There is no denying that the cost of electricity in Hawaii is considerably higher than the rest of the US. With a heavy dependence on oil and the lack of a reliable centralized grid for backup throughout the islands, the average cost of residential electricity for the island of Maui in 2013 was 37.82 US cents per kWh – the equivalent of ZAR 4.41 as at 17 December 2014 and compared with the highest 2013/14 IBT Tarrif for Nelson Mandela Bay at R1.3803 per kWh.
Homeowners share the common pain of demanding costs on top of an unsettling reliance to the local utility grid. However, one luxury homeowner in Maui had demands of his own—achieve complete grid independence and gain confident access to clean quality power. This has been a demand to a solution shared only by those who realize this opportunity, but it is no longer a dream of the future to be energy independent and to be their own energy producer on the Hawaiian Islands.
To address this need, Ameresco Solar and Maui Builders Inc collaborated to bring together a robust and extensive hybrid system for their client. Being an impressive estate equipped with the latest smart home technologies, the hybrid system needed to be a beast of its own. It must seamlessly power large loads on a daily basis that would otherwise be sensitive to fluctuating power quality from the grid.
In addition to ground-mounted PV arrays and a 5.5 tons flooded lead acid battery bank (with a capacity of 3200 amp hours at 48 volts), the installation included the following from Schneider Electric:
- 4x Conext XW 6048 120 240 60
- 4x Conext MPPT 80 600
- 2x Conext ComBox
- 2x Conext System Control Panel
- Conext Automatic Generator Start
The Conext XW inverter/charger proved to be the perfect choice for Ameresco Solar and Maui Builders for this installation. The XW inverter/charger delivers clean and stable power through its superior AC output voltage regulation of 120 V with +/- 3%. This offers the capabilities and performance to support large power loads required of a home and lifestyle of this magnitude. Completed by its integrated solar charge controller, generator control, monitoring, and configuration systems, the overall XW system becomes the secure and reliable grid for this Maui homeowner’s new off-grid lifestyle.
Schneider Electric expressed pride that their Conext XW inverters, MPPT 80 solar charge controllers, Conext ComBox monitoring system, Conext System Control Panels (SCP), and Conext AGS were chosen for this project to deliver superior and stable power for this Maui homeowner’s new off-grid lifestyle.
Contrary to popular belief, even a large system such as this pencils out to have a reasonable pay-back analysis when compared to the high cost of electricity in Hawaii. It also has the added benefit of grid independence, high reliability, and superior power quality.