Finally Grid Tie Solar with some backup off grid capability

Looks like many folks, myself included, may finally be able to get a grid tie inverter that will run to a limited amount in off gird mode with the power out. Of course there are battery based grid tie units that provide all sorts of islanded capacity, but the trade off is significant extra cost up front, more expensive installation and battery replacements on 3 to 5 year intervals. I had just heard about SMA making a unit that might be the ticket and started a thread on another site I participate on. A SMA factory employee replied with limited details.

http://www.solarpaneltalk.com/showthread.php?8565-SMA-Inverters-with-Emergency-backup

My understanding from some web research is the Japanese government is rolling out a new very high dollar solar PV incentive and it requires "emergency backup capability" and therefore SMA is coming out with a product to meet the requirements.

I expect 12 amps at 120 volts only when the sun is out is not much but with a UPS and some planning, I expect many folks might be able to keep some critical intermittent loads operating long enough each day to make it through an outage.

Sunny (SMA) (, Sunny Island) and Outback ,( Radian) have battery based backup systems, but you pay a hefty front end cost and have to change batteries every few years. Of course if someone is willing to put in a parallel charge controller and inverter and run the array at lower voltage there are other options. The SMA (sunny) set up is the only one I have seen with no batteries, its basically an option on a standard grid tied inverter.

quote="begreen, post: 1220851, member: 5"]Sunny and Outback have had this capability for a while now. I remember looking into this last year.[/quote]

http://www.solarcity.com/residential/energy-storage.aspx

Nice modular system
Uses same Li batteries in Tesla cars and tesla supercharges
Should have economy of scale to drive down home storage EV amd public charging prices

2760 watts at 240v is about 12 amps. Maybe some inverters run on 120v, but 240v is much more common.

The big headache with the backup is the UL Listing that requires the inverter to drop the feed if the grid goes down.

Be green

Solar city pushes the lease model for solar power
One poster on another site said it was 10 per month extra for the back up module
No info on how much they are charging for this to buy outright


Cloudy days are really common near Puget Sound eh??

Tom

All months except July and August are dominated by clouds, rain, and darkness. The transition months of June and September can be decent or awful depending on the year.

I think macmaine was being sarcastic, or at least just poking fun. Generally, weather does suck here. If you're planning an outdoor event, go for august where you almost always have great weather and extremely long daylight hours. The sucky weather is more entertaining than the same ol' thing everyday though and the rain gives us lots of green.