A visiting German expert in integrated energy concept development, Prof. Dr.–Ing. Lars Kühl, has cautioned that accurate scoping of requirements and demands is critical and should not be glossed over in the quest for greater energy efficiency.
Citing the experience in Germany, where energy efficiency has been on the agenda since the 1970s, Prof. Kühl said that the detailed analysis of the demand side is the main factor for the successful development of suited energy and economically efficient supply concepts. “The management of generation, storage and the distribution of energy always depend on the characteristics of the demand side of each project, which varies from project to project. Every advanced energy supply system needs the adoption of an integrated and constantly monitored energy management system as a basic requirement,” he said.
Prof. Kühl is a guest of Skills for Green Jobs, an initiative between South Africa and Germany to promote alternative energy efficiency solutions. He was speaking at Vaal University of Technology (VUT)’s Science and Technology Park last week which is running a project for Skills for Green Jobs to significantly reduce carbon consumption at Danone SA and to create technological capabilities in the use of alternative energy at VUT. His lecture follows a study visit to Germany by a preselected team from VUT.
Reducing carbon consumption at Danone SA
The Danone SA project seeks to apply Multi-fuel Combustion and Combined Heat and Power (CHP) technologies to reduce energy consumption, the cost of energy and the greenhouse gas impact of the energy used. By using alternative energy sources (in this case, natural gas) the company will significantly reduce the carbon footprint of the energy used in the milk processing plant.
The first phase involves the conversion of existing standby diesel generators to run on a combination of natural gas and diesel, technology which is called Diesel Dual Fuel or Multi-Fuel Combustion. The waste heat of the engine (heat energy available from the engine cooling system and exhaust gases) is recovered to generated steam and hot water. In this way, the thermal efficiency of the complete system – a combined heat and power system – is 90%.
SA’s energy landscape
Heinrich van der Merwe, Operations Manager of the Technology Transfer and Innovation (TTI) unit of VUT’s Science and Technology Park in Sebokeng, said that the South African energy landscape is characterised by high demand as well as unreliable and expensive power supply which is expected to continue to rise.
“Following a period of load shedding and the subsequent purchase of generators by many South African users, there are opportunities to improve and supplement our existing supply with combination power sources. It is clear that there are a number of renewable and alternative energy options available at various costs, so the best combination of solutions differs depending on the application. At the VUT Science and Technology Park, we are focused on building capacity to properly analyse demand to enable the selection of the best integrated solution which will include components such as CHP, biogas and solar (solar thermal and solar PV) solutions. We are also building capacity to properly monitor and evaluate energy integration, specifically the use of heat waste,” he said.
Lovell Emslie, an engineer at Pegasus Engineered Green Mobility, said that natural gas is already available in industrial hubs in South Africa and that CHP projects are already financially viable for industries that have natural gas available and require electricity or low grade heat sources for internal processing. “While electricity costs have risen steeply and are expected to rise further, CHP systems can provide significant cost savings. Even greater savings are possible when alternative and renewable fuels like natural gas and biomethane replace thermal fuel, oil or diesel,” he says.
There are many differences in the energy requirements of Germany and South Africa. In Germany, the biogas industry is said to have revitalised the agricultural sector to a certain degree. The stimulated biogas industry, in turn, created a larger industry around heat pumps, CHP and dual fuel engines.
“In Switzerland, about half of all heating systems are heat pump-based and this market is steadily growing. In Germany we see that the use of boilers for heating is decreasing. In South Africa, opportunities exist to stimulate activities in the air-conditioning and ventilation systems market as well as water-driven cooling systems like concrete core activation or cooling ceilings, given that South Africa has a greater need for cooling than heating.” said Prof. Kühl.
He discussed various renewable energy sources available for integration in Germany, including geothermal energy, wind energy, solar energy and of course, heat waste through CHP units.
Staff Writer
