Wednesday 12 June 2013

Dapatkah EKONOFISIKA Menjinakan Kompleksitas Perekonomian Indonesia?

The Emergence of EconoPhysics



Penjelasan Apa Itu Ekonfisika 

Oleh: Prof. Jean-Philippe Bouchaud

Is a French physicist born in 1962. He is founder and Chairman of Capital Fund Management (CFM) and professor of physics at École polytechnique.

Born in Paris in 1962, Jean-Philippe Bouchaud studied at the French Lycée in London. Graduated from École Normale Supérieure in 1985, he worked on his Ph.D. at the Laboratory of Hertzian Spectroscopy, studying spin-polarized quantum gases with Claire Lhuillier. He then worked for the French National Center for Scientific Research, in particular on liquid Helium 3 and diffusion in random media. 

He spent a year at the Cavendish Laboratory, University of Cambridge in 1992 before joining the Laboratory of Condensed Matter Physics of the French Atomic Energy and Alternative Energies Commission (Commissariat à l'énergie atomique or CEA) à Saclay

Pioneer in econophysics, he co-founded the company Science et Finance in 1994, which later merged with Capital Fund Management (CFM) in 2000. 

He is now the Chairman of CFM. After teaching statistical mechanics for ten years at ESPCI, he was appointed as an adjunct Professor at École Polytechnique, where he teaches a course on Complex systems. His work covers the physics of disordered and glassy systems, granular materials, the statistics of price formation, stock market fluctuations and the modelling of financial risks. 

He criticizes the dogma of the efficient-market hypothesis and the methodology of economics and mathematical finance, in particular the use of the Black–Scholes model which leads to a systematic underestimation of risk in options trading.


Mampukah Ekonofisika memperbaiki Ekonomi Indonesia saat ini? 

Dalam beberapa seminar tentang pengenalan ekonofisika di berbagai daerah di tanah air, pertanyaan ini seringkali dikumandangkan. 

Apa sumbangan yang dapat dikontribusikan oleh ekonofisika dalam memperbaiki situasi perekonomian nasional kita saat ini?

Bangsa ini sedang terjebak hutang, terhimpit ekonomi dunia yang tengah didera krisis energi sehingga melambungkan harga BBM (bahan bakar minyak), tingginya tingkat pengangguran, ekonomi yang cenderung high cost dan tidak efisien oleh karena meluasnya praktik korupsi, dan berbagai permasalahan ekonomi di Indonesia

Bisakah Ekonofisika memberikan solusi?

Secara sederhana, ekonofisika dapat dipandang sebagai sebuah bidang penelitian interdisipliner yang mengaplikasikan berbagai teori dan metodologi yang pada awalnya dikembangkan dalam lingkungan ilmiah fisika dalam memecahkan berbagai persoalan dalam ekonomi. 

Pendekatan yang sering digunakan adalah pendekatan elemen stokastik dan dinamika non-linier, misalnya model-model magnetisasi dalam memahami gerak fluktuasi pasar modal, model-model prediksi gempa bumi dalam memahami ambruknya pasar modal, model transisi fasa dalam memahami sifat distribusi yang tak normal seperti halnya distribusi pendapatan, dan sebagainya. 

Mengapa ekonofisika memiliki arti penting dalam perkembangan analisis ekonomi? 

Setidaknya terdapat dua hal untuk menjawab pertanyaan ini.

Yang pertama, dalam perkembangan kontemporer fisika, pengembangan model matematika tentang kompleksitas oleh Fisikawan penerima Nobel, Prof. Murray Gell-Mann dan dan teori informasi yang dikembangkan Prof. Claude Shannon telah memberikan pembagian minimal dua level deskripsi analitik level makro dan level mikro. 

Berbagai indikator terukur dalam fisika seperti suhu, tekanan, fasa zat, dan sebagainya merupakan makrokosmos yang muncul secara tak linier dari interaksi mikrokosmos seperti halnya atom, molekul, dan sebagainya. Observasi, simulasi, dan kalkulasi fisika harus memuaskan kedua hal ini, dan meski tak mudah, telah ditemui banyak sekali terobosan-terobosan ilmu fisika yang berupaya memberikan kontribusi untuk permasalahan ini.

Sekarang coba kita lihat fenomena ekonomi. 

