OFFSHORE wind farms could generate enough electricity to power all Scotland's homes within a decade, according to ambitious Scottish Government plans published yesterday.  The blueprint said nearly 3 gigawatts could be produced by 2020, sufficient for three million households.  Dr Dan Barlow, head of policy for WWF Scotland, said: "This announcement marks a major step toward Scotland fully realising the massive renewable resource around its coastline and ending our reliance on dirty coal and nuclear power."  aedan Smith of RSPB Scotland, said: "The plan is key to ensuring the necessary growth in offshore renewables is delivered without having an impact on Scotland's sensitive marine environment."