Ron Wagner + 702 November 8, 2023 https://www.newscientist.com/article/2401171-ocean-heat-could-supply-essentially-endless-clean-energy-to-islands/ Ocean heat could supply essentially endless clean energy to islands An old idea to use ocean heat to generate clean electricity has long failed to gain traction, but the technology – known as ocean thermal energy conversion (OTEC) – is seeing a resurgence of interest from islands dependent on fossil fuels By James Dinneen 7 November 2023 An artist’s impression of Global OTEC’s planned power system Global Otec A 140-year-old idea to exploit the temperature differences between layers of the ocean is gaining new interest as a way to provide clean power for people living on islands. Called ocean thermal energy conversion (OTEC), the idea is to use surface water warmed by the sun to heat a fluid such as ammonia or water, which then spins a turbine as it evaporates, just like a power plant driven by steam. Cold water from deeper layers of the ocean would then be piped up to cool the fluid and repeat the cycle. Theoretically, oceans could provide vast amounts of energy in this way. Researchers estimate that there is enough ocean heat to supply 7000 gigawatts of power a year without affecting the ocean’s circulation, enough to easily supply the entire world’s annual electricity demand – if we can access it. Advertisement The idea was first proposed in 1881, but went largely unexplored until the 1970s oil crisis drove a search for new sources of energy. A few demonstration projects were built at the time, then the 2000s again brought some interest — including an effort to design bigger pipes for large-scale plants. But progress has largely been “disappointing”, says Al Binger at SIDS DOCK, an organisation that promotes clean energy development in small island countries. Now, the fresh urgency to transition away from fossil fuels, plus some technological advances in offshore energy, have brought hints of an OTEC resurgence. “It’s the most promising it’s been in many decades,” says Andrea Copping at the Pacific Northwest National Laboratory in Washington. A small OTEC plant has been supplying energy to the grid in Hawaii since 2015, and another has been running in Okinawa, Japan, since 2016. In 2019, a Korean company tested an OTEC system planned to be installed on the Pacific island of Kiribati. And Chinese researchers recently tested a small, ship-based system in the South China Sea. Sign up to our Fix the Planet newsletter Get a dose of climate optimism delivered straight to your inbox every month. Sign up to newsletter These are all tiny projects, but Gérard Nihous at the University of Hawai’i at Mānoa says any demonstration that the technology works could help get past a “psychological barrier” to investing in OTEC after past flops. “What’s lacking is operational record and visibility.” Read more Ash from wildfires may fuel the growth of plankton in the ocean If UK-based company Global OTEC has its way, a demonstration of commercial viability could come soon. The firm has designed a 1.5-megawatt floating system, which is planned to supply power to the islands of São Tomé and Príncipe off the coast of West Africa by 2026. The company has been in talks with other interested island governments, such as Fiji. “This isn’t just a bunch of guys tinkering around in a garage,” says Dan Grech, the company’s CEO. Tropical islands in particular are strong candidates for OTEC because of current high energy costs – diesel generators are common there – and the presence of deep cold water not far from shore, says James VanZwieten at Florida Atlantic University. Islands also have less space for other types of renewables and fewer options for sources of continuous power, such as a natural gas power plant. A diagram explaining the principle behind ocean thermal energy conversion Global Otec “[With OTEC] we keep our ecosystems, we keep our land and we keep our water resources,” says Binger, who is working with Global OTEC to promote this form of energy. In addition to generating electricity, he says the systems could be used to desalinate seawater and produce hydrogen fuel. A major barrier for past projects was the cost of installing kilometres of large-diameter pipes to reach deep water. Global OTEC’s design aims to avoid that problem by extending a shorter pipe from a platform floating in deep water 10 kilometres offshore, then transmitting electricity back via a cable. Grech says advances in offshore wind and in oil and gas technology have already done some of the “heavy lifting” to improve designs. “OTEC will be part of providing an equitable energy transition so these places aren’t depending on diesel imports from the richest petrol states in the world,” he says. Topics: Climate Change/ Oceans/ Energy/ Hydrogen Advertisement Quote Share this post Link to post Share on other sites
notsonice + 1,254 DM November 8, 2023 1 hour ago, Ron Wagner said: https://www.newscientist.com/article/2401171-ocean-heat-could-supply-essentially-endless-clean-energy-to-islands/ Ocean heat could supply essentially endless clean energy to islands An old idea to use ocean heat to generate clean electricity has long failed to gain traction, but the technology – known as ocean thermal energy conversion (OTEC) – is seeing a resurgence of interest from islands dependent on fossil fuels By James Dinneen 7 November 2023 An artist’s impression of Global OTEC’s planned power system Global Otec A 140-year-old idea to exploit the temperature differences between layers of the ocean is gaining new interest as a way to provide clean power for people living on islands. Called ocean thermal energy conversion (OTEC), the idea is to use surface water warmed by the sun to heat a fluid such as ammonia or water, which then spins a turbine as it evaporates, just like a power plant driven by steam. Cold water from deeper layers of the ocean would then be piped up to cool the fluid and repeat the cycle. Theoretically, oceans could provide vast amounts of energy in this way. Researchers estimate that there is