Komunitas Energi Indonesia

Pengembangan Panas Bumi, Pertamina Butuh Rp18 T

2010-08-24T19:06:00.000-07:00

Tuesday, 24 August 2010

energiterbarukan.net- PT Pertamina Geothermal Energy (PGE) memerlukan US$2 miliar atau sekitar Rp18 triliun untuk mengembangkan pembangkit listrik tenaga panas bumi (PLTP) dengan kapasitas 1000 megawatt (MW) pada 2014.

Direktur Utama PGE Abadi Poernomo mengatakan kebutuhan pendanaan sebesar itu akan dipenuhi dari pinjaman dari luar negeri seperti Inggris, Prancis, Jerman, Jepang, dan Bank Dunia. "Kami membutuhkan US$2 miliar atau Rp18 triliun, itu akan kami penuhi dari pinjaman,"ujar dia di Jakarta Selasa 24 Agustus 2010.

Abadi menjelaskan, dalam waktu dekat juga pihaknya bakal segera mengerjakan PLTP Karaha Bodas dengan kapasitas 30 MW, kemudian selanjutnya menyusul membangun di wilayah lain yaitu Lahendong di Sulut, Sibayak, Ulubelu di Lampung, Lumutbalai, Hululais, Kotamubagu, dan Sungai Penuh di Jambi.
"Dengan adanya Kepmen ESDM nomor 32/2010, harga jual listrik dari PLTP ke PLN dipatok sebesar 9,7 sen per kwh maka pembangunan PLTP itu sudah sangat layak,"tuturnya.

Hanya saja, menurut dia, jangkauan jaringan dari PLN untuk mencapai titik-titik PLTP yang letaknya tidak bisa terlalu jauh dari sumber panas bumi yang ada, serta belum adanya interkoneksi di seluruh Sumatra dan pulau lainnya, serta interkoneksi Jawa-Sumatra.

"Kita akan lihat dulu mana yang memungkinkan bisa digarap lebih dulu, karena listrik yang dihasilkan juga harus disalurkan," kata dia.

Untuk membangun PLTP , kata Abadi, bukan perkara mudah pasalnya hampir 60 persen cadangan panas bumi Pertamina Geothermal berada di hutan konservasi yang menurut Undang-Undang (UU) hutan konservasi tidak bisa diganggu sehingga ada kendala tumpang tindih lahan.

Sumber : energiterbarukan.net

PLTMH Silou 2 Hatonduhan Ditargetkan Operasi Tahun Ini

2010-08-24T18:48:00.000-07:00

Monday, 23 August 2010

energiterbarukan.net- Pemerintah Kabupaten (Pemkab) Simalungun menargetkan Pembangkit Listrik Tenaga Mikro Hidro (PLTMH) Silou 2 Hatonduhan dengan kapasitas 8 megawatt (MW) dapat beroperasi tahun ini.

Berdasarkan data yang diperoleh dari Pemkab Simalungun Senin, 23 Agustus 2010 disebutkan saat ini proses pembangunan PLTMH tersebut sudah 70 persen dan total investasi keseluruhan proyek Rp140 miliar.

Jika sudah beroperasi, pendistribusian listrik dari PLTMH tersebut akan dilakukan oleh PT Perusahaan Listrik Negara (PLN persero) Sumatera Utara guna memenuhi kebutuhan listrik di Kabupaten Simalungun sebesar 27,5 MW. Walaupun pendistribusian dilakukan oleh PLN, tetapi pihak pengembang tetap memiliki kewajiban seperti Corporate Social Responsibility (CSR) terutama di wilayah sekitar PLTMH ini.

Untuk merealisasikan pembangunan PLTMH ini bukan perkara mudah pasalnya PLTMH tersebut berada di kawasan hutan lindung, tetapi mengingat kebutuhan listrik di wilayah Simalungun sangat mendesak maka Pemkab Simalungun telah meminta ijin kepada Menteri Kehutanan RI untuk menggunakan areal ini dengan tidak merusak kawan hutan yang ada dengan menginstruksikan kepada pihak kontraktor agar tetap memelihara kondisi kawasan hutan.

Selain PLTMH Silou 2 ini, Pemkab juga membangun PLTMH yang sama dengan memanfaatkan empat titik daerah aliran sungai yaitu satu titik di Kecamatan Raya dengan memanfaatkan aliran sungai Bah Simata dan tiga titik memanfaatkan aliran sungai Bah Karai. Investasi untuk pengembangan 4 titik aliran sungai ini menjadi PLTMH ini mencapai Rp900 miliar dan akan memproduksi listrik 31 MW dan jika berjalan sesuai jadwal maka proses pengerjaannya akan memakan waktu selama selama dua tahun untuk proses konstruksi sesuai dengan kontrak kepada PLN.

