Conclusion
Electrical energy storage systems

To conclude, we propose a rough diagram (figure 27) of the main technologies in the "time constant" plane – and a comparative table of their respective merits.

To complement the figure 27, the table 1 shows a quantitative and qualitative comparison of the main properties of interest. The investment cost should be considered as an order of magnitude, which can vary considerably (downwards) for emerging technologies, and possibly upwards if a significant proportion of the price is linked to the price of raw materials. Depending on the technology, cost is often expressed in terms of power or energy...