Pacific Gas & Electric (PG&E) has begun Public Safety Power Shutdowns, with the first phase affecting just over 500,000 households, the second phase affecting 234,000, and the third phase affecting 4,000. Between 110,000 and 130,000 households have had their power turned back on. The below map, found on this address search website provided by PG&E, shows the regions affected. The company’s Twitter account shows available Community Resource Centers that will remain open during daylight hours with restrooms, bottled water, electronic-device charging, and a/c seating for up to 100.
This article will outline some potential solutions to keep electricity on while Public Safety Power Shutdowns are ongoing.
First, a warning – only a small, single digit percentage of the nation’s over 2 million solar power plants are designed to stay on when the broader power grid shuts down. This feature – called “anti-islanding” – was put in place to protect line workers from electrocution due to solar power systems feeding the grid during power outage events.
AC coupled energy storage
For those of you with a currently installed solar power system of the standard nature, it might be best to consider an AC-coupled energy storage solution. Solutions like this can be found by sonnen, Tesla, SimpliPhi, Sunrun and others. These solutions, when sized and installed appropriately, can run your home when the grid shuts down.
The sonnenbatterie by Sonnen – probably the most advanced energy storage management solution we have available to residential customers – offers 3 to 8 kW of instant power, and 5 to 15 kWh of energy storage in various products. The hardware has intelligence to predict when power outages might be coming, and manages itself to maximize available electricity. As well, you can program the system to shut down all plugs that aren’t considered mission critical.
The Tesla Powerwall is also in this class of products with its single offering that peaks at 5 kW power output, and 13.5 kWh of energy storage. Tesla recommends two units to meet daily consumption needs. This is because an average American home uses 30 kWh/day – so any of these units will have to be used judiciously. If a homeowner does in fact have solar power (and it isn’t needed for these units to run), then potentially, they can power themselves perpetually. Tesla is a local company
SimpliPhi offers their battery solutions coupled with inverters on and off-grid manufacturers, AC or DC coupled. As well, their hardware to an existing solar installation by using the companies fully integrated AccESS. Truly, SimphiPhi has a broad package of products – and not all of them have to be full home solutions, like their Big Genny Emergency Power Kit that can be pulled around by hand. And – as a kicker – they’re located in California, and quite conscious of what all is going on around them.
A second solutions involves a product from global inverter manufacturers SMA and (maybe – if it made it into production) SolarEdge, but these are more complex retrofits that would involve changing out hardware if you’ve not already installed these devices.
SMA’s solution is called the “Secure Power Supply” and it is integrated into a large number of its residential solar solutions. SMA has released a video on it. The unit, essentially, lets you use up to 2 kW of electricity when the grid goes down, as long as the sun is up. It really is just a place for you to plug directly into the inverter. A simple solution.
SolarEdge’s HD Wave was pitched with a “Self-Sustaining Power Outlet“, which is very similar to the SMA unit above. The hardware allows for a 1.5 kW max power output and is available in the company’s HD Wave 3,000 and 3,800 watt units. edit: A reader has notifed pv magazine USA that this feature might not have made it into production hardware.
Battery add on to current inverter installed solutions
Certain products from SimphiPhi, LG, Panasonic and others must be coupled with inverter solutions – so make sure to choose smartly. Already installed solar inverters should be able to integrate these less than optimal solutions, however, it’ll be necessary to do some extra wiring to get the hardware working – which is why you should consider the more expensive, more complex AC coupled solutions. SolarEdge’s StorEdge solution offers an inverter that can be installed without energy storage, but can later – cheaply and easily – have energy storage added in.
Lastly, one future solution is coming from Enphase – the IQ8. This system has the integrated intelligence to listen to electricity demand coming from the home, and to deliver as much power as it can via the available sunlight at that moment. This system will not power your home after sundown. Unfortunately, the product isn’t available yet.
A very new, and extremely short as of now, pair of lists has been started by the California Energy Commission (CEC) as of August 27, 2019 for purpose of tracking battery and energy storage solutions approved by a state regulatory review body. Currently, Sungrow has three energy storage solutions, and e-On batteries has a single battery on the list. The CEC solar module list has thousands of modules and has become a nationwide standard.
Preparation & microgrids
There are many areas of the state that have been planning for these outages. For instance, the City of Calistoga, California has solicited Clean Coalition to conduct a feasibility analysis for developing a community microgrid as one potential tool to manage the Public Safety Power Shutoffs (PSPS) that will come during the California fire season. The below image is the fire threat map of the city put out by the electricity utility, essentially noting that the whole of the city – and specifically the 60 kV power lines coming into the city – surrounded by fire risk.
Per the above linked to map provided by PG&E, the city is currently affected by the power shut offs.
