Feasibility of integration of synthetic fuel as an energy storage vector for offshore wind

The need to decarbonise is an ever-pressing problem for a world facing the continued effects of climate change and aiming for a Net Zero future. A key area for decarbonisation is the energy sector, encompassing electrical supply, fuels for transport, and chemical sector raw materials. Renewables can directly decarbonise the first, but also the other two by powering green synthetic fuel plants to produce green alternatives. This work explores the feasibility of using offshore wind to power production of four fuels, hydrogen, methane, methanol, and ammonia. Feasibility was defined as sufficient wind farm energy levels to synthesis the fuels, sufficient space on standard offshore infrastructure for the synthesis plant, and suitability of coupling technologies with variable supply. This involved both modelling and experimental work.

The modelling work involved the creation of a dataset detailing the power production levels of 59 offshore wind farms in the UK without reductions from curtailment or transmission losses. This was calculated by a range of methods with two methods out of the five applied found suitable. Factors affecting curtailment were explored including geographical location, wind farm age, distance from shore, time of year and wind farm capacity. Curtailment levels, as well as total energy production levels, were used to determine synthetic fuel production levels, with concluding that dedicating entire farms to synthetic fuel production was more suitable.

This dataset fed into a mass and energy balance and physical sizing of synthetic fuel production of all four fuels at the 59 farms on existing offshore infrastructure. This analysis was performed twice, the second time including alternative technologies. Pre including alternative technologies the number of suitable wind farms ranged from 6 - 44, post inclusion this increased to 22 - 50, in both instances the higher number was for hydrogen production. Of the technologies assessed the Battolyser was the most promising, both in terms of space saving potential as well as room for future work.

This conclusion fed into experimental work encompassing the experimental construction and testing of both a lead acid and lead carbon Battolyser. The experimental work proved the functionality of a lead acid and lead carbon Battolyser unencumbered by hydrogen inhibitors in the electrode. The lead carbon unit functioned better both as a battery and as an electrolyser, produced higher volumes of hydrogen and showed greater promise in its resistance to corrosion of the grid on which the electrode is built.