Green Hydrogen Plant: Optimal control strategies for integrated hydrogen storage and power generation with wind energy

Abstract

The intermittent nature of renewable energy resources such as wind and solar causes the energy supply to be less predictable leading to possible mismatches in the power network. To this end, hydrogen production and storage can provide a solution by increasing flexibility within the system. Stored hydrogen can either be converted back to electricity or it can be used as feed-stock for industry, heating for built environment, and as fuel for vehicles. This research examines the optimal strategies for operating integrated energy systems consisting of renewable energy production and hydrogen storage. Using Markov decision process theory, we construct optimal policies for day-to-day decisions on how much energy to store as hydrogen, or buy from or sell to the electricity market, and on how much hydrogen to sell for use as gas. We pay special emphasis to practical settings, such as contractually binding power purchase agreements, varying electricity prices, different distribution channels, green hydrogen offtake agreements, and hydrogen market price uncertainties. Extensive experiments and analysis are performed in the context of Northern Netherlands where Europe's first Hydrogen Valley is being formed. Results show that substantial gains in operational revenues of up to 51% are possible by introducing hydrogen storage units and competitive hydrogen market-prices. This amounts to a e126,000 increase in revenues per turbine per year for a 4.5 MW wind turbine. Moreover, our results indicate that hydrogen offtake agreements will be crucial in keeping the energy transition on track.

Centralized Offshore Hydrogen Production from Wind Farms in the Baltic Sea Area—A Study Case for Poland

“…Outlet pressure from electrolyser is 3 MPa. To calculate the diameter of the pipeline, the transformed Renouard hydraulic equation was used [54]: (8) where: D-pipeline diameter (m) Q-hydrogen flow rate in (m 3 /s) Z-hydrogen compressibility factor: 1.03198 L-pipeline length between platform and shore: 36 km T-gas temperature: 298 K d-relative density of hydrogen: 0.07 p 1 -inlet pressure to pipeline: 10 × 10 5 Pa p 2 -pressure from pipeline: 9.9 × 10 5 Pa After calculating the diameter, the appropriate pipeline diameter was selected using the catalog [55].…”

“…Wind energy generation has increased rapidly during the last few decades. Its utilization climbed from 0.2% to 4.8% of total power output between 2000 and 2018, and is anticipated to reach more than 12% by 2040 [8]. Many European countries have turned their focus to the study and development of offshore renewable energy, citing various benefits over onshore energy resources.…”

“…During times of excess supply, power may be transformed into green hydrogen and stored for later use. In times of supply constraint, the hydrogen stored can be turned back into electricity [8]. Hydrogen, as a recognized clean energy, will play an increasingly essential part in the future energy system due to its benefits of being pollution free, enabling diversified application, inducing minimal losses, high utilization rates, and allowing convenient transportation [18].…”