Friday, 29 April 2011
Saturday, 9 April 2011
Cold Ironing: Movable shore power supply of the Case Study in Port of Shanghai
The source for land-based power may be an electric Utilities and some also possibly a diesel driven generator which depending on land factors and reliable powers sources. Shorepower may also be supplied by renewable energy sources such as wind or solar.
The reasons for using shorepower are concluded such as saves fuel, alternative for allow maintenance of on-board generators, Eliminate emission and some countries to comply with domestic “anti-idling laws”.
Cold ironing as Alternative Maritime Power is the process of providing shoreside electrical power to a vessel berthing while its main and auxiliary engines are turned off. Cold ironing permits emergency equipment, refrigeration, cooling, heating, lighting and other equipment to receive continuous electrical power while the ship loads or unloads its Container, cargoes or passengers.
Cold ironing is a maritime industries term that first came into use when all ships had coal-fired engines. When a ship tied up at port there was no need to continue to feed the fire and the iron engines would literally cool down, eventually going completely cold – hence the term "cold ironing".A ship can cold iron by simply connecting to another ship's power supply – a process the US Navy and other navies have practised for many years – or from a shoreside power source. Recently cold ironing has been looked to as a means to mitigate air pollution by significantly reducing, and in some cases completely eliminating, harmful emissions from vessel diesel engine.
Unlike navy vessels, commercial ships do not sustain long port stays, and stay on power generated internally through diesel powered generators (auxiliary engines). As ships traditionally were not subject to emissions control, since the days of diesel powered ships research was largely focused on using cheaper forms of fuel to run their engines.
As a result ships throughout the world have been using Heavy Fuel Oil – residual petroleum – as the optimal choice of fuel. This fuel, the reverse of gas oils (which are derived through distillation of crude oil), is high on particulate matter; and studies show that a single ship can produce emissions equal to the same amount as 50 million cars annually. Further research indicates 60,000 cardio-pulmonary mortalities due to particulate matter from ship emissions. These deaths have been detected far inland, due to prevailing wind conditions. The total world trading fleet stands at 50,000+ merchant ships (Lloyds data as of January 2008). Each ship spends some 100 days in port in a year.
For every kilowatt-hour (kW h) of electricity, about 200 gm of bunker fuel is consumed. Each 1kg of bunker oil =3.125kg of carbon dioxide. It is assessed that globally ships use 411,223,484 tonnes of fuel annually.
Keeping these reports in mind, new regulatory norms have been mandated by the International Maritime Organization (IMO). The level of sulphur is one of the benchmarks in measuring quality of fuel and Marpol Annex VI requires use of <4.5% sulphur fuel, effective 2010. The target is to reduce world maritime sulphur output to <0.5% by 2020. Some regions (e.g. California) already require ships switch to cleaner fuel when in their local waters.
Cold ironing does away with the need to burn fossil fuel onboard ships while they are docked. In this concept, ships visiting ports are hooked on to local grid power – or other – power sources which are already regulated by local pollution norms. This shore-sourced power serves the ship’s cargo handling machinery and hotelling requirements. Effectively, all generating sources are shut down and ship is hence cold-ironed. This brings immediate relief from pollution by shipboard emissions and allows a more holistic maintenance schedule to be followed by ship operators, which are typically hard put to maintain planned maintenance schedules due to commercial operating pressures.
Concern and Restriction
Ships, built in diverse international yards, have no uniform voltage and frequency requirement. Some ships use 220 volts at 50 Hz, some at 60 Hz, some others use 110 volts. Primary distribution voltage can vary from 440 volts to 11 kilovolts.Load requirement varies from ship to ship and ranges from a few hundred kW in case of car carriers to a dozen or more MW in case of passenger ships or reefer Ship. Connectors and cables are not internationally standardized, though work has progressed in this direction. There are other legal implications to outsourcing primary power source. All these problems are addressable and work has already begun in reducing ship emissions by cold ironing
Different power forms may be used to transfer electrical energy from port to the ship/vessels: 11000 V AC / 6600 V AC (likely to become standard) / 660 V AC / 400 V AC
High voltage reduces the mass of the cable, and so reduces handling labor. One obstacle is the use of different frequencies like 60 Hz instead of 50 Hz. Which may cost 300 000 - 500 000 EUR to convert. The amount of power for an ocean-going ship is usually 2,0 - 10 MW. Cable to connect larger ships may cost 20 - 25 EUR/meter. Transformer substations cost 15 000 - 30 000 EUR. Operation and maintenance costs of the onboardMWh for electricity generated. Fuel cost for sea diesel, with sulphur content less than 0,5% cost approximately 18 EUR/MWh (12 months sliding average in 2005).
To ensure that galvanic corrosion doesn't occur an isolation transformer that provide galvanic isolation should be used, because the power grid and on board earth potential may differ.
Connecting or disconnecting takes approximately 30 minutes using 400 V AC due cable bulkiness. Thus increasing the voltage and put a portable transformer at the end might be worthwhile for the benefit of less cable area. This affects the minimum amount of time required shore time to make it worthwhile.
