In response to climate change and to prevent the next drought, the Water Resources Agency plans to build a desalination plant on the island. The Environmental Protection Agency held its 423rd environmental impact assessment meeting yesterday (13th) to review the "Tainan Desalination Plant Construction Plan" and the "Hsinchu Desalination Plant Construction Plan." Both proposals were approved. When the two desalination plants are operational, their combined water production will reach a maximum of 300,000 CMD (tons per day), but they will also consume 384 million kWh of electricity annually.
Water supply has been unstable in recent years. The Water Resources Agency: Construction of a desalination plant will increase water supply resilience.
Recent droughts have brought regional water shortages to the fore. While Tainan boasts the Zengwen and Nanhua reservoirs, they are significantly impacted by the wet and dry seasons. In seven of the past ten years, low rainfall has led to water supply cuts for residents, industries, and irrigation. In Hsinchu, due to the limited capacity of the Bao-1 and Bao-2 reservoirs, the city has long relied on water from the Shimen reservoirs in Taoyuan and the Yongheshan reservoirs in Miaoli.
To mitigate the risk of water shortages, the Ministry of Economic Affairs' Water Resources Agency plans to build desalination plants on state-owned coastal land in Jiangjun, Tainan, and Nanliao, Hsinchu. At yesterday's environmental impact assessment meeting, the agency stated that record-breaking droughts are occurring not only in Taiwan but also around the world. Since Taiwan is surrounded by the sea, building a desalination plant will help improve water supply resilience.
The Tainan and Hsinchu desalination plants, planned by the Southern and Northern Water Resources Bureaus of the Water Resources Agency, respectively, passed environmental impact assessments yesterday. The Hsinchu plant, covering 10 hectares, will produce 100,000 cubic meters of water. The Tainan plant, covering 17 hectares, will be constructed in two phases. The first phase will produce 100,000 cubic meters of water, and the second phase will be added after five years of operation, increasing production to 200,000 cubic meters of water. At that time, it will be the largest desalination plant in Taiwan.
Desalination technology consumes a lot of energy. The Water Resources Agency will reduce the load by 50% during the flood season.
However, desalination units produce water using reverse osmosis, a highly energy-intensive process. Each metric ton of water produced consumes 4.25 kWh of electricity. According to the environmental impact assessment documents for both projects, the total annual electricity consumption for the Tainan Desalination Plant Phase I and the Hsinchu Desalination Plant is 128 million kWh, with a contracted capacity of approximately 18.3 MW. The total annual electricity consumption for the Tainan Desalination Plant Phase II is a whopping 256 million kWh, with a contracted capacity of 36.6 MW.
During its initial review, the Environmental Protection Committee questioned the necessity of the energy-intensive water production of the two proposals, arguing that priority should be given to developing nearby groundwater and underground water resources, and strengthening reservoir desilting and water resource management. The Water Resources Agency, however, noted that the other proposals were susceptible to rainfall, arguing that the desalination plant was still necessary to ensure a stable water supply.
To address high energy consumption, the developers, the North and South Water Bureaus, have proposed load reduction plans. During the periods of abundant rainfall and high electricity demand nationwide from June to September each year, production will be reduced by 50% to avoid unnecessary energy loss. Furthermore, both projects will install solar photovoltaic systems at 10% of the contracted capacity, or purchase green electricity certificates if sufficient green energy equipment is not available.
Source: Environmental Information Center (https://e-info.org.tw/node/234565)
