Power is the result of a transfer of energy. Most vehicles get their power from the transfer of energy from gasoline to their engines. The electricity in our homes comes from the transfer of energy from coal, nuclear reactions, rushing water, and sometimes wind. Even when we "power" ourselves by walking from Point A to Point B, the power in our legs is a transfer of energy from the food we eat that feeds our muscles.
The law of conservation of energy captures this idea. This key "law" of physics basically says that the total amount of energy in a system (such as a car engine or a network of power lines) remains the same. Another way to think about it is the energy is "conserved" over time.
Yet in reality, as energy transfers from one part of a system to another, rarely is 100% of it conserved because the systems are not 100% efficient in converting the energy to power. We want our car engines to use 100% of the potential energy in a gallon of gasoline, but they don't. Car engines get much better gas mileage than they used to, but they're still not 100% fuel efficient in transferring energy. Neither are power grids 100% efficient in transferring the energy from burning a ton of coal to the electricity in our homes.
While some systems transfer energy to create power more efficiently than others, they all have the potential to be more efficient in that process. Because of that potential, there is much research being conducted to improve the efficiency of power. And because microgravity provides a unique environment to experiment and observe the transfer of energy, scientists on the ISS are strongly focused on this area of research.
Some of the research centers on magnets. That's right. Magnets. Surely you've experienced the force of magnets that attract metal objects or repel other magnets. That's energy — a transfer of energy, in fact. But the force of gravity also influenced your experience with magnets, right? Without the presence of gravity, it is easier for scientists on the ISS to conduct experiments and measure how much energy is "lost" in the transfer of energy.
What's exciting about magnetism is its potential to reduce the influence of forces that negatively affect efficiency. Typically, there are forces (such as gravity and friction) that prevent the transfer of energy from being 100% efficient. Gravity pulls down. Friction slows down. The forces sap some of the energy. Magnets can provide a force to counteract them.
Go back to thinking about your experiences with two magnets repelling each other. There's a force that's strong enough to counteract gravity and make one magnet hover over the other. Now, imagine an object that hovers like that and travels over an extensive system that uses that same magnetic force. There are actually some trains that already do that! A train that moves on a traditional track has friction between the track and the wheels as well as gravity slowing it down — unless the train is moving downhill, of course! Maglev (short for magnetic levitation) trains take the energy from magnets to power the train and to counteract forces that make the transfer of energy less efficient.
Now imagine using that same force on a smaller scale within a turbine. Turbines generate power through the rotation of rotors. (That name makes sense, right?!) The rotors spin, and the energy created from the spinning is transferred to power something else. Think about a windmill as one example. And for the rotors to spin, there must first be energy applied to them, right? That happens when fluids (liquids or gases) pass through the rotors causing them to spin. Again, think about a windmill where the wind causes its rotors to turn.
There are many types of turbines, including some that propel the propellers on huge cruise ships. Because all turbines require spinning rotors, they can all be more efficient in their rotation. It is that rotation that transfers the energy from the fluid. And it is in that rotation where magnets (kind of like the hovering trains) can reduce friction and the effects of gravity on the process!
To improve the efficiency with magnets requires understanding how magnetic fields can be applied most effectively. The scientists on the ISS are on it! What is also important to point out is that turbines can run on renewable energy sources like wind, water, and even the waves of oceans. So it's not simply making turbines more efficient, so turbines are better able to transfer energy — it's also a way to make renewable energy a more effective source of power!