Sumber : energiterbarukan

Link terkait :

> PLTMH Menerangi DESA Huta Tonga dan Desa Turunan

> Peninjauan PLTMH Igir Klanceng

> Peninjauan PLTMH Tabau di Kabupaten Sanggau, Kalimantan Barat

> Akhirnya Warga Latawaro Nikmati Listrik

PLTSa Gedebage Dibangun 2011

2010-08-24T18:36:00.000-07:00

Monday, 23 August 2010

energiterbarukan.net- Pemerintah Kota Bandung siap memulai pembangunan Pembangkit Listrik Tenaga Sampah (PLTSa) Gedebage pada April 2011 mendatang.

Hal itu diungkapkan oleh Wali Kota Bandung Dadan Rosada seperti dikutip energiterbarukan.net dari harian umum Galamedia, Bandung Senin 23 Agustus 2010."Konstruksi bangunan akan dipancangkan pada April 2011 mendatang,"ujar dia.

Menurut dia, saat ini pihaknya telah mengantongi skedul tahapan pembangunan dari mulai persiapan lelang minggu ketiga dan keempat Agustus 2010 hingga pendirian konstruksi bangunan April 2011, dengan demikian ditargetkan pembangunan selesai 2011 dan PLTSa tersebut bisa dioperasikan pada 2012. "Lokasi tepat pembangunan PLTSa berada tidak jauh dari Stadion Utama Sepakbola (SUS) Gedebage yang kini sudah mulai tahap pembangunan,"tuturnya.

Untuk konsep pembangunannya sendiri,kata dia, akan diimbangi dengan pola ruang terbuka hijau yang mengelilingi pabrik pengolahan sampah, diperkirakan proyek ini membutuhkan lahan sekitar 20 hektare (ha)."Sebetulnya dengan lahan 2 ha saja cukup untuk pendirian pabrik, tetapi kan saya inginnya pabrik dikelilingi pohon rimbun jadi sisa dari lahan total 20 ha tadi akan dioptimalkan menjadi kawasan hijau,"kata Dada.

Sementara itu, Kepala Dinas Pengelolaan Keuangan dan Aset Daerah Dadang Supriatna menambahkan, sampai saat ini pihaknya sudah berhasil membebaskan 5 ha dari kebutuhan lahan 20 ha."Pembangunan bisa saja dilakukan bertahap sejalan dengan pembebasan sisa lahan yang diperlukan,"papar dia.

Sumber : energiterbarukan.net

Out of Africa: Saharan Solar Energy

2010-08-14T18:35:00.000-07:00

Out of Africa: Saharan Solar Energy

Ilmuwan Jerman Simpan Surplus Energi Pembangkit Energi Terbarukan Dalam Bentuk Metan

2010-06-19T02:55:00.000-07:00

Oleh Rahman Budi, Jumat, 14 Mei 2010

Setiap tahun pembangkit listrik yang memanfaatkan potensi energi terbarukan seperti surya dan angin bertambah dalam skala MegaWatt. Namun sayangnya hingga saat ini media penyimpan surplus energi yang dihasilkan oleh pembangkit listrik energi terbarukan masih belum menemukan kematangan teknologinya. Baterai hingga kini memang masih menjadi alternatif utama, namun harganya yang mahal dan keterbatasan siklus isi ulangnya merupakan kendala tersendiri yang kini masih dicarikan penyelesaiannya oleh para ilmuwan.

Beralih dari baterai, para peneliti di Jerman telah menemukan metode baru untuk menyimpan kelebihan produksi listrik dari pembangkit energi terbarukan. Jika selama ini gas dibakar untuk menghasilkan listrik, maka proses tersebut dibalik. Kelebihan energi listrik diubah menjadi gas alam sintetis.

Metode tersebut dikembangkan oleh Center for Solar Energy and Hydrogen Research (ZSW) di Baden-Württemberg, Jerman dan bekerja sama dengan Fraunhofer Institute for Wind Energy and Energy System Technology (IWES) dan Solar Fuel Technology, sebuah perusahaan Austria yang bertanggung jawab dalam mempersiapkan implementasinya pada industri.

Proses yang digunakan untuk konversi masih mengandalkan elektrolisa dengan methanisasi, yaitu proses pencampuran antara hidrogen dan karbon dioksida. Hasil reaksi kimia yang terjadi adalah metan sintetis. Keuntungannya adalah gas metan yang dihasilkan bisa dicampur dengan gas alam dan kemudian disalurkan ke infrastruktur saluran pipa distribusi gas yang ada, tanpa perlu pembuatan infrastruktur terpisah.

Sebuah sistem untuk keperluan uji coba juga telah dibangun di fasilitas Solar Fuel Technology di Stuttgart dan berhasil beroperasi sesuai yang diharapkan. Rencananya sistem yang lebih besar akan dibangun dan menghasilkan daya hingga 10MW. esciencenewsRef. http://planethijau.com/mod.php?mod=publisher&op=viewarticle&cid=47&artid=1281

Trapping light to improve solar cells

2010-05-04T15:24:00.000-07:00

Scientists have uncovered why thinner solar cells with well organised patterns on their surface are better able to trap and absorb light.

