By Bev Mortimer
Jeffreys Bay Wind this year celebrates its connection to Eskom power grid and the erection of all its wind turbines.
In January 10 of the project’s wind turbines started supplying power to Eskom, one of the country’s first wind farms to do so in South Africa. “Our project substation has been energised… we are now connected to the Eskom grid,’ said Mark Pickering, GM of Jeffreys Bay Wind Farm.
“This is the first step to supplying enough clean, renewable electricity to power more than 114 000 South African homes and avoid over 420 000 tonnes of carbon emissions each year.
“The final turbine foundation base was completed during the first week of December and a massive health and safety high point was celebrated over the same period. “December marked a number of achievements for us, including a phenomenal 1 million hours worked without Lost-Time-Incident,” added Pickering.
This was considered a big success for one of the country’s largest wind farms considering the workforce had no experience in this sector before their first induction a few months ago. It is also remarkable given the sheer scale of the project with multiple activities taking place on site. More than 70% of the workforce comes from the local communities and are directly benefiting from gaining skills.
The energisation process included stringent Eskom and South African Health and Safety standards. The substation is divided into two parts, one for which Eskom is responsible for commissioning.
Jeffreys Bay Wind Farm spans 3 700 ha and is one of the first wind farms being developed by the South African Governments Renewable Energy Independent Power Producer Procurement Programme (REIPP). The site was chosen for its optimal wind conditions and minimal environmental constraints, as well as its close proximity to a 132 kV Eskom grid line. With demand for electricity continuing to grow in South Africa, the introduction of this clean energy will have far reaching benefits for the country’s power sector, economy and people.
A number of dedicated turbine erection crews, totalling around 90 men worked tirelessly to erect the turbines from August last year. “The crews’ focus and commitment never wavered, for this we are truly grateful,” Pickering said.
“During this period, crew members took the opportunity to gain experience and benefit from skills transfer, which they will take with them to other wind farm projects.”
Facts and Figures:
Jeffreys Bay Wind Farm spans 3 700 ha and is one of the first wind farms being developed by the South African Governments Renewable Energy Independent Power Producer Procurement Programme (REIPP). The site was chosen for its optimal wind conditions and minimal environmental constraints, as well as its close proximity to a 132 kV Eskom grid line.
With demand for electricity continuing to grow in South Africa, the introduction of this clean energy will have far reaching benefits for the country’s power sector, economy and people.
* Modern wind turbines produce 15 times more electricity than the typical wind turbine did in 1990.
* Wind turbine operational costs are minimal once erected.
* Wind turbines are erected in areas that have the right conditions to harness prevailing winds.
* The winds move the large blades of the wind turbines and so the process of converting the kinetic energy of this movement into mechanical energy begins.
* The generator within the wind turbine then converts this mechanical energy into electrical energy that is transmitted to the electrical grid.
* Environmental Benefits of Wind Energy are water saving and reduced carbon emissions: Water saving – wind energy does not consume water during the energy generation process, it also helps preserve scarce water resources.
* Reduced carbon emissions – one megawatt of wind energy equates to 2600 fewer tons of carbon emissions when compared to coal-fired energy generation.
* Wind energy generation emits zero air or water pollution.
* Wind turbines are sophisticated machines with computer controls. A typical operating sequence is as follows: when the wind speed reaches around 4 metres per second, the turbine blades will spin up to operating speed, usually around 14 to 29 rpm (varies by turbine model), and start generating electricity as the wind speed increases, the generator output increases when the wind speed increases to the rated wind speed (usually around 12-13 metres per second). The generator will output its nameplate-rated capacity (i.e. a 2.3MW turbine would now output 2.3MW) as the wind speed continues to increase. The generator output will remain at the rated capacity (i.e. 2.3MW) until the wind reaches the cut-out speed (usually around 25 metres per second)at this wind speed. The turbine will deploy its tip-brakes and then apply its disk brake, stopping the blades in a few revolutions. It will then rotate itself 90 degrees out of the wind and park itself if the wind speed drops to a level below the cut-out speed for a sufficient length of time. The turbine will point itself back into the wind, release the brake, and resume power production.
