For followers of wind power engineering, the highlight of last year was the arrival and installation last October in Rotterdam of all the massive components to assemble the prototype of the largest offshore wind turbine in the world.
For followers of wind power engineering, the highlight of last year was the arrival and installation last October in Rotterdam of all the massive components to assemble the prototype of the largest offshore wind turbine in the world. It is expected to capture more annual energy production (AEP) than any other offshore wind turbine even at times of low wind.
In typical German North Sea weather, it is reckoned that one of these 260 m high monster GE Renewable Energy Haliade-X 12 MW turbines can generate up to 67 GWh of gross annual energy production. This is said to be enough clean energy to power 16,000 European households and save up to 42,000 tonnes of CO2, which is the equivalent of the emissions generated by 9000 vehicles in one year.
The nacelle of the turbine that houses all of the generating components including the generator, gearbox, drive train, and brake assembly weighs 675 tonnes. It was shipped from St Nazaire, France to Rotterdam by barge. Lifting it into place required two 1350-tonne fully rigged crawler cranes. The structure has a rotor diameter of 220 m and blades with a length of 107 m making it the biggest offshore wind turbine globally.
Ahead of testing and commissioning of the prototype, the first orders for the new machine for locations in the North Sea and off the US east coast have already been placed, with Equinor a predictable customer. The Norwegian company as part of its continuing commitment to renewable energy solutions plans with its joint venture partner SSE to install the GE turbines in its Dogger Bank wind farm project. It will be the world’s biggest offshore wind farm development with a total installed capacity of 3.6 GW. The Total project is expected to produce enough energy to power the equivalent of 4.5 million UK homes.
Reviewing this milestone in wind turbine construction, many geoscientists engaged in the resource extraction industry might ruefully reflect that it is an ill wind that blows nobody any good. The global growth in wind turbine farms onshore and offshore for the generation of electricity is a better-sweet evolution.
The green credentials of this alternative source of energy are close to impeccable, with some relatively minor qualification such as their intrusive appearance and operation when sited in environmentally sensitive areas. There is also the danger posed to migrating birds and sometimes bats by the rotation of the turbine’s blades. For example, the Egyptian Gabal-El-Zeit 580 MW onshore wind farm, claimed to be the largest in the world, has a bird control system to stop its hundreds of turbines from spinning when migrant birds are passing.
There can be no serious argument about the value of continuing to develop wind turbine technology, hopefully becoming an unsubsidized, true competitor to traditional fossil fuels and indeed nuclear. Few governments dare to contemplate this latter as an option despite its current longstanding adoption worldwide and non-polluting operation (assuming no accidents and an eventual solution to the disposal of radioactive waste).
From a societal, climate change mitigation viewpoint wind power represents a zero emission source of power to be fostered. For geoscientists, however, this aspect of the great energy transition offers none of the job opportunities that historically have come from oil and gas exploration and production and the mining of coal. There is a need for subsurface investigation of sites for intending wind farms especially offshore, but that’s small beer. The same applies to any intensification of the search for rare earth minerals like neodymium. This is used to create the permanent super magnets used in the generation of electricity in some but not all windmills.
Alarm has been expressed about China’s current dominance of the market in rare earth minerals that as a group are an essential ingredient in consumer goods such as cell phones, TVs and battery technology. In fact rare earth minerals are found in abundance in a number of other countries including the US, Canada, Brazil, Australia, and India. The challenge of interest to geoscience would be identifying deposits sufficiently concentrated to be a viable mining proposition. Production itself is apparently a hazardous, environmentally unfriendly exercise that works for China with its cheap labour regime. This doesn’t have many fans elsewhere although China is gradually losing its grip on the market. In fact rare earth mineral projects are beginning to proliferate in other countries to meet the obvious growing demand worldwide and stymie the threat of a Chinese monopoly.
Wind power’s steadily increasing impact on the global energy mix and the electricity supply of some countries does not garner the headlines. May be this is because, according to the BP Statistical Annual Review 2019, wind energy provided a modest 4.8% of global power in 2018. That is going to change.
