Better Solar Enery Savings Estimates Using Hawaiian SunZones

Solar is an attractive proposition in Hawaii, with great solar irradiance and high utility rates. 1 out of 4 homes in Hawaii has gone solar.  A home in Honolulu that uses 1,000 kWh/month and installs a 5 kW system can eliminate over $2,400 in utility spending in the first year at an avoided cost of 33.6¢/kWh.  It’s no wonder that Hawaii has installed the second most residential solar in 2013 according to GreenTech Media.

As those of you who have vacationed on the aloha isle can attest, the microclimates vary tremendously.  You could be on the beach one minute and hiking up a mountain later in the afternoon.  For example, the Honolulu airport gets twice as much sunlight as Ahupua National Park and they’re about 25 miles apart.

To help develop more renewables the Hawaii State Energy Office put together a renewable EnerGIS map that provides the micro-climate data necessary for more accurate solar estimates. Utilizing available data in public GIS files, known as “layers”, the HSEO makes this data publicly available.

Genability now allows you to use these Hawaiian SunZones to correct for Hawaiian micro-climates when estimating solar production through PVWatts.  Using the SunZone to adjust the solar production results in  a 5 kW system in Ewa (SunZone 501-550), producing 28.5% more than the same system in Kaneohe (SunZone 351-400).  Simply select your SunZone along with the other solar system parameters when generating solar production for your account.

The example above is for Oahu, but the State Energy Office has mapped all the islands similarly.  The great news for solar developers is that utility costs are even higher on the other Hawaiian islands.   So when you create projects in Hawaii, don’t forget to incorporate the SunZone.  You’ll get more accurate estimates for your quotes and your operations and maintenance team will thank you after install.