PowerTech 2015 article online

The article I submitted to PowerTech 2015 (Eindhoven, June 2015) has been accepted. I've put online the pdf manuscript. It is an author version, since the copyright will be transfered to IEEE.

Title: "Energy Storage Control with Aging Limitation"

[Update July 7, 2015] presentation slides are now also available.

Abstract

Energy Storage Systems (ESS) are often proposed to mitigate the fluctuations of renewable power sources like wind turbines. In such a context, the main objective for the ESS control (its energy management) is to maximize the performance of the mitigation scheme.

However, most ESS, and electrochemical batteries in particular, can only perform a limited number of charge/discharge cycles over their lifetime. This limitation is rarely taken into account in the optimization of the energy management, because of the lack of an appropriate formalization of cycling aging.

We present a method to explicitly embed a limitation of cycling aging, as a constraint, in the control optimization. We model cycling aging with the usual exchanged energy'' counting method. We demonstrate the effectiveness of our aging-constrained energy management using a publicly available wind power time series. Day-ahead forecast error is minimized while keeping storage cycling just under an acceptable target level.

Big Batteries Needed ?

From Big Batteries Needed To Make Fickle Wind And Solar Power Work, on NPR :

You can think of a fully charged battery as a source of energy, ready to sell its product to the electric grid, just the way a power plant does. For that to work, battery owners would need to buy electricity to charge the battery when the price is low, and then sell that electricity back to the grid when the price is high.

But that idea turns out to be a dud.

Not many articles in mass media or in scientific journals take the time to explain how useful batteries can be to integrate renewables. But fewer also explains, like this NPR post, that batteries, at their current cost and capabilities, are not ready for the massive deployment on the grid that is predicted by some.

Fortunately, there is much on-going research on battery technology (and on other storage technologies as well). The progress on batteries has been tremendous and steady since their invention (e.g. the impressive improvement of electric model aircraft since 70s), so there may still be technological leaps to come.