[ cover story ]
The case study investigates an alkaline electrolyser of 10 MW directly connected to a 20-MW mix of wind and solar assets of equal capacity , as well as the grid . The oversized renewable sources generate enough electricity to assume 100 % green hydrogen production under monthly temporal correlation . The cost of this electricity is assumed to be determined by day-ahead prices , which is a possible pricing strategy for subsidised renewable assets . To test the full flexibility range , inflexible ( 100 % minimum load ), base case ( 25 %), and flexible ( 0 %) electrolysers are modelled with one market ( day-ahead ) and three markets ( day-ahead , intraday , passive imbalance ).
Results
We found that electrolyser flexibility and smart energy trading alone can make the business case over 50 % more viable compared to operating 24 / 7 .
While subsidies and interventions are still required to break even , fully flexible
electrolysers can become profitable with almost 25 % lower green hydrogen premiums or 50 % lower CapEx subsidies and will be less affected by the hourly correlation requirement . They can provide 10 – 30 % lower LCOH compared to electrolysers with baseload requirements ( see Figure 1 ).
Value of flexibility
Electrolyser operators can reduce energy costs by producing hydrogen when prices are low , turning down to minimum load when prices are high , and using the remaining capacity as coverage in trading electricity on multiple markets .
Asset flexibility can be leveraged to improve profitability , with up to 60 % increase of NPV compared to round-the-clock operation . Energy market optimisation can further increase profits for flexible assets , with up to 44 % improvement in NPV compared to using a single market . Next , different interventions are tested in isolation and compared to the marketoptimised case .
LCOH sensitivity to asset and market flexibility , in EUR / kg ( incl . day-ahead , intraday , imbalance trading , excl . interventions )
8
6
4
2
0
Market flexibility ( 100 % minimum load )
Market + asset flexibility ( 25 % minimum load )
Market + full asset flexibility ( 0 % minimum load )
Fig . 1 . LCOH for three flexibility ( minimum load ) levels with optimisation on three markets
Hydrogen Tech World | Issue 18 | October 2024 13