Pumped Storage Hydro Electric

By Ahmad Suhendra

PLTA Pumped Storage (Pumped Storage Hydro Electric) adalah suatu pembangkit listrik tenaga air, dimana pompa digunakan untuk memasukan air kedalam waduk dan biasanya dilakukan pada musim penghujan. Tujuannya dari pemompaan ini yaitu untuk mengurangi debit sungai agar tidak terjadi banjir di musim hujan dan dengan adanya pemasukan air tersebut maka diharapkan waduk dapat memiliki air yang cukup untuk membangkitkan listrik pada musim kemarau.

Salah satu contoh PLTA Pumped Storage di Indonesia adalah PLTA Beng (12 MW) yang memompa air dari sungai brantas pada musim hujan (Desember-April). Pembangkitan listriknya dilakukan pada musim kemarau dari bulan Mei-Oktober (6 bulan) hanya pada malam hari saja dan air yang keluar melalui turbin dimanfaatkan untuk suplai air minum di Kotamadya Surabaya.

Production Of Pure Ethanol

By P.Pruksathorn and T.Vitidsant

This research focuses on water separation from ethanol-water solution under vapor phase with the use of 3A zeolite. The first phase testing was done in a fix-bed adsorber under atmospheric pressure to study the optimum condition for adsorption and compare the performance under difference conditions.The zeolite was packed in stainless stell column with inner diameter of 1.59 cm and the lenght of 45 cm placing in a tube furnace to maintain the temperature at desired values. Click here

One Low -Tech Solution to High -Tech Problem

By Joshua & Kaia Tickell

Making your own fuel from vegetable oil can be easy, cost effective, and environmentally beneficial. What makes this fuel even more attractive is that can you make it from the waste vegetable oil produced in The United States every year, which amounts to more than three billion gallons. With a bit of know-how and persistence, you can run any diesel engine on vegetable oil.

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The state of art of Hydrokinetic power in Brazil

By Geraldo L. Tiago Fo, PhD

Abstract

This paper presents the state of the art of free-flow hydro power turbine, also known as a hydro kinetic turbine in Brazil. This kind of turbine is designed to generate electricity using only the kinetic energy of water flow in rivers and is used to generate electricity on isolated communities in the inland of Brazil.

Moreover it is relevant to say that the developed technology proved is necessary to be robust and suitable for the extremely severe conditions of the remote and isolated villages, since it is has been functioning uninterruptedly from several years with a minimum maintenance. This type of small hydro kinetic power plant typically can provide up to 2 kW of electric power, being a reliable alternative for the electrification of remote and isolated households, communities or social end-users.

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Water Turbine Speed

Type of turbine	Nominal speed(n rpm)	Runaway speed
Semi Kaplan, single regulated	75-100	2-2.4
Kaplan, double regulated	75-150	2.8-3.2
Small-medium Kaplan	250-700	2.8-3.2
Francis (medium & high head)	500-1500	1.8-2.2
Francis (low head)	250-500	1.8-2.2
Pelton	500-1500	1.8-2
Crossflow	100-1000	1.8-2
Turgo	600-1000	2

Selection type of turbine

Selection type of turbine

To determine the type of water turbine that will be used in the design of a power micro hydro, need specific speed is calculated. Specific Speed (ns) is defined as the speed in rounds per minute of a turbine in the delusion that all the geometrical indeed similar to the turbine is able to lift 75 kg of water per second up to a height of 1 meter.

ns = 3.65 . n . Q ^0.5 . H ^{(- 0.75)}

ns = 270 – 1000 Kaplan/Propeller
ns = 60 – 350 Francis
ns = 42 – 170 Cross flow
ns = 8 – 72 Pelton
Where :
n = Round turbine speed /Nominal speed (rpm)
Q = Design flow (m3/det)
H = Net Head (m)