Published on September 21st, 2012 | by James Ayre1
Solar & Wind Energy Stabilize the Power Grid
Solar power, wind power, biogas, and other renewable energy sources are becoming increasingly important in the generation of electricity. As the quantity of wind turbines and photovoltaic systems feeding electrical energy to the grid increases, it makes the grid denser, and more widely distributed. Instead of only a small number of large power plants supplying all the electricity, the larger number of small, decentralized power plants create a much more reliable, more disaster-proof grid.
But there has previously been some talk that such a dense grid would be rather hard to synchronize. In contrast to that assumption, though, researchers at the Max Planck Institute for Dynamics and Self-Organization in Göttingen “have now discovered in model simulations that consumers and decentralized generators may rather easily self-synchronise. Their results also indicate that a failure of an individual supply line in the decentralized grid less likely implies an outage in the network as a whole, and that care must be taken when adding new links: paradoxically, additional links can reduce the transmission capacity of the network as a whole.”
In terms of the power grid, synchronization is the coordinated dynamics of power-usage and supply to the same timing. In nature, there are many systems that seemingly self-synchronize — neurons in the brain regularly fire simultaneously, the blinking lights of fireflies synchronize, and crickets share the same rhythm in their chirping. In a similar way, the grid filled with many different generators may “find its own shared rhythm of alternating current,” according to the new research.
The research also found “that decentralized grids are much more robust when single lines are cut. This is because a dense grid always more often has neighbouring lines that can take on the extra load of a downed line. Unlike the case of large-meshed networks, they have few indispensable main links with the potential to cripple the whole grid.”
“Until now, concerns rather centred on the possible collective impact that a large number of small generators could have in a dense grid,” says the physicist. The fear was more frequent power outages. “But our work shows that the opposite is the case and that collective effects can be very useful.”
So, aside from the clear global warming benefits of renewable energy, it seems they have important electric grid benefits as well. Notably, in the real world, we’ve already seen record grid reliability in Germany coincide with record renewable energy growth.
Image Credits: designergold, based on outlines provided by the MPI for Dynamics and Self-Organization