Ocean Thermal Energy Conversion Market

Oceans are the world’s largest solar-energy collector and energy-storage system since they cover more than 70% of the earth’s surface. The ocean's upper layers absorb the sun's irradiation and store it as thermal energy. Ocean thermal energy conversion (OTEC) utilizes the temperature difference between the upper and the lower surface of waters to generate power in a conventional heat engine. For vertical distances of as low as 90 meters, can record temperature differences of as high as 50°C. The temperature difference between the colder deepsea layers (at 800 to 1 000 meters depth) and the warm surface is converted through a thermal cycle into electricity, heat, or cold in a heat cycle. These conversion cycles function if a temperature difference of 20°C is maintained. Since deep sea water temperature is constant at 4°C at 1 000 meters depth, the surface water temperature must be around 25 °C for OTEC to occur. One of the main drivers of the OTEC is the ability to produce non-intermittent electricity along with providing cooling without electricity consumption

Although OTEC plants exhibit a very low Carnot cycle efficiency (7%), they offer a capacity factor of 90%-95%, one of the highest amongst all power generation technologies. OTEC has the most significant potential compared to other ocean energy technologies standing at 44,000 TWh per year of steady-state power. Favorable OTEC conditions are present in the tropical belt between 30 degrees north and 30 degrees south latitudes. This technology is the most economically viable for remote island states and island countries in tropical seas. OTEC can be coupled with seawater air conditioning (SWAC) to provide cooling and seawater reverse osmosis (SWRO) to produce fresh water, and the wastewater of the electricity generation can be repurposed for aquaculture use.

Based on technology, the OTEC market has been categorized into closed-cycle, open-cycle, and hybrid-cycle power plants. In a closed cycle system, low boiling point fluid like ammonia is utilized to rotate a turbine coupled to an electric generator. The low boiling point fluid is vaporized when warm seawater is pumped through a heat exchanger. This process involves the rotation of the turbo-generator by the expanding vapor. A second heat exchanger condenses the vapor back into liquid when cold deep water is pumped through it. This liquid is recycled in the closed cycled process. An open-cycle OTEC power plant generates electricity via the ocean's warm surface. Warm seawater boils when placed in a low-pressure container, and the expanding steam drives a low-pressure turbine coupled to an electric generator. Since the steam leaves behind the salt & contaminants in the low-pressure container, it is now pure fresh water. Thus steam is condensed back into a liquid by exposure to cold temperatures from deep-ocean water. Therefore, desalinated fresh water suitable for irrigation or drinking purposes is attained from this method. Hybrid-cycle combines open and closed cycles where the steam generated by flash evaporation is then used as heat to drive a closed cycle.

Based on location, the OTEC market is segmented into land-based, shelf based, and floating. The OTEC power plants near shore do not require lengthy power cables, sophisticated mooring, or expensive maintenance. Land based OTEC plants also support the mariculture industry, and since they can be built inland from the shore, they offer more protection from the storm. Shelf based OTEC plants can be mounted to the continental shelf at depths up to 100 meters. They can be built in a shipyard, towed to the site, and fixed to the bottom of the sea. However, challenges associated with this location are more difficult product delivery & higher costs. Floating OTEC facilities are preferred for systems with a large power capacity. These OTEC plants are more susceptible to damage, especially during storms.

Based on application, the OTEC market is segmented into power generation, desalination, and others. Others include refrigeration & air conditioning, and mineral extraction. Power generation is the most popular OTEC application. Expanding the working fluid in the OTEC plant spins a turbine coupled with a generator to produce electricity. Desalinated water can be generated in an OTEC plant by using surface condensers. An OTEC plant generating 2-MW of net electricity could produce about 4,300 cubic meters of desalinated water daily.

The global ocean thermal energy conversion market can be segmented into North America, Europe, Asia Pacific, and the Rest of the World. South Korea runs a successful 20 KW OTEC plant which can operate in the summer months. Since the South Pacific has better year-round conditions for operating an OTEC plant, the Korea Institute of Ships and Ocean Engineering (KRISO) is developing a 1 MW plant in Kiribati. The Ministry of Oceans and Fisheries of the Republic of Korea has funded this project and has the potential to contribute to increasing Kiribati’s share of renewables by 26% by 2025. This is expected to drive the market in the Asia Pacific. In October 2019, the Ministry of New and Renewable Energy of India officially declared ocean energy as a renewable energy source under the Renewable Purchase Obligations (RPO). The National Institute of Ocean Technology (NIOT), the leading OTEC institute in India with an OTEC test lab and multiple operating low-temperature thermal desalination (LTTD) plants, is expected to act upon these policy developments will spur market growth.

The major players operating in the OTEC energy market include Ocean Thermal Energy Corporation (US), Makai Ocean Engineering, Inc (Hawaii), Yokogawa India, Ltd (India), Xenesys Inc (Japan), TransPacific Energy, Inc (US), and Global OTEC (UK).

Frequently Asked Questions (FAQ)

Q1. What is the current market size of the global OTEC market?
Q2. What are the challenges associated with the OTEC market?
Q3. What are the international standards which are regulating the OTEC market?
Q4. Who are the top five players in the global OTEC market?
Q5. What revolutionary technology trends could be witnessed over the next five to ten years?
Q6. How are the companies implementing organic and inorganic strategies to gain increased OTEC market share?
Q7. Which will be the leading regions with the largest market share by 2030?
Q8. What will be the revenue pockets for the OTEC market in the next five to ten years?
Q9. Which technology segment will have the maximum growth opportunity during the forecast period?
Q10. Which region held the highest market share in OTEC?
Q11. What is a key factor driving the market of the OTEC market?
Q12. Which location is leading the market of OTEC during the forecast period?