The discovery could mean cheaper and more efficient solar cell technology.

Scientists have known that the efficiency of solar cells is improved when light is allowed to bounce inside the cell, increasing the chances that it will be absorbed.

One way to do this is by 'roughening up' the surface of the solar cell so that photons entering the material tend to be reflected inside it.

Reporting on the pre-publication website ArXiv, Dr Zongfu Yu and fellow researchers from Stanford University in California, have calculated the fundamental limit to the amount of light that can be trapped in a nano photonic solar cell.

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Clean Tech Investments Soaring in 2010

2010-04-09T19:04:00.000-07:00

Worldwide, investors put $1.9 billion into clean tech startups in the first three months of 2010. That is an 83% increase from the same quarter last year and a 29% increase from the fourth quarter of 2009. Additionally, the number of deals hit a record high.

This is what a new report from Cleantech Group and Deloitte shows.

Sheeraz Haji, president of Cleantech Group, says: “The bounce back in venture investment from lows in early 2009 has continued, with the first three months of 2010 representing the strongest start to a year we have ever recorded.”

The results come from a survey of investments made in 180 companies from North America, Europe, Israel, India, and China.

Electric car-related startups and solar technology startups received the most investment.

$704 million went to electric car-related startups, half of which went to one company — Better Place. Better Place is a Silicon Valley company that has signed contracts to build electric car charging stations and other infrastructure in Australia, California, Canada, Denmark, Hawaii and Israel.

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FREE Solar Electric Vehicles! [PICS]

2010-04-09T19:00:00.000-07:00

There are large steps and small steps that can be made to reduce our greenhouse gas emissions and other pollution. I think these solar electric vehicles are something in between, but definitely something to start using!

The Solar Electric Vehicle Company creates innovative electric shuttles (i.e. large golf carts) for universities, resorts, stadiums, governments, shopping malls, airports, arenas, medical centers, etc. that combine electric vehicle (EV) technology with solar power technology. Looks like a good combination.

Not only that, but these vehicles are FREE!

As The Solar Electric Vehicle Company states, “Founded on the principles of national and community involvement, corporate responsibility, and most importantly, environmental responsibility, The Solar Electric Vehicle Company is dedicated to the Greening of America. Using an innovative business strategy and partnering with corporations committed to combating climate change and dependence on foreign oil, The Solar Electric Vehicle Company provides clean and reliable solar-electric shuttles to communities and institutions cost free.”

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Pedal Power from Nuru Light Replaces Kerosene with Clean Energy

2010-03-16T02:01:00.000-07:00

A clean energy startup called Nuru Lights has come up with a low cost pedal-powered LED light kit that is designed to help households in East Africa and India ditch their kerosene lamps. Kerosene lamps are ubiquitous in the developing world. They’re a notorious fire hazard and can cause carbon monoxide poisoning when improperly vented. In impoverished areas, kerosene soaks up scarce cash that households could use to improve farming or pay school fees.

For communities dependent on kerosene a cleaner, more affordable alternative is a big deal, and Nuru Lights is getting some significant recognition for its efforts. The company has just been named one of 24 semifinalists in this year’s MIT Clean Energy Prize. Earlier this month it won the grand prize of the Global Social Entrepreneurship Competition in Seattle, and in February it was awarded a United Nations Environment Program Saskawa sustainability prize.

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Circuit uses light to power itself

2010-02-13T03:03:00.000-08:00

Scientists have created a circuit that can power itself, as long as it's left in a beam of sunshine.

Created by scientists from the University of Pennsylvania, the world's first photovoltaic circuit could eventually power a new line of consumer devices or even model the human brain.

"This has the potential to create a new generation of optical and electronic devices," says Dr Dawn Bonnell, a scientist from the University of Pennsylvania who co-authored a recent ACS Nano paper describing the research. "The touchscreen of your computer could act as both the electrical charger and the computer chip."

Bonnell and her colleagues can only coax minuscule amounts of electricity from their photovoltaic circuits, far too little to power consumer electrical devices. But those amounts could quickly skyrocket.

"We would have one amp with one volt in a sample the diameter of a human hair and an inch long," says Bonnell. "If the efficiency scaled up without any additional limits."

There are plenty of other ways Bonnell can squeeze more electricity from light. About 10% of the photovoltaic circuits on a glass side work. Increasing that number will boost the power output.

Yet another way to get more power is by turning their 2D structures into 3D structures. Stacking multiple layers of light-collecting and electricity-using circuits would also boost power.

The photovoltaic circuit developed by Bonnell and her colleagues is a scientific breakthrough, not a technological one. These new circuits will most likely never replace their silicon counterparts.

