Diesel generators are the most common means of electricity back-up during power outages but besides being noisy and polluting, they are also the most expensive means of alternative electricity. Such devices boast an operating efficiency of just 25%, require frequent maintenance and bring with them diesel storage requirements and fears connected to diesel theft.
The building-integrated back-up power system – called OneBox – handles the electricity loads of an elevator; five air-conditioners; two ovens; water pumps; slow-charging electric vehicle points; communal lighting; and lights, fans and plug points for one full floor of the building it was installed in.
The system offers a high peak discharge current which enables it to handle loads such as the elevator and air conditioners – which require an high starting current – with a comparatively small lithium battery capacity. The system also supports single-phase outage and has a claimed response time of seven milliseconds, ensuring uninterrupted supply and zero blackout.
“OneBox is a do-it-yourself hybrid solar solution that consists of the world’s smartest lithium battery, hybrid inverter and solar charge controller to give a hassle-free, plug-and-play solution for back-up [power],” Vision Mechatronics director Rashi Gupta told pv magazine. “It takes care of uninterrupted, flicker-free power supply with [a] response time of seven milliseconds, which keeps all electronic items unaffected by power [cuts] and fluctuations.”
The inverters and batteries come pre–configured in the OneBox to suit customer requirements, according to the manufacturer. “Users neither need to worry about the compatibility of the inverter and lithium batteries nor about the complex wiring [during] installation,” added Gupta. “Integrating solar panels in OneBox not only helps in reducing their carbon footprint but also makes the system cost effective and improves power availability. Users with excess renewable generation can save money with net metering by using [the] grid feed feature of OneBox.”
As for lifespan of the batteries, the product pictured in this article has a lifespan of 4,000 cycles at 80% depth of discharge.
Predictive monitoring ensures minimal downtime
Robotics, industrial automation and renewables technology company Vision Mechatronics claims its lithium battery features active balancing and internet of things capabilities along with predictive and preventive monitoring, helping extend battery life. The predictive monitoring feature observes cell-level data to signal, usually by email, when the battery or system will need attention, 15 days in advance. The auto-on/off feature, says its developer, sees the smart battery email details of the cause of failure, enabling customers to take corrective actions.
OneBox, according to Gupta, is a cost-effective, eco-friendly substitute for diesel generators with a claimed return on investment figure of around 20-and-a-half months to three years and an operating cost which reaches grid parity.
The Bureau of Indian Standards recently published safety and performance requirements for grid-interactive energy storage systems and for battery management systems – an important step towards the standardization of new technology such as lithium batteries.
“India is globally the first country to publish a battery management system [BMS] standard and the BMS used in the OneBox is compliant to the Indian standards,” said Gupta.
This article was amended on 03/03/20 to clarify the claimed response time of the OneBox is seven milliseconds, not seven microseconds as previously stated.