Thursday, June 9, 2011

Making waves

I had a very interesting visit this week to Ohmsett, a huge wave testing facility in New Jersey. Resolute Marine Energy, who I mentioned about a year ago, is testing one of their wave energy conversion (WEC) devices there.

Ohmsett is four times a long as an Olympic swimming pool, and generates controlled waves at varying sizes and frequencies. Repetitively measuring output of their WEC with different waves, and adjusting parameters on the device itself produces reams of data. A little (or rather, a lot of) number-crunching later, they should have a pretty good model for some real in-the-water prototypes.

The first in-water tests should be next summer (2012) in North Carolina. We had discussed possibly doing some tests off Criehaven, but NC looks like a better opportunity for them. There definitely will not be any Criehaven tests in 2011; no plans have yet been made for 2012.

Resolute's shallow water design is meant for a water depth (MLW) about 10 to 40 feet - one of the tank testing goals is to decide an optimal depth. It is completely underwater, with a vertical "paddle" that oscillates with every wave. Since it is invisible from the surface, there should be little resistance from beach-goers and landowners, and deep enough to be a non-issue for recreational boaters. I think it will be a very useful technology for islands and some other off-grid situations. The Navy is quite interested for some of their island bases; they have a mandate to supply 50% of their shore-side power from renewable resources.

The obvious question: would this wave energy be appropriate for Matinicus? Maybe. The waving paddle clearly would not work tangled with lobster gear, so a dedicated "no-fish" zone would be needed, and respected. The no-fish zone to produce a useful amount of electricity might be 50 feet by 100 feet, parallel to the shore, in 20-40 foot depths, in an area with good wave action. It would not completely replace the diesel generators, but since waves don't "disappear" instantly (unlike wind), there would always be time to start the generator. My very rough guess (without wave data or design data) is that it could produce 90% of the winter electricity demand and 50-75% of the summer demand. However, unless the fishing community is 100% behind it, there is no point in pursuing it.

Does anyone have any estimates on how often we have no surf, winter or summer? Love to hear from anybody.

No comments:

Post a Comment