Power stations have quickly become one of the more popular products we test. It’s easy to see why: They offer silent operation and easy to move to wherever you need power. Their rising popularity has driven the emergence of many new brands and models in the past couple of years. And those new models, are getting bigger and more capable, as demand increases for emergency power solutions when the electrical grid goes down.
The basic strategies to surviving an power outage:
- Emergency power: Plug devices or appliances directly into an alternate power source.
- Emergency backup power: Uses a manual transfer switch connected to an alternate power source to supply power to a number of circuits in your home’s service panel.
- Emergency standby power: Uses an automatic transfer switch that senses when the power goes out and then supplies power from an alternate source to some or all circuits in your home’s service panel.
These strategies work basically the same regardless of the power source, which traditionally has been generators. But power stations have rapidly made their way into this arena, with bigger, more powerful standby models, that can be expanded to meet your specific power requirements. And, unlike a generator, they can wait silently in your basement for an outage, and then be used right there where they sit. And, while these units are not exactly portable, they’re typically on wheels and can be moved and used for other purposes. They can also leverage connectivity through apps to manage your power in ways you’ve never considered.
To fully understand what’s required to install a standby power system, and how they work, we tested Eco Flow’s Smart Home Panel 2, paired with their Delta Pro Ultra. The Delta Pro Ultra consists of a big, 6kWh (6 kilowatt hour) battery and power inverter, capable of producing 120 and 240-volt AC current. You can plug devices and appliances directly into the Delta Pro Ultra—or it can connect to a manual transfer switch just like a portable generator. But, when used with the Smart Home Panel 2, the Delta Pro Ultra becomes part of a fully automated standby power system when the grid goes down.
The Smart Home Panel 2 can power up to twelve 120-volt circuits—fewer if you need to power 240-volt circuits. Critical circuits for things like heat, air conditioning, sump pumps, refrigerators, freezers, or medical equipment can be powered through the Smart Home Panel 2, so that it can direct power to them, from the DPU during outages.
Installation
Getting a standby power system set up in your home is no small undertaking. First and most important, you will most likely need an electrical permit and have an inspection when the installation is complete. It is possible to do the work yourself, if you’re familiar with the electrical code and have experience installing sub-panels. For most folks, though, we recommend hiring a licensed electrician. If anything were to go wrong, resulting in a fire or damage to appliances, your homeowners’ insurance is going to check that the work was permitted, done by a licensed contractor, and inspected. If it wasn’t, they may balk at covering a claim.
The Smart Home Panel 2 is the key to using the Delta Pro Ultra as a standby power source. It monitors power from the grid and switches over to the Delta Pro Ultra when an outage occurs. The Smart Home Panel 2 is installed in the same manner as a sub panel, with a double pole 240-volt breaker feeding power from the main panel. Then the circuit breakers for critical circuits—up to 12—are relocated in the Smart Home Panel 2. Additionally, the Smart Home Panel 2 has a provision to accept power from a backup generator, in the event the Delta Pro Ultra runs down during a power outage and needs recharging. The Delta Pro Ultra can also be recharged independently via solar panels.
Capacity and Expansion
Note that for our testing we used one Delta Pro Ultra, but if we needed more backup capacity—for longer runtime—than 6kWh, up to four more Delta Pro Ultra batteries can be connected to the Delta Pro Ultra inverter for a total of 30kWh. And, even more capacity is needed, the Smart Home Panel 2 can accept two more inverters with five batteries each, for a total system capacity of 90kWh.
For reference, the single Delta Pro Ultra could run the critical circuits for about 24 hours in the home we installed it in—depending on specific usage of appliances and devices. The test home is a 2,500 square foot, stone farmhouse, roughly 200 years old, and 10 circuits were used in the Smart Home Panel 2 to cover the following appliances and devices:
- hot water boiler with baseboards, serving four zones.
- 2 refrigerators
- 1 chest freezer
- 2 sump pumps
- 1 well pump
- 1 septic pump and septic alarm
- kitchen, family room, and bedroom lights
- fan for heat exchanger on wood stove
- cable router, WiFi, networking and security cameras
These circuits in our test home have relatively low power consumption, generally using 100-300 watts on average at any given point in time. There are peaks of about 500-700 watts when the boiler or sump pumps kick on. If the home had (or if we powered circuits with) a heat pump, mini-splits, an electric range, or an electric water heater, power consumption would be higher. We did experience numerous outages during our test period, the longest of which was 2 hours, 36 minutes. The Smart Home Panel 2 switched over to the Delta Pro Ultra during outages remarkably quickly, as fast as 20 milliseconds (claimed), with lights dipping for a split second. Having power on standby in our old home is critical, with sump pumps keeping the basement from flooding during storms, and with our own private well and septic systems to keep operational.
