What is ocean gradient energy?
Ocean Thermal Energy Conversion (OTEC) is a renewable energy technology that uses the natural temperature difference in oceans to produce clean, reliable electricity, day and night, year-round.
What is ocean thermal energy used for?
Ocean Thermal Energy Conversion (OTEC) is a process that can produce electricity by using the temperature difference between deep cold ocean water and warm tropical surface waters. OTEC plants pump large quantities of deep cold seawater and surface seawater to run a power cycle and produce electricity.
What causes ocean thermal energy?
There is a difference of temperature between water at the surface of ocean and at depper level. Ocean thermal energy is due to this temperature difference.
Is Ocean Thermal Energy reliable?
The pros are OTEC is fuel free, has a low environmental impact, can supply pure water for both drinking and agriculture, can supply refrigeration and cooling and can provide a coastal community with reliable energy. [1] The cons are that OTEC is economically expensive, and it only works in a few regions of the world.
What are the advantages and disadvantages of ocean thermal energy?
Comparison Table for Advantages and Disadvantages of Ocean Thermal Energy
| Advantages | Disadvantages |
|---|---|
| It creates electricity without the discharge of greenhouse gases. | A constant supply of cold and warm water is needed. So the plant can be built in only appropriate for tropical areas. |
Why is ammonia used in ocean thermal energy?
In a closed cycle OTEC system, water flows through a large pipe and heat exchanger, which heats a liquid with a low boiling point, such as ammonia. As the boiling ammonia creates steam, it turns a turbine generator to produce electricity.
What is the cost of ocean energy?
The World Renewable Energy Report estimates the cost of wave energy at an average of 9 cents/kWh and tidal and current an average of 8 cents/kWh. Recent EPRI reports have found that, presently, the cost of power from ocean technologies ranges from 7 cents to 16 cents/kw in a low case scenario.
What are the disadvantages of ocean thermal energy?
Disadvantages of OTEC system
- Capital investment is very high.
- Conversion efficiency is very low about 3-4% due to small temperature difference in between the surface water and deep water.
- Low efficiency of these plants coupled with high capital cost and maintenance cost makes them uneconomical for small plants.
Why ocean thermal energy is not possible?
Upwelling of cold water from the deep ocean is replenished by the downwelling of cold surface sea water. The resource potential for OTEC is considered to be much larger than for other ocean energy forms. Up to 88,000 TWh/yr of power could be generated from OTEC without affecting the ocean’s thermal structure.
What are the disadvantages of ocean?
Disadvantages – Sometimes there will not be a lot of waves (which means no energy), It could interfere with ocean ecosystems in the area of the currents, and the temperature is raised wherever ocean currents are happening (which could also ruin an ecosystem).
What is a disadvantage of ocean thermal energy?
Disadvantages of OTEC Electricity produced from OTEC would currently cost more than that produced from fossil fuels. Discharging of cold and warm sea water needs to be carried out several metres away from the shore to avoid any dwelling impact on marine ecosystems.
How does OTEC works in real life?
An OTEC power plant works by pulling in warm ocean surface water and this is used to heat a ‘working fluid’ such as ammonia or propane into a gas. These fluids have a low boiling temperature, which when turned into gas, moves the steam into pressurised shafts that are then used to drive turbines.
How is the thermal gradient used in OTEC?
OTEC uses the ocean’s warm surface water with a temperature of around 25°C to vaporize a working fluid, which has a low-boiling point, such as ammonia. The vapor expands and spins a turbine coupled to a generator to produce electricity.
How is electricity produced in a thermal gradient?
The vapor expands and spins a turbine coupled to a generator to produce electricity. The vapour is then cooled by seawater that has been pumped from the deeper ocean layer, where the temperature is about 5°C. That condenses the working fluid back into a liquid, so it can be reused. This is a continuous electricity generating cycle.
What is minimum temperature difference for ocean thermal energy conversion?
Ocean Thermal Energy Conversion (OTEC) is a method that employs naturally occurring temperature differences between warm surface water and colder deep seawater (Thomas, 1993). To be effective a minimum temperature difference between the ocean surface layers is 20oC .
How does ocean thermal energy conversion ( OTEC ) work?
Ocean Thermal Energy Conversion (OTEC) is a renewable energy technology that uses the natural temperature difference in oceans to produce clean, reliable electricity, day and night, year-round. The heat from the warm ocean surface and cold from the deep ocean drives a Rankine Cycle, which produces electricity.
