No savings with net metering off

Thank you Paul for your attention to this forum,

I'm on Hawaii where NEM is no longer an option. All islands have basically the same rate structures available now (though Kauai has its quirks.)

I was trying to model a commercial system that we call a "non-export" system under a "standard interconnect agreement."

Basically, there are so many issues raised by utility companies about their grids not being able to handle more solar on the islands that the only way to install certain projects is to prevent export to the grid.

In standard interconnect agreements, all production must stay "behind the meter." "Self-supply" allows export but compensates you nothing for it. "Grid-supply" does compensate for excess production, but not at the same rate as the avoided purchases.

In both "standard interconnect agreements" and "self-supply", savings would be purely the demand that is met by the system rather than the utility. "Grid-supply" would also require some changes to your financial model from what I can tell.

In the particular SIA project I was exploring SAM with, I was able to export the time data (hourly) and sum up the "electricity peak load met by system" to get a rough estimate for year one savings. Another way I could have done this would be to go to the average daily profile plot (annual) and calculate the area below both the "power generated by the system" and "electricity load" curves.

Again, thanks for your efforts. As it sits now, SAM is great for certain things but I cannot rely on it for most projects on Hawaii. Probably your biggest issue here is the lack of accurate irradiance data for all parts of the islands. Solar Prospector is way off.

Thank you Scotty for the description of the current "no net metering" option in Hawaii. I understand that this kind of self-supply arrangements is also common in other countries. The next version of SAM (due for release in early 2016) will have no net metering options where excess generation (calculated either on an hourly or monthly basis) is sold at a different rate than the buy rate.
Also, you may be interested in the new version of NREL's National Solar Radiation Database (NSRDB) at nsrdb.nrel.gov where you can download solar resource and weather data in the SAM CSV format for any location in the U.S., including Hawaii at a 4 square kilometer resolution.
Best regards,

Paul.

Thank you. The new weather data is much more accurate but I still notice some discrepancies. We simply have too many micro-climates here due to the dramatic terrain. The state of Hawaii did a study a while back that seems more accurate.
maps.hawaii.gov/enerGIS/

Thank you for that link -- one note for anyone who tries it: It uses Microsoft Silverlight, which on my computer works with Microsoft's Internet Explorer without installing additional software. For other browsers, you may need to install the Silverlight software to see the data.

Is there hourly data available through that website, or is it just the annual average DNI and GHI data that is available?

Best regards,
Paul.