The Challenge

Many hotels in Hawaii, among other commercial buildings, have installed rooftop solar photovoltaic (PV) systems to combat high electric rates and contribute toward the state’s renewable energy goal of 100% by 2045. The Maui Beach Hotel, an oceanfront facility built in 1968 with 147 guest rooms, has spent several years investing in property renovation and upgrade projects. One of the upgrade projects includes the installation of a 303 kilowatt (kW) solar array positioned near the hotel’s rooftop pool. In Hawaii, businesses generally install solar in order to reduce their electric utility expenses, which have the highest dollar-per-kilowatt-hour retail rates in the country. However, the value of solar is reduced significantly in Hawaii because of the island’s successor net energy metering (NEM) program, which attributes very little value to exported solar production. As a result, standalone solar applications in Hawaii either receive a big haircut on the value of solar produced or are forced to size small relative to site load to prevent grid exports.

The Solution

The Maui Beach Hotel retrofitted an 85-kW Delta/Samsung ESS to its existing solar array to maximize bill savings and capture the full value of its PV production. By adding storage, the hotel was able to self-consume more solar at over 40¢/kWh and reduce reliance on Maui Electric Company. The system was delivered integrated with ETB Controller and Acumen AI™, and was configured for self-consumption and demand charge management. Acumen AI’s machine-learning algorithms forecast demand spikes and shave peaks, reducing demand charges for the customer under Maui Electric’s Rate Schedule J, which features $13/kW demand charges. This marks the first ETB Controller and Acumen AI storage project in Hawaii