Israeli Ambassador to South Africa Dov Sergev-Steinberg and Public Enterprises Deputy Minister Enoch Godongwana on Monday inaugurated the 117 flat panel collector solar water heating installation above the rooftop of the Hotel Da Vinci, in Sandton.

The hotel is the latest development of the Legacy Group, which is also the developer, contractor and owner of the Michelangelo, the Michelangelo Towers and the Raphael Penthouse suites in Sandton.

The company responsible for the solar installation is Kayema Energy Solutions, and the Kayema international solar experts worked together with Legacy's architects and design engineers to implement the solution.

The project is complete and commissioning of the system will start in the next two to three weeks.

The solar water heating system is capable of preheating 30 000 litres of water before it enters the hotel's electrical heating system, which is expected to reduce the electricity usage by about 60%.

Kayema also introduced a remote monitoring system, which monitors flow rates, temperatures and water pressure and will allow an instantaneous view of this system's efficiency and performance from any computer desktop at any time.

It was estimated that 500 000 kWh/y of electricity would be saved, while some 210 t of carbon-dioxide emissions would be mitigated.

The installation consists of 117 2-kWh flat plate collectors, which use Israeli technology, and are said to be reliable, and easy to maintain.

Kayema Energy commercial projects manager Dovi Finger explained that the installation took about six months to complete, and two months of that was dedicated to the engineering and planning phase of the project, while installation took about three months.

It was described as a challenging project because of the shape of the roof. Also, the fact that the roof is used as a fire escape meant that the panels needed to be raised above head height to allow movement under the panels. This required structural steel platforms for the panels, as well as having to take into account wind factors.