  Demand response (DR) is not only a crucial solution to the demand side
management but also a vital means of electricity market in maintaining power
grid reliability, sustainability and stability. DR can enable consumers (e.g.
data centers) to reduce their electricity consumption when the supply of
electricity is a shortage. The consumers will be rewarded in the case of DR if
they reduce or shift some of their energy usage during peak hours. Aiming at
solving the efficiency of DR, in this paper, we present MEDR, a mechanism on
emergency DR in colocation data center. First, we formalize the MEDR problem
and propose a dynamic programming to solve the optimization version of the
problem. We then design a deterministic mechanism as a solution to solve the
MEDR problem. We show that our proposed mechanism is truthful. Next, we prove
that our mechanism is an FPTAS, i.e., it can be approximated within $1 +
\epsilon$ for any given $\epsilon > 0$, while the running time of our mechanism
is polynomial in $n$ and $1/\epsilon$, where $n$ is the number of tenants in
the datacenter. Furthermore, we also give an auction system covering the
efficient FPTAS algorithm as bidding decision program for DR in colocation
datacenter. Finally, we choose a practical smart grid dataset to build a large
number of datasets for simulation in performance evaluation. By evaluating
metrics of the approximation ratio of our mechanism, the non-negative utility
of tenants and social cost of colocation datacenter, the results demonstrate
the effectiveness of our work.