Preparations for six AP1000s

2010-02-12T03:38:00.000-08:00

Chinese planners are moving ahead with three new nuclear power plants based on AP1000 reactors - the first to be developed after technology transfer from Westinghouse.

The US-based reactor vendor is already constructing pairs of AP1000 reactors in China with its partner Shaw at Sanmen and Haiyang, but these new units are to be the first built independently after the technology transfer that was part of Westinghouse's contract. They are also China's first nuclear power plants not located on the coast.

The sites are Xian'ning, Hubei province, Tauhuajing in Hunan, and Pengze in Jiangxi. All have been given the go-ahead for final design and initial construction work, such as site clearance, for the first two reactors at each site. Main construction is set to start on all three sites around this time next year, with commercial operation following around 2015.

A further wave of AP1000 build will include at least one other pair of units at each of the above sites, while up to six new locations are already pencilled in for AP1000 development.

Each of the latest sites is to be led by a different Chinese firm: Xian'ning by China Guangdong Nuclear Company; Taohuajing by China National Nuclear Company; and Pengze by China Power Investment Corporation. Transferral of the AP1000 technology is being carried out by State Nuclear Power Technology Corporation, which will now take the engineering lead on new AP1000s.

Nuclear production line

Having developed its own reactors and imported a wide range of units from international vendors, China is now focused on two designs for mass deployment: the CPR-1000, developed from French 900 MWe-class units imported in the late 1980s, and the AP1000.

According to plans, fleets of these reactors will be constructed with exponential speed for China to achieve a nuclear capacity of over 60 GWe by 2020 - and as much as 120-160 GWe by 2030. Such an achievement would make China by far the biggest generator of nuclear power in the world.

Successive CPR-1000 projects have featured increasing amounts of local engineering and now around 90% of plant components are sourced from Chinese firms. The AP1000 features modular construction and China has quickly set up specialised nuclear facilities to produce the very large modules - effectively creating a production line for nuclear power plants.

Wow, China is serious about clean energy !

2010-02-09T13:50:00.000-08:00

Wind Power

The world’s largest wind power project is currently in Texas (with a capacity of 782 MW), but China“is in the midst of building a wind corridor that could grow to a staggering 20,000 MW, 25 times the size of Texas’ Roscoe Wind Farm.” (emphasis mine) This wind farm in China is expected to have a capacity of 5,000 MW by the end of this year.

Solar Power

Additionally, China just “announced it would build a 2,000 MW solar thermal project, five times bigger than the current largest one, California’s Solar Energy Generating System.”

And in the fall, China announced plans to build a 2000 MW solar photovoltaic farm, “33 times bigger than the world’s largest today, a 60 MW farm in Spain.” (empasis mine)

Washington State thought it would take the world title with a planned 75 MW solar PV plant — think again. It may complete this plant before China’s, but don’t think that it will be the big news for long.

See article

Quote interesting response:

Europe has big wind ambitions too. Consider this ” link” and those projects are not with expected load factors under 20 but well above 30. Almost 100 GW of off-shore wind projects are under consideration in the North and Baltic Seas alone. 1 GW (more) of off-shore windmills are to be connected to the grid in 2010 in europe.
.....a study by the Energy Foundation found that “Residential and commercial rooftop space in the U.S. could accommodate up to 710,000 MW of solar electric power,” which is 75% of the nation’s current electric consumption.
You left out China’s biggest source of new clean power: “Additional reactors are planned, including some of the world’s most advanced, to give a sixfold increase in nuclear capacity to at least 60 GWe or possibly more by 2020, and then a further substantial increase to 160 GWe by 2030.” And a watt of nuclear capacity is worth about three of wind or solar.

Global warming makes trees grow at fastest rate for 200 years

2010-02-07T02:58:00.000-08:00

By Steve Connor, Science Editor

Tuesday, 2 February 2010

Trees across North America are growing at an unprecedented rate as a result of higher temperatures and CO2 levels

Enlarge

Forests in the northern hemisphere could be growing faster now than they were 200 years ago as a result of climate change, according to a study of trees in eastern America.

The trees appear to have accelerated growth rates due to longer growing seasons and higher concentrations of carbon dioxide in the atmosphere. Scientists have documented the changes to the growth of 55 plots of mixed hardwood forest over a period of 22 years, and have concluded that they are probably growing faster now than they have done at any time in the past 225 years – the age of the oldest trees in the study.

Geoffrey Parker, a forest ecologist at the Smithsonian Environmental Research Centre in Edgewater, Maryland, said that the increase in the rate of growth was unexpected and might be matched to the higher temperatures and longer growing seasons documented in the region. The growth may also be influenced by the significant increase in atmospheric carbon dioxide, he said.

Higher concentrations of carbon dioxide and extended growing seasons could be favourable for agriculture in some parts of the world, mainly in the northern hemisphere. The study in Maryland suggests that the extra growth in trees could help to act as a more efficient carbon "sink", which could offset the carbon dioxide being added to the atmosphere by the burning of fossil fuels.

