The electricity produced by the photovoltaic system, but that is not
self-consumed by system users or stored in batteries, can be sold to
the grid operator. There are two types of contracts for the sale of
electricity fed into the grid:
Net metering: With this
contract for the sale of energy, the owner of the PV system receives
a credit for the energy they feed into the grid. Since for each
country can be different interpretations of this sales policy, the
program offers a generic approach where you need to set some parameters.
The credit that is granted is based on the valorization of energy fed
into the grid. If this value is the same as the purchase price of the
energy, then the grid behaves as an energy storage: that which has
not been used can then be withdrawn in a deferred way without
additional costs. If the energy that feeds into the grid is greater
than that which is taken, it creates a credit which can be possibly
used in subsequent years.
Note that, in the economic evaluation,
the net metering is considered a revenue even though there may not
be a bill, and you may see as a savings.
With these parameters you configure the net metering:
- Managing credit balances:
In the case in which there is a credit, this can be used in the
subsequent years (with a limit of Credit
energy period) or paid annually.
- Credit energy period:
Number of years within which can be taken the credit.
- Price of energy valorization
exchanged different from the cost of electricity withdrawn:
Specifies whether the value of the energy fed into the grid is
different from that taken, in this case you must specify the Price
of energy valorization.
- Price of energy valorization:
Amount by which valorizes the energy fed into the grid.
The economic value of net metering is calculated as follows:
Revenue from net metering = Min ( Price
of energy valorization * Energy
fed to grid, Cost of energy withdrawn
from the grid )