Advanced Features
The Smart Home Panel 2 and the Delta Pro Ultra can do so much more than just provide emergency power. Using EcoFlow’s app, you can connect to and manage both from anywhere with a smartphone—and this may be the most impressive thing about these two devices. While you can connect to either one individually, when both are connected, the Smart Home Panel 2 settings take precedence and control charging and discharging operations for the Delta Pro Ultra.
When using the system strictly as standby power, you can set up a charging schedule to be sure the Delta Pro Ultra is topped off with a full charge at regular intervals. There is also a “Storm Guard” setting, that will monitor your local weather reports. Any time there is a significant storm forecast within 24 hours, it will override the charging schedule and charge the batteries to 100 percent, automatically. You can also set which circuits must be supplied in the event of an outage, and those that can be supplied when there is sufficient battery capacity, but not when it dips below a set level.
The most surprising thing we discovered with the Smart Home Panel 2, is that it can be used to save money on your electrical bill. If you have a variable electricity rate, where it changes based on the time of day, you can schedule charging to occur during the low-rate periods, and then to switch to power circuits from the battery during high-rate periods. And, if you enter the rates for those time periods, the app will even keep track of how much you save. While we are billed a flat rate, we were able to test the scheduling, and found this functionality remarkable.
Monitoring and managing power with the app and the Smart Home Panel 2 is simple and informative. At any given time, you can check the app to view current or historical power usage both from the grid and the Delta Pro Ultra. And, you can drill down to individual circuits for the same information, and turn them on or off.
One unexpected benefit we encountered, was the ability to discover a failed sump pump, due to a larger than normal amount of power being drawn by its circuit. The circuit was using over 1000 watts when it usually topped out around 600. Checking the usage history in the app, we saw that the power spiked the previous day, and never dropped. Sump pump inspection revealed hot water in the pit, and when it was drained with a backup pump, the failed pump was so hot that steam rose off it. We wouldn’t have discovered it until the basement flooded, or the water eventually dropped enough to stop cooling the pump—causing it to get hot enough to trip the circuit breaker.
One thing to note, to take full advantage of the app and everything it can do, you need to make sure your internet and networking devices are powered from a circuit serviced by the Smart Home Panel 2. That way, in the event of a power outage, you’ll still have access to control and manage it, because—in our experience—cable internet is still accessible.
Solar Charging
The Delta Pro Ultra also has an integrated solar charger, so it can be completely independent from the grid by pugging it in directly to panels. When solar panels are connected, it will charge whenever the sun is bright enough to do so. You can also schedule grid charging, but it will only kick in if the Delta Pro Ultra is below the charge levels specified through the app. If you’re using solar to charge, then you really are generating free electricity and scheduling the Delta Pro Ultra to supply electricity at higher rate periods can really have an impact on your electric bill.
Unlike many smaller power stations, one Delta Pro Ultra can handle a significant amount of current from solar panels. In some cases, it can handle 3 to 4 times the amount of power—up to 5600 watts, which translates to 6 to 10 solar panels, depending on their size and capacity.
60 Days With the Delta Pro Ultra and Smart Home Panel 2
After two months using the system as standby power, we’ve had 12 power outages, most for just a few seconds. The longest, as previously noted, was 2 hours and 36 minutes, and we kept the heat, refrigerators, freezer and, perhaps most importantly, sump pumps running. We have peace of mind with the sump pumps backed up, because under the right conditions with rain and the frozen ground in the winter, we’ve seen water come in at a rate close to 8,000 gallons per hour. We’ve also learned a lot about our power consumption. We know when we use the most power, we know specifically what is using it, and we discovered an issue with the sump pump before it became a problem.
Unlike a generator, we don’t need to worry about surprise fuel costs when the system kicks on. And, we haven’t seen a noticeable uptick in our electric bill from charging the Delta Pro Ultra. While we didn’t install an array of solar panels for this test, that would be a logical next step to save on our electric bill and help the system deliver more value.
The initial setup via the app took a little time to work through and understand the best specific settings for how we would use it. But it was definitely worth the effort once it was set up, as everything became virtually autonomous. And that’s perhaps the best thing we can say about it.
Brad Ford has spent most of his life using tools to fix, build, or make things. Growing up he worked on a farm, where he learned to weld, repair, and paint equipment. From the farm he went to work at a classic car dealer, repairing and servicing Rolls Royces, Bentleys, and Jaguars. Today, when he's not testing tools or writing for Popular Mechanics, he's busy keeping up with the projects at his old farmhouse in eastern Pennsylvania.