* Large parts of South Africa’s coastal land, as well as various areas inland, have an economically viable source of wind energy.
* The scale and maturity of the global wind industry have made it a cost-competitive energy option, compared not just to other renewable technologies but also many fuel-based technologies capacity.
* The average power output of a wind development divided by its maximum power capability, is its rated capacity. Capacity factor depends on the quality of the wind at the turbine. Higher capacity factors imply more energy generation. On land, capacity factors range from 0.25 (reasonable) to over 0.40 (excellent). Offshore, capacity factors can exceed 0.50.
*The cut out speed – The wind speed at which the turbine automatically stops the blades from turning and rotates out of the wind to avoid damage to the turbine, usually around 55 to 65 mph.
* The controller starts up the turbine generator at wind speed of about 8 to 16 mph and shuts off the generator at about 65 mph.
* Arising from the South African Government’s Renewable Energy Independent Power Producer Procurement Programme (REIPPP), Jeffreys Bay Wind Farm signed a 20-year Power Purchase Agreement with Eskom as well as an Implementation Agreement with the Department of Energy.
* The wind farm will supply 460 000 MWh per year, enough clean, renewable electrical energy to meet the needs of 100 000 average South African households. *The project will effectively reduce annual carbon emissions by 420 000 tonnes and lifetime carbon emissions by 8 400 000.
* The project received full Environmental Authorisation from the Department of Environmental Affairs in 2011
Wind farms in the EU: According to the EWEA (Eurpoean Wind Energy Association), a 2007 Stanford University study published in the Journal of Applied Meteorology and Climatology, interconnecting 10 or more wind farms can allow an average of 33% of the total energy produced to be used as reliable, baseload electric power, as long as minimum criteria are met for wind speed and turbine height.
Electricity…The output of a wind turbine depends on the turbine’s size and the wind’s speed through the rotor.An average onshore wind turbine with a capacity of 2.5–3 MW can produce more than 6 million kWh in a year – enough to supply 1,500 average EU households with electricity.
An average offshore wind turbine of 3.6 MW can power more than 3,312 average EU households.
Wind provides 26% of electricity in Denmark, while Portugal and Spain get around16% of electricity from wind power respectively, followed by Ireland (12%) and Germany (11%).
The total installed wind power capacity in Europe at the end of 2012 covers 7% of the EU-27’s electricity demand.By 2020, EWEA estimates that 230 GW (including 40 GW offshore) of wind power capacity will be installed in the EU, meeting 15-17% of the EU’s electricity demand (4.2% from offshore). By 2050, EWEA estimates that wind power will meet 50% of the EU’s electricity demand.
The European Commission believes wind energy will supply between 32% and 49% of the EU’s electricity by 2050. The key will be a Europe-wide power grid which will transport wind energy from where it is produced to where it is consumed – the wind is always blowing somewhere.
Today, in Denmark, over 26% of electricity demand is already supplied by the wind, and is managed successfully by the grid operator. The Danish government aims to get 50% of its electricity from wind by 2025. In Spain 16% of electricity demand is met by wind, and at times wind provides over half the electricity needed.
About the company: Jeffreys Bay Wind Farm: Jeffreys Bay Power (RF) (Pty) Ltd is majority owned by Globeleq, the emerging markets power company, and its consortium partners, Mainstream Renewable Power South Africa, Old Mutual, Thebe Investment Corporation, Jeffreys Bay Community Trust, Enzani Technologies and Usizo Engineering. Siemens will provide, install and commission the wind turbines and will maintain them for the first ten years of operation. A consortium of Murray & Roberts and Conco are responsible for the engineering, procurement and construction of the balance of plant, including turbine foundations, civil works, the electrical collection network and the main substation. Construction is being managed by Mainstream Construction. The project company is managed by Globeleq.
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