Guardian: If Britain is to generate a third of its electricity from wind power, many upland areas will be blanketed in wind farms, but people in the lowlands may be shocked to find giant pylons carrying 400,000 volts across favourite areas of the countryside. Bringing so much wind power from Wales, the Highlands and offshore demands a £5bn-£9bn upgrade and expansion of the high-voltage grid with larger, heavier pylons, up to 220ft high, according to National Grid, the company responsible for …