$k$-times bin packing and its application to fair electricity distribution
Dinesh Kumar Baghel, Alex Ravsky, Erel Segal-Halevi
TL;DR
The paper studies $k$-times bin packing ($k$BP) as a framework to allocate fixed supply $S$ among $n$ households with demands $D[i]$, by duplicating items across bins so that each item appears in exactly $k$ bins. It extends classical bin-packing algorithms to $k$BP, proving strong approximation guarantees for Fast and PTAS-based schemes, and demonstrates the existence of a finite $k$ that yields the optimal egalitarian electricity allocation. The authors provide both theoretical bounds—$FFk$ with asymptotic ratio $1.5+\frac{1}{5k}$, PTAS variants with $(1+2\epsilon)$ guarantees, and NFk with ratio $2$—and empirical validation on real electricity-demand data, showing superior egalitarian performance relative to prior heuristics. This work enables fair, efficient electricity distribution under capacity constraints and suggests broader uses for $k$BP, such as multi-copy data redundancy, with provable performance guarantees and practical algorithms.
Abstract
Given items of different sizes and a fixed bin capacity, the bin-packing problem is to pack these items into a minimum number of bins such that the sum of item sizes in a bin does not exceed the capacity. We define a new variant called \emph{$k$-times bin-packing ($k$BP)}, where the goal is to pack the items such that each item appears exactly $k$ times, in $k$ different bins. We generalize some existing approximation algorithms for bin-packing to solve $k$BP, and analyze their performance ratio. The study of $k$BP is motivated by the problem of \emph{fair electricity distribution}. In many developing countries, the total electricity demand is higher than the supply capacity. We prove that every electricity division problem can be solved by $k$-times bin-packing for some finite $k$. We also show that $k$-times bin-packing can be used to distribute the electricity in a fair and efficient way. Particularly, we implement generalizations of the First-Fit and First-Fit Decreasing bin-packing algorithms to solve $k$BP, and apply the generalizations to real electricity demand data. We show that our generalizations outperform existing heuristic solutions to the same problem in terms of the egalitarian allocation of connection time.
