The dream from hydrogen

In despair about the insufficiency of lead acid batteries as electric power storage, the dream from hydrogen and fuel cell started.

Beaten by the efficiency

We take again the sea water desalination as a study object. A 1000m³ drinking water system needs 2500 kWh electric power per day. A little bit more than 100 kW continues power. Let's take dreamlike good parameters. 65% with an usage of waste heat, 85% efficiency for the electrolysis and about 3 kWh to compress 1 kg hydrogen into the pressure tank.

0,85 for electrolysis * 0,90 for pressure tank * 0,65 electric power efficiency = 0,497

At this parameters, even a cost free hydrogen system is compared to the lithium batteries to expensive, because the photovoltaic has to be so much larger, to compensate the low efficiency compared to the lithium batteries.

Dimension for 1000 m³ water per day

	Hydrogen	Lithium
Batteries		2500 kWh
Photovoltaic	1000 kW	550 kW
Elektrolysis	1000 kW
Fuel cell	105 kW

Calculator with great optimism for hydrogen. Elektrolysis with 100 EUR per kW, Fuel cell with only 1000.-EUR per kW. Both with 50.000 hours usage time would be equal to 2000 cycles at this task Some money is also necessary for the storage. So we calculate this application with 100.-EUR per kWh storage and 2000 cycles.

Attention! Extrem optimistic parameters for hydrogen

Usage time for fuel cells anc prices are not today's reality!