Solar w/480v three-phase commercial power?

 General question for the group: what is involved in connecting a solar
array to a 480v three-phase system?  My employer has an opportunity to
receive approx. 4500 kW of panels and would like to install them on
one building of our complex. We generate our own (dirty) power and
distribute through a 480v three-phase system to a few dozen buildings;
the panels would carry only a small fraction of the load in the
intended building (but it's a start).  While I have a general sense of
how one ties an inverter into a 240v residential main, I'd like to
know how it's done with three-phase power. Can anyone provide a
summary or pointer to a web page?

We'll have an EE on this if it goes forward-- I'm just looking for
basic information for my own interest and so I can provide a general
answer to those making the decisions. They'll be particularly
interested in learning if connecting to a three-phase system requires
a lot of additional equipment/cost as compared to the residential
systems I'm more familiar with.

thanks,

Kiwanda

 
                       ^^^^^^^^^^^^^^^^^

Sorry about the typo-- 4.5 kW really --we don't have enough roofs for
4500kW!

-kiwanda

 Kiwanda wrote:

The simplest thing to do would be to use a 480V three-phase inverter.
The problem is that such inverters tend to be quite a bit larger than
4.5 kW. See, for example:

http://advancedenergyonline.com/catalog/Inverters/3-Phase.htm

There are probably several ways that you could work a lower-voltage
and/or single-phase inverter into your system, which would allow you to
buy a properly sized inverter, but that's getting a bit out of my area
of expertise. Plus, what will work best for you is probably going to
depend on some of the details of your system.

You might try calling up Xantrex or some other inverter manufacturer --
I'm sure they would have some helpful ideas, and they *might* even be
able to configure a smaller inverter to do three-phase.

 for the group: what is involved in connecting a solar

If it's "only" 4.5 kW, consider whether there is single-phase 240V
somewhere, maybe in one of the buildings.  That would only be a 20A
circuit, and you could use a residential single-phase inverter for
your proof-of-concept.

By the way, this would not be a bad way to wire the whole thing if you
expand, lots of smaller inverters distributed around the buildings.
It would certainly save on wire losses.

 50g2000hsm.googlegroups.com:


Bear in mind that if you own an American home with a 200 Amp circuit
breaker panel (pretty common), under full load, your panel is delivering
48 K.Watts to run your residential property.  That is 10 times as much
power as you're expecting to get from the solar panels that you intend
to use in an industrial environment.
   Instead of trying to supplement your high-power industrial supply in
your facility, why not use it to supplement the orange-outlet isolated
clean power that might be going to your computer equipment in you
facility?
Many industrial installations use this orange-outlet designation to
distinguish which outlets are free from switching spikes and power noise
so that computer equipment will have clean power.

   If nothing else, you can then have the chance to tell your ISO9000
compliance inspector (who asks what your alternate plans are for
retrieving data when the power goes out to your computers) that your
understanding is that the sun won't go out for another 8 billion years,
give or take a few.

   (Actually, don't try that:  these people have NO humor!)


Rick