Frequently Asked Questions

What is the benefit of having battery storage on the grid?

Large scale battery storage systems like KES benefit the local electrical grid by providing resiliency and flexibility from a non-emitting capacity resource.  Moving toward 100% renewable energy on an island grid such as Oahu’s will require balancing resources like KES that can quickly adapt to evolving grid conditions over time. 

How did you choose the project location for KES?

The Plus Power team considered a variety of siting criteria including but not limited to land use designations, archaeological and cultural resources, topography, and proximity to critical Hawaiian Electric infrastructure.  The KES location met the optimal criteria across all of these categories.  

What prompted Plus Power to propose KES to Hawaiian Electric?

KES was proposed in response to Hawaiian Electric’s highly competitive Stage 2 RFP for Dispatchable Renewable Energy & Energy Storage. The specific objective was for KES to help fulfill the “Storage Requirement” identified as necessary in order to backfill the firm capacity currently provided by the AES coal plant. Based on a variety of quantitative and qualitative criteria, the KES project is amongst nine projects selected by Hawaiian Electric for the island of Oahu.

Will I get a bill from KES in addition to my bill from Hawaiian Electric?

No. Customers will continue to get a bill from Hawaiian Electric. Separately, KES will operate under a fixed-price contract that allows Hawaiian Electric to operate the battery system in a manner that is most beneficial to ratepayers.

What is the impact of KES on my electric utility bill?

In the Hawaiian Electric filing for the KES project, they estimate KES will provide a cost saving of approximately $0.28 per month on average over the 20 year contract life. This calculation assumes a residential load of 500 kilowatt-hours per month.

How long will the batteries last? What will happen to them after that?

The KES project will have a lifespan of at least 20 years. The original battery systems installed at the site are anticipated to operate for at least 15 years. As the original system naturally degrades, KES will be augmented with supplemental battery storage units in the future. At the end of the project’s operating life, KES is required to remove the battery system and restore the land to pre-existing conditions. Because the battery components contain valuable minerals, the system will be shipped off-island for recycling and salvage value.

Are there environmental, cultural or archaeological features that could be disturbed on the KES project site?

A Phase I Environmental Site Assessment (ESA) has been performed which did not identify any environmental issues. The KES site has been previously disturbed for light-industrial use, and there are no known cultural or archaeological features within the KES footprint.

What considerations are being taken to ensure the safety of the KES project?

Safety is paramount to Plus Power and its KES project. Wid-ranging measures are taken to ensure reliable and safe operation of the system. From a technology perspective, KES will utilize best-in-class lithium ion cells, using Lithium Iron Phosphate chemistries. In addition, the system relies on a variety of thermal management systems as well as remote monitoring strategies in order to maintain system stability. The Honolulu Fire Department was engaged in preliminary discussions regarding KES as part of the Conditional Use Permit - minor (CUP-m) application, and the Plus Power team will ensure there is significant collaboration and training with first responders in order to guarantee proper techniques are used in the unlikely event of an emergency.

Will KES be able to withstand a natural disaster?

The KES site is located approximately 55 feet above sea level and outside the Tsunami Evacuation Zone. The project is designed per ASTM standards to ensure foundations and infrastructure are designed in accordance with local requirements. A retention basin is utilized on site to manage stormwater and drainage.

Will the KES projects impact my views?

KES is ideally situated within a natural depression away from densely populated areas. As seen in the photo below, the project is screened by natural features on multiple sides. As such, the impact to local views from KES will be very limited.