Beginning in the second half of the 19th century large areas of the mountainous rainforests of West Java were transformed into tea gardens. The volcanic soils, high rainfall and cool climate proved the perfect environment for such plantations. During this period many of the tea factories were powered by Minihydro Power (MHP) plants. The location of the factory within the estate was often determined by the availability of a suitable site for the power plant. This renewable energy was the perfect match for the moderate power requirements of the tea factories.
Fig. 1 – Dewata Tea Estate
The first hydro power plants in West Java were built as early as 1880. According to records, by 1910 already 40 hydro-electric power plants had been erected throughout the tea estates of West Java, mostly by private entrepreneurs. In 1925 all over Java approximately 400 small power plants with a total capacity of 17’000 HP were in operation. Commonly Pelton or Francis turbines were used. Their power outputs ranged from 40 to 200 HP.
A study conducted in 1995 revealed that from the 44 hydropower sites identified at tea estates from historical data, only 18 schemes were still operational. Of the schemes still running, almost all were still operating with the original equipment still installed. In many cases this machinery had never been refurbished. Much of the equipment was more suited for a museum than a power plant, but was still functioning.
Over the past decades more and more estates have obtained a connection to the national electricity grid to power the factories, regardless of the untapped hydropower potential at many of these sites. Where the national grid was not available, diesel generators were installed. Low prices for diesel fuel as a result of Government subsidies provided little incentive for investment in exploiting the hydropower resources.
Fig. 2 – Dewata Tea Factory
The Dewata Tea Estate is a typical example of a West Javanese tea estate with an interesting hydropower potential. The estate was established in 1932 covering an area of approximately 600 hectares. It is located in a secluded forest area covering the Gunung Tilu Forest Preserve and the Perhutani Forest range, about 60 km south-west of Bandung. Attached to the plantation is a tea factory with a green-leaf processing capacity of 35 tons per day. Dewata is home to over 1,000 people of which the large majority live in the village located next to the tea factory.
There is no other source of electrical energy at the estate apart from four diesel generators installed at the factory. The factory has so far relied exclusively on diesel powered electricity generation, consuming appr. 360,000 l of diesel fuel per year. The distance from the Estate to the nearest grid supply is around 8 km. In addition to the tea processing equipment at the factory, the buildings for the administration of the factory as well as most village houses are also connected to the electricity supply from the diesel generators.
Fig. 3 – Forebay
Running through the estate is the Cikahuripan River with an average flow rate exceeding 500 l/sec. The river can be harnessed at a natural drop appr. 1 km from the factory.
Fig. 4 – Weir and Intake Gate
When the project was discussed at the first time, the price of the fuel – heavily subsidized was Rp. 600 per litre. It was still cheaper to produce electricity by diesel, compared to the cost of minihydro generation. However, in view of future price increases for diesel, the estate’s management decided to invest in a 2×120 kW minihydro power plant to substitute more than 90% of the diesel fuel, and today in 2002/2003 with a fuel price of Rp. 1900, the minihydro plant is by far the more economical solution. Now at 2013 diesel fuel price its about Rp6000 so hydro power is solution to this typical estate.
Fig. 5 – Penstock
The Dewata Minihydro Plant was inaugurated by H.E. the Ambassador of Switzerland on December 14, 2002 with the participation of more than 100 personalities from private sector and government. A total of 78 personalities, important for future promotion, received a set of information materials on mini hydro, the Dewata project and ACE activities in the Renewable Energy field. Beside the inauguration part of the event, the programme contained the explanation of all major technical features of the MHP, a video presentation, a visit of the tea factory, a welcome address by the owner of the Dewata estate Mr. Rachmat Badruddin, the keynote address by H.E. Georges Martin, and a speech by the Hon. Coordinating Minister of Economy Dr. Dorodjatun Kuntjorojakti.
Fig. 6 – Minihydro Turbines System
The Minister thanked the Ambassador of Switzerland and the Swiss government for the assistance provided and expressed the hope for continuation: this kind of project must be replicated in other regions to enable the local people to generate electricity for their own use and possibly to sell electricity to the national grid. Indonesia needs the inputs of advanced technology from Switzerland and is looking forward to continue this fruitful cooperation.
Fig. 7 – Inside Power House
Lively discussions took place between the Minister and the minihydro experts with the keen interest from the Minister on further minihydro development in Indonesia. The event also provided a chance to P.T. Heksa Prakarsa Teknik as the turbine factory to present and explain their range of turbine productions to the officials and private sector investors. Clearly, the Dewata inauguration was not merely the starting of a new power plant but materialized as a major promotional event for Minihydro utilization in Indonesia.
Fig. 8 – Below Dewata Tea Estate Forebay