Home battery backups can provide value even when the power is on by taking advantage of time-of-use (TOU) electricity rates. The battery can supply power during expensive peak periods, usually in the afternoon and evening, then recharge from the grid when rates are lower. After four years on a traditional fixed-rate plan, the homeowner discovered that the utility offered TOU billing, switched plans and tested the approach with BioLite batteries.
Limited scheduling options
Setting a battery schedule in the backup app is straightforward. Users can choose when each day the battery should start operating and when the system should switch back to grid power. The app also allows users to pause charging during specified periods and set a minimum level for the battery. Weekends can be excluded from the schedule.
However, the scheduling system has significant limitations. It does not support multiple on-and-off cycles in a single day, which would be useful because the utility has two peak billing periods during the winter. It also cannot apply different schedules at different times of the year, even though the utility uses three billing schedules depending on the month. When a backup battery costs thousands of dollars, more control over how it is used would be helpful.
There was also one bug while saving a schedule, although force-quitting and restarting the app eventually resolved the problem.
No usage logging
Another missing feature is data logging. Users may want to know how long the battery runs each day, how much power it supplies during each cycle, how much electricity is needed to recharge it and how much money the system may be saving. The backup app has no logging system beyond a basic record of outages, errors and software updates.
The potential savings can still be estimated. In the fall, four hours of refrigerator use between 5 and 9 p.m. would normally cost 8.6 cents per kilowatt-hour. Shifting that usage to BioLite batteries, which recharge during off-peak hours at 4.3 cents per kilowatt-hour, can reduce the cost. The calculation is imperfect because of energy losses between the various components, but about 680 watt-hours of usage can currently be moved from the higher rate to the lower rate each day.
That works out to roughly 3 cents per day, or about $1 per month. The savings are higher during the summer, when peak rates reach 16.2 cents per kilowatt-hour, but still amount to no more than about $3 per month.
That is not especially impressive, but it is not nothing.
An expensive safety net
BioLite also includes a power strip with an optional magnetic backing that can attach to the side of a refrigerator. The strip connects to a second backup outlet and can power additional devices from the battery system. It has three standard outlets, two USB-A ports and two USB-C ports.
The power strip is optional, and it was not used because there was no convenient place to install it or device to connect to it. Still, it could be useful during a winter outage when additional equipment needs to run in the dark. With an output of 1,800 watts, the battery can power appliances ranging from a microwave to an air fryer.
This is a modest extra that adds value to Backup by BioLite. At $1,999 for one battery and $3,499 for a pair, however, the financial case is difficult to justify based on TOU savings alone. In practical terms, the system’s main benefits are emergency-related: it can help prevent hundreds of dollars’ worth of groceries from spoiling during an unexpected ice storm and allow people to cook while the rest of the house is without power.
Source: www.wired.com