Ekonom terbiasa melihat indikator ekonomi seperti indeks saham-saham, laju pertumbuhan tenaga kerja, pergerakan harga-harga komoditas mulai dari pasar global hingga pasar tradisional, inflasi, pendapatan rata-rata penduduk, tak ubahnya fisikawan klasik memandang besaran fisika seperti temperatur, tekanan gas, dan sebagainya. 

Pembagian makro dan mikrokosmos yang saling bertautan  meski tak linier jarang menjadi fokus perhatian. Jelas sekali, pergerakan harga ataupun berbagai besaran ekonomi apapun merupakan hasil interaksi mikrokosmik antar manusia. Segala besaran yang menjadi indikator ekonomi dan sosial berasal dari bagaimana satu individu memandang masalah, memilih pilihan yang menguntungkannya secara terbatas, dan seterusnya.

Dalam hal ini dan analisis berikutnya,: ekonofisika memberikan kontribusi bagaimana  memandang sistem agregat dan mikrostruktur secara komprehensif sebuah medan yang sering terlupakan pada ekonomi konvensional maupun financial engineering sebelumnya. Meski tentu ada satu masalah besar, jika analisis fisika menerangkan hubungan mikro-makrokosmos ini dengan hal elementernya adalah atom atau molekul, maka ekonomi harus berurusan dengan manusia sebagai agen elementernya.

Di sini, bagaimana manusia mengakuisisi informasi jelas jauh lebih rumit daripada partikel atau molekul yang memiliki derajat kebebasan yang relatif sangat terbatas. Namun setidaknya, di sini ekonomi menjadi bergerak selangkah lebih maju.

Ekonomi konvensional biasanya berkutat dengan angka-angka indikator agregat jika tidak berkutat dengan pendekatan kualitatif tak terukur yang berusaha menghubungkan faktor psikologis manusia dengan kondisi ekonomi secara global. Dalam ekonofisika, hal ini coba dijembatani melalui pendekatan yang oleh karena pola terukurnya dan sifat metodenya yang peka terhadap dinamika tak linier menjadikan analisis yang lebih akurat dan berbagai kebijakan dapat bersandar padanya secara terukur.


Hal kedua yang menjadikan ekonofisika memberikan kontribusinya pada ekonomi adalah bahwa model-model yang secara matematis rumit ini pada bidang aslinya, fisika, miskin dengan data. Seringkali satu eksperimen fisika harus menunggu waktu bertahun-tahun untuk dapat menghasilkan data yang cukup layak untuk menguji berbagai teori dan metodologi.

Hal ini berlawanan dengan situasi pada sistem ekonomi. Dalam sistem ekonomi, khususnya ekonomi keuangan dan investasi, dalam tiap detik dapat terjadi ratusan bahkan ribuan transaksi yang menyimpan data.

Data-data yang sedemikian banyak jumlahnya ini seringkali kurang diperhatikan oleh karena sedikitnya perangkat metodologi ekonomi keuangan klasik untuk mengekstrak informasi di dalamnya.

Pendekatan ekonofisika jelas mengatasi hal ini. Pendekatan ekonofisika menyediakan seribu satu macam metodologi untuk mengekstrak informasi yang terkandung dalam data-data ekonomi atau keuangan tersebut. Dengan memahami seluas mungkin ekstraksi informasi yang terkandung di dalam data, maka berbagai kebijakan ekonomi yang bersandar padanya tentu akan lebih dapat dipertanggungjawabkan.

Kedua alasan inilah yang menjadi titik tolak kita dalam melihat, seberapa jauh ekonofisika dapat memberikan kontribusinya pada perekonomian nasional kita saat ini. Kita mengetahui bahwa solusi dan permasalahan ekonomi konvensional seringkali kurang memperhatikan kondisi mikro-makrokosmos sebagaimana diterangkan di atas atau jikapun ia memperhatikan level mikro-makro-nya, pendekatannya akan cenderung kualitatif sehingga cenderung kurang terukur dan sulit untuk diverifikasi yang berujung pada perdebatan yang berkenaan dengan ideologi ekonomi klasik.