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Relative article

Methane on ice: a climate shock in store?

2010-02-07T02:28:00.000-08:00

Known frozen methane sites around the world: a nasty climatic surprise in store? (Pic: Oak Ridge National Lab)

Anna Salleh - ABC Science Online

Vast stockpiles of frozen methane on the seafloor are more unstable than previously thought, and their sudden release may have been linked to global warming in the past.

Led by Dr Kai-Uwe Hinrichs of the Woods Hole Oceanographic Institution in Massachusetts, USA, the new evidence is published in this week's issue of Science.

The researchers examined the by-products of ancient methane-using bacteria in sediments of the Santa Barbara Basin, off the coast of California. They found evidence that methane trapped in ice crystals (known as methane hydrates) on the seabed was released into the water 44,000 years ago - at the same time there was a rapid, but as yet unexplained, rise in global temperatures.

Methane is a potent greenhouse gas, about 10 times more powerful than carbon dioxide. Scientists estimate that approximately 3,000 times the volume of methane in the atmosphere is currently trapped in hydrates at the bottom of the sea.

While conclusive proof is still lacking that the seabed methane released into ocean sediments 44,000 years ago reached the atmosphere, the fact that the hydrates are not as stable as scientists believed raises the possibility that they could be a climatic time-bomb in the future.

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Scientists confirm positive CO2 feedback

2010-02-07T02:02:00.000-08:00

Anna Salleh
ABC, Thursday, 28 January 2010

Scientists have calculated the most accurate estimate to date on how rising temperatures will trigger the release of more CO2 from the ocean and land, further amplifying the greenhouse effect.

But some experts warn it still won't tell us exactly what will happen to the planet as CO2 in the atmosphere continue to rise.

Palaeoclimatologist Dr David Frank of the Swiss Federal Research Institute in Birmensdorf and colleagues report their findings in today's issue of the journal Nature .

"It's well known that the CO2 increase will cause a temperature increase," says Frank.

"But what also happens is that you have increased temperatures that causes the ocean and the terrestrial biosphere to also release more CO2 into the atmosphere."

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BUMI - Perkembangan Benua dari waktu ke waktu

2010-01-18T23:23:00.000-08:00

Bagaimana wajah Bumi jutaan tahun yang lalu, dan bagaimana kira-kira perkembangan benua dimasa depan, sekitar 250 juta tahun lagi ?

Topik terkait hal itu, yang dimuat oleh sdr. Rovicky dalam situsnya "Dongeng Geologi" beberapa waktu lalu sangat menarik dan dapat menambah wawasan bagi awam yang belum banyak mengetahuinya.
Tidak kalah menariknya tentang benua mitos / khayalan Atlantis, yang masih kontroversi dan masih diperdebatkan sampai saat ini.
Silahkan baca artikel selengkapnya dibawah ini

- Benua Geologi, Benua Sejarah dan Benua Khayalan-1
- Benua Geologi, Benua Sejarah dan Benua Khayalan-2
- Benua Geologi, Benua Sejarah dan Benua Khayalan-3
- Wajah Bumi 250 juta lagi (Benua Masa Depan )
- Benarkah Indonesia itu Atlantis ?

SAVE ENERGY !!

2010-01-11T00:16:00.000-08:00

GLOBAL CLIMATE CHANGE

2010-01-05T23:27:00.000-08:00

NASA Eyes On The Earth

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Perubahan Iklim : Review tahun 2009

2010-01-05T20:26:00.000-08:00

Steam rises from oil refineries just before dawn over Edmonton, Alberta following a drop in temperatures earlier this month

Meskipun melumpuhkan krisis ekonomi, tantangan tetap hijau menonjol pada agenda publik dan politik selama tahun 2009. Ini kontras dengan kemerosotan sebelumnya, di mana lingkungan pada umumnya telah diasingkan ke daftar "untuk melakukannya nanti". Alasan itu tidak menghilang kali ini adalah karena semakin jelas bahwa "nanti" mungkin terlalu terlambat - terutama dalam kaitannya dengan tantangan perubahan iklim. Pertanyaannya adalah bisakah kita mengubah realisasi ini menjadi perubahan praktis?

Perundingan pada KTT iklim di Kopenhagen bulan lalu dilakukan antara lain dengan tujuan untuk melakukan perubahan praktis yang di maksud. Mempertimbangkan kepentingan nasional yang berbeda yang ada di antara hampir 200 negara yang terlibat dalam proses PBB merupakan hal yang paling rumit, hal itu mungkin tidak mengherankan bahwa perjanjian berbasis ilmu pengetahuan diperlukan untuk menghindari dampak terburuk perubahan iklim masih sulit dipahami.