enough ocean heat to supply 7000 gigawatts of power a year without affecting the ocean’s circulation, enough to easily supply the entire world’s annual electricity demand – if we can access it. Advertisement The idea was first proposed in 1881, but went largely unexplored until the 1970s oil crisis drove a search for new sources of energy. A few demonstration projects were built at the time, then the 2000s again brought some interest — including an effort to design bigger pipes for large-scale plants. But progress has largely been “disappointing”, says Al Binger at SIDS DOCK, an organisation that promotes clean energy development in small island countries. Now, the fresh urgency to transition away from fossil fuels, plus some technological advances in offshore energy, have brought hints of an OTEC resurgence. “It’s the most promising it’s been in many decades,” says Andrea Copping at the Pacific Northwest National Laboratory in Washington. A small OTEC plant has been supplying energy to the grid in Hawaii since 2015, and another has been running in Okinawa, Japan, since 2016. In 2019, a Korean company tested an OTEC system planned to be installed on the Pacific island of Kiribati. And Chinese researchers recently tested a small, ship-based system in the South China Sea. Sign up to our Fix the Planet newsletter Get a dose of climate optimism delivered straight to your inbox every month. Sign up to newsletter These are all tiny projects, but Gérard Nihous at the University of Hawai’i at Mānoa says any demonstration that the technology works could help get past a “psychological barrier” to investing in OTEC after past flops. “What’s lacking is operational record and visibility.” Read more Ash from wildfires may fuel the growth of plankton in the ocean If UK-based company Global OTEC has its way, a demonstration of commercial viability could come soon. The firm has designed a 1.5-megawatt floating system, which is planned to supply power to the islands of São Tomé and Príncipe off the coast of West Africa by 2026. The company has been in talks with other interested island governments, such as Fiji. “This isn’t just a bunch of guys tinkering around in a garage,” says Dan Grech, the company’s CEO. Tropical islands in particular are strong candidates for OTEC because of current high energy costs – diesel generators are common there – and the presence of deep cold water not far from shore, says James VanZwieten at Florida Atlantic University. Islands also have less space for other types of renewables and fewer options for sources of continuous power, such as a natural gas power plant. A diagram explaining the principle behind ocean thermal energy conversion Global Otec “[With OTEC] we keep our ecosystems, we keep our land and we keep our water resources,” says Binger, who is working with Global OTEC to promote this form of energy. In addition to generating electricity, he says the systems could be used to desalinate seawater and produce hydrogen fuel. A major barrier for past projects was the cost of installing kilometres of large-diameter pipes to reach deep water. Global OTEC’s design aims to avoid that problem by extending a shorter pipe from a platform floating in deep water 10 kilometres offshore, then transmitting electricity back via a cable. Grech says advances in offshore wind and in oil and gas technology have already done some of the “heavy lifting” to improve designs. “OTEC will be part of providing an equitable energy transition so these places aren’t depending on diesel imports from the richest petrol states in the world,” he says. Topics: Climate Change/ Oceans/ Energy/ Hydrogen Advertisement it is possible to actually gain some electricity......however the cost of building the mouse trap is not competitive with building a solar farm and using battery storage......remember your mouse trap has a lot of energy losses in the pumps as you have to move alot of fluid..... your mouse trap is another angle on heat pumps.....and heat pumps do not run without energy inputs ie in winter when it is below zero and the ground water at 1000 feet below the surface is at 20 degrees C try making electricity using your system......in theory you should generate power however in reality you do not......because those pesky pumps consume a lot more power than what you generate the engineering principle of KISS applies 1 Quote Share this post Link to post Share on other sites
footeab@yahoo.com + 2,187 November 9, 2023 3 hours ago, notsonice said: .and heat pumps do not run without energy inputs ie in winter when it is below zero and the ground water at 1000 feet below the surface is at 20 degrees C try making electricity using your system......in theory you should generate power however in reality you do not......because those pesky pumps consume a lot more power than what you generate Heat pumps as electric generators works just fine, The problem with GROUND based heat pumps as electrical generators is VOLUME of water is miniscule and DRAG caused by TINY pipes. Also Linear with Temperature and heat exchanger size. Why Ground based power Generators go for high temp ground water as extracting the water without horrid other substances is the problem, not the temperature. OTEC on the other hand could use pipes made out of nothing but hanging plastic and could literally be 100m in diameter dropping drag and pressure differential to near zero making the pump efficiency(assuming a closed loop) would be next to zero other than the ground based heat exchanger and it is the ground based heat exchanger which is where the $$$ is. Quote Share this post Link to post Share on other sites
notsonice + 1,254 DM November 9, 2023 Heat pumps as electric generators works just fine????? please post the links to these magical heat pumps that act as electric generators..... I bet you flunked your thermodynamics course during your undergrad studies....... 1 Quote Share this post Link to post Share on other sites
