Deutsche Welle: Scotland has set itself a target of meeting 100 percent of its electricity consumption from renewable sources by 2020. That seems like an ambitious goal. How are you going to achieve it?

Fergus Ewing: We are confident, that the target, while being ambitious, is achievable. Renewables and emissions targets go hand in hand. Like Germany, we do not wish to see nuclear power stations. We are - in relation to our emissions - almost two thirds of the way towards meeting our 42 percent target by 2020. Our emissions have fallen by 27.6 percent from 1990.

With regard to our renewables targets, in 2011, we generated 35 percent of our electricity from renewables, which is a substantial increase from before. We have a long way to go, and there are many challenges. We are tackling these methodically and working with industries and universities as well as seeking to build and maintain a constructive relationship with the UK government, which shares our objectives on renewables and emissions.

Presumably one of the challenges would be getting the renewable energy from the areas where it's produced onto the national grid and then transported to where it is needed?

The upgrade of the grid is essential in Scotland and the UK. The grid was constructed around fifty or sixty years ago to take power from coalfields in the industrial heartlands of Scotland and England to the population who were living in the heartlands. So there was no need to connect the grid to the Pentland Firth [Ed. note: the area between northern Scotland and the Orkney Isles] or the West Coast of Scotland.

So we now need to connect the grid to where the offshore wind, the wave, tidal, onshore wind energy prospects are. And they are not in the center of our cities. We have a plan to upgrade the grid, and we have an improved investment of seven thousand million pounds ($11.3 billion). These are practical problems, which can be solved by government and industry working together. It takes some time - years to do that - but where there is a clear leadership and a will to succeed. I think in Germany and in Scotland and the UK, we can succeed.

Are you confident the grid will be extended in time to meet the 2020 targets?

We have already made substantial progress - faster than our friends south of the border. Obviously, the capacity to do that is another challenge, because it requires design, civil engineering and companies to deliver it. The government has to make sure we can provide the necessary training for people in the construction sector perhaps, to diversify into grid work away from their traditional construction sectors, which have had difficult times recently.

Had it not been for the success we had in onshore wind, there would have been no case, no rationale, no justification for the grid upgrade. Perhaps in forty or fifty years' time we will be seeing a European supergrid, and electricity being traded as freely as other goods, services and commodities are. That surely would be a desirable outcome.

When it comes to the share of the different technologies, what part would the marine energy sector play?

Well, here we have sought to take a lead. We set up EMEC - that's the European Marine Energy Center in Orkney. It has twelve berths. Now its problem is one of capacity. The berths are full, and we're looking to the future. It is the sole grid-connected testing center for prototype wave and tidal energy devices in the world. It's given a lead, and we want to see it continue and succeed further. We've moved away from the prototype stage now, and we have plans from a variety of major companies to proceed with very large projects in the Pentland Firth, which is where the Atlantic Ocean meets the North Sea, and there's a lot of wave and tidal activity.

The applications in cumulo for wave and tidal projects for the Pentland Firth are of the order of 1.7 gigawatts. That's a massive quantity, bearing in mind that, in Scotland, we consume six gigawatts. So we are moving from the prototype stage to setting up demonstration arrays, then commercial arrays. We have other exciting projects off the West Coast of Scotland, and we want to see wave and tidal energy succeed.

I think it was Barack Obama who said the country that develops new forms of energy will be the country that leads the world economy, and that sounds like quite a good prospect to aim for.

Fergus Ewing has been Scotland's federal minister for energy, enterprise and tourism since May 2011.

Interview: Irene Quaile