A powerhouse of production

A year ago we hailed the MAN Truck & Bus Pinetown assembly plant for its endeavour to become carbon neutral and as energy efficient as possible. Has the system been a success?

MAN’s global Climate Strategy aims to reduce carbon emissions at its production sites – in Europe, Africa, Asia and South America – by 25 percent by 2020. A year after installing 6 300 m2 of photovoltaic (PV) solar panels at the South African assembly plant in Pinetown, Durban, the local company has confirmed its carbon-neutral status and recorded some substantial cost savings to boot.

The R10-million system, designed and installed by Solaray, reached one gigawatt hour (1 000 000 kWh) of energy generated on May 11. Looking at the 2015 year, the plant’s energy consumption was 672 000 kWh and the power generated by the PV system was 717 000 kWh. This means that 45 000 kWh of power was transferred back to the grid.

The total savings amounted to about R500 000 and 710 t of CO2, according to plant manager Vijay Yelne. These figures are in line with original design estimates.

“We’re happy with what the system has delivered,” he says. “The estimate for the size of system we have was about 800 t of CO2, but one needs to take into account that the projected savings were theoretical and based on historical weather data which was used as the basis for projections of system performance.

The PV system generates most of its energy between 10:00 and 14:00 – when the sun’s radiation is at its highest. In the early morning, late afternoon and on overcast days it is necessary for the plant to draw part of its energy requirements from the grid. During the peak generation times, however, the PV system generates more energy than is actually used by the plant, which is fed back into the grid.

“We have to produce more green energy than we use to maintain CO2 neutrality over the period of a year. Most of the energy we feed back to the grid is generated during the peak time of day and on weekends,” explains Lynette Kühn, SHEQ and process manager, MAN Truck & Bus SA.

There is potential to save more, as the savings gained in the first year were linked only to the reduction in the plant’s actual energy usage, while its fixed energy costs remained. Yelne elaborates: “A huge portion of our energy bill is for the provision of demand – a fixed monthly fee for the council to always have 450 kWh of energy available for the plant. We didn’t want to reduce that available energy during the first year of operating the PV system, which meant we still had to pay that higher fixed demand charge.”

Naturally, the council compensates the plant for the energy it feeds back to the grid.

Kühn explains, though, that it is not possible for an operation like the plant to go completely off the grid. Currently, being tied to the grid and implementing an efficient genset is proving to be the most economical way to power the plant.

“The genset was implemented purely as a back-up system for power outages. It runs with a MAN motor, which is extremely energy efficient. If there’s a power dip or outage it switches on within ten seconds. We haven’t needed to run it to date and so it hasn’t influenced any of our CO2 savings,” she says.

In the event of a power outage, the PV system is designed to shut down to protect itself. In such an instance the genset is used primarily as a power source for the PV system. Once the genset starts running, the PV system sees it as an alternative power source to the grid and then begins to operate again with the genset falling into an efficient low-power mode.

Yelne adds that throughout the year there has been only one issue with the system, in which one of the 23 inverters went down. “We have a five-year maintenance agreement with Solaray, so they flew in a new inverter from Germany (none were available locally) to replace it immediately. There was a small dip in power production, but the system still ran. There have been no issues since and we can’t complain about the support and backup we have received from Solaray,” he says.

The PV system is not the plant’s only green initiative. A water recycling system was installed at the same time, and, with the country being affected by drought, the plant is investigating more water-saving initiatives. These include a current motivation for a water harvesting and grey water system for use in the shower and ablution facilities.

Furthermore, the adherence to standards is taken seriously. In 2015, the plant successfully implemented and achieved the ISO 14001 Energy Management System certification. “We also want to implement the ISO 50001 Energy Management System. We’re partnering with NCPC South Africa, with support from head office in Germany, as all certifications are done internationally by TÜV SÜD,” concludes Yelne.

Surely the folk at MAN head office are enthusiastic about this. The Pinetown plant is, after all, a clear leader in the company’s global Climate Strategy.

A melting pot of culture

The MAN Truck & Bus Pinetown assembly plant brings together vehicle components from Europe, South America and India, to be assembled for the South African market. It’s little surprise, then, that you’ll hear German (MAN is a German brand), Brazilian and Indian accents mixed in with the local dialect.

For the plant’s new manager, Vijay Yelne, this is one of the most appealing aspects of the job. Having arrived in South Africa only on December 1, 2015, Yelne joins the local operation after ten years at MAN India. He is responsible for all operations of assembly of bus and truck vehicles at the plant.

“It’s a different challenge for me, because of the diversity of products from around the world. South Africa is a major change and quite different from India. The market is challenging with a lot of competition, but it is a good place to work,” he says.

Yelne holds a Bachelor of Engineering and Mechanical Engineering degree, as well as a Diploma in Business Management from Bombay University. Before joining MAN, he worked for American-based engine manufacturer Cummins India Limited in Pune, India, for 23 years, where he played a key role in setting up the company’s Indian manufacturing facilities.