Water crisis behind the wall of power plants and refineries / How much water does the energy industry consume?

The water crisis is not only limited to thermal power plants and oil refineries or petrochemical complexes, but energy production is dependent on water, but in Iran, an integrated and up-to-date picture of the amount of harvest, net consumption, and the share of wastewater in the water supply of these industries is still not available to the public, which needs to be corrected.

According to the report of energy reporter Safir Arjan, Iran's water crisis is not only limited to low water dams, the drop in underground aquifers, or restrictions on citizens' consumption. A part of water is consumed in industrial processes, without which electricity generation, oil refining, and the operation of petrochemical complexes are not possible; From the cooling of power plants and steam production to the washing of equipment, the processes of refining and purifying products.

Scientific research indicates the significant difference in water consumption between electricity generation technologies and the significant capacity to reduce consumption in refineries; An issue that becomes more important in areas with water stress. How much water Iran's energy industry consumes in total cannot be limited to a simple number. Power plant, oil refinery, petrochemical complex and upstream oil and gas facilities have different water consumption patterns. Part of the harvested water may return to the environment and another part may be lost in processes such as evaporation.

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In addition, water consumption in electricity production is not the same as water consumption in fuel extraction and processing, and collecting the statistics of these sectors without checking the overlap and calculation method can create a false picture of the country's situation.

The review of published studies about Iran shows that, at least in the electricity generation and oil refining sector, there are both serious differences between technologies and capacities to reduce water consumption have been identified. However, converting these capacities into real results requires the publication of performance statistics of industrial units.

Significant difference in water consumption in electricity production

Thermal power plants need heat removal to produce electricity, and the type of their cooling system affects the amount of water needed. In cooler systems, part of the water is consumed mainly through evaporation; Whereas dry cooling systems mainly use air to dissipate heat and can reduce the need for water. However, dry cooling may increase the investment cost and affect the production efficiency at high air temperature.

A study published in Scientific Reports in October 2025 examined the intensity of water consumption of a number of power plants in Iran using data from 2007 to 2017. The results of this study show that the difference in water consumption per power generation is significant among different power plants.

Water consumption intensity (cubic meters per megawatt hour)

The importance of publishing updated water consumption statistics of power plants

This comparison shows that in the investigated samples, the intensity of water consumption in some heating and combined cycle power plants with more cooling is many times higher than the combined cycle power plants with lower consumption intensity. The research reports a consumption intensity of about 0.18 cubic meters per MWh for several combined cycle power plants and relates the higher consumption of some units to the use of more cooling technology.

This difference shows the importance of technology and operating conditions; But it alone does not prove that all power plants of a group have the same performance in all conditions. The actual intensity of consumption depends on the type of equipment, ambient temperature, production rate, water quality and usage method. The same study has estimated the average annual water consumption of Ramin power plant in the period from 2007 to 2017 at about 22.4 million cubic meters and at Neka power plant at about 26.5 million cubic meters. 16.3 million cubic meters per year for Bandar Abbas power plant and 9 million cubic meters per year for Muftah power plant.

These figures are historical data and they cannot be considered the definitive consumption of these power plants in 1403 or 1404 without receiving more recent information. However, the magnitude of the historical figures shows why it is important to publish up-to-date statistics on power plant water use, especially in water-constrained areas.

Water consumption in the hidden processes of fuel production

In oil refineries, water is not only used for cooling equipment. Steam production, some separation and refining processes, equipment washing and supply of ancillary needs are also dependent on water. The type of crude oil, refining technology, the quality of the final product and the design of the water and sewage network affect the amount of water needed.

A study published in 2024 in the Water Resources and Industry magazine has investigated the possibility of reducing fresh water consumption in an Iranian refinery using the "water pinch analysis" method. In this method, different water and wastewater streams are evaluated for quality and reusability to determine how much fresh water can be replaced by recycling.

The necessity of providing reliable information about Iran's refining industry

The results of this research show that in the modeled scenarios, fresh water consumption could be reduced by about 79 cubic meters per hour, equivalent to approximately 45%, or in another scenario by about 99 cubic meters per hour, equivalent to approximately 56%. These scenarios have also estimated the reduction of oily and sanitary wastewater production in the range of 31 to 52 cubic meters per hour.

These numbers are the potential savings in a case study; Neither the performance statistics of all refineries in the country nor the proof that this amount of reduction has been achieved in practice, however, the findings show that reducing the need for fresh water is not only dependent on the construction of new equipment, and redesigning the consumption network, separating wastewater streams and reusing water in compatible processes can also be effective.

