SNP leader alex Salmond s pledge to produce 100% of Scotland s electricity needs through renewable energy by 2020 has been branded  pure fantasy  by Labour.  The party s manifesto targets a renewable energy target of 100% in just nine years, as well as the creation of 130,000 jobs in the  low-carbon economy .  Mr Salmond, who launched the manifesto at the Royal Scottish academy of Music and Drama in Glasgow, said:  We are going to engineer the 21st century, just as this city and this country engineered the 19th century.  He said he wanted to  reindustrialise Scotland through the green energy revolution where we lead the world .  Scotland s vast renewable power sources are an enormous opportunity,  he added.  The proposal says the 100% target can be reached because of the scale of Scotland s offshore renewable potential. It predicts Scotland will be a major exporter of electricity with  no upper limit to our ambition .  However, Lewis Macdonald, the Labour Party energy spokesman, said:  Labour is behind the drive to produce more electricity from renewable sources but alex Salmond s manifesto pledge is pure fantasy.  The current target of 80% for 2020 is already extremely ambitious and will be difficult to achieve, so to go beyond that is simply unrealistic.  This pledge is from a party that when in government for the past four years failed to process many applications for new wind and hydro power projects within their own targets.  While they dithered, thousands of megawatts of potential renewable energy was going to waste.  He said the SNP was yet again in danger of making promises they knew they could not keep.  But the targets were welcomed by Dr Richard Dixon, director of environmental group WWF Scotland. He said:  The SNP s new 2020 renewable electricity target is a vital step in moving towards a low-carbon economy.  This excellent commitment will help Scotland meet climate targets, create green jobs and exports, and sends a strong message to other countries.  a widely publicised report from energy consultants Garrad Hassan, sponsored by Friends of the Earth Scotland, RSPB and the WWF, claimed last year Scotland could comfortably meet 100% of ele