What is the Problem?

Using consumers’ flexibility by the TSO is a way to provide extra AS required to accommodate higher level of renewable generation. This can be done by a time-varying prices submitted to flexible loads. However, effective models are needed for the TSO to generate price signal.

Why is it Interesting?

Larger renewable generation in the power system is not going to have without providing enough flexibility for safe operation of the system. Demand flexibility resources are free of charge, available at all times, and will be achievable with minimum upfront cost of infrastructure. An efficient and detail model to estimate consumers’ reaction to price signals is necessary to achieve this.

What is the Approach?

We formulated consumers’ flexibility as an optimisation problem for rational end-users. Consumers willingness to respond to price signals are modelled stochastically and actual aggregated load data are used for 29 categories of load demand. The deterministic optimisation model was converted to a chance-constrained program to account for the stochasticities.

What is New?

The proposed formulation was new in essence and including different load categories to solve the problem was unique. Converting the deterministic problem into a stochastic one was offered to estimate load flexibility considering the confidence level.

How was it Tested?

Optimisation model was implemented in GAMS and the problem was solved in MATLAB by calling GAMS model using CPLEX solver. The normality assumption of the stochastic terms are tested and proved, and the problem was solved for two confidence levels.