Sunlight into Power

I found this old article while looking up for potential materials for my report in Development Economics.

Note, all credits go to:
By Antonio C. Abaya
Written October 20, 2004
For the Philippines Free Press,
October 30 issue

With the price of oil going through the $50-per-barrel barrier in the New York and London markets, and the likelihood of even higher prices looming in the coming winter months as demand for heating oil shoots up, the search for alternative energy sources keeps recurring like a song.

The Philippines had its first garbage-into-power generating plant inaugurated at the Payatas dumpsite in Quezon City last month. (See my article “Garbage into Power”, Oct. 7.)

This week, the country’s first large-scale solar farm, the largest of its kind in the entire developing world, will be inaugurated in Barangay Indahag, Cagayan de Oro City, a joint project of the Cagayan Electric Power and Light Co. (CEPALCO) and the Global Environmental Facility (GEF) through its executing agency for this project, the International Finance Corp. (IFC), the private arm of the World Bank.

Solar energy panels are not new in the Philippines. The German government funded experimental solar energy stations in several powerless islands in the past decades. USAID has had a similar project in the ARMM. But this is the first time that a large-scale solar farm has been put together to generate power that is fed into a major grid.

The CEPALCO-GEF solar farm in Bo. Indahag has 6,480 polycrystalline silicon photovoltaic modules (made in Japan by the Sharp corporation) covering a two-hectare area. The system has an installed capacity 1,082 kilowatts of direct current at 400 volts.

At ideal sunlight conditions, it generates more than 950 kilowatts. This output is then converted by an inverter into alternating current at 220 volts. A sub-station transformer steps up the voltage to 13.8 kilovolts and feeds the current into the CEPALCO distribution system.

There are no moving parts and there are virtually no operation and maintenance costs. The system turns itself on when sunlight strikes the solar panels, and turns itself off when there is no more sunlight.

If the solar farm were connected directly to a community, instead of its energy being fed into the grid, it could energize some 770 average homes every month.

In the near future, the solar farm will be run in tandem with CEPALCO’s 7mw hydro plant on the Bubunawan River. This conjunctive operation will be the first of its kind in the world.

But solar energy is still expensive, compared to energy generated by the burning of fossil fuels such as coal, diesel or natural gas. The rule of thumb for estimating the cost of power plants is one million dollars for every megawatt of capacity.

The CEPALCO-GEF solar farm, with a capacity of a little less than one megawatt, cost $5.3 million, making it more than five times more expensive in capital cost than a comparative diesel- or gas-powered plant. But since there is no fuel cost and very little operating cost, the cost of the energy that it generates will OVER TIME match the cost of the energy from other sources.

But will solar energy ever replace fossil energy as the main source of power in the future? Very unlikely. Unless there is a quantum leap in the efficiency of photovoltaic material or in the design of solar panels, the vast expanse of real estate needed to generate one unit of electricity would prevent solar energy from ever becoming the main power source for urbanized towns and cities.

Moreover, solar energy is totally dependent, of course, on sunlight. At night and on cloudy days when there is little or no direct sunlight, there is also little or no output. Wind energy is equally intermittent.

For countries with active volcanoes, like the Philippines, geothermal energy holds greater promise. But even geothermal energy has its downside: tapping it sometimes releases poisonous hydrogen sulfide.

For better or for worse, the world will continue to be dependent on fossil fuels, even when and until the price of oil reaches, perhaps, $200 per barrel. Oil is just too cheap and more readily available than the alternatives.

But the finiteness of supply is underscored by the fact that the known reserves are declining as fewer and fewer new oil fields are discovered, while demand escalates with the fast industrial development of China and India.

Sooner or later, the world will have to kick its dependence on fossil fuels or carbon energy, and switch to the more abundant energy available from hydrogen. Fuel cells are the energy source of the future.

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