Banking group Standard Bank has invested R2,3-million in a hybrid solar water heating and heat pump system at the company's head office in Johannesburg, as it moves to increase energy efficiency and reduce its carbon footprint.
The new R2,3-million system, installed by Kayema Energy Solutions, was expected to save nearly R1-million a year in energy costs, thus a return on investment would be seen in just over three years.
The 200-kW hybrid system consists of 100 solar water heater collectors, which will heat about 20 000 l of water, while another 28 000 l of water is heated using energy efficient heat pumps.
It reduces the building's energy consumption by 5%, and Standard Bank noted that the energy saving was equivalent to powering seven households for a year.
The 100-collector installation, which took about four months to design and install, covers over 200 m2 on the roof of 6 Simmonds street in central Johannesburg. A back-up and top-up system consisting of two heat pumps supports the solar installation for days when the sunshine is not optimal.
The solar collectors were specifically chosen as they make use of a black chrome absorber, which performs better than painted collectors, and ensures a longer life-span of the panels. There is an ultrasonic weld between the absorber thins and the copper pipes, which allows more efficient heat transfer.
The installation consists of some 700 m of copper piping.
The 4 mm tempered glass used in the panels is hail resistant, and has a low metal content, which also allows for better heat absorbency.
With the introduction of alternative energy solutions in the areas of water heating, light control and air-conditioning, Standard Bank said that it had reduced its energy demand to 56 W/m2, which was below national averages.
"Water heating, lighting and air-conditioning are three of the biggest energy consumers at Standard Bank. They are also the areas of energy consumption that can most easily be addressed in existing buildings," said Standard Bank director of channel development director Marius de la Rey.
He added that the challenge in implementing clean energy solutions was changing older infrastructure in existing buildings and upgrading and converting to cleaner more efficient systems using alternative power sources where possible.
"We have to be more creative in reducing the energy consumption in our older assets. The Standard Bank Centre is already achieving benchmark energy efficient performance," De la Rey stated.
"In implementing new technologies, companies like Standard Bank can reduce the demand for fossil-fuel based energy and take pressure off the electricity grid. Energy constraints are currently a potential cap on growth within the economy and the challenge to all companies is to increase economic output with less energy," explained Standard Bank group sustainability director Karin Ireton.
Standard Bank was considering introducing energy saving measures across the group.
This pilot large-scale solar system, combined with the use of energy efficient heat pumps could be used in areas where energy constraints hinder new business development or the full optimisation of properties within Standard Bank's portfolio.
"We are committed to building all of our new real estate developments to four-star green building standards, and cater for reducing carbon dioxide emissions, optimal energy use and savings, and the introduction of the latest green technology," added De la Rey.
Standard Bank also upgraded the air conditioning chillers at its Johannesburg head office, and continuous energy audits were conducted to assist with the introduction of energy efficient technology and other improvements.