In order to convert this capacity into reliable information about Iran's refining industry, it is necessary for operating companies to publish the amount of fresh water consumed, the volume of wastewater produced, the share of recycling and the results of consumption reduction projects by refinery and year.

petrochemical and oil and gas chain; Why is a national number not enough?

Petrochemicals and oil and gas processing facilities are also in the energy chain, but their water consumption cannot be summed up without separating the processes with the consumption of power plants or refineries. Product type, production scale, technology used and water supply method are the determining factors in the consumption of these units.

In this section, a distinction should be made between water needed for product production, water used in cooling systems, water used for steam production, and water entering wastewater treatment units. Water may also be used in several stages of an industrial chain; Therefore, summing the figures of different units without checking the possibility of recounting can distort the result.

Researches related to the effluents of petrochemical complexes in Iran also show that the quality of the industrial output should be carefully checked. The wastewater of an industrial unit is not necessarily suitable for reuse in all processes just because it is treated; Some applications require additional treatment to control salinity, organic matter or other contaminants. As a result, the evaluation of water consumption in the oil, gas and petrochemical chain should consider both the volume of incoming water and the quality and fate of outgoing water. Without such separation, neither the amount of pressure on water sources is determined nor can the real contribution of recycling be evaluated.

National capacity against the needs of industries

One of the ways to reduce extraction from conventional sources is to use treated municipal and industrial wastewater. This option, especially in areas where industrial units are located near treatment plants, can provide part of the process or cooling water requirement; Of course, on the condition that the quality of the effluent is suitable for the intended use and the cost of transportation and additional treatment can be justified.

According to the statements of one of the officials of the country's water and sewage engineering company, about 6.3 million cubic meters of sewage are collected and treated daily in more than 300 cities and villages. In this report, the number of wastewater treatment facilities is 322 and the industry's share of produced wastewater is described as very small.

This statistic shows the country's overall wastewater treatment capacity; But it does not specify how much treated wastewater is available to energy industries, what volume is delivered to power plants and refineries, and what share of the total water they need.

To measure the actual result, it is necessary to distinguish between the nominal capacity of the treatment plant, the volume of usable effluent, the contracted amount and the actual volume delivered to the industry. In addition, it should be determined to what extent the use of wastewater has reduced surface, underground or municipal water withdrawal. Merely announcing the implementation of a wastewater transfer plan alone does not prove that the pressure on water sources will decrease.

How should the performance of industries be measured?

The Executive Regulations, Part 1, Paragraph "B", Article 39 of the Seventh Development Program Law, deals with the use of conventional and unconventional waters by water-bearing industries. In the rules related to the first year of implementation of the regulation, industrial, mining, oil, gas, petrochemical, and energy and electricity production units with a consumption of more than 300,000 cubic meters per year are included as water-bearing units.

This legal framework makes the water management of large industries an issue that can be pursued; But the existence of a law or assignment to use non-conventional sources does not in itself indicate a reduction in conventional water consumption. The result of the implementation of regulations should be measured by the actual withdrawal statistics, the share of wastewater in meeting the needs, the amount of recycling and the changes in the consumption of each unit. Regular publication of these indicators can determine whether water management policies have led to real reductions in withdrawals or remain merely at the program and commitment level.

Lack of integrated statistics for comparison

The review of scientific sources and public information shows that for some power plants there are specific data on the intensity of water consumption, and about an Iranian refinery, the capacity to reduce water consumption has been estimated with technical methods. But these data alone do not answer the question about the total water consumption of Iran's energy industry.

To calculate a defensible national figure, the statistics of thermal power plants, oil refineries, petrochemical complexes and other related units should be collected, with a specific statistical year and the same definitions. Then it should be clear whether the figures refer to water harvesting or pure consumption; Are the returned and recycled water included in them? Whether water consumption is recalculated in different parts of the fuel chain or not.

In the absence of such a collection, announcing a general number for the entire energy industry can lead to a false perception of the scale of consumption rather than clarifying the reality. Therefore, disseminating disaggregated and verifiable data is part of the answer to the water management problem in this sector.

A specific demand from the Ministry of Energy and the Ministry of Oil

In order to clarify the energy industry's share of the pressure on the country's water resources, the Ministry of Energy, power generation companies, the Ministry of Petroleum and operators of refineries and petrochemicals should publish the following information by unit and year:

The volume of water withdrawal from surface, underground, urban network and treated wastewater.