EV and Solar with Secure Backup – Video


The month of September is Disaster Preparation month, and September is also when we celebrate National Drive Electric Week. How many of you would have thought that we can put these two together?

Many electric car enthusiasts and drivers know that pairing an electric vehicle with a solar system is an ideal way to further reduce your carbon footprint and to avoid paying higher electricity costs commensurate with an increase in electricity consumption. However, many EV drivers may not yet know about the secure backup power supply option now available in some solar PV inverters. Such a feature could prove essential to keeping food safe in the short term, or providing essential mobility during an extended power outage.

EV with

EV And Solar With Secure BackuP

SMA Solar Technology AG manufactures the Sunny Boy TL series of inverters, which feature a Secure Power Backup that can provide 1500 watts, or 12.5 amps at 120 volts, of electricity without being tied to the grid. This notable feature, also called Standalone Operation, is able to provide backup power without the need for a battery storage system. Of course, with no battery pack present, this also means the inverter requires sufficient sunlight on the panels in order to support the load. Depending on the orientation of the panels, and the size of the system, a peak load above 1400 watts may only be supported during the best 2/3rds of the day, and I learned this from personal experience.

The Sunny Boy inverter display provides a reading of how many watts the load is consuming, providing excellent insight into how much power your different loads require. I suggest you run some experiments and tests before a power emergency actually strikes. This enables you to plan for which loads may be able to operate concurrently, and which low-power loads should be used in the early morning and late afternoon. Seasonality will also be a factor, and the system capability near the winter solstice may be disappointing, so be prepared and have modest expectations.

Below is a brief video that shows “proof positive” that a Secure Backup is capable of Level 1 charging of an EV, such as the Nissan Leaf. This test was conducted after the solar system was commissioned, but before the grid tie was installed. Power that would have otherwise gone to waste was collected into the EV battery. (Astute readers may wonder why a separate grid tie was needed, and that question will be addressed in a future article.)

Charles' Solar W/Backup Setup

Charles’ Solar W/Backup Setup

The Chevrolet Volt, with its Level 1 charging cord that has a selectable 8- or 12-amp charging rate, would play very well with a Secure Backup of this type and capability. By setting the charge cord to 8-amp mode, the Secure Backup will be more likely to maintain sufficient power for the load for more hours of the day. Additionally, during peak sunlight, the Secure Backup may be able to power an additional load of up to 4 amps or 480 watts.

Of course, during an extended power outage, your immediate concerns may be more focused on keeping a refrigerator running for as many days as possible, refreshing the temperature during the daylight hours. But once the food supply is exhausted, it may well be time to charge up the EV and start scouting for supplies and other resources.

Categories: Charging, General


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22 Comments on "EV and Solar with Secure Backup – Video"

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Good article.
If I had it to do over I would have gone with an inverter like this instead of my Enphase micro inverters.

Can battery backup be added to this system?….well I mean a fully integrated system. The simplest way would be to just have a couple deep cycles charged from the SMA emergency power outlet.

You would need the Sunny Island for battery backup. Be sure to use non toxic long lasting advanced batteries and not old toxic, short life Lead acid batteries.

lead batteries are not toxic handled correctly and are required by law to be recycled and are in the 98-99%
Your computer you are writing your post on it more toxic likely than a lead battery. I get $10 each recycling mine though usually save them for core charge.
In home service lead batteries last 5-10 yrs but so low cost they even needing replaced are lower cost that any others, most by a lot.
Soon lithium will cost the same in 5 yrs or so but for now lead is still best.
So the smart thing is lead now and by the time they need replacing, lithium will have dropped to the same price, switch to
Personally I just bought a Volt lithium pack to replace lead batteries in my EV where it’s qualities justify it’s $200/kwhr

George, I wouldn’t have a system without batteries and back up DC generator to charge them if the grid goes down.
It also is my lightweight EV RE which also is intergrated into the system both to be charged and supply power.
I ran my home from my EV’s for 3 days during a hurricane.
I’m moving soon but will go offgrid because it costs less eliminating the hassles, fees, costs of connecting to the grid, lower inverter costs easily pay for batteries and back up generator.
Some plug in hybrids come with inverters to supply a home, etc when needed.
Ford built E Rangers in the late 90’s with V2G built in by ACPropulsion with built in 15kw charger.
You can still buy these used that switched to lithium batteries makes a great EV.
You can

I have the exact same setup as the author, X 2.