Case Study : The Port of Shanghai use a movable 2000 kVA shore power supply system with AC drives to supply electricity from the national grid to the ships in dock.
So far a few ports in the world have adopted a shore power supply system for docked ships, meaning that ships are supplied with low-emission, noise-free electricity from the national grid through a shore power box and a link cable.
An important import and export base for goods in China, the Port of Shanghai, which is the second largest port in the world, uses a 2000 kVA shore power supply system with Vacon AC drives, capable of converting the 10 kV shore power into 440 V/60 Hz or 380 V/50 Hz high-quality clean power for the ships in the port. This solution is not only good for the environment but also gives other benefits such as a low level of noise, low power consumption and vibration, high efficiency, accuracy and stability of the power supply, and has a long life.
Satisfying various application requirements
At present, an average of nearly 170 large ships as well as numerous small ships dock in Shanghai port every day. The grid standards used on ships coming from all over the world differ from each other. Many ocean-going vessels have a 440 V/60 Hz 3-phase, 3-wire system, while a 380 V/50 Hz 3-phase, 4-wire system is used in China. Since the wrong power supply can damage marine equipment, the shore power supply system is used to convert shore power to ship power, and to provide power for ships using various grid standards.
The annual import and export trade through Shanghai, in terms of value, accounts for a quarter of China’s total foreign trade. In 2009, the Port of Shanghai ranked the largest in the world in terms of cargo throughput and was the second largest container port.
Shore power supply systems can cut costs considerably. Based on an oil barrel cost of USD 80, the annual savings for a cruise liner can be up to EUR 400,000. If one port includes a shore supply system, the annual savings for a container ship can be up to EUR 150,000, and if 15 % of ports include shore supply system, the annual savings for a container ship can rise to EUR 500,000. In Europe, the ports in Kemi and Oulu in Finland, Gothenburg in Sweden, and Lübeck in Germany have a shore supply system.
Reliable products and outstanding control
A key component in the design of the 2000 kVA shore power supply system at the Port of Shanghai was the Vacon NXP AC drive, featuring coated PCBs, a compact structure and high control performance. In addition, it conforms to ABS and DNV standards.
After the Vacon NXP output is filtered by a sinusoidal filter, a pure, smooth alternating current is supplied to the ship through a special flexible cable reel. To prevent the impact of inductive loads and startup currents, the voltage converter monitors variations in the voltage in real time, and the PID controller compensates for any voltage drop within milliseconds. In addition, the powerful software programming tool Vacon NC61131 also plays an important
Reduced carbon emissions in future
Ships need to burn a large amount of heavy oil or diesel to maintain normal operation while in dock. Data shows that port cities produce 25 % more exhaust emissions than other cities because ships run their generators while in port. For instance, 93.3 tons of harmful substance, such as lead, and 31,000 tons of CO2 are emitted by the large ships in Shanghai port every day.
The 2000 kVA shore power supply system developed jointly by Shanghai port and its partner Wuhan Guide has shown unprecedented technical benefits. Implementing this technology for all the large ships in the ports of the Shanghai Port International Group (SIPG) will eliminate the emissions of at least 33,800 tons of harmful substances and 11,3150 thousand tons of CO2 annually and save 366,000 tons of standard coal. SIPG has filled a gap in the international shipping industry, and in future this technology can be expected to become an international standard.
In the future, moreover, the converter power application derived from the shore power voltage technology will have a more extensive application area, such as the power supply for medium-frequency heating furnaces with 400 Hz medium-frequency AC current, and for temperature rise testing of motors and generators using adjustable frequency and voltage. Compared to conventional devices, it has significant advantages such as a small volume and low noise and costs.
Summary.
Malaysia ports are understudying the demand and practicability to provide shore power supply in its facilities. As mentioned above, the restriction to covert mainland power to ship power and the investments to build the system will be major challenge to ports in Malaysia. Major of ports are operated by private companies which are focusing on the operation efficiency and business development while Port Authorities are less emphasize sustainability in the Port Development Plan. Environment and sustainable development seek integrated plan and implementation from both parties in line with the evolution in Maritime industries and The Government commitment to reduce carbon emission by 2015
Ahmad Mansor Sa
Monday, 28 March 2011
The Star : Renewable energy needs a push
Saturday March 26, 2011
FAST-DEPLETING fossil fuels and rising greenhouse emissions have led to a race among
nations to drive the agenda of renewable energy (RE).
In Malaysia, while the pursuit of renewable resources may pale in comparison to other major
countries, there have been a few strides towards this end.
Just over the week, the country's largest renewable energy park by Cypark Resources Bhd was
launched while a milestone is expected to be marked with the Renewable Energy Act expected
to be passed soon. Public participation has also increased, especially following the near-nuclear
disaster in Japan which has prompted the masses to urge the Government to relook its plans to
introduce nuclear energy in Malaysia.
