Designing a “green” power alternative for the tropics
Sea Solar Power
Solid Edge facilitates the design optimization needed to make ocean solar power profitable
Power from the sun, via the sea
Sea Solar Power Inc. has designed an economically efficient system for generating electricity from the solar energy in tropical oceans. The system is based on a proven technology called ocean thermal energy conversion (OTEC), which takes advantage of the temperature difference between the solar-heated surface water and the cold bottom water, using the warm surface water as the heat source and the cold bottom water as the heat sink.
“The OTEC concept has been around for more than 100 years,” says James Anderson, III, vice president of Sea Solar Power. “The tricky part is making it affordable and profitable.” In designing its OTEC system, which above the water resembles an offshore oil platform, Sea Solar Power is using the Solid Edge® design solution from Siemens PLM Software to hold down development costs and make the system as cost-effective to operate as possible.
Designing a green alternative
The need for additional power generation capacity is a given, but how we will get it is not. Sea Solar Power’s contribution is to offer a green alternative that not only creates electricity but can also desalinate water. “During the next 20 years, experts foresee a need for 1,500 gigawatts of additional power to meet new demand,” says Anderson. “This equates to 15,000 power plants of 100 megawatts each and 59 million barrels of oil consumed each day, and would mean enormous quantities of fossil fuel and 2.2 billion tons of carbon dioxide released to the atmosphere each year.”
OTEC is a non-polluting alternative that will work only in tropical seas, but that would still make it available to millions of people, particularly those in developing nations where energy demand is soaring. What has held OTEC back so far is the initial investment. An OTEC platform costs hundreds of millions of dollars to build, which is where Sea Solar Power comes in. With its own design for an OTEC system that focuses on the optimization of every component, Sea Solar Power is hoping to turn a good idea into a reality. “If we’re going to commercialize this technology, we have to design less plant that makes more power,” Anderson notes.
To achieve this, the company’s engineers are using Solid Edge to design (or redesign in some cases) every aspect of the system, from the smallest components to the largest turbines, looking for opportunities to remove excess weight and enhance performance. “We could buy a turbine that was already designed for another purpose, which would work well, but not as well as one we design for our specific working fluids and pressures,” explains Anderson. “It’s this kind of design effort that’s enabling us to drive down the cost of the system.”
3D’s many advantages
The company actually began designing the OTEC system with a 2D CAD program but gave that up when the design got too complex to see how everything would fit together. They upgraded to 3D solid modeling, choosing Solid Edge over the competition because it was easier to use than other programs yet had all the functionality they needed, including the ability to create an assembly model of the entire system. Another point in Solid Edge’s favor was the good support available from the local reseller, Solid Technologies and Siemens PLM Software.
The superior visualization provided by 3D “was a huge difference,” says Anderson. “It lets us check how parts fit together, and it’s easy to know right away if you’ve done things correctly. We look at assemblies from all sides and create animations to find interferences. Solid Edge makes it easy to visualize the process of building the system to know if it can actually be built.” The company also uses the Solid Edge models in its marketing material. “Because they look so real, they make the OTEC concept understandable,” he adds.
Solid Edge helps the company in the critical work of optimizing the OTEC system in several ways. First, its ease of use allows engineers to try out multiple design iterations. “That’s the biggest advantage,” says Anderson. “It’s unbelievably fast and cheap to keep making design changes in search of an optimal solution.” Second, the Solid Edge data forms the basis for subsequent performance simulations using finite element analysis (FEA) and computational fluid dynamics (CFD) analysis. “With FEA and CFD, we know very quickly if something we’ve designed will actually work,” Anderson adds. For example, FEA can simulate a part under stress in minutes and let engineers know if there’s excess material that can safely be removed. CFD is used on turbine and compressor designs to see if the desired velocities and pressures are achieved. “Years ago, this would have taken weeks or months of testing and a lot of engineers,” he adds. “Now we can do it in a matter of hours.”
Designing the OTEC system with Solid Edge is allowing Sea Solar Power to minimize material needs and costs while maximizing the efficiency of the system. It is also helping lower development costs. “You could do what we’re doing without Solid Edge, but it would require many more engineers,” says Anderson. In these ways, Solid Edge is helping make this green source of energy a viable alternative for the future.