Last Updated 3 months ago by Kenya Engineer
Introduction
The water-energy nexus is the interrelationship of both water and energy. It highlights the extent to which energy and water are intertwined. By considering them jointly one gets a comprehensive view. This approach also promises more sustainability than analyzing them in distinction. Water and energy are so intimately conjoined that what affects one will have a profound effect on the other. The competition between water and energy should be of a critical importance to business, security, and environmental stakeholders; it is yet observable that it has not received the attention that it merits.
Energy nexus to water
Currently, 82 percent of Kenya’s power is supplied by hydropower. Other major energy sources include geothermal (8%), thermal (8.7%) and wind (0.01%).
All types of electricity generation consume water either to process the raw materials used in the facility or fuel, constructing and maintaining the plant, or to just generate the electricity itself through turning of a turbine etc. Renewable power sources as photovoltaic solar and wind power, which require little water to produce energy, require water in processing the raw materials to build the turbines and solar panels. If a wind turbine is mounted on a concrete or steel tower, additional water is required in the tower’s construction.
Kenya is highly dependent on hydropower and the bulk of the electricity produced in the country is generated by the damming of rivers to produce hydro-electricity. Plants along the Upper Tana River Basin, which include Masinga, Kamburu, Kindaruma, Gitaru and Kiambere, produce the bulk of the electricity. Kenya Electricity Generating Company {KenGen} is the leading electric power generation company in Kenya, producing about 80 percent of the electricity consumed in the country.
Hydropower generation absolutely depends on availability of water. Fluctuations in climatic parameters such as rainfall, temperature and wind speeds significantly affect the rate of evapo-transpiration, which in turn affects water in reservoirs and dams. This makes hydropower highly dependent and sensitive to climatic fluctuations, especially the extremes such as droughts and floods which are all functions of water. Droughts are known to be associated with low water levels in the major dams, while floods bring a lot of silt into the dams and can sometimes lead to destruction and damage to the turbines. It must be noted that the impacts of such climate fluctuations which vary water available for the hydro energy resource is direct.
Inadequate rainfall during the prolonged 1999-2000 drought, for example, led to severe water scarcity and shortage in electrical power supply, causing serious power rationing throughout Kenya. Consequently, the power industry was in dire straits due to its connection to water and with it dragged the whole economy down. In particular, the estimated losses in hydropower generation and industrial production due to water shortage during the 1999/2000 drought were over 2 billion US dollars according to World Bank in 2006.
In the effort to produce energy a considerable amount of water is used to: cool thermoelectric power plants, grow feedstocks and convert them into biofuels, extract oil and natural gas from geologic formations, and extract oil shale in the event commercial production of this energy source becomes economically feasible in the future.
Some of these sources of energy, such as biofuels that require the use of large amounts of fertilizers and pesticides to grow the feedstock, will also negatively affect water quality in the shape of runoff pollution.
The developments of oil and gas resources need a lot of water to develop and exploit. In the process they produce large volumes of wastewater—known as “produced water”—that must be disposed of or treated to allow for its reuse. With the imminent entry of Kenya into the league of oil producing countries this must be considered closely.
Taking up water for use in cooling for thermal power generation leads to the reintroduction of the water to join the main water body. It may join having different but harmful properties including at a higher temperature or with radiation which will prove harmful for the marine ecosystem and even humans.
Creating energy consumes enormous quantities of water; this consumption can be considered along three critical dimensions: consumption, withdrawal, and quality.
Consumption refers to water that disappears or is diverted from its source, for example by evaporation, incorporation into crops or industrial processes, drinking water, etc. The source may or may not eventually be replenished. If replenished, the process could potentially take many years decades, centuries, or longer.
Withdrawal refers to water that is essentially “sucked up” for a given use, but then returned to its source. The quality of the returned water may or may not be the same as it was prior to removal.
Quality is an umbrella term that can refer to pollutants that enter the water; changes to oxygen content, salinity, and acidity; temperature changes; destruction of organisms that live in the water; and other alterations to the water make up.
Water nexus to energy
As energy requires water, water supply and sewage disposal needs energy. Drinking water must be pumped to the treatment plant, pre-treated, and then pumped to consumers. In areas where fresh water is scarce and drinking water must be brought in from a long distance, the energy footprint for this drinking water is extremely high. The energy consumed for pumping groundwater is typically between 537 kWh and 2,270 kWh per million gallons depending on pumping depth
Significant amounts of energy are needed to extract, transport, treat, and use water in urban areas, additionally contributing to energy demand. Massive pumps must be set up by the service companies which are always augmented by smaller pumps by the consumers. Boreholes and wells need energy to drill and even more to continuously use.
Pollution from energy production or consumption also has a profound effect on the quality and availability of water. Damming to produce electric power reduce water levels. The 6,000-megawatt Grand Ethiopian Renaissance Dam on Ethiopia’s Blue Nile River, set to be completed in 2017 has raised concern in Cairo that it will reduce the flow of the Nile. The Nile provides almost all of Egypt’s water. Closer home the Ethiopian government is putting up the hydro-electric power dam dubbed Gibe III along River Omo, which is the main source of water for Lake Turkana. Environmental activists fear that the lake’s water level may drop by as much as 33 feet as a result, compromising its status as a world heritage site besides the depletion of fish stocks and water accessible for human use.
The burning of fossil produce green house gases which have a huge effect on the water cycle this is besides direct pollution that results from the exploitation of these resources.
Policy
Water and energy are both multifaceted issues with many variables impacting their supply, demand, and management. Legislators and other stakeholders should consider the following variables which add complexity and underscore the importance of management of water and energy jointly.
Growing population: As long as people increase in number they will need more energy and water to satisfy their daily needs.
Agriculture and manufacture: Water demands will increase as agricultural demands increase with the need to feed a growing population. To process the raw agricultural produce will require more water and energy in the form of fuel and electricity to run the plants.
Geographical water demand: geography plays a major part in the availability of both water and the opportunity of power production like dam construction. All Kenyan dams are constructed to exploit geography of the different locations they are found in.
Climate Change: The impacts of climate change will also impact water and energy supply and availably as Kenyans must be aware with hindsight of 1999-2000 and 2003- 2004. Global warming also touches on both energy and water and must be treated with much care.
Conclusion
Water and energy are critical, mutually dependent resources. The production of energy requires large volumes of water and water infrastructure requires large amounts of energy.
As water and energy demand increase and they always will as long as the population grows, managing the two resources in tandem will help Kenya maintain reliable and sustainable supplies of both energy and water. There have been reforms some misguided and others timely.
The reforms in the water sector kicked off in 1986 following public outcry of deteriorating service provision not only caused by non functional infrastructure but also declining quantity and quality of water resources. The process culminated into the National Water Master Plan (NWMP) of 1992 which recommended that water policy should be changed such that water service provision is separated from water resources management.
Following this recommendation, a water policy was published in 1992 and a water act enacted in 2002. As a result the Water Resources Management Authority (WRMA) was created to manage the resource while regional water boards were charged with service provision.
On a close scrutiny one notices that water is closely intertwined with all aspects of life and the economy. Disjointed efforts and policies to handle water are doomed to only give rise to myopic pyrrhic results.
Water energy nexus promises a synergistic approach with more comprehensive results. All new policy and actions that touch on water must be drafted with this insight.