Energy, Green Technology and Water Ministry's RE/Malaysia Building Integrated Photovoltaic
Technology Application (MBIPV) national project team leader and chief technical adviser Ahmad
Hadri Haris says the RE prospects are bright as Malaysia has resources it can readily tap, such
as solar, biogass, biomass and hydro.
“However, renewable energy needs intervention to grow. It will get a push from the Renewable
Energy Act. With the Act, interested parties can develop renewable energy in a safe and secured
manner as the generation can be sold to Tenaga Nasional Bhd (TNB) over a guaranteed period,”
says Ahmad Hadri.
Essentially, the RE Act will enable individuals/investors to earn income by selling electricity
generated from renewable resources at home to utility companies.
“We expect the second and third reading this month ... the Act will be enforced probably in May
or June, so the feed-in-tariff (FiT) will also come on board then,” says an industry player.
Promoting renewables. Concurrently, the Sustainable Energy Development Authority (Seda) Bill, which is to institute the establishment of Seda Malaysia will also be tabled. Seda will be responsible to spearhead
renewable energy development as well as to manage the FiT programme. A fund will also be
established and administered by Seda. A 1% tariff hike could come about to cover cost
associated with the FiT scheme when it comes into force.
Ahmad says it would be a very minimal impact given that 1% of a RM100 electricity bill would
cost RM1. He says some 56% of the nation would not be impacted as they consume less than
200kwh a month.
Under the FiT, up to 30MW of electricity generated from four renewable sources, solar
photovoltaic, biogas, biomass, and small hydro, are eligible to apply to connect its power
generator to the national grid, and sell the power back to utility companies such as TNB, Syarikat
Sesco Bhd and Sabah Electricity Sdn Bhd.
What it means is that if you have a solar photovoltaic (PV) generator at home, you can apply to
connect this generator to the grid, and get paid for selling the electricity to TNB over an agreed
timeframe.
Ambitious targets
Malaysia plans to achieve 985MW or 5.5% share of renewable energy in the energy mix by
2015. Currently, renewable energy contributes less than 1% to the energy mix in Malaysia. By
2020, the target is for renewable energy to comprise 11% or 2,080MW of overall electricity
generation in the country.
Currently, the country's energy demand is largely met by fossil fuels. OSK Research head Chris
Eng says the passing of Renewable Energy Act would be “crucial” to achieve the Government's
target: “I think key to driving the adoption of renewable energy at the end of the day would be the
act.”
He says the target of 985MW by 2015 and 2GW energy to be sourced from renewable energy
remains tough as currently the electricity generated from green energy is limited.
According to the Energy Commission chairman Tan Sri Ahmad Tajuddin Ali, renewable energy
will be moved out from its portfolio to be managed under Seda once the Act is passed.
He says currently the country is producing some 500MW electricity from renewable energy but
only 50MW is connected to the grid as other are used in-house such as the plantations sector.
Tajuddin says the FiT has to be ready in order to lower the hurdle in investing in renewable
energy project or many project will not kick off as it is not viable economically.
MBIPV's Ahmad believes the target of achieving 11% of overall electricity generated by
renewable energy by 2020 is achievable.“Yes, because the target is very modest in comparison to what has been achieved in other countries (closest to us is Thailand).
International FiT expert and independent energy policy consultant and researcher at the
Environmental Policy Research Centre of Freie Universitat, Berlin, David Jacobs believes the
short-term target of 5.5% is definitely achieveable. He says, however, Malaysia should have a
more ambitious long-term target.“With Malaysia targeting to achieve 25% of total usage of renewable energy by 2050, other countries would be in the 60%-70% range by then.
”Hurdles aplenty Among the challenges faced in this drive towards renewable energy is the lack of understanding as well as the current distortion that exists in power generation cost given the subsidy elements.
In addition, others contend that while Malaysia may appear to be a solar-rich country, effective
sunlight is low, curtailed by the fact that its skies are cloudy. As for wind turbines, others contend
that the wind speed in the country is not strong enough.
Cypark director K.K. Siow does not agree with critics who say that cloud covers make it less
attractive to invest in solar energy. He says the radiance is strong enough, explaining that 10MW
produced in Pajam could supply power to some 40,000 to 50,000 people in the area.
Ahmad is confident these challenges can be overcome: “There are solutions for any problem. We
just need to adopt the correct one for Malaysia ... a technology in Europe may not be suitable in
Malaysia.“For example, the thin-film solar technology is less accepted in Europe, but is proven to be better
in Malaysia's cloudy climate. In Malaysia, we can generate 1.3 times more solar power output
than Germany (the current No. 1 country in the solar market),” he says, adding that the same
applies to wind. “Thus we just need to find the right technology for Malaysian climate.”
Whither electricity prices?
On the impact of the RE Act to end users, most observers contend it would likely be minimal and
not as significant as say, if gas subsidy were to be removed or if coal prices continue to climb.
“The impact from Act is only 1% at the next tariff review. In any case, for this year, the
Government has already allocated a fund to start the Act. In the mid to long term, as the country
uses more than 50% of renewable energy in the mix, Malaysia can better control its energy
imports and would be less affected to price volatility. Thus, we can become more energy
independent,” Ahmad Hadri says.
