G033-3

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Across
  1. 5. A PV panel converts ________ into electricity.
  2. 6. Solar cells produce ________ current, and therefore need inverting to produce A.C.
  3. 7. UPS stands for ____________ power supply.
  4. 11. In the gross feed-in tariff scheme all solar energy is measured by a __________ meter.
  5. 12. Fuel cells convert fuels like natural or hydrogen gas into electricity without the need to burn the fuel, and hydrogen has the advantage that only water is produced as an emission, but natural gas is more _______ available.
  6. 14. Grid connected inverters have active and passive anti-islanding techniques, and whereas passive protection disconnects inverter when a under or over voltage condition occurs, active protection induces a voltage ________.
  7. 15. A grid connected inverter must disconnect itself from the grid when the inverter detects that the grid is not __________ normally, such as a blackout.
  8. 16. Batteries that produce flammable hydrogen gas should be stored in a well ________ area to avoid explosions.
  9. 17. You must ensure that installing UPS system protection devices do not _________ neutral and earthing conductors.
  10. 19. Stand alone inverters will be rated according to their instantaneous (peak/surge), continuous and 30 min continuous output ________.
Down
  1. 1. PV cells are connected in series and parallel to produce the familiar PV _________ (panel) that we then install on the roof to produce strings and arrays.
  2. 2. The in-line type UPS can also be used as a power __________.
  3. 3. The PV ______ is the basic building block of solar systems.
  4. 4. A rectifier changes ac to dc but an inverter __________ dc to ac.
  5. 8. Unlike solar panels, wind turbines can produce _____ and DC.
  6. 9. Furling is intended to protect a wind turbine from strong winds whereas ________ ensures optimal generator output by positioning the blades into to wind.
  7. 10. Wind turbines are classified by the axis direction of the generator shaft, the most common being the _____.
  8. 13. In the net feed-in tariff scheme only the _______ solar energy is measured by the principle meter.
  9. 15. At the anode of a hydrogen fuel cell, the hydrogen (H2) is _________ (has the electron removed) allowing the electron to flow in the electrical circuit. The oxidised hydrogen ion (H+) is then recombined with the returning electrons in the electrical circuit and oxygen in air to produce water as the emission.
  10. 18. SAPS stands for standalone ________ systems.