Wanted to thank everyone who responded to our recent questions and comments regarding solar microgrid components, including panels, inverters, gateways, and battery storage arrays. We’ve made our decisions and we expect our new microgrid to come online before the end of 2019.
Will share a few details on our choices in case they will help others:
- Hanwha panels, SolarEdge string inverter, Tesla Powerwall 2 battery array
- Generator power = 10 kilowatts
- Generation plan = average 1.1 megawatt hours per month (NC location, less sun than FL)
- Max energy storage = 40 kilowatt hours (three PW2 units, gateway)
- Max continuous storage load = 15 kilowatts
- Max peak storage load = 21 kilowatts
- Projected utility grid offset = 100%
- Turnkey pretax installed price was roughly $53K
- $26K for the generator elements and $27K for the Powerwall 2 storage system
- After-tax pricing works out to about $39K all-in
- Monthly payments are roughly $190/month with 100% financing (just adding $39K to the final mortgage amount)
- Projected electric bill with no microgrid was roughly $300/month.
- Assuming no surprises, we’ll be saving roughly $1,300 per year, ever year, starting immediately after the microgrid installation
- Increase in home value = roughly $40K.
- Home equity increase starts at $600/yr, grows annually as mortgage is paid down
- Our first turnkey microgrid project with Powerwall storage
- First fully self-powered solution, we rarely expect to pull energy from the grid
- Net-metering was not offered by local electric utility, only dual metering. Found creative zero-export inverter configurations as a workaround to allow direct microgrid to connect to the grid with no net-metering
- All equipment consolidated in basement electrical room
- Lead the market transition to renewable energy rather than follow - ambassador for others
- Save $$$
Based on all the feedback here we avoided dealing with Tesla direct and engaged a local Tesla reseller instead now that Powerwalls are readily available. Will report back early next year with installation results.
Wishing blue skies and free megawatt hours to all!