One of the notable developments in the industry is the opening of a 26ha renewable energy park
in Pajam, Nilai by the Prime Minister Datuk Seri Mohd Najib Razak. Cypark invested RM94.29mil
to build the park with national grid connection on a remediated landfill.
Comprising a 2MW biogas plant and a 8MW solar power facility, the RE Park is expected to
generate RM12.16mil in gross national income in 2020.
The RE Park involves the integration of three potential resources available at the landfills such as
solar, landfill gas and waste into a scalable renewable energy project generating up to 10MW of
power in the Pajam landfill.
Cypark group chief executive officer Daud Ahmad says Pajam landfill is one of the 17 landfills
that the Government has mandated to close down. Cypark will replicate ways of unlocking the
economic value of the land for the remaining 16 landfill sites and it has also proposed to do the
same for another 32 landfills.“With the additional 32 landfills and the existing 17 landfills, producing 100MW is not an issue,”he says.In Cypark case, it uses land (landfills) of no economic value which could not be use for any activity for the next 20 to 30 years. It is basically transforming a tract of land of negative value. “It
is a 100% beneficial from an economic point of view to convert negative-value land to a fullyutilised
land to produce electricity,” Daud says.
OSK's Eng says the current projects are “not particularly lucrative” given the 21 sen per kWh
tarriff for all renewable energy projects but this could change. “While the final tariff rates may still change, based on information published on May 5, 2010, the FiT for solar power generators ranges from RM1.25 to RM1.75 per kWh while that for biogas is from 28 sen-35 sen per kWh. “This would make it much more lucrative to run a solar power and biomass or biogas power plant. Indeed, TNB has announced its own RE plants including a joint venture with Felda Global for a RM120mil fresh fruits bunches biomass plant and feasibility studies for its RM60mil solar power plant,” Eng says.
FAST-DEPLETING fossil fuels and rising greenhouse emissions have led to a race among
nations to drive the agenda of renewable energy (RE).
In Malaysia, while the pursuit of renewable resources may pale in comparison to other major
countries, there have been a few strides towards this end.
Just over the week, the country's largest renewable energy park by Cypark Resources Bhd was
launched while a milestone is expected to be marked with the Renewable Energy Act expected
to be passed soon. Public participation has also increased, especially following the near-nuclear
disaster in Japan which has prompted the masses to urge the Government to relook its plans to
introduce nuclear energy in Malaysia.
Energy, Green Technology and Water Ministry's RE/Malaysia Building Integrated Photovoltaic
Technology Application (MBIPV) national project team leader and chief technical adviser Ahmad
Hadri Haris says the RE prospects are bright as Malaysia has resources it can readily tap, such
as solar, biogass, biomass and hydro.
“However, renewable energy needs intervention to grow. It will get a push from the Renewable
Energy Act. With the Act, interested parties can develop renewable energy in a safe and secured
manner as the generation can be sold to Tenaga Nasional Bhd (TNB) over a guaranteed period,”
says Ahmad Hadri.
Essentially, the RE Act will enable individuals/investors to earn income by selling electricity
generated from renewable resources at home to utility companies.
“We expect the second and third reading this month ... the Act will be enforced probably in May
or June, so the feed-in-tariff (FiT) will also come on board then,” says an industry player.
Promoting renewables. Concurrently, the Sustainable Energy Development Authority (Seda) Bill, which is to institute the establishment of Seda Malaysia will also be tabled. Seda will be responsible to spearhead
renewable energy development as well as to manage the FiT programme. A fund will also be
established and administered by Seda. A 1% tariff hike could come about to cover cost
associated with the FiT scheme when it comes into force.
Ahmad says it would be a very minimal impact given that 1% of a RM100 electricity bill would
cost RM1. He says some 56% of the nation would not be impacted as they consume less than
200kwh a month.
Under the FiT, up to 30MW of electricity generated from four renewable sources, solar
photovoltaic, biogas, biomass, and small hydro, are eligible to apply to connect its power
generator to the national grid, and sell the power back to utility companies such as TNB, Syarikat
Sesco Bhd and Sabah Electricity Sdn Bhd.
What it means is that if you have a solar photovoltaic (PV) generator at home, you can apply to
connect this generator to the grid, and get paid for selling the electricity to TNB over an agreed
timeframe.
Ambitious targets
Malaysia plans to achieve 985MW or 5.5% share of renewable energy in the energy mix by
2015. Currently, renewable energy contributes less than 1% to the energy mix in Malaysia. By
2020, the target is for renewable energy to comprise 11% or 2,080MW of overall electricity
generation in the country.
Currently, the country's energy demand is largely met by fossil fuels. OSK Research head Chris
Eng says the passing of Renewable Energy Act would be “crucial” to achieve the Government's
target: “I think key to driving the adoption of renewable energy at the end of the day would be the
act.”
