Pumped Storage Hydropower Advantages and Disadvantages

Pumped storage hydropower, also known as ‘Pumped hydroelectric storage’, is a modified version of hydropower that has surprisingly been around for almost a century now.

As one of the most efficient and commonly used technologies with a consistent and reliable track record, hydropower is well established as the most desirable means of producing electricity.

Similarly, the following scrutiny of pumped storage hydropower plants is based on the comparison of ways in which such storages are desirable and/or non-desirable, respectively.

Advantages of Pumped Storage Hydropower Plants

Following are some of the many advantages associated with the use of pumped storage hydropower generation, instead of relying on the more conventional, thermal, and nuclear sources.

Low operating cost and long service life

Once constructed, pumped hydropower plants have a long life and minimal maintenance requirement.

Fossil fuels have the risk associated with changing fuel prices and possible government interventions to reduce carbon emissions, whereas pumped storages need no such expensive raw material operation.

The plants themselves have an exceptional lifetime of more than 80-100 years, that too, granted just minimal maintenance.

Renewable and Sustainable

Pumped storages are allegedly called ‘green batteries’: The only viable means of storing energy on such a large-scale level with so little ecological repercussions.

The entire idea relies on a water cycle, which is driven by the sun and turbines. Hence, it is a completely renewable source of energy generation.

It is even more sustainable than conventional hydropower sources as, mostly, the reservoir collects a certain amount of water and creates an isolated cycle out of it.

Apart from abundant and sustainable raw material availability, these pumped storages are constant return on investment because of the bare minimum maintenance they require.

Minimal Environmental Repercussions

Hydropower is majorly famous, precisely, for being a clean source of energy.

Post-construction, there are no direct waste products of pumped hydropower storage.

Compared to coal and natural gas power plants, there is a negligible contribution to atmospheric pollution by the emission of greenhouse gases.

Besides, pumped storage can easily be characterized as domestic energy sources. They can be established by any country, provided they have the right means and suitable terrain.

Making the country self-reliant, in terms of fulfilling local energy requirements, instead of being dependent on international fuel sources. The sources whose transit, as well, causes plenty of harm to the climate.

There are only minor effects to the rivers and ecosystem downstream of the plant. However, to further minimize the environmental impacts, pumped storage can also utilize underground water tables and abandoned mine pits as lower reservoirs. Making sure that the river system is disrupted as minimally as possible.

Controllability

Engineers can control the flow and generation of electricity almost exclusively, with the help of the pumped storage concept.

The turbines can be programmed to pump water to the upper reservoir – consuming excess cheap energy and to generate electricity by letting the water lose potential energy. This transition can take place in a matter of minutes.

This makes it possible to produce electricity on short-term demand.

Thanks to this peculiarity, pumped storage can respond to energy fluctuations in the short-term. Subsequently, they help in bridging the gaps in the energy supply and demand during the day and night. It can be characterized as generating and absorbing energy according to the requirement of the situation. 

Recreational Opportunities

Most hydropower installations are required to provide public access to a certain extent. That means, making use of the large reservoirs (water bodies) when they are idol.

The aforementioned rule is basically in place to increase the efficiency of harnessing the economic and recreational worth of landforms owned by a country. Consequently, such reservoirs created for the pumped storage plants often become tourist attractions in their own accord.

This gives rise to opportunities like fishing, swimming, boating, water sports, and other leisure activities for residents and tourists.

Furthermore, these same reservoirs can also be used for irrigation and aquaculture purposes in the surrounding regions.

Water Supply and Flood Control

Reservoirs cum dams provide water flow control and a pseudo water reserve in case of emergency water shortages for nearby areas.

On the contrary, these emergencies can also be floods. Such landscaping is especially beneficial in case of flooding. The excess water from the drainage system can be hoarded in the reservoirs, storing vast quantities of water, keeping the nearby localities safe.

Disadvantages of Pumped Storage Hydropower Plants

The major issues associated with pumped storage hydropower plants lie in the scarcity of suitable sites for two reservoirs and a pumping station to be built with considerable elevation difference.

This fundamental issue along with others gives rise to the series of problems that are discussed below.

High cost relative to other technology

The biggest and most popular issue with pumped storage hydropower plants is the extremely high initial capital cost associated with setting up one such project.

Hydroelectric power stations, in general, can be extremely expensive to build, regardless of the form of construction, because of logistical difficulties.

Due to such high initial costs, the total cost of electricity and hence, the cost per MW can get higher. So, the pumped storage plant needs to be considerably large to ensure profits. This means such projects are not feasible on smaller scales.

Energy Losses

The biggest drawback for the overall efficiency of pumped storages is the fact that the water needs to be ‘pumped’ from the lower reservoir to the upper reservoir for the cycle to be completed. And this part of the cycle consumes electrical energy itself!

Furthermore, while stored in the upper reservoir, water losses occur due to various reasons such as evaporation, leakages, and water theft. All these contribute to the loss of potential energy that can no longer be converted to electrical power.

Despite all these drawbacks, pumped storages are more than 80 percent energy efficient in a complete cycle. And can provide almost double the electricity compared to lithium-ion batteries.

Possibility of Affecting Aquatic Life

The fish population can be threatened due to hindrance in their migration patterns. Linking of previously separate catchments can introduce non-native species and threatened endemic and endangered species present in the particular habitat.

Mortalities in this situation can escalate the damage to the aquatic habitat, initiating a recurring cycle of oxygen deprivation in the water leading to a phenomenon called eutrophication.

Although there are solutions for this particular issue, research and development departments have been working on “trap-and-haul programs” as well as “salmon cannons” which aid local fishes pass hurdles created by the projects’ reservoirs and continue on their natural migrating routes.

Impact on Water Quality in the Vicinity

Hydropower reservoirs and dams as well as underground water hoardings can impair water quality and flow. Both these issues in-turn become the major reasons behind the deoxygenation of water bodies downstream of the pumped storage plant. Such a condition in riparian (riverbank) habitats is particularly dangerous.

However, extensive work has been underway in research and development departments throughout the world, on aeration techniques and more innovations that shall counter such water quality issues.

Climate Dependent

Pumped storages are sustainable and renewable sources of energy no doubt, yet they are not entirely independent. These storage hydropower plants can be severely threatened by droughts.

Apart from such an extreme condition, the production capacity of a pumped storage plant can easily fall due to evaporation and leakages in case of harsh, hot, and dry climates.

Nonetheless, such factors are always taken into consideration when researching a suitable plant location for the project. All these factors are considered, and cost-benefit analyses are approved by local and national authorities before construction work starts.

So, this issue can easily be avoided as locations with climates holding risks of such situations would be avoided when setting up pumped storage hydropower plants.

A threat to Habitats and Sites Entailing Sentiment

Setting up pumped storage requires plenty of land resources. Construction of such projects may harm the ecosystem and disrupt the people living in the vicinity.

Clearing the landscape to make a pumped storage project can cause humans, flora, and fauna to lose natural habitats. Local cultures or cultural heritages might be trampled upon. Locations holding sentimental value to residents may impinge.

Presumptions on the Prior Analysis

Just like all renewable and non-renewable energy sources, pumped storages too have their share of benefits and risks associated with their implementation.

It is an extremely flexible source of energy generation, as its production can be controlled almost entirely. Along with this, the large capacity, long storing period, high efficiency, and relatively low running cost per unit of energy makes for a good argument why pumped storage hydropower plants are highly desirable.

As clearly defined by the analysis above, it is evident that the benefits associated with pumped storage outweigh the potential repercussions.