However, almost all electricity generation thereafter was based on burning coal. In 1964 coal accounted for 88% of electricity, and oil for 11%. The remainder was mostly hydroelectric power, which continued to grow its share as coal struggled to meet demand. The world's third pumped-storage hydroelectric power station, the Cruachan Dam in Argyll and Bute, Scotland, came on line in 1967. The Central Electricity Generating Board attempted to experiment with wind energy on the Llŷn Peninsula in Wales during the 1950s, but this was shelved after local opposition.