DEMAND/SUPPLY MATCHING

2. MATCHING DEMAND/SUPPLY FOR PHOENIX

Fig.1 Hydrogen production & utilisation

Fig.2 Demand & supply during over a winter week

Fig.3 Demand & supply during a spring week

Fig.4 Demand & supply during  a summer week

The simulation with the "Merit" software indicates that 60 PV panels are required to power the electric load of a dwelling in Phoenix. Fig.1 shows the volume of hydrogen produced in excess (positive area) and used to balance the deficit of demand (negative area) during different months of the year. The system has to store 28 cubic meters of hydrogen during summertime, 2 cubic meters remaining unused during the winter period.

As Phoenix is located in the Arizona Desert, air conditioning is required. The cooling load necessary is 7,300 kWh per year. To power this cooling load 60 more PV panels must be implemented. During the winter months the system is not self-sufficient and the dwelling's electrical load is powered by using the fuel cell and hydrogen stored during the summer as the energy provider.

During January the system requires the 7.7 cubic meters of hydrogen that was stored during the summer. During spring and summer, the PV array supplies the autonomous dwelling with electricity. During these periods of high solar irradiance excess energy can be used to power the electrolyser and stored for seasonal storage in the form of hydrogen. The system can generate 5.8 cubic meters of hydrogen during April and 2.6 cubic meters of hydrogen during August for use during wintertime. The 120 PV panels required to power the dwelling have an area of 80 square meters and the fuel cell has a rating of 6 kW to supply the electrical load, which includes the air conditioning.