Assessing Techno-Economic and Environmental Impacts of Gas Compressor Fleet as a Source of Flexibility to the Power System

In the Great Britain's high-pressure gas transmission network, there are 24 gas compressor stations with 68 operational compressor units of different types and sizes. As of 2021, the aggregate capacity of electric-driven gas compressors was 200 MW. By using linepack as a form of gas storage buffer, the compressors can be operated flexibly to achieve a minimum operational cost under fluctuating electricity prices. Furthermore, since electricity consumed by electric-driven compressors can affect the balance of the power grid, the ability of electric-driven compressor units to regulate their electricity consumption is useful to be quantified. In this article, the value of flexibility from the hybrid compressor stations (compressor stations in which both electric-driven and gas-driven compressor units exist) is analysed. The operation of the high-pressure gas network in Great Britain was formulated as a Mixed-Integer Second Order Cone Programming (MISOCP) problem. The modelling results show that employing the flexibility from hybrid compressor stations in the gas network can reduce more than 20% of the operational cost and 50% of emissions from the compressor fleet. Furthermore, a cost-benefit analysis was carried out to assess the investment viability of installing electric-driven compressor units. It is demonstrated that the economic feasibility of investing in electric-driven compressors is sensitive to the future carbon price.