Renewable Energy Sources

“Integrating Wind Power into the Electricity Grid of Bangladesh” 

                               Chapter-1

1.1 Introduction

In the near future, wind energy will be the most cost effective renewable source of electrical power. In fact, a good case can be made for saying that it has already achieved this status. By 2050 except coal all other fossil fuel sources (oil & gas) will be depleted.

Wind energy has a fundamental advantage over traditional solar power, however in that its energy is more and the wind being available in a mechanical form is easily converted to useful work.

The major technology developments enabling wind power commercialization have already been made. India has been working well in wind energy. They have taken a master plan to generate 1200MW power from the wind mills.

1.2 Wind energy 

A windmill is a machine with rotating blades that is designed to convert the energy of the wind into more useful forms. Most modern windmills, more appropriately called wind turbines, are used to generate electric power. Generation of electricity by the kinetic energy of wind requires a minimum average wind speed of 21.6 km/hr, which equals 11.67 knots (1 knot = 1.85 km/hr). In Bangladesh there are some coastal areas which have similar wind power to install a wind mill. Compared to other renewable energy wind mill is most familiar in the world because in the most of the country of the world like Denmark, USA, UK, Sweden, Netherland, Argentina, Bulgeria, Kenya, are established in wind mill. India has done better in wind mill.

Wind data from Bangladesh Meteorological Department and different previous and ongoing wind resource assessment projects are briefly described in the subsequent sections.

1.2.1 Advantages:

·         This energy is the least expensive. It is available round the clock.

 

·         It doesn't cause any pollution like power plants do. Power plants depend on the combustion of fossil fuels which can pollute the air.

 

·         Windmill generators do not give off atmospheric emissions that can cause acid rain and greenhouse affect.

       ·         As wind turbines are usually built on ranches and farms, these places benefit most from them. Farm owners get rent payment from the power plant owners and at the same time, they can continue to work on their property since these turbines only use a portion of the land.

·         One of the greatest advantages of wind energy is that it is simple and renewable. The cost of producing wind energy has come down by at least eighty percent since the eighties. Along with economy, Wind Energy is also said to diminish the greenhouse effect.

·         One other advantage of wind energy that it is readily available around the clock. Wind energy may be the answer to the globe's question of energy in the face of the rising petroleum and gas prices.

·         Before the invention of steam engine wind energy was extensively used in boats, ships etc.

1.2.2 Characteristics of Wind Power:

 

1. Wind power systems are non-polluting

2. It is a renewable source of energy

3. The energy generated by wind power systems it cheaper

4. Wind energy system avoid fuel provision and transport 

1.2.3 Wind Energy Source:

All referable energy ultimately comes from the sun about 1-2% of sun’s energy that received by the earth is converted to wind energy. A wind turbine obtains its power by converting the force of the wind into torque acting on the rotor blades.

 1.3 Others Sources of Renewable Energy:

1.3.1 Biogas energy

Biogas may be the most promising renewable energy resource for Bangladesh. Presently there are tens of thousands of households and village-level biogas plants in place throughout the country. Biogas units are of three major types: floating cover, fixed cover, and plastic bag plants. Of these models, the fixed cover (dome) model has become very popular and units are disseminated throughout the country by the Institute of Fuel Research & Development (IFRD) of BCSIR. These is a real Potential to harness basic biogas technology rural electrification, via village-level biogas production and internal combustion (or even micro turbine) power generation. Such an arrangement would have the added value of providing some self-sufficiency to rural populations during periods of power shortfalls and load shedding.

 

1.3.2 Hydro energy

Micro-hydro and Mini-hydro have limited application in Bangladesh, with the exception of Chittagong and Chittagong Hill tracts. Previous hydropower assessments have identified a handful of possible sites from 10 KW to 5 MW; however, no appreciable capacity has been installed. There is one large hydro facility in the country at Kaptai, installed in the 1960s and producing 230 MW (Three unit of 50 MW and four unit of 20 MW).

 

1.3.3 Bio-diesel energy

Bio-diesel may also be one of the promising sources of energy in Bangladesh. Government of Bangladesh has taken necessary steps for Jatropha plantation, a source of Bio-diesel. A Pilot project has already been considered to verify its commercial viability. This may be a potential source of renewable energy.

1.3.4 Biomass power

Biomass is the most significant energy source in Bangladesh which accounts for 70% of the total final energy consumption in Bangladesh. The main sources of biomass fuels are

• Trees (wood fuels, twigs, leaves, plant residues)
• Agricultural Residues (paddy husk, bran, bagasse, jute stick etc.) and
• Livestock (animal dung).

 Land use pattern and different biomass fuels of Bangladesh are described below in separate subsections. Approximate land use pattern of the country is

• Agricultural land : 64 %
• Forests : 18 %
• Human Settlement : 8 %
• Water and other : 10 %

1.3.5 Geothermal power

Geothermal energy is the natural heat of the Earth. It is a renewable source of energy if the exploration process doesn’t hamper the ecosystem or emit greenhouse gases. Geothermal reservoirs that are close enough to the surface to be reached by drilling can occur in places where geologic processes have allowed magma to rise up through the crust, near to the surface, or where it flows out as lava. The crust of the Earth is made up of huge plates, which are in constant but very slow motion relative to one another. Magma can reach near the surface in three main geologic areas:

• Where Earth's large oceanic and crystal plates collide and one slides beneath another, called a subduction zone The best example of these hot regions around plate margins is the Ring of Fire and the areas bordering the Pacific Ocean: the South American Andes, Central America, Mexico, the Cascade Range of the U.S. and Canada, the Aleutian Range of Alaska, the Kamchatka Peninsula of Russia, Japan, the Philippines, Indonesia and New Zealand.

• Spreading centers, where these plates are sliding apart (such as Iceland, the rift valleys of Africa, the mid-Atlantic Ridge and the Basin and Range Province in the U.S.A.).

• Places called hot spots fixed points in the mantle that continually produce magma to the surface.

Because the plate is continually moving across the hot spot, strings of volcanoes are formed, such as the chain of Hawaiian Islands. There is a known hot salt water spring, known as Labanakhya, in Bangladesh at 5 kilometer to the north of Sitakunda (40 kilometer from Chittagong). Possibility of extracting energy from this site or any other unknown sites can be investigated by Satellite Remote Sensing or Physical Surveys.

1.3.6 Marine power

Bangladesh has got 710 km (441 mi) long coastal belt along the Bay of Bengal. If the marine RETs become viable option in the future, then the country may harness energy from marine RETs. The main marine RETs are

• Tidal
• Wave
• Oceanic Thermal Energy Conversion

“Integrating Wind Power into the Electricity Grid of Bangladesh” is a bona-fide record of work done by S.M Mizanul Haque.

ØInformation has been collected from different books, internet websites etc.