Our very own magical Pacific Island paradise. Beautiful beaches, beautiful water, beautiful scenery, the occasional volcano. Hawaii is an amazing place. It also happens to be one of the first States to have reached grid parity and where plummeting solar prices and super high electric rates provide a staggeringly fast payback on installing solar.
Our sample assumes a 10 KW solar PV installation and installed cost of $3.00 per watt. This keeps the math simple and allows you to estimate your own needs for your own property based upon electric bills.
The Big Island gets on average 4 sun hours per day. Using a 10 KW solar PV system one could expect to produce about 11,311 kWh annually, or 942 kWh per month which is significantly over the average home electric usage of 505 kWh for the State. Estimated Annual Savings would be $4,805. At a $30,000 total cost to install your simple payback is in 6 years.
On the island of Kauai we picked a spot in the town of Lihue which has an awesome 5.3 sun hours per day, and would produce 14,842 kWh annually or 1,236 monthly. Estimated annual savings are about $6,679, which gives a 4.5 year payback on a $30,000 install cost.
Unfortunately, Hawaii’s electric utility HECO has made it difficult for home owners and small businesses to connect to the grid by basically forbidding export of electricity back to the grid, but that doesn’t mean you can’t have a smaller than needed system to help offset costs.
The above payback calculations do not take in to account any incentives, State or Federal. If you want to run your own analysis for your home town feel free to check out how we calculate solar power using PV Watts Database. If you want to learn more about various incentives, all the information you need can be found through the DSIRE database.