More power from the water

Text and Photos by Henrylito D. Tacio
“Electricity is more than just a commodity,” said Antonio R. Moraza, the chief operating officer and president of Aboitiz Power. “It is the lifeblood of our country. It fuels both the economy and individual opportunity.”
Moraza said those words during the inauguration of the Sabangan Hydropower in Mountain Province. “We… consider it our responsibility to provide reliable and ample power supply when needed and to ensure that the supply of electricity is provided at a reasonable and competitive price.”
Sabangan Hydropower uses a run-of-river system. An intake weir, which situated in barangay Napua, diverts part of the river’s water into the system. The 3.2-kilometer tunnel feeds the water to the penstock which goes to the powerhouse in barangay Namatec. The natural force of gravity creates the energy required to spin the two Pelton turbines that in turn generate electricity.
“The water leaves the generating station and is returned to the river without altering the existing flow or water levels,” said the press statement released during the inauguration.
With a total capacity of 14 megawatts (MW), the Sabangan Hydropower has the capacity to deliver additional 55-gigawatts of clean and renewable energy annually to the Luzon Grid, the press statement said.
Operating the mini-hydropower plant is Hedcor, Inc., a wholly-owned subsidiary of Aboitiz Power Corporation. The biggest developer of run-of-river hydropower plants in the country today, it has 21 such kind of power plants in Benguet, Davao, Ilocos Sur, and Mountain Province.
Hydropower is a zero-emission, dispatchable, base-load power source. In the United States, hydropower makes up more than half of renewable electricity generation. In 2013, Canada exported more than 60 terawatt-hour (TWh) of electricity to the US, the vast majority of which is hydropower.
Water is one of the country’s renewable energy sources that has not been fully tapped until now. Electricity produced by water movement has been used for decades. About 16 percent of the world’s electricity is generated by hydropower.
According to the Washington-based Worldwatch Institute, the world’s top five producers are Canada, China, Brazil, the United States and the Russian Federation. Several countries, including Brazil and Norway, obtain almost all their electricity from this one source.
Hydropower can be generated by water falls (the first hydroelectric plant was built on Niagara Falls in 1878), rushing rivers and streams, and manmade dams, all of which allow a controlled amount of water to pass through the pipes that spin turbines – creating electricity.
Electric power is measured in units called watts. A watt is equal to one joule per second. The total generating capacity of a power plant is measured in kilowatts for 1,000 watts and megawatts for one million watts. One terawatt-hour is equal to a sustained power of approximately 114 megawatts for a period of one year.
Enormous dams such as the Hoover (1,455 megawatts) and the Grand Coulee (6,180 megawatts) produce large quantities of power. “Growing interest in developing hydroelectric power is largely an outgrowth of governments’ desire to be more self-sufficient in energy and to provide low-cost electricity,” wrote Cynthia Pollock Shea in Renewable Energy: Today’s Contribution, Tomorrow’s Promises.
A World Bank report in the 1980s showed the Philippines as one of the “thirteen largest additions to hydroelectric capacity in developing countries.” From an operating capacity of 940 megawatts in 1980, it went up to 2,195 megawatts in 1985. In 1998, the total hydropower capacity stood at 2,304 megawatts or almost 20 percent of the country’s total installed capacity.
According to the Department of Energy, there are 1,081 hydropower potential sites scattered throughout the country. “Hydropower can produce a lot of megawatts,” then energy undersecretary Rufino Bomasang told participants of a media briefing on business and economics reporting convened by the Press Foundation of Asia at Los Baños, Laguna in 1994.
Most of the hydropower plants in the country are in the form of a dam that backs up the water and raises the level. The released water falls into a turbine that generates electricity. “Impounding a river radically changes the surrounding ecosystem,” Shea wrote. “Nutrient-bearing sediments, instead of being deposited on agricultural floodplains and providing food for downstream fish, accumulate behind turbines and dams. Hydroelectric dams may also change the temperature and oxygen content of downstream waters, altering the mix of aquatic and riparian species.”
Smaller hydropower plants, however, do not necessarily require dams. They use a series of pipes with turbines inside which are turned by the current. During his lecture, Bomasang said that “we have the mini-hydro and micro-hydro plants, with a potential of as much as 200 megawatts in the Cordilleras alone.”
He added, “No rice floods are flooded – just a very short dam to collect and divert the water, use it to turn the turbines, and then return the same amount of water to the creek.” Indeed, they have less negative impact on the local ecosystem.
“The introduction of mini-hydro is very environmental friendly,” said Mountain Province Governor Leonard Mayaen during the inauguration of Sabangan Hydropower Plant. “It has no pollution at all.”
But are hydropower plants really environment-friendly? Some scientists believe that hydropower from manmade dams produce significant amounts of carbon dioxide and methane, which are greenhouse gases closely connected to climate change.
“Large amounts of carbon bound up in trees and other plants are released when a reservoir is initially flooded and the plants rots,” Worldwatch points out in a recent report. “And as plant matter settling on the reservoir bottom decomposes without oxygen, it leads to a buildup of dissolved methane, which is released into the atmosphere when water passes through the dam’s turbines.”
To operate well for many decades, hydro projects require sound management, not just of equipment, but of entire watersheds. “Hydroelectric power will not be truly renewable until the functions of flood control, irrigation, transportation, power production, tree planting, fisheries management, and sanitation are coordinated within the overall goal of maintaining healthy and productive rivers,” Shea reminded.
In the final analysis, however, “hydroelectric power creates virtually no pollution problems,” writes H. Steven Dashefsky, the man behind Environmental Literacy: Everything You Need to Know About Saving Our Planet. “Small-scale projects cause little harm to the environment, but larger projects are environmentally destructive.”