Large Dams Are A Source Of Energy But Unsustainable
Many pairs of words are used wrongly, interchangeably in Pakistan, this goes same with the world at least for some of the word pairs; renewable and sustainable.
Central Power Purchasing Agency (CPPA) on its website and NEPRA in its reports give description of generation cost of various energy extraction methods; Hydel doubtlessly takes lead in terms of being economical and potential resource.
As an early learner, one easily opts for Hydropower as a readymade solution to make energy transition, not considering its destructive social and ecological impact.
Hydro electricity is considered as the only conventional renewable energy resource of the world, but whether this renewable is sustainable?
Building up of a dam starts with encroaching thousands of acres of agricultural land, emptying at least tens of villages, displacing thousands of families, making them helpless to vacate, causing heritage destruction. Still, these are the minimal losses of mega Hydro projects.
It is safely considered as clean low-carbon, renewable, and cheap source of electricity but far from being sustainable. This highlights that renewable is not necessarily eco-friendly. It threatens rivers’ natural flow and poses a threat to fish living in it. It leaves serious impact on quality of water and causes sedimentation.
Nations are opting for Renewables to get rid of dirty fossil fuels. However, scientists highlight some of the ecological dangers this wave of ‘green‘ energy poses. Large hydro projects increase the risks associated with the climate change. They can also be placed in list of non-renewables because of the sedimentation.
There are some technological ways out to help the fish migration and decrease sedimentation, with fish ladder and sediment bypass. A lot of research specific to the river Indus, the lifeline of Pakistan, has been done so that we can get some way out. And till then, one must strongly discourage the building up of dams, one after the other, destroying the natural eco-system. The cost of this cheap hydro could be so high in terms of vulnerability that we may run out of our resources to pay off.
As compared to large hydro, small hydro projects do not pose such gigantic threats to the ecosystem. NEPRA in its report “Hydel Power Potential in Pakistan” has identified multiple sites throughout the country where small hydropower projects (<30 MW) could be implemented, and advantage of this low-carbon energy source could be tapped without causing any substantial loss to the environment.
Though Pakistan has utilized less Hydropower than its potential, it is already home to world’s few largest dams: Tarbela and Mangla. And some dams like Diamar- Basha dam are under construction.
Disturbance of river ecology by these large dams may contribute to climate change by releasing greenhouse gases from the decomposition of flooded lands and forests.
Not only that hydro is giving a largest chunk of about 30% in the energy mix, but country is planning for same in coming years. Alternative and Renewable Energy (ARE Policy 2019) is to contribute towards Sustainable Development Goal-7 dedicated to Clean Energy. Recently approved in August 2020 by Council of Common Interests, it aims to get same proportion in total power production, equivalent to some 25,000 MW.
We take decisions in panic and in doing this, we fall in a vicious cycle: Remember Energy crisis, a problem that existed just a few years ago due to demand-supply deficit; now power system is suffering from woes of surplus. We must understand from this fact, and this time, we should move with more inclusive and evident base work.
Large hydro dams are though a source of renewable electricity but not sustainable and have very harmful impact on life of water system of a country or a region.
As per website of WAPDA, its environment cell was established in 1987 but any report on Ecological impact of constructing dams on River Indus, on which country mainly relies for its needs, could not be found.