Micro Hydro Terminologies - First Batch

I have been trying to find and collect some important terminologies of micro hydro power. The sources of the definitions are Wikipedia, International Electrotechnical Commission, Manitoba Hydro and some coming from internal sources. The list is not covering all detail technical terms (e.g. detail definition of a generator or a turbine). The list will only covers very general that newbies will find it easy to understand more about micro hydro power. The first batch will contain only terminologies that I categorized into "general".

• AC Alternating Current: An electrical system fed by alternating voltage
• Benefit-cost ratio: The ratio of the present value of project benefits to the present value of the project costs, used in economic analysis.
• Bidding: An offer (often competitive) of setting a price one is willing to pay for something
  
• Black start facility: Internal facility to restore a power station to operation without relying on external energy sources
• Community participation: Involvement of people in a community in projects to solve their own problems
• Contour line: In cartography, a contour line (often just called a "contour") joins points of equal elevation (height) above a given level, such as mean sea level
• Earthing system: An arrangement of connections and devices necessary to earth equipment or a system separately or jointly
• Efficiency: Energy conversion efficiency is the ratio between the useful output of an energy conversion machine and the input, in energy terms
• Feed in tariff: An incentive structure to encourage the adoption of renewable energy through government legislation. The regional or national electricity utilities are obligated to buy renewable electricity (electricity generated from renewable sources such as solar photovoltaic, wind power, biomass, hydropower and geothermal power) at above market rates set by the government
• Frequency: Frequency is the rate or number of times a bar magnet rotates a full 360 degrees inside a coil, during one second. Most people just say 60 cycles, and the "each second" is understood. AC current is generated at 60 cycles in North America and 50 cycles in most of the rest of the world. The term 60 cycles is usually shortened even further and referred to as 60 Hertz. Utilities accurately control AC power production to this 60-Hertz value, since it is the basis of operation for many devices, especially clocks
  
• Hydroelectric installation: An ordered arrangement of civil engineering structures, machinery and plant designed chiefly to convert the gravitational potential energy of water into electricity
  
• Hydroelectric plant: A power plant that produces electricity from the power of rushing water turning turbine-generators.
• Hydroelectric power station: A power station in which the gravitational energy of water is converted into electricity
• Hydroelectric set: A generating set consisting of a hydraulic turbine mechanically connected to an electrical generator
• Hydrologic cycle: The natural recycling process powered by the sun that causes water to evaporate into the atmosphere, condense and return to earth as precipitation.
• Interconnected operation: The operation of two or more networks interconnected by links (for example: lines, transformers, d.c. links) enabling the mutual exchange of electrical energy
  
• Kilowatt (kW): An electrical unit of work or power equal to 1000 Watts
• Kilowatt-Hour (kWh): Basic unit of electric energy equal to one kilowatt of power applied over one hour. A unit energy equivalent to one thousand watthours
• Megawatt (MW): One million watts of electrical power
• Megawatt-hour (MWh): One million watt-hours of electrical energy
• Neutral: The designation of any conductor, terminal or any element connected to the neutral point of a poly phase system
• Nominal voltage of a system: A suitable approximate value of voltage used to designate or identify a system
• Phase: The designation of any conductor, bundle of conductors, terminal, winding or any other element of a polyphase system, which is intended to be energized under normal use
  
• Power factor (cos phi): The ratio of the real power flowing to the load to the apparent power, and is a number between 0 and 1 (frequently expressed as a percentage, e.g. 0.5 pf = 50% pf). The power factor is equal to cos phi)
  
• Power purchase agreement: A legal contract between an electricity generator (commonly a utility company) and a host site owner or lessor. The host site owner or lessor purchases energy or capacity (power or ancillary services) from the PPA Provider (the electricity generator)