GT possible?

DC Builders

Greetings,

(I hope Bill is around)

My brother lives on a small 2.5 acre farm in Santa Rosa. He is serviced by PG&E.

He is the last customer on the power line---primaries only. (no more poles or wiring past his property)

There is a transformer on the pole and a 200 amp single phase 120v/240v 4/0 aluminum underground service approximately 40 feet in length from the pole to the meter.

There are no secondaries running back or forward to any of his neighbors from the pole, nor any planned developed nearby. The nearest PG&E power pole is back-line 330 feet.

Can he do a 6kW GT system, with rebates, incentives etc?

Thanks
Dan

BB.

Re: GT possible?

As far as I know--there should be no regulatory issue with his farm.

For insentives, look through www.dsireusa.org

One possible engineering issue... Some folks at the end of a feed like that may have wide swings in the voltage at their home.

The XW Hybrid inverter is defined to operate from 214-260 VAC +/- 3 volts.

If the home's line voltage is very high or low--or fluctuates with load (starts at 260 VAC with no load, and goes down to 220 VAC with load--Adding a 6 kW GT inverter can push the 260 Volts higher, or if the internal AC charger is enabled, pull the 220 down lower.

Also, if the GT Inverter is located (for example) on the roof a detached outbuilding 200' away from the meter--the resistance of the feed from the meter to the out building can also add "voltage swings" to what the Hybrid Inverter will see...

And every time the GT inverter sees an out of range voltage (or frequency)--it will shut down for 5 minutes and try again.

Not to say that your brother will have issues--just things to watch out for in rural areas.

-Bill

DC Builders

Re: GT possible?

Thanks Bill,

I guess my question is, does the surplus power then go back through the transformer to the high voltage lines.

I thought PG&E's program was for secondary distribution lines only.

Not sure I can see how PG&E could use the power.

Dan

BB.

Re: GT possible?

Yes, the whole distribution system is bi-directional. Right up to the generators (they probably do not like to be run backwards--although there are some pump/generate hydro stations that do both (pump at night, generate during day).

One reason the utility wants to keep GT solar (and other small generators) to 1% or so of system capacity--is they do not have to plan for anything special. If there are a lot of solar GT systems (such as a new development)--I have read of power companies that will limit the whole development to ~1% solar GT (1 in 100 homes). If every home had solar GT--the development could generate 2-3x more peak power than they consume--so there would be a lot of infrastructure costs that the utility cannot charge for.

The only areas I have heard that local generation sources are "banned" are a few places like down town San Francisco... They have parallel power lines that run into the city center... And if one of them has the "current flow the wrong direction"--they open their circuits.

-Bill