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Scotland is betting on tidal energy

As Scotland transitions from fossil fuels to renewable energy, it is investing in an unexpected source: tidal currents. Similar to wind turbines, which sit above ground, tidal turbines are one hundred feet below water and use tides instead of wind to generate power. In the first of a two-part series, Hari Sreenivasan reports on what may become the world’s biggest tidal power resource.

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  • HARI SREENIVASAN:

    There has recently been a steady drumbeat of reports from climate scientists warning that there is less and less time for us to take collective action to slow the disastrous effects of climate change.

    The United States has withdrawn from the Paris climate agreement, and the president has been an open skeptic of established facts. This has not deterred a global green revolution; countries around the world are continuing to move forward with investments in renewable energy.

    We'll be looking at various, innovative energy efforts periodically, starting with one underway in Scotland. The country is nearly 70 percent powered by renewable sources already, with the goal of reaching 100 percent by 2020, 10 years ahead of schedule.

    Their power traditionally came from deep sea oil and gas, but the ocean has a lot more to give, as you'll see in this, the first of a two-part series.

  • HARI SREENIVASAN:

    In a giant industrial hangar on the eastern coast of Scotland, technicians are servicing two turbines — each with 3, 30 foot blades.

    They're not wind turbines. These are actually designed to be 100 feet underwater, capturing energy not from the wind, but from tidal currents.

    Once they get this 150-ton turbine into the water, this entire thing will swivel with the tide, four times a day, generating about enough power for 1,000 homes.

    For the past year these turbines, and two others, have been in the Pentland Firth, a strait off the northern coast of mainland Scotland. It's called the MeyGen project.

  • EDDIE SCOTT:

    The blades, for example, we made from carbon fiber.

  • HARI SREENIVASAN:

    Eddie Scott is the health and safety manager with SIMEC Atlantis Energy, and part of the team that oversees installing these devices underwater.

    To get them in place, the turbines are guided onto steel bases on the seafloor.

  • HARI SREENIVASAN:

    You can drop this in to its base and get it plugged in how long?

  • EDDIE SCOTT:

    We can do that within about 30 to 40 minutes.

  • HARI SREENIVASAN:

    As the tide ebbs and flows, the turbines spin between 7 and 15 times a minute, generating power, similar to a wind turbine. Cables carry the energy back to the shore, first underwater, then underground, where it's then fed into the national grid.

    The tides are so predictable that Atlantis says it can tell how much energy these turbines will generate every 15 minutes for the next 25 years.

  • HARI SREENIVASAN:

    So you don't have to worry about whether there's clouds on a sunny day for solar. You don't have to worry about whether there's a stiff breeze or not.

  • EDDIE SCOTT:

    That's the real advantage of tidal energy, it's very, very predictable.

  • HARI SREENIVASAN:

    Scotland is estimated to have a quarter of all the tidal energy resources in Europe. And Scottish companies have helped lead the way in developing technology to harness those currents. MeyGen, here in northern Scotland, is the world's largest planned tidal project, and over the next four years, SIMEC Atlantis is planning on installing more than 250 additional turbines.

  • TIM CORNELIUS:

    When it's fully done, you're talking more than a quarter of a million homes can benefit from the power that's generated from this array of turbines.

  • HARI SREENIVASAN:

    Tim Cornelius is the CEO of SIMEC Atlantis Energy. The company says the turbines at the MeyGen site are expected to last 25 years, and only need to come out of the water for maintenance every six years.

  • TIM CORNELIUS:

    It's in a very, very stable environment, and more importantly from a permitting and consenting perspective, you don't see them and you don't hear them, and that's very, very important for local communities.

  • HARI SREENIVASAN:

    But it's expensive being first. The cost of producing tidal energy is more than two and half times the more established technology of offshore wind.

    The MeyGen project has cost about $64 million so far, and has been largely subsidized with public money. Almost half of the total cost has come from the Scottish government.

  • TIM CORNELIUS:

    We are very, very grateful for the support that we have received over the past 10 years from the U.K. government, and in specific reference to Scottish government support because it's been outstanding. But, of course, the aspiration is to eventually wean itself off subsidy.

  • HARI SREENIVASAN:

    As the project continues to expand, Cornelius says costs are coming down. A year after the turbines were installed, the price SIMEC Atlantis charges the utility company for its tidal power has decreased by 50 percent.

  • PAUL WHEELHOUSE:

    The Scottish government has provided consistent and long term support for these technologies.

  • HARI SREENIVASAN:

    On stage, Paul Wheelhouse. He is the Scottish minister for energy, connectivity and the islands. We sat down with him at a conference on ocean energy in Edinburgh.

  • HARI SREENIVASAN:

    Can this industry survive without government subsidy?

  • PAUL WHEELHOUSE:

    We believe key technologies are already close to being in a position where they can survive without subsidy. Other technologies, which are newer, emerging technologies do need we believe continued support to get them to commercial scale, utility scale projects that will then get the economies of scale and the manufacturing process and drive down the price and prove their competitiveness.

  • HARI SREENIVASAN:

    Wheelhouse says these government investments will help Scotland reach its goal of being 100 percent powered by renewables by 2020.

    And then there's the transfer of technology that's happening.

  • TIM CORNELIUS:

    The great secret about the tidal power industry is while it looks like an incredible leap forward in engineering actually all we've been doing is just stealing the great ideas of the oil and gas industry over the last decade.

  • HARI SREENIVASAN:

    The facility where the tidal turbines are maintained also supports oil and gas platforms.

  • EDDIE SCOTT:

    Big cranes, heavy lifting equipment, moving large portions and large chunks of steel around. Some of the subsea technology is very, very similar, so there's a tremendous amount of of existing technology that we're using and capitalizing on.

  • HARI SREENIVASAN:

    For Wheelhouse, relying on the technology and knowledge gathered from decades of oil and gas exploration means continued jobs in this new energy sector.

  • PAUL WHEELHOUSE:

    We don't want to leave communities, entire communities behind as has happened in the past with coal mining, you know, just abandon them and leave them to their own devices.

  • HARI SREENIVASAN:

    So you're saying that you are creating opportunities for whether its coal miners or oil and gas workers to transition to this new renewable economy?

  • PAUL WHEELHOUSE:

    Yes.

  • HARI SREENIVASAN:

    And with the growing threat of climate change, Wheelhouse says the time to invest in new forms of renewable energy is now.

  • PAUL WHEELHOUSE:

    We have long argued that there is an economic advantage in moving early not least because we will have to do this. I believe firmly that climate change is happening and we cannot avoid tackling this issue globally.

  • HARI SREENIVASAN:

    While the tides these turbines are gathering energy from are predictable, the political winds around them are not. How Brexit could hamper this emerging industry; that's the subject of our piece tomorrow night.

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