Speaking at a meeting of the SA Black Technical and Allied Careers Organisation in Johannesburg on Thursday, Mahlangu said there was approximately 8-million square metres of roof-top space available on government-owned buildings in the province
"Our calculations indicate that a mass roll-out of solar panels on government roof-tops will come at a cost of about R11.2-billion and lead to the generation of up to 300 MW of electricity."
Mahlangu said the investment would be in line with the province's integrated energy strategy, and was one of several infrastructure projects that her department would initiate in the current financial year.
Plans to invest in natural gas infrastructure
These, she said, included "ambitious plans" to invest in natural gas infrastructure.
"Gauteng has the most developed natural gas infrastructure in South Africa. This constitutes a natural gas pipeline infrastructure connecting from the supply source in Mozambique through Secunda to Babelegi.
"March 2014 will herald the end of [petrochemicals company] Sasol's natural gas monopoly and the start of a natural gas industry regulated by Nersa [the National Energy Regulator of South Africa]," Mahlangu said.
"It is at the back of these developments that our ambitious plans for natural gas are rooted."
Her department's first project would be to replace the 77 coal-fired boilers in the province's state hospitals with natural gas or diesel-fired boilers. "Twenty-one boilers are planned for replacement this fiscal year and the balance over the next three years."
Mahlangu also said that her department had entered into a partnership with state company iGas (the South African Gas Development Company) to conduct a feasibility study on the infrastructure required to supply natural gas to hospital boilers.
"Our biggest showcase for the use of gas to meet hospital energy needs will be the tri-generation plant proposed for Chris Hani Baragwanath Hospital as a pilot project. In this regard, the consultation process with stakeholders, such as the Department of Health and Treasury, is at an advanced stage."
Mahlangu added that natural gas infrastructure had the potential to benefit up to 2-million middle-class residents in Gauteng's townships and suburbs, by way of natural gas reticulation for cooking and heating.