He says the target of 985MW by 2015 and 2GW energy to be sourced from renewable energy
remains tough as currently the electricity generated from green energy is limited.
According to the Energy Commission chairman Tan Sri Ahmad Tajuddin Ali, renewable energy
will be moved out from its portfolio to be managed under Seda once the Act is passed.
He says currently the country is producing some 500MW electricity from renewable energy but
only 50MW is connected to the grid as other are used in-house such as the plantations sector.
Tajuddin says the FiT has to be ready in order to lower the hurdle in investing in renewable
energy project or many project will not kick off as it is not viable economically.
MBIPV's Ahmad believes the target of achieving 11% of overall electricity generated by
renewable energy by 2020 is achievable.“Yes, because the target is very modest in comparison to what has been achieved in other countries (closest to us is Thailand).
International FiT expert and independent energy policy consultant and researcher at the
Environmental Policy Research Centre of Freie Universitat, Berlin, David Jacobs believes the
short-term target of 5.5% is definitely achieveable. He says, however, Malaysia should have a
more ambitious long-term target.“With Malaysia targeting to achieve 25% of total usage of renewable energy by 2050, other countries would be in the 60%-70% range by then.
”Hurdles aplenty Among the challenges faced in this drive towards renewable energy is the lack of understanding as well as the current distortion that exists in power generation cost given the subsidy elements.
In addition, others contend that while Malaysia may appear to be a solar-rich country, effective
sunlight is low, curtailed by the fact that its skies are cloudy. As for wind turbines, others contend
that the wind speed in the country is not strong enough.
Cypark director K.K. Siow does not agree with critics who say that cloud covers make it less
attractive to invest in solar energy. He says the radiance is strong enough, explaining that 10MW
produced in Pajam could supply power to some 40,000 to 50,000 people in the area.
Ahmad is confident these challenges can be overcome: “There are solutions for any problem. We
just need to adopt the correct one for Malaysia ... a technology in Europe may not be suitable in
Malaysia.“For example, the thin-film solar technology is less accepted in Europe, but is proven to be better
in Malaysia's cloudy climate. In Malaysia, we can generate 1.3 times more solar power output
than Germany (the current No. 1 country in the solar market),” he says, adding that the same
applies to wind. “Thus we just need to find the right technology for Malaysian climate.”
Whither electricity prices?
On the impact of the RE Act to end users, most observers contend it would likely be minimal and
not as significant as say, if gas subsidy were to be removed or if coal prices continue to climb.
“The impact from Act is only 1% at the next tariff review. In any case, for this year, the
Government has already allocated a fund to start the Act. In the mid to long term, as the country
uses more than 50% of renewable energy in the mix, Malaysia can better control its energy
imports and would be less affected to price volatility. Thus, we can become more energy
independent,” Ahmad Hadri says.
One of the notable developments in the industry is the opening of a 26ha renewable energy park
in Pajam, Nilai by the Prime Minister Datuk Seri Mohd Najib Razak. Cypark invested RM94.29mil
to build the park with national grid connection on a remediated landfill.
Comprising a 2MW biogas plant and a 8MW solar power facility, the RE Park is expected to
generate RM12.16mil in gross national income in 2020.
The RE Park involves the integration of three potential resources available at the landfills such as
solar, landfill gas and waste into a scalable renewable energy project generating up to 10MW of
power in the Pajam landfill.
Cypark group chief executive officer Daud Ahmad says Pajam landfill is one of the 17 landfills
that the Government has mandated to close down. Cypark will replicate ways of unlocking the
economic value of the land for the remaining 16 landfill sites and it has also proposed to do the
same for another 32 landfills.“With the additional 32 landfills and the existing 17 landfills, producing 100MW is not an issue,”he says.In Cypark case, it uses land (landfills) of no economic value which could not be use for any activity for the next 20 to 30 years. It is basically transforming a tract of land of negative value. “It
is a 100% beneficial from an economic point of view to convert negative-value land to a fullyutilised
land to produce electricity,” Daud says.
OSK's Eng says the current projects are “not particularly lucrative” given the 21 sen per kWh
tarriff for all renewable energy projects but this could change. “While the final tariff rates may still change, based on information published on May 5, 2010, the FiT for solar power generators ranges from RM1.25 to RM1.75 per kWh while that for biogas is from 28 sen-35 sen per kWh. “This would make it much more lucrative to run a solar power and biomass or biogas power plant. Indeed, TNB has announced its own RE plants including a joint venture with Felda Global for a RM120mil fresh fruits bunches biomass plant and feasibility studies for its RM60mil solar power plant,” Eng says.
By LEONG HUNG YEE
hungyee@thestar.com.my
Tuesday, 8 March 2011
What is Photovoltaic - basic system
Photovoltaics (PV) convert sunlight directly into electricity. Photons in sunlight interact with the outermost electrons of an atom. Photons striking the atoms of a semiconducting solar cell free it's electrons, creating an electric current. The Photovoltaic effect was first discovered in the 19th century, and was used by Bell Labs in 1954 to develop the first PV solar cell. PV found its first applications in space, providing electricity to satellites. These early PV cells were produced in small quantities from exotic materials. While early cells were inefficient, converting less than 1% of the incident sunlight into electricity, they quickly increased to 6% when researchers experimented with crystalline silicon, the principal component of sand.Current conversion efficiencies have surpassed 30% in the laboratory, and 15% in large-scale production.
