The cap existed because power system operator Red Eléctrica de España (REE) believed that if it accepted more wind onto its network, customers could wave goodbye to secure supplies of electricity. It advised government that a disaster was in the making. Just 18 months ago, the Spanish market was in danger of peaking not long after the German market, but for lack of utility co-operation, not lack of windy sites.
System operators can live and learn, however. REE's growing familiarity with wind power has taught it much. In August it allowed spot penetration of wind to go as high as 31% of demand -- and it is not batting an eye at 20 GW. Indeed, REE is showing every sign of rising to the challenge of integrating ever more wind.
The wind industry deserves much of the credit for REE's change of heart. Nearly three years ago it recognised that confrontation with a frightened utility was not the way to go. Since then, cat and dog scraps with REE at Spain's wind conferences have stopped.
Today, it is heads together to tackle the technical challenges of running a power system with fluctuating supply as well as fluctuating demand. The work is well advanced, but like the progress bar on a PC, has slowed to a snail's pace at 98% completion. Blocking the way is agreement on a few milliseconds here or there in the speed that wind plant must respond to grid faults. Those fine details will determine technology requirements, so the uncertainty is slowing new development.
Such is the political pressure to continue the wind success story, that once agreement is made, there will be little hindering the floodgates from fully opening. Central government is fighting rising CO2 emissions and the 17 regional governments, mindful of 30,000 jobs already created by the wind industry, are pushing for a target of over 30 GW.
What's more, REE's four utility shareholders are beginning to push hard too. Iberdrola proudly proclaims itself the world's leading wind operator and wants to remain so. Competitor Endesa, Spain's biggest coal burner, increasingly sees wind as the way to reduce its hefty fines for exceeding CO2 emission limits.