Energy Audit of Mauritian Industries

Abstract: Abstract Three companies namely Esko & Co Ltd, Cuttings Work Ltd and The Message Ltd were targeted for the purpose of this project study. The first one is Esko & Co Ltd. The company has diversified its production activities to produce sweets, bubble gums, chocolates, wafers and noodles both for the local market and export purposes. Cuttings Works Ltd is the second leading company in the manufacturing of top grade products using the best possible gemstones for the jewellery grade. The company is also diversifying and expanding its market. On the other hand ‘The message Ltd’ is another company involved in the designing and make up of high class casual wear. Previously the company was only designing and preparing samples and the bulk order done in another textile factory. With respect to the highly demanding market, they have now started the production of their shirts in-house. Being exposed to competition threats from other local and overseas suppliers, it is imperative for these factories to investigate on cost saving possibilities and process improvement opportunities. A walk-through audit was carried out where data were collected. The objective of the audit was to obtain energy savings through low cost improvements that optimise the building systems and process operation so that the companies operate efficiently and effectively. On the basis of observations and calculations, the following cost savings options can be suggested:’ 1.       Savings on Fuel (HFO) used at Esko & Co Ltd. A saving on fuel consumed of MUR 458 572 [PH1] (Euro 11 464 based on exchange rate of Euro 1 = MUR40) per year can be achieved by recovering the heat loss through the flash steam for pre-heating the feed-water to the boiler. Another saving on fuel of MUR 105 578 (Euro 2639) per year can be done by recovering the heat loss from the Wafers machine exhaust. Also by recovering the heat loss from the boiler chimney exhaust a saving of MUR 137 457 (Euro 3436) per year can be achieved. 2.       Savings on Electrical components. It was found that in a big manufacturing company like Esko & Co Ltd, a direct saving of MUR13 278 (Euro 332) per year can easily be achieved by substituting the existing Fluorescent tube lights (18W) by 9W-T8 lamp with a return on investment of 2.8 years. However in smaller scale enterprise like The Message ltd and Cuttings Ltd, the shift on economic lamp can also lead to savings of MUR 3700 (Euro 92.5) and MUR 1386 (Euro 34.7) yearly. Most often large scale enterprise was found to be always paying a penalty fee for power factor. Hence the investment on an Automatic Correction Unit will also help doing savings. For instance, Esko & Co Ltd can save MUR 3200 (Euro 80) monthly on its electricity bill with a payback of 3.1 years for the power corrector unit. Next we noticed that big companies are used to a penalty fee for power factor. As this fee is for a period of six months for every month of excess power consumed, it is worth investing on an Automatic Power Correction unit. As such foe Esko & Co Ltd we found that a saving of MUR 3200 Euro 80) per month will be made with a payback period of 3.1 years for the equipment. Furthermore it was found that the power consumed by air conditioning units is quite significant. For instance for Esko & Co Ltd 33 % of the total power consumed are by the air conditioning units. A direct saving in this respect is achievable by only increasing the set point temperature by 1 to 2 oC. Other simple measures can be shading of windows to prevent sunlight or using wind curtains at doors and to switch on the AC when needed can largely help to decrease the air conditioning load However there is also room for future investment in variable speed drive for the compressors of the air conditioning units which is still costly at present. 3.       Steam leakage optimisation Reduction of steam leakage can be done by replacing the return condensate line from the oil heat exchanger at Esko& Co Ltd by a smaller one. It was not possible to calculate the savings as the leaks could not be measured – however results will show in the fuel bills. 4.       Reduction of heat dissipated Insulating the exhaust pipes from the Wafer machine at Esko& Co Ltd by using mineral wool of thickness 57mm will considerably decrease the heat dissipated to the surrounding by 80 % and hence improving the working environment around the machine since no air conditioner is found in that room. Air conditioning load in other rooms are expected to reduce and once again here it is difficult to conduct any calculations on how much can be saved. But by taking this measure the effects are immediately seen. 5.       Transport Fuel optimisation Normally big companies like Esko& Co Ltd which has many lorries for their product delivery that consume around 2330 litres of diesel monthly. As the transportation fuel is continuously increasing, this area also requires monitoring and optimisation. Simple measures like smooth driving, regular tuning and servicing of your engine can help improving the fuel economy of the company. 6.       Use of solar energy To alleviate the increasing world oil prices, the use of renewable energies are becoming important. As such we found that in a country like Mauritius where there is great potential for solar energy, the latter can be an option for companies to invest on. It was found that a grid connected system will be more advantageous and depending on an agreement with the local grid, a payback of less than 5 years can be achieved for a tariff around MUR 3 (Euro 0.08) per kWh. 7.       Avoided carbon dioxide emissions. To decrease the impact of global warming, it is important to cut down the emissions of greenhouse gases as it will be a serious threat to the third world countries and small island states in the first place as they are the most vulnerable. With the savings in the amount of HFO burned at Esko& Co Ltd, we found that the avoided amount of GHG emissions amounts to 98.96 kg CO2-e/year.