In an exclusive interview Anders Jansson, CEO, Minesto, explains the company´s new concept for tidal power plants, called Deep Green.
What according to you is the potential for tidal power?
Tidal power has an enormous potential and I am convinced that that tidal power is soon to experience a breakthrough. To give an example: In 2017 Minesto will start the construction of a 10 MW array near the Holyhead Island in Wales, which eventually will supply electricity to approximately 8,000 households. Add to that the Welsh waters hold a potential of several 1,000´s of MW. But Wales is not the only place. Deep Green can change the electricity market in many countries. Those include: The entire UK where Minesto doubles the tidal energy potential according to Carbon Trust. Republic of Korea, a country depending on 85 per cent imported energy and DHI has estimated the theoretic potential for Deep Green to more than 50 per cent of the electricity demand. South Africa where the potential in ocean currents is 42 GW according to the largest utility company and Deep Green has been identified as the most suitable power plant for harvesting the energy by the University of Cape Town.
How can tidal power plants handle unpredictable offshore environments?
During normal operations, when producing electricity, the power plants are submerged and not exposed to weather, waves and winds. However the power plants will be exposed during installation and maintenance operations. The low velocity currents in which Minesto´s Deep Green is efficient are easier to access since the operational windows are much longer due to the lower flow velocities. Many of the challenges that the tidal power industry will face have been handled for a long time in the offshore oil & gas industry, so we need to learn from them.
Can tidal power be generated from low velocity tidal and ocean currents?
Yes! Deep Green enables commercial power production from low velocity tidal and ocean currents. Add to that, Minesto´s award winning and patented product, Deep Green, is the only proven marine power plant that operates cost efficiently in areas with low velocity currents. Deep Green resembles an underwater kite with a wing and a turbine that is attached by a tether to a fixed point on the ocean bed, moving swiftly in an 8-shaped trajectory in the current.
Which are the latest technologies being developed that will give a big boost to tidal power development?
The development of tidal power plants is enhanced by many enabling technologies, including sensors, advanced materials, simulations and computer models.
How economical is the cost of producing tidal power?
Minesto´s Deep Green will eventually compete with other energy sources-both renewable and fossil-without subsidies. Deep Green is small and lightweight which means that capital costs are lower than for other technologies. Also, the offshore operations can be made with smaller vessels thus decreasing operational costs. Through ocean trials in Northern Ireland, Deep Green has achieved performance comparable to producing electricity at the same cost as offshore wind. Furthermore, multiple improvements are targeted, without any significant design changes, with the power output expected to be doubled.
Is the tidal power space witnessing enough investments coming in?
The tidal power industry is still in a stage of technology development but several commercial arrays are consented and even under construction. However, in order to enable cost reductions and large scale implementation, investments from both public and private sources are required. Today the economic climate is tough and we need to see additional funding coming in-otherwise Europe risks to miss the train and not receive the payback from already invested money.
Given the fact that tidal power is intermittent in its nature, how will commercial large-scale tidal power plants get around this obstacle?
Tidal currents are highly predictable which means that you know exactly when during the day you will produce power, which is not the case with e.g., solar or wind power. On the electric grid you have a mix of energy sources and some of these like hydropower can be regulated instantaneously to balance the demand and supply. Studies have shown that the electric grid can handle much larger amounts of intermittent power than originally thought. However, when transforming the entire power system to a renewable system, power storage in various forms may be required.
Will tidal power plants prove to be detrimental to marine life?
Understanding the potential effects on the marine ecosystem is of highest importance to us. The effects are assessed in many ways, e.g., through own studies, scientific research, industry studies and expert knowledge. An important part of our own studies is the marine mammal surveillance during the sea trials.
So far our extensive environmental studies have shown positive effects on marine life and that mammals adapt well to the device. Foundations placed on the seabed can create artificial reefs where the number of species in the marine environment grows; this is also seen with i.e., bridges and offshore wind power stations. The array area also becomes protected from bottom trawling.
What Minesto has seen so far is also in line with independent studies. For example IPCC states that ´Environmental effects from tidal energy devices may be somewhat limited because they will be located in already energetic, moving water environments, which have low species diversity and abundances´. Anyhow, Minesto continues to proactively assess the effects on marine life to get a greater understanding of potential impacts.
- Devarajan Mahadevan
What is deep green?
Deep Green is based on a fundamentally new principle for electricity generation from tidal currents. The power plant is applicable in areas where no other known technology can operate cost effectively due to its unique ability to operate in low velocities. Minesto expands the total marine energy potential and offers a step change in cost for tidal energy.