Water scarcity threatens power supply

CLIMATE CHANGE: Without sufficient water, power plants will not be able to generate electricity

IMAGINE a day without water. Not many would want to experience that. It is no less miserable going through a day without electricity.

Water and electricity have no doubt become indispensable in modern day living. Life is impossible without water and intolerable without energy.

Here in Malaysia, there is already serious discussions about water scarcity. Selangor, for example, is contemplating bringing water from Pahang through an expensive tunnel system. This is despite the fact that we enjoy very high rainfall year in year out. Not to mention the frequent flooding. And in Kelantan, the public has lamented for years about the quality of their piped water. This still remains unaddressed.

What is the relation between water and electricity? Will reduced water availability impact on energy? There is now growing evidence that as a result of climate change, energy supply will be curtailed because of problems with water.

A recent study published in Nature Climate Change paints grim prospects on the supply of electricity in the United States and Europe as a result of changing water temperatures arising from global warming.

Higher water temperatures coupled with reduced river flows in Europe and the US in recent years have resulted in reduced production, or temporary shutdown, of several thermoelectric plants, both nuclear and fossil-fuelled. This has to some extent pushed up electricity prices, raising concerns about future energy security in a changing climate.

Are we in the region spared from this? There have been reports of reduced water flow negatively impacting our hydropower plants.

It is a major issue in the US and Europe. This is because in the US, about 91 per cent of its electricity comes from thermoelectric power.

In Europe, it is not much less at 78 per cent. Any disruption to plant operation is, therefore, a significant concern for the energy sector in both countries. As there has yet to be a solution to the warming of the world, the study projects further disruption to supply in the coming years.

According to their analysis, there is a likelihood of a decrease in thermoelectric generating capacity of between six and 19 per cent in Europe and four and 16 per cent in the US for the period 2031-2060, all because of lack of cooling water.

The thermoelectric power sector is one of the largest water users in the US. This now stands at 40 per cent. In Europe, 43 per cent of surface water withdrawals end up being used as cooling water in thermoelectric power plants.

Malaysia is not far different because we also rely heavily on thermoelectric power based on coal.

According to the study, power plants that rely on "once-through cooling" are the most vulnerable. These plants pump water direct from rivers or lakes to cool the turbine condensers. Water is then returned to its source, often at higher temperatures causing problems for downstream users. This can adversely impact on river ecosystems. For example, the life-cycles of aquatic organisms can be disturbed.

It is a real paradox. Fossil-fuel-driven thermoelectric power plants are known to be a major emitter of greenhouse gases which drive global warming. And global warming raises the water temperatures of rivers and lakes, making it difficult to supply cooling water needs of the power plants. It is as if the gases emitted return to haunt the power plants. Either we do away completely with thermoelectric power plants or we look for new sources of cooling water or we design power plants which do not require water-cooling.

The problem is even renewables, such as biomass, would require cooling in their power generation system. Whatever it is, the issue warrants serious attention of researchers.

One option is to switch to gas-fired power plants that are both efficient and use less water.

It is clear water is an important component of power plants. If the supply and character of water change, then the performance of power plants will be affected.