Favored Wind Speed Source: Dvorak, M. J., Archer, C. L., and Jacobson, M. Z., (2010). California offshore wind energy potential. Renewable Energy. Funnel flow at the GG Bridge: • Northside flow additive • Southside flow subtracts Better Wind Good Wind Of course tidal currents are also a consideration
Error (% of wind farm) Adopted from Ahlstom, et al., 2013 and WEPROG Persistence best: You don’t need a strategist to tell you which way the wind blows… Physics based model (e.g. Sail Tactics) best: 40 minutes plus Stochastic + machine learning best: 10-40 minutes
40 minutes • Forecast error increases over time, i.e. yesterday’s forecast is less accurate than today’s • Having the newest forecast gives strategic advantage (but Rule 41…) 10 What we learned from wind power forecasting:
Create fresh forecasts every morning to improve accuracy • Use supercomputing to deliver just-in-time forecasts • Make beautiful maps that captivate the sailor’s mind 11
(www.vapor.ucar.edu), a product of CISL at NCAR Angel Island Marin Headlands San Francisco Treasure Island Berkeley Oakland Tiburon Pacific Ocean Richmond
"We studied your forecast and kept to the right of the fleet to take advantage of the shift to the right expected to take place around 2:30 PM. And the shift of almost 90 degrees happened a few minutes after 2:30 PM as you had predicted, and we passed all boats in our class and about half of the entire fleet.“ -Trig Liljestrand, Skipper, J/90 Ragtime 19 Photo credit: norcalsailing.com
sails "The Sail Tactics wind forecast …was very helpful, and contributed significantly to our win of that event. As the forecast indicated, the wind was light at our East Bay start and built significantly in the Central Bay. We carried the #1 jib with a flattener on the main through the brief heavy winds, expecting from the forecast, that the winds would be lighter outside of the bridge – thereby eliminating two costly jib changes." -John Clauser, Skipper, 1D48 Bodacious+ 24 Photo credit: Bodacious+ Facebook page
Created a 200-m resolution forecasting system for SF Bay • Created a responsive website and mapping backend at SailTactics.com • SailTactics.com subscribers 1st place in every major race of 2014 in the SF Bay 31