Experts have divergent opinions on the cost-effectiveness of power generation via hydroelectric power plants; however, according to one analyst, hydropower is by and large more economical in comparison with conventional and generally costlier alternatives such as thermal power plants.
Hydroelectric power plants are designed for electricity generation while peak demand, preventing a large amount of natural gas from being burnt. Generating electricity from hydroelectric power plants is economical once "gas costs" are taken into account, Mohammad-Ebrahim Raeisi, an energy economics expert told Persian daily, Forsat-e-Emruz.
"Gas costs" encompass potential revenues which could be generated if gas was consumed differently, e.g. exported, injected into oilfields, or provided as feedstock in petrochemical complexes. The electricity production through hydropower plants would be economical if the price of gas was considered 20 cents per cubic meter, according to Raeisi.
High life expectancy is also among advantages of hydroelectric power plants, Raeisi noted. With a life-span of 50 to 100 years, hydroelectric power stations can last longer compared to other types of power plants such as a nuclear power plant with a lifespan of only 30 to 40 years. With no sulphur dioxide emission and only minimal emissions of methane and carbon dioxide, hydroelectricity is one of the cleanest sources of power currently available. Aside from zero sulphur dioxide emission, a hydroelectric power plant does not produce common pollutants such as dust and nitrogen oxide.
Most Expensive Option
Massoumeh Zafarnejad, a water expert, disagrees with Raeisi, asserting that hydropower plants are among the most expensive worldwide. Since dams are extremely expensive to build, they must operate for many decades to become profitable.
Zafarnejad disputes economic appraisals carried out to assess viability of hydropower projects, claiming that not only the assessments are drafted partially, but they also take no notice of environmental and social costs.
People living in villages and towns that are in the valley to be flooded, must move out. This means that they lose their farms and businesses. In some countries, people are forcibly moved so that hydro-power schemes can go ahead.
The building of large dams can cause serious geological damage. For example, building of the Hoover Dam in the USA triggered a number of earth quakes and has depressed the earth’s surface at its location. Dams built blocking the progress of a river in one country usually means that the water supply from the same river in the following country is out of their control. This can lead to serious problems between neighboring states.
The creation of dams can also create flooding of land, which means natural environment and the natural habitat of animals, and even people, may be destroyed.
On hydropower being uneconomical, Zafarnejad made reference to the recent dust storm in the southwest of the country, which incurred 9,000 billion rials ($173.5 million) loss on the country in three days only. Zafarnejad suggests that improvident dam constructions in the region over the past years have given rise to the dust storms.
Partial Cost Assessments
Costs of generating one kilowatt-hour of electricity via hydropower plants has never been calculated precisely. Almost all figures in economic appraisals are nominal and exclusive of important factors, Zafarnejad noted.
She lamented lack of independent authorities to conduct economic appraisals for such projects, saying that assessments are carried out in affiliated companies of the principle contractor, which is the energy ministry.
These companies are thus compelled to meet the expectations of the contractor by presenting nominal figures, which would rarely regard a hydropower project as uneconomical. The figures are thus partial and imprecise because if the company assigned with the economic appraisal deems the project as uneconomical, the contractor will most likely hand it over to another company, Zafarnejad said.
Pointing to the fact that 30 percent of Iran's green gas emissions is attributed to thermal power plants' operations, Raeisi called for an increase in the share of renewable energies in Iran's energy basket. The government should not focus on a certain type of power plant and rather consider a variety of different alternatives, depending on energy potentials of the region and the costs and opportunities of the project.
On whether wind or solar power plants are suitable alternatives for construction of hydropower plants, Raeisi said efficiency of wind power plants is very low in Iran. Wind power plants can be utilized should their efficiency be enhanced to 20-24 percent, he added.
Iran's hydropower capacity is approximately 30-40 megawatts (MW), while installed hydropower capacity stands at 7,000 MW.
