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Infographic on grid-tied vs. off-grid solar power.

How Mi-Grid’s Comprehensive Solution is Better Than Grid-Tied Solar

Congratulations, you installed a solar array at your home and the system is tied to the utility grid. If the solar doesn’t generate enough electricity, you can rely on the utility and you might even net meter power back to the provider. Sounds great, but what happens when the utility loses power?

You are out of luck. Utility distribution is susceptible year-round to storm outages, whether from snowstorms, thunderstorms or hurricanes because of the extensive network of strung wires. Ice weighs them down and downed trees yank them loose. Your solar array may be standing, but UL 1741 requires your grid-tied inverter to shut-down for safety’s sake. This prevents any power from a home from reaching the grid when repair workers are on the lines.

Here’s the beauty of a Mi-Grid energy management system: while disconnected from the grid, it operates on a stand-alone basis. Solar power can keep the lights on and that energy can also be stored to batteries within the configuration. If the batteries run low, a generator automatically kicks in to power the home and recharge the batteries, shutting down once the batteries are recharged.

Making Renewable Power Reliable

This is why the Mi-Grid can be installed as a grid-tied system or an off-grid system. It technically doesn’t need to be grid-tied. Hence, the smaller Mi-Grid sizes are ideal for remote locations as well as mobile applications, such as food trucks and RVs.

The brains of the operation can be installed in a variety of packages, including wall-mounted, indoor, outdoor or trailer mounted. The outside options are housed in NEMA 4 enclosures for durability. Mi-Grid systems range in size from 1 kW to 2 MW and can serve residences as well as businesses that want complete electric reliability.

When a Mi-Grid is connected to a distribution grid, that utility power enters the mix. The Mi-Grid is essentially a dispatch system that selects the lowest-cost available power at a given time. When grid-tied, the utility supplies power at night and can take excess power from the solar system during the day.

The batteries are kept full for backup and the generator sits in stand-by mode. This cycle runs daily, with solar power providing electricity during the day and the utility providing any needed power overnight. Mi-Grid ties together all of the energy sources, providing multi-layered power and backup.

As the consumer, you won’t see lights flickering because the shifts among power sources are seamless. For example, a customer of ours who lives in a rural area was surprised to hear at a community breakfast that everyone else lost power the day before when the local supplier dropped offline. He did not realize his inverter had kicked in under the Mi-Grid system.

Think of times when you have lost power and were out of commission when it comes to connectivity and conveniences. But it’s not just major storms that can cut into productivity and quality of life. Local power outages are fairly common events. Also, if you wish to live off-grid but not entirely replicate a previous century’s lifestyle, then Mi-Grid gives you that personal freedom. And at a lower cost than either a stand-alone solar system or a generator alone.

The other benefit to Mi-Grid is you don’t need to manually mess around with the typical emergency generator that requires frequent refilling of the fuel tank as well as oil changes. Each time you tend to such a generator, the power is turned off. Instead, the Mi-Grid generator is only turned on when the system’s batteries are low. By cycling the generator only when needed, the system saves on fuel and maintenance. And you don’t have the constant roar of many generators.

Why invest in solar alone when you can invest in a fully-integrated system to provide truly reliable power? Mi-Grid has you covered, grid-tied or off-grid, sunshine or clouds, day or night, 365 days a year.

 

What is Net-Metering?

Net Metering is a method of billing used by some utilities. Solar Production in excess of your immediate needs is exported to the utility. The utility measures the outflow and credits them against your inflows of electricity. You pay only on the “net” inflow.

For most Grid-Tied Solar PV, the solar energy is converted and fed into the existing AC electric system. This is done without regard to how much power is needed at any given time. The excess flows “Out” into the electric lines. The energy is available to be used by others.

Net metering is a simplified method of compensation for these out flows. Your electric bill is calculated at the “net” difference between what you consume and what you produce. You use 2000 kWh per month. The solar array produces 1500 kWh. You pay for 500 kWh. Simple, huh?

Except, the price you pay your utility really comes from two different pieces: Energy and transportation. In electric bills in most of Texas, you see both retail electric energy charge and the energy transportation charge. Remember, there are costs in maintaining the electric lines, PLUS the cost of maintaining the power plants you use when the sun isn’t shining.

When I “make my own” energy, I am reducing the energy I buy from the utility. When the sun isn’t shining, or not enough, I buy power from the utility. But if I make too much, I have to do something with it. I sell it to the utility. But this energy I sell has to be transported to other users. The utility transports the power.

Most grid tied users see the utility as a “storage” system. They “store” power and then use it later. But it isn’t really stored. When power is pushed onto the grid, a power plant somewhere has to reduce output to compensate. But the power plant can’t shut-down because it has to be available to provide power in case more power is needed. For example, when a cloud goes by.

When solar makes up a tiny percentage of the network, it doesn’t affect the overall economics of the power system. It may in the end be cheaper for the utility to bill “net meter”. But as the percentage of installed solar goes up, the “loss” by the utility goes up with it. It must compensate by raising the price of electricity. Your neighbors without solar pay.

It really is fair to compensate a solar producer only for the electric generation portion of the power.  As renewables become more wide-spread, net metering will be reduced and eventually abandoned. Hawaii, California and Germany are abandoning net metering. Massachusetts, like many states, reached the limit of net metering.

Mi-Grid stores your excess renewable energy for your own use later. You truly are “NET” with the meter, since you do not sell power to the utility, you save it for yourself to use when you need it.