Solar power anyone ?

[Depmandog]

Thanks guys for the posts. TnAndy, apologize I didn't catch that your system was what i was referring to. Remember, I am a Newb, so at times reading these posts it's like reading a foreign language HAHA

 

[sld]

We tend to get large hail at times. How much abuse can these panels take usually?

 

[ultrarunner]

My electrical averages 11kw per day and does not vary much year round by more than 15%

Seems I don't use enough to make the numbers work... home is 2300 square feet of 1950's construction with no energy upgrades like dual pane windows or applicances... Freezer, Washer, Dryer date from the 1960's.

The companies that advertise Solar beat a quick retreat when they see my usage.

 

[dave1949]

My electrical averages 11kw per day and does not vary much year round by more than 15%

Seems I don't use enough to make the numbers work... home is 2300 square feet of 1950's construction with no energy upgrades like dual pane windows or applicances... Freezer, Washer, Dryer date from the 1960's.

The companies that advertise Solar beat a quick retreat when they see my usage.

The numbers may not work for their business model but solar electric costs are relatively linear. There just isn't much difference in the cost of the first kW and the last kW.

My usage averages 14-15 kWh per day and the numbers work from my perspective as the owner. The installer has up-front fixed costs to cover, so I can see how doing a $15K job versus a $40K job makes a difference to their numbers.

 

[ultrarunner]

One home in the area is covered in panels... we just couldn't understand the pay back...

After the place was foreclosed... found out the owner had a sophisticated grow operation.

 

[catfishdaddyengineering]

Sunny Boy (SMA America) now has a line of string inverters that will produce up to 1500 watts (at a dedicated outlet connected to the inverter) while the grid is down, and of course the sun is shining.

Outback and a couple others now offer a "grid-interactive" central inverter. It is a bus-bar based inverter that has a separate relay for the grid-tied line. If utility power is lost, this relay opens to disconnect from grid, but the home is still fed on the "backup" breaker panel from solar panels and/or batteries. They have smaller inverters in GT/GV series, but their Radian series has dual AC input where you can connect generator to charge batteries in event of low solar output while disconnected from grid. This beats having to buy two inverters to accomplish the same thing.

Outback Power Inc. - Grid-Interactive

 

[dave1949]

Sunny Boy (SMA America) now has a line of string inverters that will produce up to 1500 watts (at a dedicated outlet connected to the inverter) while the grid is down, and of course the sun is shining.

Outback and a couple others now offer a "grid-interactive" central inverter. It is a bus-bar based inverter that has a separate relay for the grid-tied line. If utility power is lost, this relay opens to disconnect from grid, but the home is still fed on the "backup" breaker panel from solar panels and/or batteries. They have smaller inverters in GT/GV series, but their Radian series has dual AC input where you can connect generator to charge batteries in event of low solar output while disconnected from grid. This beats having to buy two inverters to accomplish the same thing.

Outback Power Inc. - Grid-Interactive

That's interesting and sounds useful.

I wonder if it is necessary to do some manual demand management when used without batteries? For example, if a well pump and the water heater cycles at the same time, in many grid-tied systems that combined demand would exceed the momentary solar PV output, and the grid back-fills the deficit. With no grid power and no batteries, I wonder how this works out?

 

[TnAndy]

With no grid power and no batteries, I wonder how this works out?

It doesn't.

All off grid systems ( and the 'normally' grid tied hybrid ones, like the Outback ) HAVE to have batteries to work. Otherwise, a passing cloud would put you out of power. SunnyBoy's new inverter seems to be the one exception to that, though it's use would appear limited to non-motor type uses....where that 'passing cloud' effect wouldn't matter too much.

The new Radian inverter that Outback makes now is simply a combination of what I have......2 GTFX inverters ( 120v each on separate phases ), and a Hub ( that co-ordinates the phasing ) in a single package with more inverter power ( I think they are 8,000watts )

 

[TnAndy]

My electrical averages 11kw per day and does not vary much year round by more than 15%

Seems I don't use enough to make the numbers work... home is 2300 square feet of 1950's construction with no energy upgrades like dual pane windows or applicances... Freezer, Washer, Dryer date from the 1960's.

The companies that advertise Solar beat a quick retreat when they see my usage.

Simply means you'd need a smaller system. Using micro-inverters, which mount one per panel, you could start with a few panels, and keep expanding until you hit your usage, and knock out your bill. The micro inverter system is about as close to "plug and play" as it gets !

 

[TnAndy]

We tend to get large hail at times. How much abuse can these panels take usually?

We haven't had more than 1/4" hail on ours, which did nothing. They are tempered glass on them, but my guess is something like baseball sized would put you in a world of hurt.