If any readers have questions, please don’t hesitate to sent them to firstname.lastname@example.org. We will do our best to get your request to qualified contractors, or to direct you to manufacturer’s websites. We do suggest also reaching out to local solar and electrical contractors that can be found on various websites. This great, searchable member list from the California Solar and Storage Association happens to represent many manufacturers, installers and others focused very specifically on this topic in California – so it is probably a great resource to tap into.
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Good to see this article, as the blackouts really emphasize the need for these products. My understanding is that the IQ8 From Enphase when it ships in volume next year will be revolutionary in this space as it provides the anti-islanding. Is that correct? Are there any other inverter vendors out there that promise the same capabilities in their products? The Enphase microinverter is an AC solution which is safer and many come built into solar panels from companies like SunPower. I am waiting eagerly to see if the Enphase Ensemble battery storage system lives up to its hype and can provide true grid neutrality to home owners.
The issue is most of these solutions are limited in one way or another. 30 kWh/day may be “average” consumption throughout the USA over a year, but that will not supply enough for any type of air conditioning.
A fully integrated system includes batteries, inverter, a generator and controls to integrate the entire system. And the system must match the needs of the homeowner.
It depends on the efficiency of your AC unit and the size of your house. Mine draws 3.2 kW when cooling. I have the Tesla PowerWall (27 kW) and can run the AC to keep the temperature in a reasonable range. The peak power draw was 13 kW (charging my electric car, running AC and the rest of the house. No issues.
Sergej: And the size of your A/C system. And the number of your A/C systems. 13 kW exceeds the max output of 2 Powerwalls (27 kWh = 2 Powerwall 2). With 27 kWh of storage, The Air Conditioner plus the rest of your house will not last too long.
Aidan: Outback is also missing from the list. It is a very flexible system. We implement both AC and DC coupled systems. Although these days, with the new 600V charge controllers, I prefer to do Grid-Tie to DC Coupled conversions.
Aloha, love your reporting John but I wonder why there’s no mention in this article about offerings from Generac(Pika)? The utility here in Hawaii has capped simple grid-tie systems and my installs lately have been about 50/50 between Pika and Tesla/Solaredge for residential solar+storage. Honestly I strongly prefer the former due to ease of installation, system sizing and esthetics. Seems perfect for Californians who just want some lights and charged phones in a blackout. From all I’m reading about SPI this year, Generac(Pika) really seems to be taking the anti-islanding solar system to the next level with regards to load management especially, why not have them in this list?
“Tesla recommends two units to meet daily consumption needs. This is because an average American home uses 30 kWh/day – so any of these units will have to be used judiciously.”
@ John Weaver: Do you know of any “study” done by say SEIA, DOE, NREL or some other group that has at least pundited a “nominal” battery storage solution for the “average” across the country? The number of 30kWh seems to be a target point. Depending on the design criteria, one could have 21kwh to 24kWh of energy available. If we look at how hybrid and BEV battery packs are designed and used, to get longevity and reliability the battery packs are oversized, so one doesn’t discharge below the 70% to 80% DoD on any given day. In the desert Southwest, like Phoenix AZ, a typical 5 ton air conditioning unit could require 180kWh of electricity for 24 hour operation during the summer months. In the Northeast all electric heat would probably be close to this during those ice storms. Then again, if one is using a natural gas furnace, just a 3/4 to 1 H.P. blower fan might be all that is needed.
For me, 30 kWh comes from 12,000 kWh/year average household usage / 365. I’d love to see an emergency panel average that would let us all know life going at a simple, but safe, level.
Add to these large, complicated expensive solutions a simple one: Install a 1000 watt inverter in your car, and run a 120v extension cord to ONE freezer/refrigerator.
Idle the car to keep the battery charged. Most cars have at least a 500 watt alternator. My Scion does, and with just a 1.5 liter engine, it will idle a LONG time on 12 gallons. The freezer intermittently draws 200 watts. LED lights, 3×10 watts. Phones and computer 40 watts.
We don’t all live in McMansions.
You’d prefer saving your gas, but in times of need…
I connected an inverter directly to my car battery and idled the vehicle to keep things charged during one of the CA ‘safety’ blackouts, but drawing 300W from the battery/alternator continuously for several hours was problematic for the alternator. It got pretty toasty and I didn’t feel it was safe. So at a minimum I would find the specs to your alternator to see what it can actually handle safely on a continuous basis with the car at idle. That said, certainly drawing something lower, such as 150W, ought to work safely under any circumstances without overheating the alternator, and can be drawn through the car cig power port instead of directly connecting to the battery.
Car cig power ports are fused, so check and don’t exceed 5A below the rating. So for a 15A fuse do not exceed 100W and for a 20A fuse do not exceed 150W. It is best to match the inverter to what the socket can deliver to ensure that you don’t blow the fuse. And also be sure to use a real inverter… a pure sine wave inverter, and not something really cheap that only produces a pseudo sine wave (which looks almost like a square wave).
Eguana Technologies?? Battery storage 13-39kwh expandable home storage. http://www.eguanatech.com/
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