General Motors South Africa (GMSA) has cut energy costs at its two Port Elizabeth plants by R11,34-million a year, in response to power utility Eskom's tight supply situation, and a growing green agenda.
GMSA facilities area manager Lushen Govender says R7,2-million of this was achieved by three actions alone.
One was to reduce the paint shop spray booth operating temperature, another to facilitate a drop in spray booth operating humidity, and the last to better control the paint shop oven start-up and shut-down times.
“Around 70% of our energy use comes from the paint shop and vehicle finishing,” notes Govender.
“We used to, for example, start the oven up an hour before a vehicle got there, now we start it up just before it arrives.”
Other energy savings measures include installing a oven flue-gas heat recovery system, switching off the hot water circulating pumps after hours, and reducing the number of pretreatment pumps in operation during production.
GMSA has also reduced the lighting levels in the plant by a calculated 200 kW, and retrofitted eight-foot fluorescent fittings with five-foot energy efficient fittings, reducing energy consumption and demand in terms of lighting by 25%.
A lean approach to print, scan, fax, and copier operations have also reduced this number of devices by 45%, which has reduced energy significantly, notes Govender.
He says the aim is for the company to consume 2,09 MWh per unit produced this year, at a planned 36 000 units annual production.
Last year, when the economy and vehicle demand were still upbeat, production reached 51 000 units, with the economies of scale this enabled ensuring energy use of only 1,89 MWh per unit.
A cut-back in production, therefore, does not neccesarily equate reduced energy consumption.
GMSA's Port Elizabeth facilities use roughly 4 500 MWh of electricity a month.
All in all, says Govender, GMSA Port Elizabeth has, to date this year, achieved a 29% reduction in electricity consumption compared with 2008.
GMSA manufacturing vice-president Richard Demuynck says energy costs make up about 10% of the company's annual manufacturing costs.
The target for water consumption per unit produced at GMSA is 4,25 m3 per unit, compared with last year's 3,67 m3 per unit, at a higher production rate.
Govender says the company's production facilities have, to date, achieved 52% saving in water use in 2009 compared with 2007.
Initiatives implemented since 2000 to save water include reusing affluent streams in the paint shop, introducing rain sensors to ensure the minimal watering of the gardens, and decreasing the plant's water supply pressure.
The attempts to green the plant have also reduced its waste streams.
GMSA environmental services coordinator Joel Wolf says GMSA has a waste goal of 30,04 kg a vehicle produced for 2009, compared with 34,24 kg in 2008.
This waste refers to any land-filled waste generated as a result of the vehicle manufacturing process, such as sludge from the paint shop.
“GM demands an annual 5% reduction, but we want a 10% reduction and, so far this year, we have achieved that,” notes Wolf.
A stringent recycling effort has seen the company initiate a process to recycle plastics, wood, electronics, kitchen grease, auto fluids, gloves, rags, scrap metal, food waste (which goes to a pig farmer), paper, card board, garden waste and solvents.
Edited by: Creamer Media Reporter
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