How Does a Mi-Grid save 30% more than Grid Tied Solar?

All solar energy systems produce more power than can be used at times. The larger the system, the more likely this is to occur. On utilities that do not have Net Metering, power sent to the utility is paid out less than what is paid for purchased power.

With a Mi-Grid system, power is not sold to the Utility. The extra energy is stored locally in a battery bank. This energy is released later on in the day after the solar array stops producing power.

Studies conducted by Tetra West Solar found that Mi-Grid systems save 30% more than Grid-Tied systems of similar solar array size. The reason is that all solar energy produced offsets full price electric purchases.

Solar power is produced all day long but reaches maximum at solar noon, or the time of day the sun is highest in the sky. But most electrical energy usage occurs in the morning and evening. If the best solar production to the utility, you may only get half the value. By storing it with a Mi-Grid, you keep all of the value.

For example, over a month $100 worth of electricity is produced by a solar array. The utility charges $0.10 per kWh, but only pays $0.05 for solar electricity exported to the grid. If half of the solar is sold to the utility, $50 of power is offset directly (never purchased) and a credit of $25 is generated. Net saving is $75. If the energy is stored locally, then the entire $100 is saved. The additional savings is $25 over $75, or 33%.

You achieve true Net-Metering by not selling any power to the utility.