Worldwide, targets for renewable energy continue to be the primary means by which governments express their commitment to renewable energy. As at year-end 2015, 173 countries had established renewable energy targets at national or state/provincial level. Targets have also been adopted at regional level, incorporating joint commitments by several countries, according to the REN211 in its Global Status report about renewables of 2016.
Growth of growth of renewables is led wind
Dr. Fatih Birol, Executive Director of the International Energy Agency, highlights the rise in the importance of wind energy: “In 2015, the increase in wind-powered generation was equal to almost half of global electricity growth… for the second successive year, global CO2 emissions remained stable despite growth in the world economy. This was due to industrial restructuring, improved energy efficiency and the substantial growth of renewables – led by wind.”2
Exceptional history of renewable energy development since 2005
What`s happening around the globe? China crossed the 100,000 MW mark in 2014, adding another chapter to its already exceptional history of renewable energy development since 2005. This year it made history again, strengthening its position on the leaderboard. 2015 was a strong year for Europe and North America, with Germany and the US leading the way on their respective continents. Guatemala, Jordan and Serbia each added their first large commercial wind farms, and South Africa became the first African market to pass the 1 GW mark.
Emission-free until 2050?
Studies by the Global Wind Energy Council (GWEC) have identified three main drivers3 of the mid-term growth of wind energy. The first is the positive outcome of the climate negotiations at the UNFCCC’s COP 21 in December, which was an unexpected pleasant surprise. The long-term targets adopted by the 186 countries gathered in Paris are a de facto call for a 100% emissions-free power sector by 2050 at the latest.
Wind energy costs have fallen
Second it is obvious that the costs of wind energy have fallen dramatically in recent years, and new and complex financing structures are creating conditions that will make renewables competitive in an increasing number of markets.
On-off nature of the US market
Third we have to look to the United States. As a pioneer in the global wind power industry with some of the best wind resources in the world, it has had much lower prices than most of its OECD competitors for some time. However, the difficulty has always been the on-off nature of the US market. The US Congress passed a law for a long term extension and phase-out of the Production Tax Credit (PTC) that has been the main federal policy support for wind energy in the US.
By 2030 wind could supply up to 19% of global`s electricity reducing 30 tons of CO2 p. a.
The studies also show that under certain conditions, wind-powered generation could reach 2,000 GW by 2030, supplying up to 17-19% of global electricity, creating over 2 million new jobs and reducing CO2 emissions by more than 3 billion tons per year. By 2050, wind power could account for 25-30% of global electricity supply. Countries with the biggest wind power capacity are China, the United States, India, Germany, Spain, Italy, the UK and Brazil. We are hugely excited about this development.
What exactly is behind a wind turbine for electricity generation?
The rotor blades are a key component in the overall turbine, and particular attention must be paid to their fabrication at every stage from design through to production. In two-piece blade construction, two composite shells are bonded together along their leading and trailing edge and in the area around the shear webs. Since the blades are exposed to all kinds of weather and enormous stresses for decades, the adhesives used to bond them have to be just as durable. It has been shown that the toughened system is more resistant to damage initiation than the standard material with increasing numbers of cycles. For instance, after one million cycles in severe conditions, the standard adhesive material shows at least twice as many cracks as the toughened system.
Then right adhesive for bonding highly stressed wind turbine blades
Sikadur® WTG-1280 LD is a tough, high-strength, solvent-free, thixotropic epoxy adhesive. It is used for structurally bonding highly stressed components in the assembly of wind turbine blades. The product offers long open times at elevated temperatures, easy pumping and application and fast processing times. Sikadur® WTG-1280 LD therefore has class-leading toughness and fatigue properties for enhanced durability, ensuring longevity and reliability in today's multi-MW wind turbines – even under the toughest conditions. Since the adhesive is load bearing in this type of construction, high mechanical and fatigue properties are required. Consequently toughened epoxy adhesive systems are used nowadays. Between 500 and 800 kg of adhesive is used per blade.
Sika accompanies you in every step of the process: fabrication of molds and models, manufacturing and assembly of blade shells, finish and repair as well as surface protection and the attachment of interior and exterior elements. Sika`s standard adhesive range includes products for bonding lightning protection systems, balancing blocks, vortex generators, winglets and much more.
High-altitude wind turbines for 9,000m above sea level
What will the future bring? Scientists are racing to develop high-altitude wind turbines capable of harnessing stronger and more consistent winds higher in the atmosphere. Although different models are either in the design or testing stage, there is significant feasibility, and particularly, viability issues associated with their development. Though in 9,000m above sea level winds are up to 20 times stronger, but still before there is much to do to use wind efficiently on earth on all continents.
1Renewable Energy Policy Network of the 21st century. The network stands at 700 renewable energy, energy access and energy efficiency experts; see current report: http://www.ren21.net/wpcontent/uploads/2016/06/GSR_2016_Full_Report_REN21.pdf
2Global Wind 2015 Report, p. 6: http://www.climateactionprogramme.org/images/uploads/documents/GWEC-Global-Wind-2015-Report_April-2016_22_04.pdf
3Market Forecast 2016-2010, Global Wind Energy Council (GWEC) 2016: http://www.gwec.net/global-figures/market-forecast-2012-2016/