Hydrogen

One study drives this page: study.hydrogenModel (P2-16), an hourly electrolyser and fuel-cell energy dispatch for a microgrid. The electrolyser is modelled as an adjustable load: the electric power is converted into a hydrogen mass flow through the specific energy consumption (m_H2 = P_el / kWh per kg), limited by rated power, minimum and maximum load rate and ramp rate, and it produces nothing below its minimum load instead of silently scaling. The fuel cell is a PQ or V-f source whose output follows the efficiency on the lower heating value (P_fc = m_H2 x LHV x eta_FC), limited by rated power and start times. Hydrogen storage is a capacity-constrained store whose state of charge is held in kilograms with an initial value and an operating window. Each hour, surplus generation (PV minus load above zero) goes to the electrolyser, a deficit is covered by the fuel cell, and anything beyond either capability is reported separately as curtailed energy or as unmet energy - never quietly absorbed. The round-trip efficiency, the electrolyser utilisation and the 24-hour profiles of power and state of charge come back as engine values. The model reuses the delivered time-series semantics, the PV time series, the reactive capability circle and the V-f droop estimate, and its scope is the energy balance - not hydrogen fluid dynamics or electrochemistry.

Hydrogen is sold as long-duration storage, and the honest question is what it actually does over 24 hours: how much of the surplus it absorbs, how much electricity comes back for the same kilograms, and how much of the deficit it can still cover. Those three numbers decide whether the store is sized for the surplus, for the deficit or for neither - and they are far cheaper to check here than to discover after the equipment is bought.

Input = the electrolyser, fuel-cell and storage data plus the PV and load profiles and studyOptions.enableHydrogenModel. Chain: per hour the net power is formed from generation minus load; if it is positive the electrolyser consumes it within its load range (m_H2 = P_el / consumption per kg), if negative the fuel cell is asked for the deficit and returns P_fc = m_H2 x LHV x eta; the state of charge is integrated in kilograms and clipped to the operating window, anything that cannot be absorbed is booked as curtailment and anything not supplied as unmet energy. Output = study.hydrogenModel with the hourly series (electrolyser power, fuel-cell power, state of charge) and the summary statistics: produced and consumed mass, round-trip efficiency, curtailed and unmet energy, electrolyser utilisation. Honest rule: a value you do not supply falls back to a flagged engineering default (specific consumption 50 kWh per kg, fuel-cell efficiency 50 % on the lower heating value, hydrogen LHV 33.33 kWh per kg) and the basis block marks it as defaulted, while storage capacity and initial state have no default - their dependent values stay null with an unknown flag instead of a guessed number. Linkage: PV capacity and the load profile decide the surplus and the deficit; the storage window decides how much of it can be shifted; the electricity not taken from the grid changes the annual bill and the payback on the economics page.