducting core for carrying the electricity with an outer ring of liquid hydrogen, which would act both as a coolant and an energy storage mechanism. During times of low electricity demand, excess electricity from renewable sources would be used to create the hydrogen via electrolysis.

Though such a grid is technically feasible, cost is a major issue, though the speaker was quick to note that anything transmission related is expensive. He quoted a figure of roughly $2.5 million per mile to install these cables. Water scarcity may also be an issue in some places.

Lessons from Norway - an unlisted speaker, didn't get his name

(A grad student actually did this talk in place of his professor, who was scheduled to speak but couldn't make it.)

This talk mainly focused on the challenges facing Norway in meeting its future electrical demand and making use of its vast renewable energy potential (enough to supply twice that of its current annual consumption.) Currently, 99% of Norway's generation comes from low cost hydropower. However, similar to here, demand is outpacing supply. More supply will have to be brought on in coming years.

I was struck by how similar the challenges facing renewable energy are to here - public resistance (in the case of wind), cost (wind energy is still more significantly more expensive than hydropower), and political uncertainty (will subsidies continue?) Norway is also facing transmission limitations, just like here.Especially of note is that public resistance to wind energy projects has increased in recent years, for all the typical reasons - avian mishaps, other wildlife impacts, and aesthetics.

Planning for Renewable Energy at a MN Utility - Glen Skarbakka, Mgr of Resource Planning, Great River Energy

The speaker talked about the challenges of meeting GRE's rapidly growing load (about 100 MW/year) while incorporating renewables. GRE's load is mostly residential, meaning that demand goes way up in the summer, but varies a lot day to day, depending on weather. This makes it a challenge to use wind energy, which is not dispatchable in the traditional sense (though forecasting has gotten highly accurate.)

I was mostly impressed by GRE's goals to reduce its CO2 emissions to 2000 levels by 2020, as well as doubling its renewable objective of 10%. The speaker admitted that meeting the first will be extremely challenging, to say the least.

Wind Energy - Present Projects and Potential in Minnesota - John Dunlop, American Wind Energy Association

The speaker talked about how wind turbine technology has advanced over the last 20 years and how wind energy continues to grow rapidly in the US and elsewhere. He also provided a nice summary of the recent situation with the Dept of Defense blocking new wind farms due to concerns over radar. The report finally came out on Sept. 27, 143 days late. It didn't really say anything that could not have been written in one day - only that wind farms can interfere with radar. It didn't offer any mitigation measures to help current or future projects move forward. Sounded like a great use of taxpayer dollars.

Update on CapX 2020 - Terry Grove, GRE

The CapX project is an ongoing transmission planning project involving all major utiltiies in Minnesota, planning transmission needs through 2020. I already knew how long this process takes, but the uninitiatied would probably be shocked. Though, there are good reasons it takes this long. The Certificate of Need process for the first group of lines, mainly to improve reliability, alone will take through 2008. Then route permits have to be aquired, which will take through 2010. During this time, lots of meetings are held with city governments, landowners, and other agencies. The proposed Brookings -SE Minnesota line alone will require that 200,000 landowners be notified. This is just a massive undertaking.

From what I've heard, the last round of tranmission construction was an extremely drawn out and painful process. It will be even worse this time around, due to the industry restructuring that has occured since then. Now, independent power producers can bid in new projects to the MISO queue. Most of these projects fail to get off the ground, since banks won't supply the financing until a power purchase agreement is signed - a chicken and egg problem - meaning that planners don't know where new generation will actually be.

Results of Research Funded by NSF, Xcel Energy, and ONR - Ned Mohan, Electrical Engineering, U of MN

Ned gave an overview of renewable energy-related research in the EE department, then talked mainly about a matrix converter his research team developed. The converter can be used with any variable speed generator, including wind turbines and will boost power output by 1.5X of nameplate ratings. This would also eliminate the problem of bearing currents in typical motors, which eventually destroy the bearing and represent a major maintenance headache. Ned also talked about the benefits of using silicon carbide (SiC) in power electronics, which improves device performance by 10-100 times over plain silicon (Si). The cost of SiC continues to fall, making the use of this material more feasible.