2014.11.24 Net Metering Definition

Hi Paul,

My customers' net metering policies allow them to carry credits forward month to month and even into the next year. Using SAM, if I don't check enable net metering the end of year credits are lost and therefor the cost savings are lower than they will be in every year beyond year one. If I do check net metering and there is an excess of generation at the end of the year, then the reported cost savings will be too high, as we don't have a year end buy back option. So, is there a way to allow a bank of credits from previous years to carry forward to offset the first months consumption and more accurately reflect their multi-year savings?

Thanks,
Drew

I figured out a work around. I increased the load on December enough to use up any excess generation that would be consumed in subsequent months, but not high enough to consume the 12 month average excess generation of the system.

Dear Drew,

Thanks for the post and suggested workaround. As I've written elsewhere, we've tried to make SAM's net metering model flexible enough to reasonably model most comment net metering arrangements, but because of the large number of different variations and details, we do not expect to be able to represent all of the variations.

For the next release of SAM planned for the end of this month (June 2015), we are adding options for monthly accounting of excess generation in either dollars or kWh, and an annual minimum charge, so stay tuned for that.

Best regards,
Paul.

Hello Paul,

I try to model a situation (Brazil) where there are taxes to be pais on the energy fed-in by net-metering. This means that energy fed-in in excess of the actual demand is losing value. How would I model this?
Situation 1) Monthly reading: The excess at the end of a month will be roled over but with re-purchasing it I will have to pay a tax on this energy
2)On medium voltage, same scenario but balancing within 15minutes
Any idea how to do that?
BR
Sascha (again:-))