We at the Power Panda get a lot of questions about whether the Power Panda works with "my meter which is X". The short answer (also found on our Frequently Asked Questions ) is yes but we expect the savings to be at the lower end of the range.
However we ask all of our customers what type of meter they have, and a substantial portion of them are unsure of the difference, so we thought we'd try to explain it in case you were in the same situation.
Anytime/24hr - This type of meter has lots of names with Anytime and 24hr being the most common. This is the most common type of meter, it supplies electricity to everything 24 hours a day (power cuts and external outages not included).
Controlled/ economy - these meters are the meters the lines company is able to turn off when desired. Often these meters are labeled with the code CN18, or CN19 on your bill. Usually these meters are wired to your hot water cylinder only, as everything wired to them goes off when the lines company cuts the power to the meter. This off time can be for up to 6 hours on a CN 18, and 5 hours on a CN19. Your hot water still stays hot and you can still use it. However the reason only hot water is wired up to these is simple - would you want your TV cutting off at 7pm during the winter?
Night Meters - These meters only allow power to flow at night, generally this is 11pm til 7am, however the exact hours vary depending on your network company. The largest exception is the Orion Network. Usually only underfloor heating is hooked up to this. You can hook a hot water cylinder, but most people will notice the temperature drops towards the end of the day. On your Power Bill these generally have the code NO8.
These three meter types are the most common. 24hr is the most expensive, however Controlled is generally 2-3 cents cheaper per KwH (it used to be even cheaper, but now it's hardly worth it). The Night Rate is generally half the cost again in the South Island, but only another few cents cheaper in the North island.
When we post again we'll talk more about some other rarer types of meters.