Alternative energy cannot take over from fossil fuels without a way to bridge over the peaks and troughs that can occur when the wind fades or the sun dips. That's what gets us so excited about advances in grid scale batteries.
In the most recent breakthrough, the good folk at the Fraunhofer institute in Magdeburg, Germany, have risked taking their own facility off the power grid, leaving their many sensitive experiments at the mercy of a megabattery to prove the concept.
In Germany, where solar power supply has set records fulfilling over 50% of the total electricity demand, the technology cannot come too soon. After all, if you obtain 5% of your electricity from solar, and the supply dips by 50%, the grid can easily redistribute to cover the small hiccup. But when 50% of electricity drops by half...well, that is where the vision and reality meet on the battlefield of progress.
The mobile 1-Megawatt battery with a capacity of 0.5 Megawatt-hours consists of approximately 5000 lithium ion cells packed into a container the size of a rail car. The firm SK Innovation, part of Korea's third-largest conglomerate, SK Group, built the megabattery.
The megabattery can serve a single or several large production facilities (equivalent to 100 households), which could be useful to replace the many stand-alone generators that still serve to ensure stability in production facilities throughout the developing world.
More importantly, the megabattery can be integrated into regional power supply networks as well. The optimization of regional energy management remains the current focus at the Fraunhofer IFF: the megabattery is being tested with the micro-Smart-Grid to help with the development of software and control systems to manage the networks of tomorrow.
The megabattery has been officially named "Smart Grid Energy Storage System" (SGESS forshort). The successfully tested SGESS will be in use already in 2015, for example by the Hamburg based company Enerparc AG.
Lithium ion batteries are almost certainly not the ultimate answer for the power grid stability issue. Breakthroughs in supply rate flexibility, like flow-battery technology, and cost-effectiveness, like metal-liquid batteries, will be needed. But the SGESS megabattery serves as an important stepping stone for learning how to use batteries to create an energy infrastructure free from fossil fuel dependency.