Menurut ekonom Australia penulis buku best-seller internasional Debunking Economics (1997) yang berusaha menyingkap berbagai teori ekonomi konvensional yang justru seringkali menjadi landasan resep IMF dan World Bank dalam mengatasi problem ekonomi berbagai negara pasca krisis Steve Keen, ini merupakan entri poin penting mengapa ekonofisika memberikan arti penting dalam ekonomi, lebih khusus lagi, dalam penyusunan kebijakan ekonomi nasional sebuah negara.

Semoga rakyat dan Bangsa Indonesia semakin Cerdas dan lebih maju lagi.

Amin.

Semangat Indonesia

Sumber:

1. http://www.bandungfe.net/
2. http://qact.wordpress.com/
3. Prof. Yohanes Surya, Ph.D.
4. https://www.cfm.fr/en/

Solar Power Satellite III

Satelit tenaga surya adalah satelit yang diusulkan dibuat di orbit Bumi tinggi yang menggunakan transmisi tenaga gelombang mikro untuk menyorotkan tenaga surya kepada antena sangat besar di Bumi yang dpaat digunakan untuk menggantikan sumber tenaga konvensional.



Working lifetime:

The lifetime of a PV based SPS is limited mainly by the ionizing radiation from the radiation belts and the Sun. Without a protection method, this is likely to cause the cells to degrade by about a percent or two per year. Deterioration is likely to be more rapid during periods of high exposure to energetic protons from solar particle outburst events. If some practical protection can be designed, this also might be reducible (eg, for a CPV station, radiation and particle shields for the PV cells out of the energy path from the mirrors, of course).

Lifetimes for SD based SPS designs will be similarly limited, though largely for structural or mechanical considerations, such as micrometeorite impact, metal fatigue of turbine blades, wear of sliding surfaces (although this might be avoidable by hydrostatic bearings or magnetic bearings), degradation or loss of lubricants and working fluids in vacuum, from loss of structural integrity leading to impaired optical focus amongst components, and from temperature variation extremes.

As well, most mirror surfaces will degrade from both radiation and particle impact, but such mirrors can be designed simply (and so to be light and cheap), and replacement may be practical.

In either case, another advantage of the SPS design is that waste heat developed at collection points is re-radiated back into space, instead of warming the adjacent local biosphere as with conventional sources, though some care will likely be required to provide for the radiation of this waste heat.

Thus thermal efficiency will not be in itself an important design parameter except insofar as it affects the power/weight ratio via operational efficiency and hence pushes up launch costs. (For example SD may require larger waste heat radiators when operating at a lower efficiency).

Earth based power handling systems must always be carefully designed, for both economic and purely engineering reasons, with operational thermal efficiency in mind.

One useful aspect of the SPS approach is that, at the end of life, the material does not need to be launched a second time, at least in principle. In theory, it would be possible to recycle much of the satellite 'on-site', potentially at a significantly lower cost than launching an SPS as new.

This might allow a very expensive launch cost to be paid for over multiple satellite lifetimes, but does require an in orbit re-processing facility which doesn't currently exist.
Energy Payback:
Clearly, for an SPS system (including manufacture, launch and deployment) to provide net power it must repay the energy needed to construct it.

Solar satellites can pay back the lift energy in a remarkably short time. It takes 14.75 kWh/kg for a 100% efficiency system to lift a kg from the surface of the earth to GEO; no such launch system exists and so energy costs are always higher. If the satellite generated a kW with 2kg of mass, the payback time would be 29.5 hours. Assuming a much less efficient (and more realistic) 3% efficient rockets, the energy payback time is only extended to about 6 weeks for such an SPS.

For current silicon PV panels, production energy requirements are relatively high, and typically three-four years of deployment in a terrestrial environment is needed to recover this energy.

With SPS, net energy received on the ground is higher (more or less necessarily so, if the system to be worth deploying), so this energy payback period would be reduced to about a year. Thermal systems, being made of conventional materials, are more similar to conventional power stations and are likely to be less energy intensive during manufacture. They would be expected to give quicker energy break even, depending on construction technology. The relative merits of PV vs SD is still an open question.

Clearly, for a system (including manufacture, launch and deployment) to provide net power it must repay the energy needed to construct it. For current silicon PV panels this is relatively high. With an SPS, the net energy received on the ground is higher so this energy payback period would be somewhat reduced; however an SD based SPS, being made of conventional materials, are more similar to conventional powerstations and are likely to be less energy intensive during production and would be expected to give a quicker energy break even, depending on construction technology and other variations.