Two main types of silicon cells vie for market share: crystalline and thin-film. Crystalline silicon cells are produced by slowly extracting large crystals from a liquid silicon bath. These crystals are sliced into 1/100th-of-an-inch thick slices, or "wafers", which are processed into solar cells that are then connected and laminated into solar "modules." While this production process yields highly efficient (10-15%) cells, the production process is expensive. Thin-film silicon cells are produced by depositing vaporized silicon directly onto a glass or stainless steel substrate. While the efficiencies achieved are lower than with crystalline silicon, the production process is less expensive. Modules from crystalline cells have a lifetime of over twenty years. Thin-film modules will last at least ten years. Other PV technologies, such as Gallium-Arsenide or Cadmium Telluride, are also being used. These types are highly efficient, but more expensive at the present time.
PV is measured in units of "peak watts"(Wp). A peak watt figure refers to the power output of the module under "peak sun" conditions, considered to be 1000 Watts per square meter. "Sun hours," or "insolation," refers to how many hours of peak sun, on average, exist in different countries. North America averages 3 to 4 peak sun hours per day in summer while eqatorial regions can reach above 6 peak sunlight hours
Solar Home System:
A standard small SHS can operate several lights, a black-and-white television, a radio or cassette player, and a small fan. A 35 Wp SHS provides enough power for four hours of lighting from four 7W lamps each evening, as well as several hours of television. "System Size" (20, 35, or 50Wp) determines the number of "light-hours" or "TV-hours" available.
Solar Home Systems are 12-volt direct-current (DC) stand-alone systems which use PV to electrify small rural homes. Each SHS includes a PV module, a battery, a charge controller, wiring, fluorescent lights, and outlets for other appliances. Descriptions of the components follow:
Module:
Solar modules for an SHS range between 20-60 Wp. They are mounted on a rooftop or atop a pole. Both crystalline and thin-film technologies are appropriate for an SHS, with price, weight, long-term guarantees and degradation being the determining factors.
Battery:
An electrochemical storage battery is used to store the electricity converted by the solar module. During the day, electricity from the module charges the storage battery. During the evening, the battery is discharged to power lights and other applications. Batteries are typically 12-volt lead-acid batteries, ranging in capacity from 20-100 Amp-Hours (Ah). Batteries are typically sized to provide several days of electricity or "autonomy", in the event that overcast weather prevents recharging.
Deep-cycle batteries are best for an SHS, as they are designed to operate over larger ranges of charge levels. While car batteries are only designed to be discharged 15% of their maximum charge, deep-cycle batteries can be discharged to 70-80% without incurring damage. Both deep-cycle and automotive batteries are typically used, as they are readily available throughout the developing world. Car batteries have a 3-5 year lifetime; deep-cycle, both sealed and unsealed, can last 7-10 years.
Charge Controller:
A charge controller is utilized to control the flow of electricity between the module, battery, and the loads. It prevents battery damage by ensuring that the battery is operating within its normal charge levels. If the charge level in the battery falls below a certain level, a "low voltage disconnect (LVD) will cut the current to the loads, to prevent further discharge. Likewise, it will also cut the current from the module in cases of overcharging. Indicator lights on the controller display the relative state of charge of the battery.
Lights:
Compact fluorescent lightbulbs as well as fluorescent tube lights are used for lighting. An SHS normally includes two to six lights. By utilizing efficient fluorescent lighting, an SHS can provide substantially higher lighting levels than would be possible with incandescent lighting. A 9 watt CFL provides equivalent illumination to a 60 watt incandescent bulb. Compact fluorescent lights have a 5 year lifetime; tubes have much shorter lives, but are cheaper and are more readily available in most developing countries.
Wiring & Mounting:
An SHS also contains additional materials for mounting and connections. Metal frames are included to attach the PV Modules to a pole or roof. SHS components are connected by wires and contain switches for the lights. In some cases, wiring is housed inside conduit attached to interior walls.
Latest Photovoltaic Technology.
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Monday, 7 March 2011
Marine Air Pollution,
Air pollution is a matter of grave concern. The marine industry contributes a large percentage of the total air pollution that is emitted in the world. Marine diesel engines are the main source of toxic pollutants for this. In this article, find out how marine engines cause air pollution.
Green Technology Defination
Nowdays, many peoples say that "green technology" is must in our life and every one eagerly to claim they are developing something in line with methods of "GT". Organizations such private companies also looking for the same which is promoting that they operate the business by deploying Green technology. While public sectors , regulatory bodies and authorities presenting their commitment and involvement towards changes and revolution of green technology.
What is the Green Technology?
The term "technology" refers to the application of knowledge for practical purposes.
