Hybrid Power Plant

Hybrid Power Plant in Saint Martin Island Using Renewable Energy

MD.Shazzad Hossain

B.Sc. in EEE, AIUB, e-mail: sazjad@gmail.com

A proposal regarding power plant using solar and wind energy

St Martin’s is one of the most beautiful Tourist Islands in Bangladesh where grid connected electric system for the inhabitants will not be possible to establish even in future. Diesel, Kerosene and wood are the main fuels for fulfilling the energy demand. Solar and Wind resources are the hybrid options for the Island. The Island has a good potential of solar and wind energy resources.

A survey was done by the Sustainable Rural Energy (SRE) Programme of Local Government Engineering Department (LGED) in 2004 and recorded that the population of the Island is 5196 where most of them are fisherman and they belong to 778 families. The annual electric energy demand was found about 359MWh . There is a 30 KW diesel generator in St. Martins Island installed by PDB, but it is not running People meet there energy demand through kerosene, coconut palm or by other biomass plants. Some of the commercial shops and hotels meet their electricity demand by Diesel Generator.

Renewable Resources:

• Solar Energy
• Wind Energy
• Biomass Energy
• Wave

Feasibility of Solar Energy:

Solar Energy is inexhaustible and pollution free. It is available everywhere; but the greatest amount is available between two broad bands encircling the earth between 15” and 35” latitude North and South. Fortunately, Bangladesh is situated between 20”43’ north and 26”38’ north latitude and as such Bangladesh is in a very favorable position in respect of the utilization of solar energy. Annual amount of radiation varies from 1840 to 1575 kwh/m2 which is 50-100% higher than in Europe. Taking an average solar radiation of 1900 Kwh per square meter, total annual solar radiation in Bangladesh is equivalent to 1010 X 1018 J. present total yearly consumption of energy is about 700 X 1018 J. this shows even if 0.07% of the incident radiation can be utilized, total requirement of energy in the country can be met. At present energy utilization in Bangladesh is about 0.15 watt/sq. meter land area, whereas   the availability is above 208 watt/sq. meter. This shows the enormity of the potentiality of this source in this country (Eusuf, 1997).

In Saint Martin:

      There is no ground measurement data of solar radiation for the Island. But from the NASA satellite, it has been found that the annual solar insulation over St Martin is 4.84 Kwh/m²/day.

      There are small Seasonal variation over the Year.

      Maximum amount of radiation is available in the month of March – April and minimum in December – January.

Feasibility of Wind Energy:

The wind speed in some regions of Bangladesh is satisfactory for operation pumps and for generation of electricity. The wind turbines may also be useful to drive hand pumps used in irrigation agricultural land. It was found that the wind speed in Chittagong is 2.57 m/sec or more for 4000 hours a year. At this available speed a wind plant can be operated both for generation of electricity and for driving pumps. Grameen Shakti has been assessing the wind resource at Chokoria, Cox’s Bazar as well.

Saint Martin’s Island is Located on the southern-most tip of Bangladesh, roughly between 20° 34² - 20° 39² N and 92° 18² - 92° 21' E  and 17 Kilometres off Tecknaf, the most southern main land of Bangladesh . The Island is flat and just only about 3m high from the sea level.

According to Bangladesh Centre for Advanced Studies (BCAS) and Bangladesh Council for Scientific and Industrial Research (BCSIR) and Bangladesh Meteorological Department:

 Wind speeds at most Met Office stations appear to be low, with typical annual mean wind    speeds of 2 to 4 knots or 1 to 2 m/s, at heights between 5 to 10 meter above ground level.

 Wind speeds appear to be higher in the east of the country than the west.

 Wind speeds in the coastal areas appear to be higher than inland.

 Wind speed exhibits a strong seasonal cycle, lowest in the winter and higher in the summer.

 Wind speed exhibits a diurnal cycle, generally peaking at noon and weakest at night. It has been found that wind speed goes to maximum and minimum at round 10 O’clock in the night and morning of local time respectively.

The maximum velocity obtained at St. Martins Island is 20 m/s and yearly average wind speed in 4.9 m/s. The maximum velocity obtained at Teknaf is 16 m/s and yearly average wind speed is 3.8 m/s. Available wind speeds in Saint Martin’s Island are presented in the Table 4 below:

Monthly average wind speeds in the island [IFRD, 2002]

Month                                                 Vavg (m/s)                               Vmax (m/s)

January                                                5.08                                         23.32

February                                              4.71                                         19.78

March                                                  4.29                                         18.94

April                                                    3.58                                         20.03

May                                                     5.75                                         26.30

June                                                     5.96                                         29.80

July                                                      5.33                                         24.20

August                                                5.96                                         20.40

September                                           4.79                                         17.70

October                                               4.17                                         15.90

November                                           3.79                                         14.50

December                                            4.08                                         15.20  

Daily Wind Speed for St Martin

Reasons for choosing Hybrid Option

• The solar radiation or wind speed is not constant throughout the year or month. But as we know to generate power a constant input supply is needed.

• This Island is suitable for solar or wind power plant.

• Environment will not be polluted

• By negotiating two options(wind and solar), we can maintain a constant supply

• If we want to construct the whole project by solar panel , it will take a huge land area which is ineffective.

• If we want to construct the whole project by wind energy , the capacity will be small because the suitable wind speed for generation is found a small distance above the land.

Practical Implementation

10 kW Wind-solar Hybrid at St. Martin’s Island

• Capacity : 10KW
• Hybrid System : 5 KW Solar + 5 KW from Wind Energy
• No & Capacity of Wind Turbine : Model Whisper 175 , 3.25Kwp( at 7 m/s) @ 7
• No of Solar Array : Module 120Wp@ 44

Resources available to simulate and design such a plant

HOMER (Hybrid optimization Model for Electric Renewables), a software developed by National Renewable Energy Laboratory (NREL), USA for micro-power optimization model, has been used to find out the best energy efficient renewable based hybrid system options for the Island. It contains a number of energy component models and evaluates suitable technology options based on cost and availability of resources. Anyone can readily design and do analysis from a single home to a combination of many homes or including an isolated area to get the most economic and technical viable options by this tool.

References

1.      Biodiversity and Eco tourism project of St Martin’s, Bangladesh, http://www.stmartinsbd.org

2.      News from Voice of America, http://www.voanews.com/bangla/2005-01-16-voa3.cfm

3.      Electricity demand survey report at the St. Martin’s Island, SRE, LGED, Dhaka, Bangladesh, May-2004

4.      A Hossain, IIFC report “Remote Area Power Supply Systems (RAPSS)”, 2001

5.      HOMER, V – 2.14, National Renewable Energy Laboratory (NREL), USA, http://www.nrel.gov/homer

6.      NASA surface meteorology and solar energy, released 5.1, http://eosweb.larc.nasa.gov

7.      High Resolution Solar Radiation Assessment for Bangladesh, SWERA project, http://swera.unep.net

8.      S Islam, Tidal data at the St. Martin’s Island,  BUET, Bangladesh, 2004

9.       M. Shamim Kaiser, S K Khadem, H R Ghosh, S Kaiser, S K Aditya “Energy efficient system for St Martin’s Island of Bangladesh”

Please feel free to contact me if I could be further helpful.