On Wed, 29 Jul 2009 13:57:39 +1000, "David L. Jones" wrote:

:S Claus wrote:
: Hi all
:
: I wanted to ask a question about something that has lightly perplexed
: me for a while.
:
: Sometimes we read about some person building e.g. a wind turbine (or
: something else) and connecting the electricity derived from this to
: their home power grid.
:
: My question is about how this sort of thing is accomplished.
:
: I mean, I do not expect it to be as simple as plugging a power supply
: to a wall outlet and then the power from it automatically becomes
: available to all outlets in the house.
:
: Or is this basically how it is done - in other words can a standard
: wall outlet function both as 'input' and 'output'?
:
:Yes it can.
:That's basically how all grid-tie inverters work. They are basically just
:connected across your house mains supply (usually out in your power box for
:various reasons).
:You can now get smaller ones like this that plug directly into any outlet:
:http://www.gogreensolar.com/products...olar-power-kit
:Often called plug-in or micro inverters.
:
: And a second question derived from this, is it possible to also be
: plugged into the communal power grid at the same time or will there be
: some sort of a interference? If there is interference, how can that be
: reduced?
:
:Grid-tie inverters are designed to supplement your existing community mains
:connection and are simply connected in parallel, they are designed to sync
:with the existing mains connection. So technically, when you are not using
:the power, someone else nearby gets the benefit instead. In many countries
:and states you can get a "feed-in" credit for the power you put into the
:grid in this way.
:
ave.


There is far more to installing and using a grid tie inverter than just plugging
one in to a GPO. Grid tie inverters must, by law, be connected to the phase wire
via an isolation switch and the meter box must have appropriate signage inside
warning that a grid tie system is in operation. If anyone (linesman or
electrician) was working on the phase (eg. the premises lead-in cable) thinking
that it was already isolated he might get a shock due to the grid tie inverter
pumping out 240V via an ordinary GPO.