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The Breathing Earth Simulation

2010-01-03T18:50:00.000-08:00

Welcome to Breathing Earth. This real-time simulation displays the CO2 emissions of every country in the world, as well as their birth and death rates.
Please remember that this real time simulation is just that: a simulation. Although the CO2 emission, birth rate and death rate data used in Breathing Earth comes from reputable sources, data that measures things on such a massive scale can never be 100% accurate. Please note however that the CO2 emission levels shown here are much more likely to be too low than they are to be too high

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Prof.Andrianto Handojo: “Ilmiah Populer itu Sulit Tapi Perlu” – Netsains.Com

2010-01-02T04:19:00.000-08:00

JAKARTA, Netsains – Dikenal sebagai idealis sejati. Disiplin, agak pelit memberi nilai. Setidaknya itulah gambaran seorang Prof. Andrianto Handojo di mata mahasiswanya di Departemen Teknik Fisika Institut Teknologi Bandung (ITB). Terkenal dengan sejumlah tulisan ilmiahnya di beragam jurnal internasional seperti “Imaging through Scattering Media with the Double Aperture Setup”, dimuat di jurnal bergengsi Optics and Laser Technology tahun 2001 bersama dengan J.Sumihar.
Kepada Netsains.Com, Andrianto mengungkap mengapa ada ilmuwan yang sulit menulis dalam bahasa populer. Berikut obrolan singkat namun padat dan penting Sang Profesor dengan Netssains.Com.

"Pengertian yang jelas tentang prinsip yang mendasari penemuan sains dan teknologi sangatlah penting, karena membuahkan pengenalan yang lebih erat, yang pada gilirannya dapat meningkatkan minat dan semangat untuk mempelajari bidang bersangkutan", demikian salah satu kutipan pendapatnya yang menarik.

Artikel selengkapnya : lihat disini

Fuel Cells

2009-12-12T16:29:00.000-08:00

Energy Source of the Future

According to many experts, we may soon find ourselves using fuel cells to generate electrical power for all sorts of devices we use every day. A fuel cell is a device that uses a source of fuel, such as hydrogen, and an oxidant to create electricity from an electrochemical process.

Much like the batteries that are found under the hoods of automobiles or in flashlights, a fuel cell converts chemical energy to electrical energy.

All fuel cells have the same basic configuration; an electrolyte and two electrodes. But there are different types of fuel cells, based mainly on what kind of electrolyte they use.

Many combinations of fuel and oxidant are also possible. The fuel could be diesel or methanol, while air, chlorine, or chlorine dioxide may serve as oxidants. Most fuel cells in use today, however, use hydrogen and oxygen as the chemicals.

Fuel cells have three main applications: transportation, portable uses, and stationary installations.

In the future, fuel cells could power our cars, with hydrogen replacing the petroleum fuel that is used in most vehicles today. Many vehicle manufacturers are actively researching and developing transportation fuel cell technologies.

Stationary fuel cells are the largest, most powerful fuel cells. They are designed to provide a clean, reliable source of on-site power to hospitals, banks, airports, military bases, schools, and homes.

Fuel cells can power almost any portable device or machine that uses batteries. Unlike a typical battery, which eventually goes dead, a fuel cell continues to produce energy as long as fuel and oxidant are supplied. Laptop computers, cellular phones, video recorders, and hearing aids could be powered by portable fuel cells.

Fuel cells have strong benefits over conventional combustion-based technologies currently used in many power plants and cars. They produce much smaller quantities of greenhouse gases and none of the air pollutants that create smog and cause health problems. If pure hydrogen is used as a fuel, fuel cells emit only heat and water as a byproduct. Hydrogen-powered fuel cells are also far more energy efficient than traditional combustion technologies.

The biggest hurdle for fuel cells today is cost. Fuel cells cannot yet compete economically with more traditional energy technologies, though rapid technical advances are being made. Although hydrogen is the most abundant element in the universe, it is difficult to store and distribute. Canisters of pure hydrogen are readily available from hydrogen producers, but as of now, you can't just fill up with hydrogen at a local gas station.

Many people do have access to natural gas or propane tanks at their houses, however, so it is likely that these fuels will be used to power future home fuel cells. Methanol, a liquid fuel, is easily transportable, like gasoline, and could be used in automobile fuel cells. However, also like gasoline, methanol produces polluting carbon dioxide.

More About Fuel Cells and Energy

Video: Fuel Cells
Video: Alternative Energy
Video: Energy Conservation
Article: Future Power: Where Will the World Get Its Next Energy Fix?
Quiz: Energy

What Is Global Warming?

2009-12-12T16:13:00.000-08:00

The Planet Is Heating Up—and Fast

Glaciers are melting, sea levels are rising, cloud forests are drying, and wildlife is scrambling to keep pace. It's becoming clear that humans have caused most of the past century's warming by releasing heat-trapping gases as we power our modern lives. Called greenhouse gases, their levels are higher now than in the last 650,000 years.

