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yumology
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Joined: 07/05/2009
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Posts: 4

Posted: 07:32pm 10 May 2009

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If you have solar panels on the roof and a grid tie inverter to put the power back into the grid:

1. what if the grid goes down, or you throw the main breaker, do you still have any power? (this is assuming you do not have a battery bank)

2. Do I need some sort of permission from the power company to do this?

3. If I have to get a new killowatt meter, who pays for that? How do I know if i need a new killowatt meter?

4. is the correct installation merely - solar panel to grid tie inverter to empty breaker in my breaker box. What if I just plug it into a regular outlet? Can I just use that breaker with solar power or does it go back into the grid? Is there anything else I need to buy??? Omg i'm so confused on this, why? where's a definitive guide to solar power I can read already?

Bolty

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Joined: 03/04/2008
Location: Australia
Posts: 81

Posted: 11:17pm 10 May 2009

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1. what if the grid goes down, or you throw the main breaker, do you still
have any power? (this is assuming you do not have a battery bank)

By regulation grid-connect inverters must have an "anti-islanding"
function built in. This is to ensure that should the mains supply fail, no
grid-connect inverters feed power back into the grid. This would be
dangerous for people working on the lines (when they are apparently
down). Approved inverters must disconnect within milliseconds. Therefore
no grid---no power from inverter.

2. Do I need some sort of permission from the power company to do this?

I am unsure on the permission process, but the inverter must be certified
and approved for connection to any Australian grid!

3. If I have to get a new killowatt meter, who pays for that? How do I
know if i need a new killowatt meter?

By kilowatt meter, I assume your normal domestic power meter. If you
wish to feed power into the grid, you need a bi-directional meter. In SA
this costs around $400 and needs to be paid to the power supply
authority. Without it, a domestic rotating disc type of meter will spin
backwards, effectively crediting you with power at the same rate as your
purchase price. In SA this is undesirable, as the State government pay you
a rebate of an extra 44c per Kwh fed back to the grid. Therefore without a
bi-directional meter you would lose this!

4. is the correct installation merely - solar panel to grid tie inverter to
empty breaker in my breaker box. What if I just plug it into a regular
outlet? Can I just use that breaker with solar power or does it go back
into the grid? Is there anything else I need to buy??? Omg i'm so confused
on this, why? where's a definitive guide to solar power I can read already?

In theory the inverter would work if connected anywhere in the house
installation, including a power point. Wiring regulations dictate that it
should be fed via its own circuit breaker then to the main consumer
switch. This then leads through the meter to the mains grid. I have seen
a grid-connect inverter fed through a secondary distribution board that
was in a detached shed (away from the house)

Although you can buy grid-connect inverters which plug into a power
point (and they do have anti-islanding) I suspect that the electric
authorities would possibly frown upon it. I base these thoughts on the
perceived possibility that conservative authorities would contemplate the
rare possibility that if the anti-islanding ciruitry failed, then there would
be live power on the open pins of the 3 pin connector.

As for approved wiring standards for solar, accredited installers are
required to complete certified training courses. There are standards
published, but I do not have any links.

yumology
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Joined: 07/05/2009
Location:
Posts: 4

Posted: 03:32am 11 May 2009

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Thank you thank you.
Very thoughtful post. :)

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