Pesawat ramah lingkungan

Pesawat Afriqiyah. Flightglobal.com

Amerika – Para ahli dari Massachusetts Institute of Technology (MIT) tengah membuat pesawat ramah lingkungan yang dapat menghemat bahan bakar sampai dengan 70 persen ketimbang pesawat sejenis. Pesawat ramah lingkungan yang dirancang untuk Badan Antariksa Amerika Serikat (NASA) ini juga tidak menghasilkan suara yang berisik serta gas emosi nitrogen oksida.

Pada bulan lalu, rangkaian awal telah diperlihatkan kepada NASA. Adapun kontrak pembuatan pesawat ramah lingkungan ini mencapai US$ 2,1 juta.

Rencananya, pesawat model akan digunakan oleh semua maskapai pada 25 tahun mendatang. MIT bekerja sama dengan beberapa perusahaan pembuat pesawat, yakni Boeing, GE Aviation dan Northrop Grumman. Mereka nantinya akan menerapkan konsep subsonic (lebih rendah dari kecepatan suara) dan konsep supersonik (leih cepat dari kecepatan suara) pada pesawat komersial.

NASA menginginkan pesawat komersil yang tidak bising atau lebih "kalem" suaranya (subsonic), menggunakan kurang dari 70 persen bahan bakar sehingga memiliki gas buang 75 persen dari pesawat komersial yang ada saat ini. Selain itu, pesawat ramah lingkungan ini diharapkan dapat lepas landas dari landasan pacu yang pendek.

NASA juga meminta MIT membangun dua model pesawat kompersil. Satu dengan kapasitas 180 penumpang yang dapat menggantikan Boeing 737 Class yang biasanya digunakan untuk penergangan domestik; Kedua pesawat komersir yang dapat mengangkut 350 penumpang untuk menggantikan 777 class yang biasa digunakan untuk penerbangan internasional.

Para peneliti di MIT tengah memikirkan bagaimana mengkonfigurasikan kerangka pesawat dengan baling-baling dan struktur sayap. Mereka berupaya memindahkan mesin yang semula dipasang dibagian sayap, ke belakang badan pesawat. Namun, menurut Mark Drela, Profesor dinamika fluida dan memimpin perakitan, model mitigasinya pada pesawat ramah lingkungan ini lebih lambat ketimbang yang ada pada Boeing 737 dan memiliki daya terbang yang lebih lambat. Bentuk badan pesawat juga lebih panjang, sayap yang lebih ramping dan ekor yang lebih pendek.
(From: TEMPO Interaktif

Photovoltaic Solar Energy Utilization in Indonesia

JAKARTA. Indonesia’s geographic condition which consists of many small and isolated islands is barely reachable by a centralized power grid. Fulfilling the power demand in these areas would require an independent power system, one of which that has a very large potential to be developed is photovoltaic solar energy.

Photovoltaic solar energy system may be used in rural areas where electricity demand is relatively low, including for street and area lighting, and places of worship. 100/120 Wp photovoltaic solar energy system is adequate for lighting and sound magnification purposes.

Other usage of this system is to supply electricity for public facilities. 400 Wp of electricity is able to supply electricity for public health centers and government offices. Solar power supply may also be used to power waterpumps for irrigation purposes and maintain a steady supply of potable water.

Photovoltaic development strategy in Indonesia includes the integration of Photovoltaic Solar Energy System for consumptive and productive purposes. Photovoltaic Solar Energy System is carried out in two different formats, a centralized and decentralized system, which is adapted accordingly. A decentralized system is applied in cases where houses are spread out over a large area, meanwhile a centralized system is applied in places where the houses are built in close quarters of each other.

The next step that must be carried out is the development of photovoltaic solar energy system in both rural and urban areas, supporting the commercialization of the system by increasing the role the private sector, developing an export oriented domestic photovoltaic solar energy system industry, and promoting an efficient funding system with the help of the banking sector.

In developing the photovoltaic solar energy system, the government of Indonesia faces several challenges which must be sorted, including the price of solar modules which forms the main component of the system, increasing its prices, which then reduces the interest of financial bodies to provide funding towards the development of the system.

Availability of spare parts and battery water is still very scarce, mainly for those systems which are set up in rural areas, which hinders the maintenance of the system. The vast majority of photovoltaic solar energy system installations in rural areas do not meet a set standard so it will not work effectively and is damaged in a very short amount of time. Due to the low amount of purchasing power of the local communities, development of this system largely depends on the government for funding.

One other obstacle to this system is the unavailability of solar cell industry in Indonesia, leaving a very high dependency on imported products. Falling exchange rates of the rupiah towards the dollar, have also attributed to the high cost of the solar module.

(from: http://www.esdm.go.id )

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