The National Transmission System (NTS) provides a resilient supply of natural gas to homes, businesses, and industry across the UK. The gas is moved by a complex compression system comprised of 24 compressor stations and 70 individual compressor units.
To transport and store hydrogen across the UK, compression is required to provide flow and build linepack (the total volume of gas contained within the system) at times of increased demand and in certain locations on the network.
To meet our net zero targets by 2050, we’re exploring the feasibility of converting the NTS to carry hydrogen. Through the Strategic Innovation Fund (SIF) process, we’re working to build our understanding of how our current compression equipment can be repurposed for hydrogen and hydrogen blends.
We undertook an initial Discovery phase study to determine the full range of technical requirements for potential compression drive systems and compressor technologies. This was followed by an Alpha phase project to further develop our understanding of the feasibility of repurposing compressor assets, as well as modelling future compression requirements.
The cost of a new compression system is approximately £60m per unit, so repurposing our existing assets would result in considerable cost savings for consumers.
These projects showed that our gas turbines could be modified to be fuelled with up to 100% hydrogen and our compressors could operate with up to 50% hydrogen. Above 50% hydrogen, a compressor upgrade would be required.
We’ve now applied for funding for a larger Beta phase project. A gas turbine representative of the current fleet will be fuelled by different blends of hydrogen up to 25%, then following modifications, 100% hydrogen. This will provide technical and safety evidence for the repurposing of our current gas turbine fleet. Following this, the full compression system including the power turbine, gas compressor and the cab and ancillary equipment will undergo offline testing at the Future Grid hydrogen test facility, to demonstrate that the assets can be repurposed for hydrogen blends and 100% hydrogen. A compression test loop will be constructed out of decommissioned NTS assets to test the compressor systems in a range of hydrogen scenarios.
Our funding application has been successful, and the HyNTS Compression Beta project will provide a technical demonstration and create a strategy for the transition of the UK NTS compression system to hydrogen.