We call the result global warming, but it is causing a set of changes to the Earth's climate, or long-term weather patterns, that varies from place to place. As the Earth spins each day, the new heat swirls with it, picking up moisture over the oceans, rising here, settling there. It's changing the rhythms of climate that all living things have come to rely upon.

What will we do to slow this warming? How will we cope with the changes we've already set into motion? While we struggle to figure it all out, the face of the Earth as we know it—coasts, forests, farms and snow-capped mountains—hangs in the balance.

Greenhouse effect

The "greenhouse effect" is the warming that happens when certain gases in Earth's atmosphere trap heat. These gases let in light but keep heat from escaping, like the glass walls of a greenhouse.

First, sunlight shines onto the Earth's surface, where it is absorbed and then radiates back into the atmosphere as heat. In the atmosphere, “greenhouse” gases trap some of this heat, and the rest escapes into space. The more greenhouse gases are in the atmosphere, the more heat gets trapped.

Scientists have known about the greenhouse effect since 1824, when Joseph Fourier calculated that the Earth would be much colder if it had no atmosphere. This greenhouse effect is what keeps the Earth's climate livable. Without it, the Earth's surface would be an average of about 60 degrees Fahrenheit cooler. In 1895, the Swedish chemist Svante Arrhenius discovered that humans could enhance the greenhouse effect by making carbon dioxide, a greenhouse gas. He kicked off 100 years of climate research that has given us a sophisticated understanding of global warming.

Levels of greenhouse gases (GHGs) have gone up and down over the Earth's history, but they have been fairly constant for the past few thousand years. Global average temperatures have stayed fairly constant over that time as well, until recently. Through the burning of fossil fuels and other GHG emissions, humans are enhancing the greenhouse effect and warming Earth.

Scientists often use the term "climate change" instead of global warming. This is because as the Earth's average temperature climbs, winds and ocean currents move heat around the globe in ways that can cool some areas, warm others, and change the amount of rain and snow falling. As a result, the climate changes differently in different areas.

Aren't temperature changes natural?

The average global temperature and concentrations of carbon dioxide (one of the major greenhouse gases) have fluctuated on a cycle of hundreds of thousands of years as the Earth's position relative to the sun has varied. As a result, ice ages have come and gone.

However, for thousands of years now, emissions of GHGs to the atmosphere have been balanced out by GHGs that are naturally absorbed. As a result, GHG concentrations and temperature have been fairly stable. This stability has allowed human civilization to develop within a consistent climate.

Occasionally, other factors briefly influence global temperatures. Volcanic eruptions, for example, emit particles that temporarily cool the Earth's surface. But these have no lasting effect beyond a few years. Other cycles, such as El Niño, also work on fairly short and predictable cycles.

Now, humans have increased the amount of carbon dioxide in the atmosphere by more than a third since the industrial revolution. Changes this large have historically taken thousands of years, but are now happening over the course of decades.

Why is this a concern?

The rapid rise in greenhouse gases is a problem because it is changing the climate faster than some living things may be able to adapt. Also, a new and more unpredictable climate poses unique challenges to all life.

Historically, Earth's climate has regularly shifted back and forth between temperatures like those we see today and temperatures cold enough that large sheets of ice covered much of North America and Europe. The difference between average global temperatures today and during those ice ages is only about 5 degrees Celsius (9 degrees Fahrenheit), and these swings happen slowly, over hundreds of thousands of years.

Now, with concentrations of greenhouse gases rising, Earth's remaining ice sheets (such as Greenland and Antarctica) are starting to melt too. The extra water could potentially raise sea levels significantly.

As the mercury rises, the climate can change in unexpected ways. In addition to sea levels rising, weather can become more extreme. This means more intense major storms, more rain followed by longer and drier droughts (a challenge for growing crops), changes in the ranges in which plants and animals can live, and loss of water supplies that have historically come from glaciers.

Scientists are already seeing some of these changes occurring more quickly than they had expected. According to the Intergovernmental Panel on Climate Change, eleven of the twelve hottest years since thermometer readings became available occurred between 1995 and 2006.

More About Global Warming

Article: Is Global Warming Real?
Article: Meltdown: The Alps Under Pressure
Interactive: Greenhouse Gases

2000-2010: A Decade of (Climate) Change

2009-12-12T15:46:00.000-08:00

A decade ago, global climate change was largely considered a problem for the distant future. But it seems that future has come sooner than predicted.

One of the most remarkable, and alarming, environmental changes to occur over the last decade is the melting of Antarctic ice sheets and the recession of Arctic glaciers at speeds much faster than climate change models had predicted, according to environment experts.

In addition, the Arctic ice cap reached an all-time low in the summer of 2007. Some climate scientists now predict the region will be ice free during the summer within the next decade.

Studies suggest an ice-free Arctic could result not only in a stormier North Pole region, but could also affect weather patterns throughout the entire Northern Hemisphere.

