Net Metering is a billing arrangement between San Diego Gas & Electric (SDG&E) and customers who generate their own electricity with photovoltaic or wind systems. Net Metering measures the difference between the electricity delivered by SDG&E and the excess electricity you produce using your own generating equipment. Any energy you produce that you don't use, is fed back onto the utility grid and it's deducted from your electric bill. SDG&E will credit customers up to 100% of their annual consumption.
Please visit SDG&E's Net Energy Metering website for more information.
Example of Net Metering
The Smiths installed a net metered photovoltaic generating system on their home and began generating on March 1st. Over the next twelve months, their system produced more electricity than they needed in some months and less than they needed in other months. Their monthly consumption of electricity, monthly generation of electricity, and the net amount of electricity fed into or taken from the grid are shown below.
| MONTH | MAR | APR | MAY | JUN | JUL | AUG | SEP | OCT | NOV | DEC | JAN | FEB | 12 MONTH TOTALS |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| kilowatt-hours ( kWh) consumed | 425 | 475 | 525 | 625 | 725 | 450 | 675 | 525 | 450 | 375 | 375 | 400 | 6,025 |
| kilowatt-hours ( kWh) generated | 490 | 525 | 550 | 550 | 600 | 600 | 500 | 475 | 400 | 375 | 385 | 400 | 5,850 |
| Net from/ (to) the grid | (65) | (50) | (25) | 75 | 125 | (150) | 175 | 50 | 50 | 0 | (10) | 0 | 175 |
During the summer months, because they used their air conditioning a lot, the Smiths consumed more electricity than their system produced, and they were "net" consumers. However, the Smiths were on vacation much of August so their lower electrical use made them "net" generators that month. In the spring months, their system was able to produce more than they needed and their meter often ran backwards. Their meter had a negative reading at the end of these spring months, making the Smiths "net" generators of electricity during these periods.
On the following March 1st, the first anniversary of their Net Metering agreement, the Smiths' electric service provider added up the past 12 monthly meter readings and found that over the past year the Smiths were "net" consumers of 175 kilowatt-hours ( kWh) of electricity. The Smiths' provider charged an average rate of 10 cents per kWh to residential customers like the Smiths, so at the end of the first twelve months their electric service provider billed them for $17.50 (net 175 kWh consumed x 10 cents/ kWh).
2011 SGIP Handbook
