(137d) Bittorrent-Inspired Utility Management of Electric Customers With Distributed Energy Resources

Authors: 
Titus, M. C., Rensselaer Polytechnic Institute
Bequette, B. W., Rensselaer Polytechnic Institute



This work develops a novel approach to utility management and control of distributed energy resources (DER), such as fuel cells, solar panels, wind turbines and battery storage, on a distribution grid by applying a modified version of the BitTorrent filesharing protocol1. It is proposed that customers with DER (generation, storage, flexible loads) be treated as active peers in an energy distribution swarm, in order to overcome the control challenges and infrastructure stresses they impose at high penetration2. The current paradigm of passively connecting these customers to centrally controlled grids, effectively treating them as disturbances, is limited due to the lack of controllability and observability it introduces as well as its overreliance on external generation and transmission resources.

The proposed management strategy is inspired by the ability of the BitTorrent filesharing protocol to efficiently distribute large files over bandwidth-constrained networks, while minimizing network capacity requirements by making all downloaders into uploaders3. Our modified protocol applies the principles of BitTorrent file distribution to the problem of distribution grid load balancing by means of an analogy, in which the DER a customer possesses are thought of as shared files and the power they produce or consume is treated like transmission bandwidth (both upload and download). Distributed client controllers are then able to communicate and autonomously balance their local loads by means of downloading or uploading power to the swarm, with the effect of significantly smoothing the aggregate demand profile. With this structure, it is possible for the utility to incentivize customers with DER to transparently offer balancing services to each other, which has the dual benefit of increasing the accuracy of utility load forecasts and reducing peak loads across critical transformers.

An energy-relevant BitTorrent protocol was created by modifying the pseudo-code presented by Shneidman et al4 to account for differences between data and energy, such as the inability to simultaneously upload and download energy, limited ability to discretize device services into shareable pieces, and transmission at constant power rather than variable bandwidth. Simulations performed on a hypothetical 40-node distribution grid using a MATLAB implementation of this novel protocol demonstrate its ability to reduce transformer peak loads, smooth aggregate load profiles, and to provide a framework that supports greater penetration of DER without infrastructure upgrades.

References:

1)    B. Cohen, “Incentives Build Robustness in BitTorrent,” Proc. First Workshop on Economics of Peer-to-Peer Systems, (2003).

2)     C. W. Potter, A. Archambault, and K. Westrick, “Building a smarter smart grid through better renewable energy information,” IEEE Power Systems Conference and Exposition, 1–5, (2009)

3)    A. R. Bharambe, C. Herley, V. N. Padmanabhan, “Some Observations on BitTorrent Performance,” SIGMETRICS’05, June 6–10, (2005)

4)    J. Shneidman, D. C. Parkes, L. Massoulie ́, “Faithfulness in Internet Algorithms,” SIGCOMM’04, Aug. 30–Sept. 3, (2004)