Construction World November 2017

PROJECTS & CONTRACTS

WIND FARMS connect to Eskom grid

Loeriesfontein Wind Farm and Khobab Wind Farm, in the Northern Cape, have announced that the wind farms are now connected to the Eskom grid, via Eskom’s Helios Substation and commissioning of wind turbines have commenced. “We energised the wind farm substations with Eskom Transmission’s Helios substation on 28 September, marking a pivotal point in the construction of the both of the wind farms, and will now continue the process of wind turbine commissioning,” explained Kevin Foster, Country Construction Manager for Mainstream Renewable Power. Khobab Wind Farm confirmed the completion of all of their 61 wind turbine generators, on 8 September, more than two weeks ahead of the expected schedule (see article on page 25) . The wind farms are expected to start supplying electricity to the national grid by early December and will continue to work closely with the various Eskom teams to achieve this milestone. “We’re working together with the Eskom teams in the Northern Cape and Western Cape Operating Unit to ensure a smooth and safe energisation and commissioning process,” added Foster. How the substation works and fits into the plant Each wind turbine is connected to a step-up transformer which boosts the voltage output of the wind turbine generator from 690 V to 33 000 V. These transformers are located externally at the base of each wind turbine. From there these medium-voltage reticulation power cables are routed underground from turbine to turbine according to grouped circuits; and bring the collective circuit power from the step up transformers to convene at the Wind Farm’s substation where the Main Transformer is situated. The substation built on the Wind Farm is divided into two conjoined substations. One is owned and operated by the Wind Farm; and the other – along with the overhead line – is handed over to Eskom for ownership and operation. Each substation is given a unique name. The two joined substations are situated in a central location to the grouped circuit power cables’ meeting point. At this termination point of the circuits, the collective power from the wind farm is run through several power quality checks and various measurement devices. Subsequently, the power is directed through the Main Transformer where the voltage is increased again to 132 000 V.

Loeriesfontein and Khobab Wind Farms are owned by a consortium dedicated to providing clean, renewable energy to the people of South Africa: • Lekela Power is a pan-African renewable energy generation platform delivering utility scale wind and solar power into commercial operations in Africa. Lekela is owned 60% by Actis, the leading growth markets energy investor (USD13bn funds raised across three asset classes since inception) and 40% by a consortium led by Mainstream Renewable Power (over 9 000 MW in development, construction and operations across five continents) which includes investors such as the IFC and the Rockefeller Brothers Fund. • Khobab Community Trust & Loeriesfontein Community TrustEstablished by the project company with the objective of carrying out public benefit activities to benefit the local community in the areas of enterprise development, education and health. • Thebe Investment Corporation one of South Africa’s most established broad based BEE Investment management companies and leading investor in the Energy & Resources sector (advised by Bridge Capital). • The IDEAS Managed Fund,a policy product of Old Mutual Life Assurance Company Limited, is a fund for institutional investors that invests in transport (roads and railways), government accommodation (public private partnerships), energy (gas pipelines and storage), thermal power generation (gas) and renewable energy (solar, wind and hydro projects). • The IDEAS Managed Fund is managed by African Infrastructure Investment Managers (AIIM), a subsidiary of Old Mutual Alternative Investments (OMAI). • Futuregrowth Asset Management is a fixed interest investment company that protects and grows around R170-billion of clients’ assets across the full scope of interest-bearing products, and a range of development funds, in a way that has a positive financial, economic and social impact on investors, communities and the country as a whole. • Genesis Eco-Energy is a pioneering South African renewable energy developer which has been active in South Africa since 2001. Lereko Metier Sustainable Capital is a resource efficiency private equity fund that has garnered additional support of two of its investors DEG (The German Development Bank) and FMO (The Dutch Development Bank) in the investment across the Mainstream portfolio. The power is then directed through the Main Transformer into the Eskom substation on the Wind Farm, where further power quality checks and measurements are completed prior to exporting onto the 8 km long 132 000 V overhead line. The overhead line connects to Eskom’s Helios Substation, where the power is distributed to the Eskom Grid via several separate overhead lines leading out of Helios Substation – using various separate voltage step-up and step-down transformers, similar to those utilised on the Wind Farm, to adjust the export voltages to their needed levels. The town of Loeriesfontein is supplied by one of these overhead lines at 66 000 V. Milestones • All 122 turbine foundations were completed on schedule, by 8 September 2017 • Transportation of the 1098 components to site, was completed 27 August 2017 

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CONSTRUCTION WORLD NOVEMBER 2017