Off-Grid in the City

By Maggie Williams

As electrical utilities across the country continue to increase rates and cut back on solar incentive programs, more people than ever are taking their homes off the grid — gaining in energy independence, financial stability, and alleviating the headache of dealing with the local electric company.

Cadillac, Mi – Wind and solar compatible batteries. Photos courtesy of Iron Edison

Advances in solar and battery storage make going off-grid more viable than ever before, and there are several off-grid options depending on the desired level of grid independence.

The first option is to take a home completely off the grid. To disconnect from the utility, a large solar array and battery are needed to power the home, plus a generator is recommended for backup. Going off the grid may require some power consumption sacrifices, so using energy-efficient appliances is important.

For the homeowner who is interested in reducing his or her dependence on the grid using a solar and battery system, but does not want to completely disconnect from it, the second option is called “grid backup” or “grid zero.”

Grid backup is designed to optimize the use of renewable electricity and battery storage. If additional electricity is needed, the inverter (which converts direct current from batteries to alternating current similar to what the grid provides) automatically engages the grid to help support the loads. This type of setup gives the homeowner flexibility on the size of array and battery, since all electrical loads do not need to be covered by their home PV system.

Grid backup is also a good option for the homeowner who is looking for a solar and battery system to keep the lights on when the grid goes down. In an emergency where the grid could go down for a long period of time, it can be hard to find fuel for a generator. A solar-and- battery-backup system can run a homeowner’s critical loads without him or her ever having to leave in search of fuel.

Batteries are essential to going off the grid, as they store the surplus energy a solar array creates during the day for use at night. The most common battery that off-grid homeowner’s use is the flooded lead-acid battery. With daily cycling a lead-acid battery will need to be replaced about every five years. Over a 30-year period, this battery replacement can add up to be very expensive. Further, when the lead-acid batteries are removed, most are shipped to Mexico or overseas for recycling. Most of these lead-acid recycling plants are dirty and unregulated.

Another battery option gaining popularity in off-grid applications is the nickel-iron battery, which has a 30-year life and is environmentally friendly. Developed by Thomas Edison over 100 years ago, the nickel-iron battery is freeze-resistant and can be fully discharged without damaging the cells. Just like lead-acid batteries, nickel-iron batteries require distilled water refills, but no other battery on the market today will last as long.

For the homeowner who is not interested in battery maintenance, a lithium iron battery is a great fit. A lithium iron battery is maintenance-free and will last 14 years being cycled daily. For comparison, a sealed lead-acid battery will last about four years, so this allows the homeowner to go for a much longer period of time without needing to replace the battery.

Being off-grid in the city is now a reality. It is time to gain energy independence by breaking away from the utility by generating power with a home solar and battery system.

Maggie Williams is the co-founder of Iron Edison Battery Company