D5d.1 Cost Effective Emission Reduction Strategies

In the future, hydrogen distribution grids could be more common. However, hydrogen also is an indirect greenhouse gas. This means emissions into the atmosphere should be prevented. In HyDelta 3 work package 3A it was calculated what the greenhouse gas (GHG) emissions of a gas grid were, if the current grid was used to transport and distribute hydrogen. This was done by utilizing the methane emission data of the grids, and using a multitude of sources transferring this to hydrogen emission. As hydrogen is a less potent GHG and has a lower weight per transferred amount of energy, the switch to hydrogen led to a 92% reduction of greenhouse gasses emitted compared to the transport and distribution of natural gas.

However, improvements are considered to achieve a grid with net zero GHG emissions in 2050. An extra incentive – besides environmental protection – is the rising price of carbon credits, which should be paid per kilogram emitted CO₂ equivalent. As a completely emission-free grid is an utopia, a balance should be found between investing in emission reduction versus buying emission credits. The dilemma hereby is that the pipelines that are installed today could function for more than 50 years, operating with both natural gas and hydrogen. This means that additional investments today are beneficial for the entire lifetime of the system, including its service in hydrogen distribution. This project aims to help DSOs to make financially sound investments by offsetting additional CAPEX costs versus lifetime emission reductions.

No measure was found to be cost-effective solely based on emission reduction. The payback period for every measure was beyond the expected lifetime of the asset. This underlines the ongoing effort of the grid operators to reduce emissions. Further reduction requires considerable investments and/or leads to difficulties in execution. Development of innovative solutions should be continued in order to mitigate these downsides.

The project analyzed 50 different measures to reduce emissions. In a few cases enough substantiated numbers were available to make a rough estimation of the cost reduction on carbon credits and payback time of investments. The other measures were evaluated qualitatively on their feasibility to execute and the estimated benefits. All actions are evaluated based on their emission reduction effectiveness and expected drawbacks.

There could be other contributing factors to reconsider emission reduction measures in hydrogen grids. Therefore, a ranking was made between the measures of which a cost reduction estimate was calculated. The measures which should be investigated first are: permanently monitoring the pressure reduction stations (Chapter 7), covering the gas line with tape or protective material and increasing the depth of gas lines (both Chapter 5). The last measure is less likely to be implemented due to execution constraints. Permeation emission reduction measures such as changing PE lines to steel lines have extremely long payback times and should not be considered with the current constraints.