footeab@yahoo.com + 2,187 November 9, 2023 19 minutes ago, notsonice said: Heat pumps as electric generators works just fine????? please post the links to these magical heat pumps that act as electric generators..... I bet you flunked your thermodynamics course during your undergrad studies....... One day you will actually take an engineering course. Suggest you actually understand what a pump is... Can use straight thermopile in a very inefficient manner, or more common is stirling engine after the use of a Heat exchanger to evaporate a fluid achieving a gas instead of a liquid. A poor choice, but cheap is a turbine. Your refrigerator could run on a turbine but it would be stupid to do so and horrifically inefficient. Here ends your schooling dear bitter child. One day you will mature into a functioning adult. We hope that day comes soon. Quote Share this post Link to post Share on other sites
notsonice + 1,254 DM November 9, 2023 Just now, footeab@yahoo.com said: One day you will actually take an engineering course. Suggest you actually understand what a pump is... Can use straight thermopile in a very inefficient manner, or more common is stirling engine after the use of a Heat exchanger to evaporate a fluid achieving a gas instead of a liquid. A poor choice, but cheap is a turbine. Your refrigerator could run on a turbine but it would be stupid to do so and horrifically inefficient. Here ends your schooling dear bitter child. One day you will mature into a functioning adult. We hope that day comes soon. ha ha ha you still can not post an example of one these magical heat pumps that act as electric generators...who makes them????? did you flunk thermo??? I bet you did..... Heat pumps as electric generators works just fine...what a fucking joke......... Quote Share this post Link to post Share on other sites
footeab@yahoo.com + 2,187 November 9, 2023 21 minutes ago, notsonice said: ha ha ha you still can not post an example of one these magical heat pumps that act as electric generators...who makes them????? did you flunk thermo??? I bet you did..... Heat pumps as electric generators works just fine...what a fucking joke......... 🤡🤡 --> In case you can't count as you failed preschool, you have now clowned yourself twice in a row... can you go for a 3rd time? Quote Share this post Link to post Share on other sites
TailingsPond + 768 GE November 9, 2023 If you have a heat source and a cold sink you can make power but you need a significant difference in temperature to make it reasonable. Their example figure shows only 3 degrees difference between the hot input (27C) and the warm output (24C). It is going to be tough to get much power from a small differential. Compare and contrast to a combustion based turbine where there a huge temp diff. Quote Share this post Link to post Share on other sites
notsonice + 1,254 DM November 9, 2023 (edited) 1 hour ago, footeab@yahoo.com said: 🤡🤡 --> In case you can't count as you failed preschool, you have now clowned yourself twice in a row... can you go for a 3rd time? still you post no examples.......... as usual because they do not exist........ your babbling BS about preschool shows you are just an incompetent fool Heat pumps as electric generators works just fine...you should have deleted your posting of your gibberish comment Now tell me where are these power plants based on Heat pumps as electric generators?????are they working fine????? GW's of capacity????? how about MWs of capacity....ok I will let you show us all one that has one KW of capacity......where is this one........working fine....making their investors tons of cash??? the solution to the worlds energy problems?????? As I stated earlier KISS and KISS these days is solar panels coupled with battery storage. Now do you need examples of these?????? World installs to date of solar panels is over 1300 GW now compare that to your Heat pumps working as electric generators....I will let you post your chart of these so called heat pumps working as electric generators Edited November 9, 2023 by notsonice 1 Quote Share this post Link to post Share on other sites
footeab@yahoo.com + 2,187 November 10, 2023 Ah, you did 🤡 yourself again a 3rd time. Bravo. One day you will learn to read/think. Quote Share this post Link to post Share on other sites
Rob Plant + 2,755 RP November 10, 2023 4 hours ago, footeab@yahoo.com said: Ah, you did 🤡 yourself again a 3rd time. Bravo. One day you will learn to read/think. Its you who looks the clown as all you can do is name call, you cant provide ANY evidence to back up your claim and Notsonice has outed you for the charlatan you are. Quote Share this post Link to post Share on other sites
footeab@yahoo.com + 2,187 November 10, 2023 7 hours ago, Rob Plant said: Its you who looks the clown as all you can do is name call, you cant provide ANY evidence to back up your claim and Notsonice has outed you for the charlatan you are. Ah, you are joining the 🤡 fiesta... What is the first post? Give you hint: its posted by Ron... Topic is OTEC... What were the caveats I gave for why land based heat pumps don't work? Hrmm? 🤡 Quote Share this post Link to post Share on other sites
Rob Plant + 2,755 RP November 10, 2023 Where are these mythical heat pumps that act as electric generators as you claim? 🤡 Go ahead show us all where they are installed and perform this function, youve been asked several times already but keep dodging the question and just post clown faces, which clearly are your own. keep it up its really entertaining Quote Share this post Link to post Share on other sites
Ron Wagner + 702 November 10, 2023 Gentlemen, the topic was meant to engender communication not a vendetta. We can gain from both of your expertise rather than feuding. Reminder the article was about ocean use, not land use. Can you please address that? Quote Share this post Link to post Share on other sites
James Pipe 0 November 27, 2023 On 11/8/2023 at 3:42 PM, notsonice said: heat pumps do not run without energy inputs ie in winter The new capacitor based heat pumps can work even in frigid winter. 1 Quote Share this post Link to post Share on other sites
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