Tested by Heat: How the Energy Sector Adapts to Extreme Temperatures

Heat Test: How the Energy Sector is Adapting to Extreme Temperatures

Tashkent, Uzbekistan – Podrobno.uz News Agency

Abnormal heat has become a serious challenge for energy systems. While air conditioners significantly increase electricity consumption, high temperatures simultaneously place additional strain on power plants and grids. In Uzbekistan, daily consumption reached a record 301.9 million kilowatt-hours on July 20, with peak load on the power grid reaching 14.2 GW. We will examine how extreme heat affects various types of generation, why power units may reduce output or temporarily shut down under such conditions, and how the energy sector is adapting to new temperature loads.

The main reason for increased consumption on hot days is increased demand for space cooling. According to the International Energy Agency, global electricity consumption for air conditioning has increased by approximately 50% since 2015. Cooling currently accounts for approximately 10% of annual electricity consumption, but already accounts for approximately 30% of peak load. The higher the temperature, the greater the load on air conditioners, and the greater the increase in electricity demand during peak hours.

Thus, heat impacts the power grid from two directions: it simultaneously sharply increases electricity demand and deteriorates the operating conditions of some equipment.

The Impact of High Temperatures on Various Energy Sources

The impact of heat depends on the type of generation. Gas turbines can lose some of their available power due to air heating, since high temperatures reduce the density of the air entering the turbine. The efficiency of solar panels, in turn, decreases when they overheat.

Transmission lines and transformers experience additional thermal stress. Rising temperatures limit the capacity of power transmission and distribution equipment, especially during periods when demand reaches its peak.

Hydropower also faces risks. Its production is directly dependent on river flow and the inflow of water into reservoirs. In its Global Energy Review 2026, the International Energy Agency notes a decline in hydroelectric power generation in several regions, particularly in Europe, Central America, and South America. The resulting shortfall has largely had to be compensated for by fossil fuels.

The water used to cool power plants requires special attention. This system is essential not only for nuclear power plants, but also for coal-fired and many gas-fired power units.

If a power plant draws its water from a river or other body of water, a drop in water level or excessive heating can lead to power limitations. Therefore, reports of temporary output reductions or the shutdown of individual power units during hot weather and low water levels do not necessarily indicate an accident.

Why a power unit can shut down without an accident

The International Atomic Energy Agency also considers extreme weather and environmental conditions as factors that may require protective actions, power reduction, or temporary shutdown of a power unit.

For example, high cooling water temperatures may necessitate reducing the power output of the plant to comply with established temperature limits. During low-water periods, the reduction in available water volume may also require power reduction or temporary shutdown to maintain the necessary cooling capacity and safety margins.

This means that climatic and hydrological parameters must be considered not only in the plant's design but also during its subsequent operation and modernization.

Nuclear power itself remains a controllable source of electricity. The International Energy Agency notes that nuclear power plants are capable of providing large-scale generation throughout the day and complementing renewable energy sources.

This is especially important for energy systems where the share of solar and wind generation is growing: nuclear power plants can provide stable output while solar and wind power generation depends on the time of day and weather conditions.

How Nuclear Power Plants Are Prepared for Hot Climates

The ability of a nuclear power plant to operate in extreme temperatures largely depends on the specific design and site conditions. Rosatom CEO Alexey Likhachev noted that Russian projects are initially developed with the climatic and natural characteristics of the construction site in mind.

"We have the northern Kola, Bilibino, and floating nuclear power plants. We also have projects for temperate climates, and we have plants and projects for hot, arid regions—for example, El Dabaa in Egypt. Each such project is developed from the ground up for a specific site, taking into account air temperature, hydrology, wind conditions, water supply characteristics, seismicity, and other natural factors," he noted.

The experience of the Rostov Nuclear Power Plant is indicative in this regard. According to Likhachev, summer temperatures there can exceed 40 degrees Celsius. After the new power units reached full capacity, it was discovered that during the hottest periods, the process water temperature became higher than optimal.

To address this issue, an additional set of forced-draft cooling towers was commissioned in 2021. They operate in conjunction with the main cooling system and, during extreme heat, enhance heat exchange.

This allows the power unit to continue operating without reducing capacity and maintain stable output. A similar set is currently being built for another power unit.

What does this mean for Uzbekistan?

For Uzbekistan, where summer peaks in electricity consumption are already setting new records, the issue of the power system's resilience to extreme heat will become increasingly important.

High temperatures simultaneously increase the load on the system and place additional demands on the operation of generation, networks, and cooling systems. Therefore, when constructing new power facilities, it is important to consider not only their installed capacity but also the actual climatic conditions of the site, water availability, and the ability of the equipment to operate during periods of peak demand.

However, heat alone does not provide a definitive answer to the question of which power generation technology is more reliable. Rather, extreme temperatures reveal how prepared a specific power plant and the overall power system are for operation under peak load conditions and the extent to which potential climate risks were taken into account during the design process.