Sunday, 5 April 2015
climate change and renewables not what you think
I guess I should say "affect" rather than "mess with," because according Holdmann, the changes are likely to be a mix of positive and negative.
Biomass, which theoretically could meet about a third of the states energy needs, could get a boost with the lengthening of the growing season already underway -- or it could take a hit as forest fires and insect outbreaks continue to increase.
Ocean energy and wind power could both be affected by changes in storm patterns, and solar power potential could drop if theres more precipitation and cloudy days. (Holdmann, a mechanical engineer, said her solar installation generally meets all her needs during the summer -- "unless Im going to run some big power tools.")
Hydropower could be affected, too. Norway, which gets almost all of its power from hydro, built most of its dams between the late 70s and early 90s at a time when the North Atlantic Oscillation was abnormally positive and there was a lot of precipitation in Scandinavia, Holdmann said. Engineers planned for those wetter conditions, and now the country is running into shortages during a drier, cooler period.
Hydropower can be also be affected by erosion associated with severe weather or thawing permafrost (siltation can decrease reservoir size and damage turbines), and by changes in the rate of glacial melting, which could increase or decrease river flow.
"If the glaciers recede to the point that they disappear, of course that poses a problem," added a woman working on hydro projects. (Holdmann spoke during an ACCAP teleconference.)
Holdmann broke down AKs (the earths?) potential renewable resources into six major categories: biomass, ocean, wind, solar, hydro, and geothermal.
Even geothermal could be affected, she said. Geothermal power relies on adequate water flow into (and back out of) the ground, as well as a source of cool water or air to create the temperature differential needed to make the power.
Holdmann finished with a slide showing the six categories. She said she had planned to tack some arrows on them showing which would likely do well and which would do less well, but canned that idea when she realized that almost all of them could be affected positively or negatively by climate change.
Ultimately, the lesson is probably that you shouldnt assume a stable climate when you plan a big project. Dan White, the head of the universitys Institute of Northern Engineering, talked about this, too -- not only are some builders using outdated assumptions about number of heating degree days and so on, theyre also assuming that the climate wont change over the course of the buildings life, he said.
People in Juneau are talking about a dam on the Susitna River as a hundred-year solution for energy in Alaska. Holdmann said it would probably be good to consider how climate change could affect the multi-billion dollar project.
Holdmann used to work at the Chena Hot Springs Resort and helped get their geothermal plants running. Heres a story on Chena from the February issue of Popular Mechanics.
Go Gwen!
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