The South African Renewable Energy Technology Centre (SARETEC) is a serious attempt to establish specialised training, education and research services to the renewable energy industry. The building itself was also built with sustainability in mind.

Set to open its doors in July 2015, the initiation of the South African Renewable Energy Technology Centre (SARETEC) is opportune and has been mooted, lobbied for and promoted since 2008. Far-sighted academics, politicians, the GreenCape initiative, members of the renewable industry, the Austrian government and the German development agency GIZ have been among those seeking to establish the facility.

Located at the Cape Peninsula University of Technology (CPUT) campus in Bellville, Cape Town, the site was chosen because it had the land available, was prepared to donate it to the project and because the CPUT had the academic credentials required for such a facility. Furthermore, wind and solar projects are largely concentrated in the three Cape provinces and as a consequence many renewable industries have established themselves in this region.

Built on the right technology

“We haven’t reinvented the wheel here,” SARETEC operations manager Sven Pietrangeli says about the new centre. “We have learned from many study tours, particularly to Germany. Entering into the renewables arena somewhat later than other countries means we have avoided their mistakes and started from an advanced base.”

The SARETEC project is a national centre and has received funding from the Department of Higher Education and Training via the National Skills Fund. About 40% of establishment costs came from private and international donors, both in cash and kind.

Perhaps the ‘biggest’ – all 126t of it – was the donation of a wind turbine nacelle, hub and drive train from German turbine manufacturer Nordex, which had to be craned into position. This 2.5MW turbine is the centrepiece of the SARETEC workshop and an essential component in the hands-on practical training students will receive.

Although non-generating, it contains all the operational features of a fully functional wind turbine, and is positioned at convenient ground level, rather than on a tower 90m high. GAPP Architects and Urban Designers spokesperson Ella Löb says some of the challenges that occurred during construction concerned timing, particularly the arrival of equipment from overseas to coincide with the correct phase of construction.

“The nacelle turbine, which was donated from Germany, needed to be placed on the suspended floor slab before any columns or walls were built. This process had to be carefully monitored and perfectly timed,” she says.

Sustainability of the building

A facility such as this should itself be as energy efficient and sustainable as possible. “The building design incorporates the latest energy efficiency features although cost constraints prevented the application of a rating with the Green Building Council of South Africa (GBCSA),” says Pietrangeli.

“There are a number of design features that stand out but perhaps the most notable is the workshop; the unusual shape of the building and large window make this a timeless, contemporary and unique structure,” says Löb. “It is sculptural, yet it remains practical and cost-effective.”

She notes the building is orientated to benefit from an ideal sun and shade balance, and incorporates a wire mesh vine support for solar shading on the north-east facade and building entrance, with a green planted screen.

Insulated roof areas and double workshop walls create air gap insulation, further minimising heat transfer. The window showcasing the nacelle is sunken to reduce heat loading into the building, and simultaneously provides a shade effect.

The building design allows exposed services to showcase sustainable energy principles and for the building itself to be used as a teaching tool. “A clear example of this is the exposed mechanical and electrical engineering services which are usually hidden for aesthetic reasons – this allows students daily exposure to the energy efficient philosophy built into the design of these services,” says Ian Mc William, electrical engineer and project manager for Royal HaskoningDHV.

“It meant the contractors had to ensure the building’s services not only performed to specification but looked good too,” adds Pietrangeli. Supplementing Eskom power is a 50kWp solar PV system installed on an insulated solar roof deck and three 2.5kW wind turbines that will reduce the electrical consumption load with a targeted 10% reduction, according to Mc William.

A building information system shows building electricity consumption vs. production so students can see and monitor the building’s performance in real time. “We hope to be able to feed our excess power back into the grid and the aim is to become at least energy neutral,” Pietrangeli says.

“To reduce the large energy consumption usually required for the full HVAC system, we deviated from a conventional air conditioning system. Instead, the building is kept cool with the combined effects of tempered ventilation air, building thermal mass and passive architectural elements such as building orientation, insulation, shading to the glazing as well as through the planted sun shading screen,” says Jaco Vorster, mechanical engineer at Royal HaskoningDHV.

The lecture theatre AC system incorporates an energy wheel to harvest energy from exhaust air that would normally be wasted when discharged to the atmosphere. The combination of the energy wheel and variable refrigeration volume condensing units provides substantial energy savings.

“GAPP architects had to ensure that sufficient natural ventilation was inherent in the architecture of the building to harness natural air flow for cross flow ventilation,” notes Vorster.

“Lighting constitutes 13% of total electrical load – of which 76% comprises LED and energy efficient light fittings – specifically T-5 lamps and electronic ballasts,” says Mc William. “We avoided over lit public areas so there is a noticeable contrast between the more dimly lit passage ways and brightly lit working spaces,” he says. Occupancy sensors in low traffic areas, such as stores, regulate lighting as needed. “The electrical engineering design has also accommodated retrofitting connectivity of the PV roof panels to the main distribution board.”

Small solar water heating plants are being considered as teaching aids. All plumbing fittings are water-efficient. A rainwater collection system provides for irrigation for the facility’s landscaped gardens. “We included bicycle parking and shower facilities to encourage administrators, students and lecturers to use non-motorised transport,” says Löb.

A tower base has been provided for a model wind turbine tower, which will allow for instruction on aerial safety and access, she adds.

By Robin Hayes

The full feature appears in the June/July 2015 issue of earthworks magazine.