 Sun Belt also overlaps with a water scarce region, water withdrawal and consumption will be a consistent challenge.
Another example is carbon dioxide capture and storage (CCS). Based on the findings from our research, current CCS technologies could capture 90 percent of carbon dioxide from a power plant’s emissions, plant-wide water consumption increases by more than 90 percent. When designing new PC plants with CCS, water availability, as well as the presence of geologic formations needed to promote secure storage, will need to be carefully evaluated.
CWR: Estimates are that an additional 350 million people will move to cities by 2030. What will this mean for energy consumption and the country’s water resources?
PJZ: A larger urban population of course means higher consumption of energy and water; new infrastructure, cleaner water and therefore more electricity use. Today’s rural population enjoys limited infrastructure and therefore uses less energy and consumes fewer resources. Urbanization, though, is a natural course with or without a specific policy because of the income gap between urban and rural communities.
In the coming two decades, China’s total installed power generation capacity is expected to double from the current level, and coal is projected to still be the dominant energy source. Thanks to modern technologies, future coal-fired power plants will be more efficient and environmentally friendly than they are today. For example, supercritical (SC) and ultra-supercritical (USC) units and dry-cooling could reduce water consumption per unit of power generated to different extend, at a commercially feasible price. Integrated gasification combined cycle (IGCC), though more expensive today, could drastically reduce wastewater discharges and cut GHG emissions. Clean coal technology, together with renewables, can help minimize water/carbon footprint of China’s power sector.
CWR: What part does water-pricing play in the discussion of the water-energy nexus?
CWT: Regarding water pricing, China is gradually shifting from government command to a market-based mechanism, which could ultimately reflect the relative scarcity of water and help address water-energy problems in the future. Over the past ten years, a number of Chinese cities have significantly increased their water price through market-based reforms, with special rates designed to help low-income consumers. Meanwhile, block pricing has been implemented to different extents and with varying degrees of success across China. After the amendment of the Chinese Water Law in 2002, all industrial and municipal water users were required to pay a water resources fee. However, the price is generally low and has not been leveraged as an economic incentive for improving water use efficiency. Current water resources fees for cooling water vary from province to province but normally range from 0.001 to 0.008 CNY/kWh for open-loop units and hydropower units (but are even lower for closed-loop units), a price that accounts for just 1-3 percent of electricity generation costs2.
PJZ: In theory, water pricing matters but we also see that in Beijing municipality, the city with the highest income levels in China and where the water price has been high, water demand continues to increase. Again, this is a matter of degree. If the price is very high then generally the end user will want to save water but this also depends on income level and awareness. Pricing is only one measure to change water demand. Command and control is the other, so planning is also important. For some cities with water stress, municipalities should avoid introducing investments that involve high water consumption. This is a matter of spatial planning for economies and cities.
CWR: The extraction, transportation, purification, and distribution of water, as well as the treatment of wastewater, are energy-intensive processes. As water issues grow, desalination will also be more firmly on the Chinese radar. Yet these all use more energy and thus more water. What do you see as the future here?
CWT: It is true t