Storing Off-Peak and Selling Peak back w/No solar, creating Net-Zero cost per day

[Fred Arde]

Hi,

What I am after is, a 12-15 KW Grid-Tied inverter/charger that will follow a Peak/Off-Peak schedule per my electric company schedule. My goal is to use power @ Off-Peak times to charge a battery bank, use Off-Peak power real-time naturally, plus store excess power in order to supply that excess power back to the utility @ Peak rates….creating a net-zero (dollar) usage each day. My rates are $0.056 Off-Peak and $0.15 Peak so this seems very doable.

Does anyone know of anyone doing such a thing?

What inverter/chargers are programmable for this? Is the Fronius Primo 15.0-1 - 15,000 Watt programmable for this? Maybe I just don't know the keywords for my search.

These companies don't seem to either know their equipment or are REALLY slack in responding.

Any help would be appreciated.

Thanks

[Paul Camilli]

Methinks two of these http://www.sma.de/en/products/battery-inverters/sunny-island-60h-80h.html SI 8.0H stacked would do everything you want, but at a price.

Good luck, Paul

[Fred Arde]

Methinks two of these http://www.sma.de/en/products/battery-inverters/sunny-island-60h-80h.html SI 8.0H stacked would do everything you want, but at a price.

Good luck, Paul

Thanks Paul

I would really like to find a hybrid that doesn't require stacking. I can't believe there are only 6-8KW units out there.

I look forward to opinions and views of other forum members too.

[Dave Schwartz]

Good luck, but charging and discharging is a pretty inefficient process. Between the losses that mean you're only going to achieve about 60% of the spread between peak and off-peak and your capital expense and ongoing maintenance (battery bank care and replacement) it may take a long time to break-even, if ever. Careful economic analysis needed here.

Basically you're trying to reinvent the Tesla Powerwall but without the system engineering and high-tech batteries AND sell the output rather than just consuming it yourself.

Of course all that is probably moot. Electric utilities aren't stupid. Before you will be granted a net-metering or FIT agreement, they will want inspection and sign-off by an electric authority and one of the rules is usually (it is here in Ontario) that the system can't contain any kind of storage. I haven't heard of any utility having rules allowing storage in a net-metering or FIT application.

If you modify the system to add storage after it was approved without storage and they find out (if you have smart meters, they know when you are consuming and when you are producing) you will be done for fraud - in addition to being disconnected to freeze in the dark.