Water Stewardship
Climate change has caused changes in rainfall patterns globally, and the rainy season can no longer be predicted based on historical trends. In addition, the frequency of rainstorms and prolonged droughts have increased. Water stewardship has become one of the issues enterprises are concerned about. Although the Head Office of Shih Wei Navigation is in the area with low to medium risk level (Medium 1-2) according to World Resources Institute (WRI) Aqueduct Tools, Taiwan’s steep terrain that makes it difficult to retain water and the impact of climate change often force it to face severe water shortage. Therefore, effective water stewardship will help with water conservation, reducing the environmental footprint, costs, and operational risks of enterprises.
Water for Ships
Water acquisition |
There are two sources of freshwater for ships, one from the ocean, and is obtained from an evaporator system that uses distillation, and the insufficient part is taken from freshwater onshore. |
Water consumption |
Water is used to cool the main and auxiliary engines, supply boiler water, clean the cargo tank and deck of the ship, and for the daily domestic water use and drinking water for sea crews. |
Water discharge |
The ship sewage and oily water is treated by the equipment system, and is discharged into the ocean or collected by the shore equipment in accordance with the regulations in MARPOL 73/78 and the discharge regulations of specific countries so as to protect the local water environment and lower the pollution to the marine ecology. |
Discharge Management of Water Resources
In addition to the discharge regulations of specific countries and regions, ship sewage water is discharged after being disinfected and decomposed by the sewage treatment system in accordance with the regulations stipulated in MARPOL 73/78.
Bilge water, on the other hand, is treated by the oil-water separator, and the clean water can be discharged into the ocean. The non-dischargeable oily waste is sent to an incinerator for burning or collected by a professional shore reception equipment provider when the ship is berthed, as prescribed in Annex I of MARPOL 73/78.
In addition, the freshwater suppliers are also required to provide healthy and safe water quality report in accordance with the local regulations. For ballast water management, please see 3.7.2 Ballast Water Management.
Methods and Handling of Water Stewardship
Due to limited space (mainly for loading) and the high salinity of seawater that cannot be directly used, waste heat recovery drives the freshwater generator to convert seawater into fresh water for crew and equipment use. Most of the ship's equipment adopts an internal circulation mechanism, which effectively utilizes the precious water resources on board by repeatedly using freshwater through heating and cooling.
Waste Heat Recovery
Ships use fuel for propulsion, and the exhaust gas from the main engines, around 400 degrees Celsius, is used to heat the boilers. The steam generated from this process not only preheats viscous fuel but also serves as a heat source in winter. Waste heat recovery helps achieve energy and fuel efficiency.
Additionally, during engine operation, cooling water is used to lower its temperature. The cooling water is heated to about 80 degrees Celsius through heat exchange and then sent to the freshwater generator. Using vacuum technology, the generator distills and cools seawater, producing freshwater.
Water Consumption
There are two sources of freshwater for ships, one from the ocean and is obtained from an evaporator system that uses distillation, and the other is from the shore that is provided by water suppliers. There is no use of surface water, ground water or other water sources. Statistics of the freshwater made by the freshwater maker on the ships are difficult to obtain; therefore, the water consumption of the fleet is based on water intake data on the shore.
100% of the tap water used in the Head Office is from Taiwan Water Corporation. There is no use of surface water, ground water or other water sources. Water is only used by employees and visitors, which has no significant impact on the water sources. Water is mainly used for drinking water, air-conditioning system, cleaning, and so on. Part of the water is for cleaning tableware and the restrooms. To follow the policy of cherishing water resources, our employees are encouraged to adjust water flow to small flow to save water resources. In addition, to protect the health of employees, we commission the manufacturers to test the drinking water quality to ensure the safety and quality of drinking water.
Water Consumption in the past three years
Unit: Megaliter(s)
| Operating activities | Source of water | 2020 | 2021 | 2022 |
|---|---|---|---|---|
| The Fleet | Third party water | 12.920 | 16.429 | 17.497 |
| The Fleet | Seawater (produced freshwater)Note 4 | N/A | N/A | N/A |
| Head Office | Third party water | 1.744 | 1.196 | 1.441 |
Note：
- 1 Megaliter= 1,000 m^3
- 1 metric ton = 1,000 liters
- Due to the impact of the epidemic during 2021 and 2022, the proportion of navigation decreased and that of anchoring or berthing increased, leading to reduced water production by the ship and increased water intake onshore
- Ship's water intake mainly comes from seawater, which is processed through a freshwater generator to produce fresh water. Currently, data on seawater intake is unavailable, and it will be required for the fleet to record this information in the future
- For detailed explanation, please refer to the company’s Sustainability Report.