The Force of Water

The persistent rains of October and November in northwest Spain are already releasing images to remember, such as those seen these days at the Eume dam, located in the municipality of As Pontes, in the province of A Coruña. At the time of its construction in the 1950s, it was one of the most impressive drops in Europe, with a height of more than 100 metres. The reservoir that rises with the dam feeds the plant, which is located about three kilometres downstream. This hydroelectric generation asset has more than 50 MW of installed capacity. In the main hall of the plant, the two units have been running at full capacity for weeks. The noise of that unending collection of gears that drives the enormous force of the water does not cease. It's a dull hum that persistently evokes nature's sensational transformative power.

It is no coincidence that the economic development that Spain experienced during the last century cannot be explained without this driving force. For example, in order to boost production in the manufacturing sector of urban centres such as Barcelona, it was necessary to dam the abundant water that accumulated in the foothills of the Pyrenees. Thus, encapsulated between tons of concrete, it served both to guarantee the consumption of the nearby populations and to start up the powerful hydroelectric power plants. The mechanism of the latter is a long-established, advanced and automated version of the old water mills. A strong stream of water is channelled into a turbine. And this gives life to a generator. The energy produced is fed into the general grid. And so progress came to many industrial areas of the country. 

Simple and, at the same time, complex because each river, each canyon, and each terrain has its own characteristics that require a customised solution. Some facilities have a lot of erosion and wear of materials; others have abrupt temperature changes between winter and summer, thawing, and dry seasons. These are small universes within the same technology that, with the energy transition, have gained new impetus thanks to their management capacity (when they are not flowing plants, i.e. without a reservoir). This allows it to produce and support other unmanageable renewable resources, such as wind and sun. When they fail or need stability, that's where the hydro comes in: 100% predictable, 100% reliable. 

But here, too, climate change, which is to be fought by decarbonising the economy and catalysing the use of green energy, has begun to take its toll. Changes in weather patterns make it necessary to reprogram the management of resources. Everything points to more concentrated rainfall today than before, on fewer days and in greater abundance, almost in an explosive manner.

This makes it more difficult to determine the exact amount of water to be released and turbined in order to avoid excessive flooding of riverbeds. In addition, global warming means that the idyllic trickle of snow melting with the arrival of spring is being accelerated. It no longer retains as much water as it did in the mountains, nor does it hold water for as long. Another factor that the technicians of the hydraulic production units, together with the hydrographic confederations, must include in their equations.

This concern to reverse or slow down the consequences of climate change is only the most visible part of a phenomenon that electricity companies such as Endesa and basin managers have been implementing for decades: hydroelectric power generation must be environmentally friendly, protect the environment and minimise its impact on ecosystems. For this reason, among many other things, important investments have been made in equipping the dams with ecological flows that allow fish to pass through the entire riverbed, turbines are being installed with sensitivity to other uses that the river may have downstream, such as recreational uses or for irrigation communities, and studies are even being promoted to analyse the health of estuaries as particular as that of the Eume.

It is the modernisation process of technology with more than 100 years of implementation and which is set to play a key role in one of the most important processes for the future of our planet. Not only with traditional formulas but with new pumping systems that allow them to operate with greater precision on the needs of the national energy system. Its hybridisation with other renewable sources has led to territories such as the island of Hierro, to move closer to energy self-sufficiency. A goal that the invasion of Ukraine by the Russian army has revealed to be of vital importance for countries dependent on fossil fuels and lacking these resources in their territories, such as Spain.

Water management is in itself a legacy for future generations. Not only because of the leap forward, the boost to the industrial transformation of the different territories, thanks to the contribution to the grid of the nearly 5,000 MW of hydroelectric power that Endesa operates throughout the Iberian Peninsula but also because of this growing respect for the environment, helping energy production to live in harmony with nature, which, in short, continues to be a support for the changes that have come and those that will come.