In other words I can charge BOTH evs simultaneously, and then use my high voltage batteries in both cars to run inverters to use what I want to in the house.

The refrigerator will not run any other way, plus the beauty of using the car for the ’emergency battery’ is that you also have power when the sun goes down, and then you can recharge both high voltage batteries again the next day, provided you have at least 950 watts for each ‘1/2 system’.

I am wondering whether there are any EVs capable of DC charging from your PV battery bank? is there a ‘lite’ version for CCS or ChaDeMo?

I’d like to see ChaDeMo to home and solar DC directly to battery as well.

Since the SunnyBoy Inverters are quite efficient, even in standby-mode, to me its unnecessarily ‘reinventing the wheel’ to try to use the solar DC power directly.

My house, and cars, are arranged to either charge or use 110-120 volt 60 hz power. The charger brick that comes with both GM cars defaults to 8 amps and the cars themselves regulate all issues related to charging the relatively large batteries, (around 14 and 16 kw, respectively). Battery conditioning (heating or cooling) is automatically handled by the cars themselves, and I don’t have to worry about it. On an emergency basis this is PLENTY of juice, even allowing some gas free driving when all the gas stations would be closed.

correction 14 or 16 kwh. As mentioned, its trivially easy to run anything in the house on an emergency basis on 110 volts AC, since all the wiring, plugs and outlets are designed for this.

Most of my house runs on natural gas, so, the ONLY things which I cannot run on an emergency basis are the 240 volt equipment namely:

1). Hot tub pumps (although the circulator pump for the hot tub gas heater will work just fine).

2). Central air conditioner (on an emergency basis, I can live without it).

Mundane loads like lighting, 500 watt glow plug for the gas oven, which runs continuously, and the washer/dryer – which would only need to be used on an extended outage, can run as necessary, the dryer off the inverter as necessary, same with the refrigerator and microwave, which must run off the inverter. Everything besides those 2 can run more efficiently directly off the sunnyboy(s). The washer is an energy star model and never draws more than 400 watts even while starting.

I see what you mean Bill. In a retrofitted house what you say makes perfect sense – no need to reinvent the wheel.

However, there is a growing amount of off-grid users who would benefit of using AC as a an extra – most equipment we have is natively DC or could be DC without any significant price hikes. Unless you plan on using AC adapters for home heating 🙂

I’m not conversant with what is generally available outside north america, but here, almost everything runs efficiently on 105-125 volts ac.

If everything was say 24 volts dc, then the amount of copper required for reasonable efficiency would be 25 X that required for 120 volts. But as I say, here, all the standardized products (and therefore the most value) run on household ac.

scott franco, the evil, greedy republican

The first thing you do when you buy solar, is you take all of that fine literature they gave gave you on microinverters.

and burn it.

You can take an inverter and add battery backup to it. You can use a multimode inverter and use it for grid tie.

If you take a grid tie inverter, the upgrade for that is the trash can.

I’m sorry, not impressed by people suddenly “discovering” things we have known for years (and are commonly printed in the literature).

I like the model SunnyBoy, both I and the author share..

THe newer larger models give useless information like ” # of lbs of greenhouse gasses saved”, when I want to know circuit voltages, currents, and power levels.

Also, these old SunnyBOys are almost totally quiet; I can’t even hear the 2 of mine run unless they are running over 2500 watts each. The slight hum from the analog mechanical revenue meter required in NY State drowns out the inverters.

I tried my 5000TL secure power outlet with my Think City EV at 12 amps and it would not start charging. I have not tried the Volt yet, but my older Volt also has only the 12 amp setting. I might get one of the Leviton EVSE that can set a 7 amp charge rate and try again.