TECHNOLOGY FOCUS - ELECTRICAL POWER AND ENERGY - Preferred Components: The photovoltaic component is a superstrate-type thin-film photovoltaic cell deposited on a glass superstrate. It is subdivided into subcells, with dimensions such that electrical loss in the transparent and conducting front contact is minimal. An additional scribe is made to bring the positive electrode of the photovoltaic unit cell from the transparent conducting front contact to an electrically isolated contact on a back contact, without shorting the positive and negative electrodes, and with minimized photovoltaic dead area. The subcells within the photovoltaic unit cell have approximately equal active areas so that a photocurrent generated in each subcell within the unit cell is approximately the same. About greater than or equal to2 subcells are connected, through scribes, into photovoltaic unit cell which has voltage to drive water electrolysis at or near its maximum power point. Each subcell is a photovoltaic unit cell. The electrolysis component is comprised of alkaline electrolyte; membrane that keeps hydrogen and oxygen separated while allowing ions to conduct through; and electrode spacing between anode and cathode. It has compact design with length, which is slightly larger than the length of the electrodes, being approximately the same as the length (or width) of the photovoltaic component; with width, which is slightly larger than the spacing between the cathode and anode, being substantially smaller than the width (or length) of the photovoltaic component; and with thickness, which is slightly larger than the width of the electrodes. The width is determined using current density on the cathode and/or current density on the anode. Each of the photovoltaic junction(s) is comprised of an undoped or lightly doped hydrogenated semiconductor material based on amorphous silicon, microcrystalline silicon, nanocrystalline silicon, amorphous germanium, microcrystalline germanium, nanocrystalline germanium, or their alloys; a p-type silicon-based semiconductor material; and an n-type silicon-based semiconductor. The substrate-type thin film photovoltaic cell comprises electrical grids (19) applied on top of the transparent conducting front electrode. The electrical grids are electrically connected together and to one electrode of the electrolysis component; and the conducting substrate is electrically connected to the other electrode of the electrolysis component, or itself is the other electrode.