Use grid power to supply inrush current?

[otownjeff]

I have a controller/battery/inverter combo unit from Blue Carbon. I know how bad it is. Not programmable. Not expandable. Everyone keeps telling me. All the time. Again and again. But I've shaved $100 off my electric bill. At this rate, the ROI will be 15 months. It's amazing. The ROI if I include the inverter fridge I bought is still only 19 months.

I could save even more if I could figure out a solution for my other refrigerator and my washing machine. I know the induction cooker and instant hot water heater won't be possible.

Is there any kind of product that can handle temporary high current flow by supplementing from the grid?

My unit doesn't do it, even when it's plugged in.

 

[1201]

How about the solution here?

 

[otownjeff]

It's interesting but it supplies all pv or all grid. It can't mix in grid power as needed to supplement the pv. I guess that's what expensive inverters are for.

People have mentioned solutions in other forum threads. They all seem kind of diy and geeky to me.

OTOH, there's probably a million people like me who would love to buy a product for this exact purpose. Suddenly, everyone's small solar systems become more useful, flexible and valuable.

 

[jamiegreen]

Kind of sounds like a grid tie inverter is more suitable, but that comes with its own issues on having to get it approved by the electric supplier in most countries, since it would be exporting to the grid any unused power. I'm not sure I can think of a solution that incorporates the unit you already have. Victron units have a power assist feature that does exactly what you mean, but that's an entire system upgrade.

 

[zanydroid]

Hard to achieve what you want without paralleling a hybrid inverter to the grid (interconnect regulation issue which implies somewhat more money) or a bigger inverter (replaces what you have). Do you have an alternate power architecture in mind?

 

[zanydroid]

In the underground parallel operation with cheap hardware camp, search around for the threads and Facebook group of the GTIL enjoyers.

GTIL (grid tie inverter with limiter) intrinsically will allow grid to assist. But you are violating a contract/regulation with your utility.

 

[HRTKD]

Out of the box, a Victron Multiplus does what you want, but in reverse. When shore power is available it uses that first and if the amps available from shore power aren't enough to satisfy the draw it pulls from the battery bank.

There are user configurable parameters deep in the Victron system that may allow you to prioritize the battery first and then supplement from shore power. But I haven't dug into it that deep.