Environmental Issues

Dewata is surrounded by the Gunung Tilu conservation forest and the Perhutani forest. An area of 9.5 sq. km within the forests holds the Cikahuripan River water catchment system, a water source for the minihydro plant. For a run-of-the-river Minihydro plant (without a dam and reservoir) it is crucial that the rain is retained by the catchment area for a long time, so the flow of the river is available for most of the year. This retaining function is provided by the forest cover.

Since the dawn of reformasi era, illegal logging has become rampant and the rainforest has been gravely denuded of trees. Realizing the threat to future water supply for the community and the environment, P.T. Chakra has engaged in a scheme for afforestation with the Forestry Department. The minihydro plant has triggered the afforestation of the surrounding forest to ensure the supply of the river water, thus maintaining the balance of its surrounding ecosystem. P.T. Chakra believes that by conserving the forest and by proper forest management, the local people can still gain advantage from the forest for their livelihoods.
 

The average water of the Cikahuripan River is 600 liter per second and it is available during 157 days (43%) of an average year. This is the so-called design flow for the Minihydro plant. To store some of the water for daily peak periods, a small storage pond of 2,275 m3 was included in the scheme. Based on the average water flow and the buffer function of the storage pond, it is possible to reach full hydropower coverage for 280 days (77%) of an average year. During the remaining time of the year the hydropower scheme is operated with some additional power input for certain hours by the diesel generators. In total the Minihydro allows for 93% of the electricity generation and for only 7% of the electricity is generated by diesel gensets.

The use of minihydro plant saves diesel which amounts up to 320,000 litres per year. This means not only a significant financial saving but also a reduction in pollution of carbon emission to the atmosphere of 975 tons per year. This operational choice also boosts a ‘green production image’ of the tea.

Carbon emission, in the form of greenhouse gases, is suspected to be the gases that promote the greenhouse effect to the earth, a condition that triggers the rise of temperature in the earth’s climate. This trend of temperature rise is expected to – directly or indirectly – cause climatic change around the globe and affects the environmental conditions of the earth. The use of hydro power as a renewable energy is a step forward into saving the non-renewable natural resources i.e. fossil fuel; and eventually reduce the contribution of carbon emission to global warming.