The loss of ice would also be a death knell for polar bears, which rely on ice to hunt and raise their young. But it would also be a boon for business, including shipping and resource extraction.

Climate change has made itself apparent in other powerful ways over the past decade.

In southeastern Australia, a ten-year drought now causes the Murray River to trickle into the sand before it reaches the sea.

For the last several decades, ecologist John Harte, has watched global warming shift vegetation in the Rocky Mountains from a palette of wildflowers to sagebrush, the latter of which is hardier.

"As snowmelt trends toward coming earlier and earlier, it has big effects on the competition among plants," said Harte, of the University of California, Berkeley.

See More :2000-2010: A Decade of (Climate) Change

Metode Baru Pemurnian Hidrogen

2009-12-02T23:38:00.000-08:00

Suatu terobosan untuk membuat bahan bakar yang bersih dan hijau, itulah yang selalu menjadi keinginan para ilmuwan.
Hidrogen adalah unsur paling sederhana yang kita ketahui. Atomnya hanya mengandung satu proton. Hidrogen juga lebih ringan daripada udara dan tidak sendirian di planet ini. Selalu ditemukan dalam kombinasi dengan unsur-unsur lain. Orang melihat hidrogen sebagai bahan bakar alternatif tetapi ia memiliki kekurangan. Salah satu rintangan terbesar dalam bahan bakar hidrogen adalah pemurnian. Ini dapat bertindak sebagai bahan bakar untuk sel bahan bakar tetapi metode pemurnian sekarang tidak begitu efisien dan efektif.

Tetapi kimiawan Mercouri G. Kanatzidis dari Northwestern University, bersama dengan Gerasimos S. Armatas - postdoctoral penelitian telah menemukan solusinya. Mereka telah mengembangkan bahan berpori baru berbentuk seperti sarang lebah. Dan kita berpikir hanya penyair yang memiliki imajinasi seperti ini ! Struktur ini berpori seperti sarang lebah yang sangat efektif memisahkan hidrogen dari gas campuran. Karbon dioksida dan gas metan membawa gas hidrogen dalam jumlah besar. Dan struktur berbentuk sarang lebah ini menunjukkan struktur pori selektivitas terbaik dalam memisahkan hidrogen dari kedua gas tersebut. Bahan yang digunakan dalam membangun struktur pemurnian hidrogen adalah keluarga baru chalcogenides – yang diperkaya dengan germanium. "Kami mengambil keuntungan dari apa yang kita sebut atom 'lembut', yang membentuk dinding membran," kata Kanatzidis. " Dinding atom ini lembut ketika berinteraksi dengan molekul lunak lain yang lewat, memperlambat mereka di saat melewati membran. Hidrogen, yang merupakan elemen terkecil, adalah sebuah molekul 'keras'. Dia dengan cepat melewati membran ,sementara molekul lunak, seperti karbon dioksida dan metana memerlukan waktu lebih lama. "

Mengapa metode pemisahan ini bisa lebih baik daripada metode sekarang? Hingga sekarang para ilmuwan yang tergantung pada ukuran molekul gas sementara memisahkan hidrogen dari karbon dioksida dan metana. Pertama mereka mendapatkan hidrogen dalam kombinasi dengan karbon dioksida dan metana. Metode ini memerlukan lebih banyak tahapan dan sulit untuk dilaksanakan. Kanatzidis dan Armatas memiliki gagasan yang lebih baik. Mereka tidak bergantung pada ukuran molekul gas untuk pemisahan hidrogen. Mereka mengambil cara polarisasi. Di sini interaksi molekul gas dengan permukaan sarang lebah seperti struktur sangat penting. Kanatzidis dan Armatas menguji membran mereka pada campuran kompleks dari empat gas. Mereka telah memilih empat gas untuk percobaan mereka yaitu : hidrogen, karbon monoksida, metan dan karbon dioksida. Sebagai molekul terkecil dan paling sulit, hidrogen paling tidak menunjukkan kedekatan dengan membran , dan karbon dioksida, sebagai molekul paling lembut dari keempatnya, berinteraksi.

Kanatzidis, Charles E. dan Emma H. Morrison, Profesor kimia di Weinberg College of Arts and Sciences, dan penulis-penulis makalah senior, memberi pernyataan, "proses selektif yang lebih berarti , lebih sedikit siklus untuk menghasilkan hidrogen murni, dan meningkatkan efisiensi." Lebih lanjut menambahkan, "Semua materi dapat digunakan dengan sangat efektif sebagai membran untuk pemisahan gas. Kami telah menunjukkan kinerja superior mereka. "Elemen berat seperti germanium, timah dan telurium membuat seleksi pemisahan hidrogen dari karbon dioksida empat kali lebih efektif.

Menurut Kanatzidis, keuntungan lain dari proses ini adalah "rentang suhu nyaman." Yang bervariasi dari nol derajat Celsius sampai ke suhu kamar! “

Naskah aslinya : New Hydrogen Purification Method