# Hydrogen Production from Offshore Wind Parks: Current Situation and Future Perspectives
## 6 Conclusions  
Hydrogen has several applications, including being mixed with natural gas in P2G, powering vehicles in P2M, and providing energy storage and grid balancing services in P2P. In the last decades, hydrogen has had carbon emissions associated with its production, and for this reason its potential has not been fully explored. However, due to recent advancements in electrolyzers and renewable energy, the cost competitiveness of green hydrogen is quickly rising and is expected to match fossil-fuel-based hydrogen in the coming years. Compared to wind energy on land, offshore wind has higher wind speeds and is more consistent, making it a more attractive resource to generate electricity. The main drawbacks have been the higher cost and technical challenges associated with transmitting the electricity to shore, though this has improved in the past years. Offshore wind farms are increasing in size and are built further and further away from shore; nonetheless, they have been experiencing LCOE reductions, almost reaching competitive values. Furthermore, with the development of floating wind platforms, wind farms can be placed in deeper waters, allowing more locations to be accessible for electricity generation. Two hydrogen production systems based on offshore wind energy are currently proposed, in which not only are electricity and hydrogen produced but grid balancing services are provided, such as frequency control. The first system utilizes an offshore electrolyzer; hydrogen is produced, compressed, and transported in a pipeline to shore. The main advantages are the reduced cost of a submarine pipeline compared to a submarine electrical cable and supporting power electronics, along with the reduction in transmission losses of gas in a pipeline (0.1%) in comparison to conventional wind farms (up to 5%). In the second system, the electrolyzer is located on land, so the electricity generated offshore is transmitted through an electrical cable to land. Once the electricity reaches the shore, it can be sold directly as electricity when the price is high during peak periods or can be fed \begin{table}
\begin{tabular}{c c c} \hline
**Electricity Source** & **AEL (\%/kg)** & **PEMEL (\%/kg)** \\ \hline Grid & 2.49–2.74 [43] & 2.26–3.01 [43] \\ Solar PV & 2.04–5.00 [20; 48] & 2.71–7.98 [20; 48; 49] \\ Solar CSP & 3.03 [20] & 3.79–8.5 [20; 49] \\ Onshore Wind & 4.33 [48] & 2.73–6.61 [44; 48] \\ Offshore Wind & 9.17 [48] & 3.77–11.75 [24; 45; 48; 50] \\ \hline \end{tabular}
\end{table} 
Table 3: Summary of LCOH. into an electrolyzer to produce hydrogen when the electricity prices are low or curtailment must occur. The advantage is the increased flexibility provided to the operator, with the option of selling electricity or producing hydrogen, depending on the most economically viable choice. The literature shows the decreasing costs for green hydrogen production, both for wind and solar energy, along with the forecast of how the technology is expected to evolve: less expensive, longer lasting, and more efficient electrolyzers. Furthermore, the integration of fuel cells and electrolyzers at a grid level can aid in overcoming some of the challenges of generating electricity from renewable energy sources, like frequency control and energy storage. Conceptualization, G.C. and R.C. ; methodology, G.C. and R.C. ; software, G.C. ; validation, G.C. and R.C. ; formal analysis, G.C. and R.C. ; investigation, G.C. ; resources, G.C. ; data curation, G.C. ; writing--original draft preparation, G.C. ; writing--review and editing, R.C. ; visualization, G.C. and R.C. ; supervision, R.C. ; project administration, R.C. ; funding acquisition, R.C. All authors have read and agreed to the published version of the manuscript. This research was funded by Fundacao para a Ciencia e a Tecnologia (FCT), grant number UIDB/50021/2020. Not applicable. EDP-NEW is deeply acknowledged for providing the adequate conditions for carrying out this work. The authors declare no conflict of interest.