Wireless power transmission to the Earth:

Wireless power transmission was early proposed to transfer energy from collection to the Earth's surface. The power could be transmitted as either microwave or laser radiation at a variety of frequencies depending on system design. Whatever choice is made, the transmitting radiation would have to be non-ionizing to avoid potential disturbances either ecologically or biologically if it is to reach the Earth's surface. This established an upper bound for the frequency used, as energy per photon, and so the ability to cause ionization, increases with frequency. Ionization of biological materials doesn't begin until ultraviolet or higher frequencies so most radio frequencies will be acceptable for this.

William C. Brown demonstrated in 1964 (on air Walter Cronkite's CBS News program), a microwave-powered model helicopter that received all the power it needed for flight from a microwave beam. Between 1969 and 1975, Bill Brown was technical director of a JPL Raytheon program that beamed 30 kW of power over a distance of 1 mile at 84% efficiency.

To minimize the sizes of the antennas used, the wavelength should be small (and frequency correspondingly high) since antenna efficiency increases as antenna size increases relative to the wavelength used. More precisely, both for the transmitting and receiving antennas, the angular beam width is inversely proportional to the aperture of the antenna, measured in units of the transmission wavelength. The highest frequencies that can be used are limited by atmospheric absorption (chiefly water vapor and CO2) at higher microwave frequencies.

For these reasons, 2.45 GHz has been proposed as being a reasonable compromise. However, that frequency results in large antenna sizes at the GEO distance. A loitering stratospheric airship has been proposed to receive higher frequencies (or even laser beams), converting them to something like 2.45 GHz for retransmission to the ground. This proposal has not been as carefully evaluated for engineering plausibility as have other aspects of SPS design; it will likely present problems for continuous coverage.

Spacecraft Sizing:

The size of an SPS will be dominated by two factors. The size of the collecting apparatus (eg, panels, mirrors, etc) and the size of the transmitting antenna which in part depends on the distance to the receiving antenna. The distance from Earth to geostationary orbit (22,300 miles, 35,700 km), the chosen wavelength of the microwaves, and the laws of physics, specifically the Rayleigh Criterion or Diffraction limit, used in standard RF (Radio Frequencyantenna design will all be factors.

For best efficiency, the satellite antenna should be circular and for the probable microwave wavelength, about 1 kilometers in diameter or larger; the ground antenna (rectenna) should be elliptical, 10km wide, and a length that makes the rectenna appear circular from GSO. (Typically, 14km at some North American latitudes.) Smaller antennas would result in increased losses to diffraction/sidelobes. For the desired (23mW/cm²) microwave intensity these antennas could transfer between 5 and 10 gigawatts of power.

To be most cost effective, the system should operate at maximum capacity. And, to collect and convert that much power, the satellite would require between 50 and 100 square kilometers of collector area (if readily available ~14% efficient monocrystalline silicon solar cells were deployed). State of the art (currently, quite expensive, triple junction gallium arsenide) solar cells with a maximum efficiency of 40.7%  could reduce the necessary collector area by two thirds, but would not necessarily give overall lower costs for various reasons.

For instance, these very recently demonstrated variants may prove to have unacceptably short lifetimes. In either cases, the SPS's structure would be essentially kilometers across, making it larger than most man-made structures here on Earth. While almost certainly not beyond current engineering capabilities, building structures of this size in orbit has not yet been attempted.

LEO/MEO instead of GEO:

A collection of LEO (Low Earth Orbit) space power stations has been proposed as a precursor to GEO (Geostationary Orbit) space power beaming system(s). There would be advantages, such as much shorter energy transmission path lengths allowing smaller antenna sizes, lower cost to orbit, energy delivery to much of the Earth's surface (assuming appropriate antennas are available), etc. And disadvantages, including constantly changing antenna geometries, increased debris collision difficulties, many more power stations to provide continuous power delivery at any particular point on the Earth's surface, etc.

It might be possible to deploy LEO systems sooner than GEO because the antenna development would take less time, but it would certainly take longer to prepare and launch the number of required satellites. Ultimately, because full engineering feasibility studies have not been conducted, it is not known whether this approach would be an improvement over a GEO installation.