The field of "green technology" encompasses a continuously evolving group of methods and materials, from techniques for generating energy to non-toxic cleaning products.
The present expectation is that this field will bring innovation and changes in daily life of similar magnitude to the "information technology" explosion over the last two decades. In these early stages, it is impossible to predict what "green technology" may eventually encompass.
1. Sustainability - meeting the needs of society in ways that can continue indefinitely into the future without damaging or depleting natural resources. In short, meeting present needs without compromising the ability of future generations to meet their own needs.
2. "Cradle to cradle" design - ending the "cradle to grave" cycle of manufactured products, by creating products that can be fully reclaimed or re-used.
3. Source reduction - reducing waste and pollution by changing patterns of production and consumption.
4. Innovation - developing alternatives to technologies - whether fossil fuel or chemical intensive agriculture - that have been demonstrated to damage health and the environment.
5. Viability - creating a center of economic activity around technologies and products that benefit the environment, speeding their implementation and creating new careers that truly protect the planet.
These goals of green technology above to be as a guideline for the selection and the justification to initiate the changes and improvement of our daily things. Innovative, creativity, revolution perspectives and "imagineering" are as tools to move forward the goals. Green technology will go a long way to help peoples with those problems arise due to limited resources and world congestion.
Presently, areas that identified as potential to be developed encompass to the below subjects
i. Energy
Perhaps the most urgent issue for green technology, this includes the development of alternative fuels, new means of generating energy and energy efficiency.
ii. Green building
Green building encompasses everything from the choice of building materials to where a building is located.
iii. Environmentally preferred purchasing
This government innovation involves the search for products whose contents and methods of production have the smallest possible impact on the environment, and mandates that these be the preferred products for government purchasing.
iv. Green chemistry
The invention, design and application of chemical products and processes to reduce or to eliminate the use and generation of hazardous substances.
Green nanotechnology
Nanotechnology involves the manipulation of materials at the scale of the nanometer, one billionth of a meter. Some scientists believe that mastery of this subject is forthcoming that will transform the way that everything in the world is manufactured. "Green nanotechnology" is the application of green chemistry and green engineering principles to this field.
Green Technology from Malaysia Perspectives
Perhaps, understand the goals, components, areas and criteria of Green Technologies, communities may start explore the methods, incorporate the developments and structure the components appropriately to nurture the application in our daily activities.
- Ahmad Mansor Sa
What is the Green Technology?
The term "technology" refers to the application of knowledge for practical purposes.
The field of "green technology" encompasses a continuously evolving group of methods and materials, from techniques for generating energy to non-toxic cleaning products.
The present expectation is that this field will bring innovation and changes in daily life of similar magnitude to the "information technology" explosion over the last two decades. In these early stages, it is impossible to predict what "green technology" may eventually encompass.
The goals that inform developments in this rapidly growing field include:
1. Sustainability - meeting the needs of society in ways that can continue indefinitely into the future without damaging or depleting natural resources. In short, meeting present needs without compromising the ability of future generations to meet their own needs.
2. "Cradle to cradle" design - ending the "cradle to grave" cycle of manufactured products, by creating products that can be fully reclaimed or re-used.
3. Source reduction - reducing waste and pollution by changing patterns of production and consumption.
4. Innovation - developing alternatives to technologies - whether fossil fuel or chemical intensive agriculture - that have been demonstrated to damage health and the environment.
5. Viability - creating a center of economic activity around technologies and products that benefit the environment, speeding their implementation and creating new careers that truly protect the planet.
These goals of green technology above to be as a guideline for the selection and the justification to initiate the changes and improvement of our daily things. Innovative, creativity, revolution perspectives and "imagineering" are as tools to move forward the goals. Green technology will go a long way to help peoples with those problems arise due to limited resources and world congestion.
Presently, areas that identified as potential to be developed encompass to the below subjects
Perhaps the most urgent issue for green technology, this includes the development of alternative fuels, new means of generating energy and energy efficiency.
ii. Green building
Green building encompasses everything from the choice of building materials to where a building is located.
iii. Environmentally preferred purchasing
This government innovation involves the search for products whose contents and methods of production have the smallest possible impact on the environment, and mandates that these be the preferred products for government purchasing.
iv. Green chemistry
The invention, design and application of chemical products and processes to reduce or to eliminate the use and generation of hazardous substances.
Green nanotechnology
Nanotechnology involves the manipulation of materials at the scale of the nanometer, one billionth of a meter. Some scientists believe that mastery of this subject is forthcoming that will transform the way that everything in the world is manufactured. "Green nanotechnology" is the application of green chemistry and green engineering principles to this field.
Green Technology from Malaysia Perspectives
Definition
Green Technology is the development and application of products, equipment and systems used to conserve the natural environment and resources, which minimize and reduces the negative impact of human activities.
Green Technology refers to products, equipment or systems which satisfy the following criterias;
* It minimizes the degradation of the environment.
** It has zero or low green house gas (GHG) emissioIt is safe for use and promotes healthy and improved environment for all forms of life.
