Most rooftop solar installs don't provide power when the grid is down.
The primary goal is to avoid sending power out to the grid where it
could injure people working to restore power, but more recently it's
been expanded to avoid energized lines extending out from the panel
where they could injure a firefighter on the roof. When we installed
solar in 2018
we
selected an
inverter which offers an outlet that provides best-effort power
("Secure Power Supply") during grid outages when the sun is shining.
I'd try to sell you on it, but the newer rules mean my inverter
wouldn't be legal for a new install.
I suspect this doesn't pass
a cost-benefit test, especially when you consider the risk of serious disasters.
Since the harms of allowing it are concentrated (firefighters) while
the benefits are
diffuse (everyone with solar) and speculative (very uncommon for a
disaster to be this serious), however, it got banned.
Still, I wanted to make sure mine was still working, and especially
that it would be able to charge my two portable power stations (Anker
SOLIX C1000 Gen1 and Gen2). I tried
over the weekend, but it was cloudy and the panels weren't producing
much. It wouldn't charge the batteries, but it could do an 8W
lightbulb:
When I came home from work today, it was a complete best case
scenario:
I turned off the Solar AC Disconnect, to simulate a grid outage:
I plugged in the Gen2, and it said it was drawing 1,004W:
The inverter said it was sending 1,031W, which is close enough:
This is enough for a full charge in about an hour. After it finished,
I plugged in the Gen1 to charge. It said it was drawing 512W:
These were both above 50%, though, so it's possible they'd draw more
power if they were less full. It looks like you can use an app with
Bluetooth to adjust how much current they pull, down to 200W. I wish
they had a button for this, but in the meantime I should ensure that
we have at least two phones in the house with the app installed.
Overall I'm pretty happy with this, but I don't like the single point
of failure with the SPS, and it also doesn't work well when it's not
very sunny: there's no way for the power bank to ramp down to draw
only as much as the SPS can produce. One neat thing about these power
banks, however, is that they have
the ability to charge directly from solar panels:
The solar input supports an 11-60V solar charger with an XT-60
connector. If you use an 11-32V solar charger, the current supports
10A max. When you use a 32-60V solar charger, the current supports
12.5A max.
You need an MC4 to XT60 cable, and you need to ensure the panel
doesn't produce more than 60V. Our first set of panels are LG Neon-R
360 (43V) and our second set are QTRON M-G2+ 425 (39V). In an
emergency it should be possible to repurpose a panel to charge the
battery. It's possible I should get another panel that wouldn't
require climbing on the roof, though!
Most rooftop solar installs don't provide power when the grid is down. The primary goal is to avoid sending power out to the grid where it could injure people working to restore power, but more recently it's been expanded to avoid energized lines extending out from the panel where they could injure a firefighter on the roof. When we installed solar in 2018 we selected an inverter which offers an outlet that provides best-effort power ("Secure Power Supply") during grid outages when the sun is shining. I'd try to sell you on it, but the newer rules mean my inverter wouldn't be legal for a new install.
I suspect this doesn't pass a cost-benefit test, especially when you consider the risk of serious disasters. Since the harms of allowing it are concentrated (firefighters) while the benefits are diffuse (everyone with solar) and speculative (very uncommon for a disaster to be this serious), however, it got banned.
Still, I wanted to make sure mine was still working, and especially that it would be able to charge my two portable power stations (Anker SOLIX C1000 Gen1 and Gen2). I tried over the weekend, but it was cloudy and the panels weren't producing much. It wouldn't charge the batteries, but it could do an 8W lightbulb:
When I came home from work today, it was a complete best case scenario:
I turned off the Solar AC Disconnect, to simulate a grid outage:
I plugged in the Gen2, and it said it was drawing 1,004W:
The inverter said it was sending 1,031W, which is close enough:
This is enough for a full charge in about an hour. After it finished, I plugged in the Gen1 to charge. It said it was drawing 512W:
These were both above 50%, though, so it's possible they'd draw more power if they were less full. It looks like you can use an app with Bluetooth to adjust how much current they pull, down to 200W. I wish they had a button for this, but in the meantime I should ensure that we have at least two phones in the house with the app installed.
Overall I'm pretty happy with this, but I don't like the single point of failure with the SPS, and it also doesn't work well when it's not very sunny: there's no way for the power bank to ramp down to draw only as much as the SPS can produce. One neat thing about these power banks, however, is that they have the ability to charge directly from solar panels:
You need an MC4 to XT60 cable, and you need to ensure the panel doesn't produce more than 60V. Our first set of panels are LG Neon-R 360 (43V) and our second set are QTRON M-G2+ 425 (39V). In an emergency it should be possible to repurpose a panel to charge the battery. It's possible I should get another panel that wouldn't require climbing on the roof, though!
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