Engineering Headlines

Mini Turbine Supply 10,000 Households with Electricity

A new type of turbine is very small and extremely effective. The turbine, which was developed by General Electric in the Research Department, runs with heated CO2 in a closed circuit. Differently than steam turbines she is ready to go in just a few minutes.

This new turbine fits easily on a desktop and has further convincing advantages in addition to their compact format. The highly efficient turbine GE global research is with highly heated carbon dioxide operated so-called over or supercritical CO2 instead of water vapor. She provide enough electricity for 10,000 homes, developers say the turbine is necessary step in power production.

Super critical CO2 = between liquid and gaseous state

Still, Doug Hofer, who global research in Albany, New York leads GE’s turbine project as an engineer, holds a prototype in the hands. It is made of lightweight plastic and comes out of the 3D printer. Later, the real turbine would made of metal, would still have a light weight but with just under 70 kg among their peers.

Mini Turbine Supply 10,000 Households with Electricity
Engineer Doug Hofer presented the newly developed mini turbine that could supply 10,000 households with electricity. Photo: GE Global Research

Otherwise, the novelty of the turbine is unusual. Not water vapor, as usual, puts the turbine in motion, but Super critical carbon dioxide. This is a special State of matter of the CO2 generated by a certain pressure and temperature. In this condition, the CO2 has properties between those of gas and liquid. The CO2 is as dense as a liquid, but has the viscosity of the gas.

This CO2 is heated to approximately 700°C to work efficiently in a turbine. While most turbines to can convert 40% of the heat into electricity, the new turbine would have an efficiency of 50%. Also the speed with which the turbine is ready for use would be beneficial. As opposed to a steam turbines, which requires about 30 minutes, until the water is heated, the mini turbine can be ready in minutes.

Eco-friendly in conjunction with concentrated solar thermal energy

Also, the energy cycle in a closed cycle might work by the CO2 would again and again heated and put under pressure. That could be combined Doug Hofer, particularly effective and environment-friendly technology of concentrated solar thermal energy.

This kind of solar energy, which is dependent on a high direct exposure to sunlight, the Sun’s rays are bundled by mirror and concentrated. In this focal point, a suitable thermal medium is heated and transported via pipes in heat storage or directly to the steam power plant. Here the turbines are powered then, which produce electricity through a generator.

For the operation of the new mini turbine, the heat in liquid salts could be cached and retrieved when needed.

Doug Hofer and his team believe that the new turbine technology is scalable to generate 500 MW of electricity enough energy to supply a city “The energy demand will rise in the next two decades by 50 percent”, says Hofer. “We can’t wait until there are new, clean solutions, but must now develop ideas and as efficiently as possible to make the already existing techniques.”