***It conserves the use of energy and natural resources; and
**** It promotes the use of renewable resources.
Four Pillars Of Green Technology Policies (as announced by PM upon 1st Council)
Energy - Seek to attain energy independence and promote efficient utilization;
Environment - Conserve and minimize the impact on the environment;
Economy - Enhance the national economic development through the use of technology; and
Social - Improve the quality of life for all.
Perhaps, understand the goals, components, areas and criteria of Green Technologies, communities may start explore the methods, incorporate the developments and structure the components appropriately to nurture the application in our daily activities.
- Ahmad Mansor Sa
Saturday, 5 March 2011
Marine Pollution from Ship's Ballast Water
Discharge of ship ballast water results in serious marine pollution that disturbs the marine ecosystem, harms marine species and endangers human health. Marine pollution from ship ballast water is one of the greatest threats to ocean life. With the rapid increase in marine pollution, the International Maritime Organization (IMO) has framed special regulations to monitor the quality of ballast water discarded from ships around the world. Unlike other sources of marine pollution, ballast water pollution does not pose a grave threat to humans, but is still a serious ecological and health issue for marine plants and animals. The effects of marine pollution from ship’s ballast water on marine life are long lasting and difficult to control.
The ship then travels to some other part of the world and discharges its ballast during cargo loading or unloading. In this way, aquatic species such as fishes, bacteria, micro-algae, and aquatic plants and animals in different life cycle stages are transported from one water region to another. When this happens, either the marine organisms that are transferred with the ballast water or the ones living in the region where the ballast is discharged become vulnerable as a result of introduction of alien species.
Introduced invasive organisms can take over areas already occupied by other species, leading to eradication of the endemic species. They can also spread diseases, or introduce new genetic materials which not only induce mutation in native marine organisms but also jeopardize their natural abilities.
Apart from introducing invasive species, ballast water from ships is responsible for sea water pollution. The ship ballast tanks are often rusted from inside which ultimately leads to contamination of the sea water taken in as ballast. Sometimes leakage of bilge or from an oil line can also lead to discharge of oil and other impurities into the ballast water making it impure. If oil is discharged with the ballast water it can cause severe harm to marine plants and animals and also to human life in coastal regions.
Ballast tanks are also coated with paints made of toxic chemicals which, on contact with water, release poisonous substances that can disturb the growth of marine organisms by altering their hormonal cycle. Effects include birth defects, damaged immune systems, and genetic disorders. If these diseased organisms get into the human food chain in seafood, they can cause adverse health conditions and even fatal diseases.
Thus, though marine pollution by ballast water might account for only a small percentage of the global pollution that can affect humans, it still poses a serious threat to the marine organisms and the ecosystem as a whole.
Ship Ballast Water Affecting Marine Life
Ballast water is carried by ships in their dedicated ballast tanks to ensure stability and balance. An unloaded ship is subjected to heavy rolling and pitching and thus requires more ballast, which provides, in return, balance and structural integrity. When a ship takes in ballast from one region, it not only takes in sea water but also native marine organisms as well.The ship then travels to some other part of the world and discharges its ballast during cargo loading or unloading. In this way, aquatic species such as fishes, bacteria, micro-algae, and aquatic plants and animals in different life cycle stages are transported from one water region to another. When this happens, either the marine organisms that are transferred with the ballast water or the ones living in the region where the ballast is discharged become vulnerable as a result of introduction of alien species.
Introduced invasive organisms can take over areas already occupied by other species, leading to eradication of the endemic species. They can also spread diseases, or introduce new genetic materials which not only induce mutation in native marine organisms but also jeopardize their natural abilities.
Ship Ballast Water Affecting Human Life
Some species introduced to new places in ballast water contaminate filter feeding shellfish, making them toxic and inedible. Consumption of these contaminated shellfish by humans can cause severe health problems and even death. Moreover, harmful microorganisms of various types can become more virulent as a result of contact with other organisms in ballast water.Apart from introducing invasive species, ballast water from ships is responsible for sea water pollution. The ship ballast tanks are often rusted from inside which ultimately leads to contamination of the sea water taken in as ballast. Sometimes leakage of bilge or from an oil line can also lead to discharge of oil and other impurities into the ballast water making it impure. If oil is discharged with the ballast water it can cause severe harm to marine plants and animals and also to human life in coastal regions.
Ballast tanks are also coated with paints made of toxic chemicals which, on contact with water, release poisonous substances that can disturb the growth of marine organisms by altering their hormonal cycle. Effects include birth defects, damaged immune systems, and genetic disorders. If these diseased organisms get into the human food chain in seafood, they can cause adverse health conditions and even fatal diseases.
Thus, though marine pollution by ballast water might account for only a small percentage of the global pollution that can affect humans, it still poses a serious threat to the marine organisms and the ecosystem as a whole.
References
Dobbs, Fred C. and Andrew Rogerson. June, 2005 "Ridding Ships' Ballast Water of Microorganisms." Environmental Science and Technology. Pubs.acs.org, Accessed July 16 2010
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