Solar power jargon buster

We aim to speak in plain english so you know what you’re getting and why you’re getting it.  Sometimes you just can’t avoid technical terms, so here’s Naked Solar’s glossary of terms to guide you through the maze of Solar PV & energy jargon.

  • PV = Photovoltaic, simply the transfer of light (photo) in to electric (voltaic).
  • W = Watts, a measurement of power.
  • kW = 1000 watts
  • Panel/Module is the name given to each individual solar panel, typically measuring around 1 meter wide and up to 2 meters long, it is a collection of silicon cells that generate electric current when photons (light particles) hit the silicon.
  • Array is a group of panels/modules working together to feed in to an inverter.
  • Wp = Watts peak.  This refers to the peak power of a panel and is measured under STC (Standard Test Conditions) which are similar to a bright sunny day, hence the term ‘peak’ as this is likely to be the highest output you’ll see from the panel.   Typical panels for the UK market are between 300Wp and 500Wp.
  • kWp = kilo Watts peak. 1kWp = 1000Wp. Domestic arrays are usually between  4kWp and 20kWp, Commercial arrays average between 20kWp and  500kWp and industrial rooftop arrays can be 1000kWp (or 1MWp) or more.
  • kWh = kilo Watt hour. This is the same as one unit of electric. We buy electric in units or kWh. If you use 1 kW (kilo Watt) for one hour then you will have used a single unit of electric i.e. a kWh.
  • Inverter = The inverter is a ‘box’ that sits in the building changing the DC electric from the array to AC electric that is acceptable for your appliances and the national grid. Inverter position is extremely important.  Naked Solar always advise on the optimum place to put your inverter.  Inverters are sized according to their maximum output power expressed in kW (kilo watts).   It is normal practice to undersize the inverter for the array e.g. a 4kWp array may be paired with a 3.68kW inverter.
  • Mounting system = This is the frame, brackets, hooks etc required to hold the panels in place. Various solutions are available to deal with the many situations that Solar PV panels can be mounted in. Our mounting system page details ground mount to roof mount options.  Naked Solar have experience in all types of mounting and can discuss every option with you.
  • FIT = Feed in Tariff, this is the government scheme which ended on 31st March 2019 and was a subsidy designed to drive down the installation price of Solar PV systems.  More on Feed in Tariffs.
  • Export = is the electricity that is generated but not used in the property.  Exporting will happen when the property is using less electric than is being generated by the solar array.  Therefore this excess electric spills over and is exported to the grid.  Various energy suppliers will pay you for your export.