Earth Based Infrastructure:

The Earth-based receiver antenna (or rectenna) is a critical part of the original SPS concept. It would probably consist of many short dipole antennas, connected via diodes. Microwaves broadcast from the SPS will be received in the dipoles with about 85% efficiency. With a conventional microwave antenna, the reception efficiency is still better, but the cost and complexity is also considerably greater, almost certainly prohibitively so. Rectennas would be multiple kilometers across. Crops and farm animals may be raised underneath a rectenna, as the thin wires used for support and for the dipoles will only slightly reduce sunlight, so such a rectenna would not be as expensive in terms of land use as might be supposed.



NSS web pages devoted to SSP:
Semoga Bermanfaat

Kunjugi Juga:


To Be Continued

Mengembangkan Inovasi Biogas Rumah (BIRU)

Energi merupakan sumber pembangunan yang tak terpisahkan. Saat ini, miliaran orang di seluruh dunia tidak memiliki akses ke bentuk energi yang dapat diandalkan. 


Bio gas Production:

Bio gas is practically produced as landfill gas (LFG) or digested gas. A bio gas plant is the name often given to an anaerobic digester that treats farm wastes or energy crops. Bio gas can be produced using anaerobic digesters. These plants can be fed with energy crops such as maize silage or biodegradable wastes including sewage sludge and food waste. During the process, as an air-tight tank transforms biomass waste into methane producing renewable energy that can be used for heating, electricity, and many other operations that use any variation of an internal combustion engine, such as GE Jenbacher gas engines.

There are two key processes: Mesophilic and Thermophilic digestion. In experimental work at University of Alaska Fairbanks, a 1000-litre digester using psychrophiles harvested from "mud from a frozen lake in Alaska" has produced 200–300 liters of methane per day, about 20–30% of the output from digesters in warmer climates. Landfill gas is produced by wet organic waste decomposing under anaerobic conditions in a landfill.

The waste is covered and mechanically compressed by the weight of the material that is deposited from above. This material prevents oxygen exposure thus allowing anaerobic microbes to thrive. This gas builds up and is slowly released into the atmosphere if the landfill site has not been engineered to capture the gas. Landfill gas is hazardous for three key reasons. Landfill gas becomes explosive when it escapes from the landfill and mixes with oxygen. The lower explosive limit is 5% methane and the upper explosive limit is 15% methane.

The methane contained within biogas is 20 times more potent a greenhouse gas than carbon dioxide. Therefore, uncontained landfill gas, which escapes into the atmosphere may significantly contribute to the effects of global warming. In addition, landfill gas impact in global warming, volatile organic compounds (VOCs) contained within landfill gas contribute to the formation of photochemical smog.

Kandungan Energi Biogas
Nilai kalori dari 1 meter kubik Biogas sekitar 6.000 watt jam yang setara dengan setengah liter minyak diesel. Oleh karena itu Biogas sangat cocok digunakan sebagai bahan bakar alternatif yang ramah lingkungan pengganti minyak tanah, LPG, butana, batu bara, maupun bahan-bahan lain yang berasal dari fosil.

Program Biogas Rumah
Program BIRU menggunakan pendekatan sektor privat, menciptakan sektor konstruksi biogas, melibatkan kontraktor dan pekerja lokal yang terlatih, didukung oleh lembaga pelatihan kejuruan regional ataupun nasional. 

Reaktor biogas tidaklah murah, maka dari itu, untuk mengurangi beban biaya, bank-bank dan/atau institusi keuangan mikro akan menyediakan pinjaman dan garansi 2 tahun kesalahan konstruksional bagi pengguna sebagai tambahan dari insentif investasi yang ditawarkan program ini. 

Pengguna BIRU dilindungi dari kesalahan konstruksi melalui garansi 2 tahun. Peran organisasi pembangunan-non-pemerintah pedesaan dan layanan jasa peternakan dan pertanian pemerintah maupun swasta terintegrasi di dalam program. 

Program ini akan menciptakan lapangan kerja baru dan sektor bisnis baru di Indonesia. 



Sumber: 
Wikipedia
Arip Nurahman Notes
Badan Penelitian dan Pengembangan ESDM
Program BIRU:
http://www.biru.or.id/

Semoga Bermanfaat