Global capacity additions are expected to sit at an annual average of 71 GW from 2019 to 2023 and 76 GW from 2024 to 2028, according to new analysis from Wood Mackenzie Power & Renewables. Its report Global Wind Power Market Outlook Update: Q2 2019 has upgraded its global wind power outlook by 11 GW from 2019 to 2028, a 1.5% increase from the previous quarter.
Luke Lewandowski, Wood Mackenzie Power & Renewables director, said: ‘A 5GW upgrade in the global offshore sector will yield 129GW of new capacity and a compounded annual growth rate (CAGR) of 26%. Overall, the outlook is positive and global wind power continues to prosper due to both economic and social benefits.’
China with installed capacity of 221 GW has over a third of the world’s capacity, according to Power-Technology. The US (96.4 GW) is second behind China, followed by Germany (59.3 GW), India (35 GW), Spain (23 GW), UK (20.7 GW), France (15.3 GW), Brazil (14.g GW). Canada (12.8 GW) and Italy (10.1).
Wind now meets 14% of the EU’s power demand on average, but 41% in Denmark, Ireland 28%, Portugal 24%, Germany 21% and Spain 19%. Last year there was cause for some celebration when it emerged that Scotland’s wind turbines generated 9.8 million megawatt-hours of electricity between January and June, enough to supply power to more than twice the number of homes in the country. The US president, who recently touted the erroneous idea that wind farms cause cancer, was probably not amused. He famously lost his legal challenge to the building of a proposed ‘ugly’ wind farm offshore the Aberdeenshire coast arguing that it would spoil the view for golfers playing at the nearby luxury golf course at Balmedie opened in 2012 by Trump International Golf Links.
Notwithstanding the views of its president, the power industry in the US has been forging ahead and currently produces around 6% of the electricity in the US. Texas, Oklahoma, Kansas and Iowa produce approximately half of the wind-generated electricity with California also a significant contributor. Future expansion is currently being clouded by a proposal to end federal financial support via production tax credits exempting wind energy equipment from sales taxes to reduce capital investment.
The subsidy issue is a dilemma for the many governments that are embracing the potential of wind power and other renewable options. Tax credits and other incentives have been widely adopted as the way to attract investors into the alternative energy market. Warren Buffet once remarked that wind turbines don’t make sense without the tax credit.
The cost of building and installing wind turbines has actually come down dramatically over the years with improved technology, for example in the reduction of the number of turbines needed to capture the wind. However, the upfront capital cost is still substantial. The pay-off is the guaranteed contract revenue over the 20 years or so of a unit’s lifetime once established. Even then recouping the original outlay takes a number of years.
In what may be a sign of the times, UK subsidies have fallen to a record low. A government auction last September revealed that the new generation of wind farms due to enter the grid in 2025 will involve £39.65 per megawatt hour, nearly a third less than the three years ago and reduction of two-thirds since the 2015 auction. The subsidy comes in the form of a guaranteed minimum price households and businesses will pay for the energy generated over a 15-year period.
Offshore prospects, if viable, are almost unlimited compared with onshore not least because ocean wind tends to be more forceful in most locations and more reliable. The global market grew nearly 30% per year between 2010 and 2018, benefiting from rapid technology improvements and about 150 new offshore wind projects are in active development around the world, according to a World Energy Outlook special report published in October by the International Energy Agency (IEA). It stated that offshore wind has the potential to generate more than 420,000 TWh per year worldwide, projecting a 15-fold increase in global capacity by 2040 in what will be a $1 trillion industry over the next two decades, thereby matching capital spending on gas- and coal-fired capacity predicted over the same period
Enthusiasm for wind power has to be tempered by some significant stumbling blocks. Transmission from remoter locations where wind farms can be located is an issue. It is of course an intermittent source of energy that is dependent on specific wind conditions that don’t necessarily coincide with demand. So a turbine’s electrical output is only about a third and at best 50% of its rated capacity, and to date there is no commercial scale method to store the energy created. Energy authorities are therefore left with a balancing act to integrate wind power into the grid.
Growing investment in renewables research and development will likely take care of most of these problems giving cause for some celebration of technological innovation. Geoscientists won’t expect to be invited to the party.
‘The global growth in wind turbine farms onshore and offshore is a better-sweet evolution.’
‘The subsidy issue is a dilemma for many governments.’
