Electricity grid failures and how Grid Tied PV systems deal with it...

[Gio]

Hello dear members!
I am installing a 10 kW PV system on the roof, which is very attractive investment due to the FIT program Ukrainian government has established.

What is my concern:
The electricity grid fails very often here (twice a month for 6 hours average).
As I know the con of grid tied system is
- No power when the grid is down. That means continuous access to the utility power grid is required for the produced electricity to be used...

Tell me please if it possible to arrange a PV grid tied system the way to provide power from PV array when the grid is down and the sun is shining (like on the image).
GridTiedPV.jpg
Not to instal baterries having 30 losses additional losses (like on the image)...
BatteryBackup.jpg

Thank you for your opinions!

[Volusiano]

Check out the new SMA 3KTL/4KTL/5KTL inverters. They have their own power outlet that can supply for up to 1.5 KW of power if the grid is down but the panels are producing during the day. When the grid is back up, the power outlet is turned off. You can check out this youtube link that talks about it more. These are for the US version, but maybe SMA make the same thing for European version as well.

Maybe you can set up a transfer switch (like how you would do with a backup generator) to feed these outlets into the house through your circuit panel without backfeeding into the grid.

Since you have a 10 KW PV system, if you want to maximize the output when the grid is down, use 2 3KTL and 1 4KTL (or maybe 3 3KTL would be enough for a 10KW system, too) so that you'll have 3 1,500W outlets, one from each inverter.

[Gio]

Check out the new SMA 3KTL/4KTL/5KTL inverters. They have their own power outlet that can supply for up to 1.5 KW of power if the grid is down but the panels are producing during the day. When the grid is back up, the power outlet is turned off. You can check out this youtube link that talks about it more. These are for the US version, but maybe SMA make the same thing for European version as well.

Maybe you can set up a transfer switch (like how you would do with a backup generator) to feed these outlets into the house through your circuit panel without backfeeding into the grid.

Since you have a 10 KW PV system, if you want to maximize the output when the grid is down, use 2 3KTL and 1 4KTL (or maybe 3 3KTL would be enough for a 10KW system, too) so that you'll have 3 1,500W outlets, one from each inverter.

Very promissing, is "Secure Power Supply" (SPS) really an exclusive feature os SMA?
Only one plug is avaliable and that one is next to the inverter, and after the grid is on gain the SPS must be turned off mechanically ...

I hope there are better solutions?
Don't you know if it's possible to adjust the system (scheme) to automatically switch to the "only house feeding" and back?

[silversaver]

Depends on how much energy you need. I'll still prefer a power generate when power are down. I still remember the SD fire cause power down for few days... I'm eating ice cream while watching the TV at home with AC on. It was like almost 100F at night lol.....

[Gio]

Silversaver, but what did cause the fire? And what is the best solution?

[silversaver]

Silversaver, but what did cause the fire? And what is the best solution?

It's a big fire down San Diego area back few years ago and I don't remember what cause the fire.

This is the link for SMA inverter SPS

http://www.youtube.com/watch?v=fF461YYNbtw&list=PL840A5336CAC32332&index=30

Watch it, so you will get an idea. It will only power on small devices. If you need to power on an AC, you will need a power generator.