As rooftop solar spreads, and battery technology continues to make strong developmental leaps forward, going off the grid is an option that is becoming increasingly viable for both residential and commercial application. Below, we will explore the benefits, drawbacks, and steps to taking a solar system off the grid.
As technology evolves and becomes increasingly accessible to the average consumer, the vision of a decentralized electrical infrastructure becomes a clearer goal for the future.
Freedom from the grid is one of the most common goals for consumers pursuing battery storage. In addition to being burdened by the possibilities of changes to net metering and other policies, a centralized power grid is also prone to downtime and outages, which potentially affects all customers of that particular infrastructure, leaving them powerless if not for private generators.
Battery storage has also proven effective in remote construction situations. Electrical infrastructure is expensive; wiring power lines to rural areas with sparse population can be range anywhere from $15,000 to $40,000 per mile. Having to extend power grids out to remote, few-and-far between properties is an incredibly arduous process, both physically and financially.
Even with the advancements that batteries have made - and continue to make - installing a solar system of sufficient capacity and battery storage remains expensive for most potential users. Many counties and communities also have regulations for homes and grid compatibility, so research may be required to ensure that no illegalities are being committed in the process of disconnecting from a centralized utility.
Batteries are also a relatively large medium, requiring storage in an indoor environment, away from the outdoor elements. While recent products such as the Tesla Powerwall are making leaps in the realm of attractive product design, batteries still require a large amount of unobstructed space in the home. In order to safely house a battery backup system, a temperature controlled indoor storage solution is required.
Going Off the Grid
What you will need:
- A solar system capable of generating roughly 200% of your peak daytime usage.
- A battery storage system.
- Battery based inverters.
- A climate controlled location for the batteries (less than 85 degrees (F) at peak temperature)
- Rewiring of the electrical circuitry in the home to be backed up into a separate service panel in the event of an outage
Rooftop solar installations operate at peak efficiency during daylight hours, but lack the ability to store it or continue harvesting energy overnight without an external battery storage system. While a grid-tie system will revert to pulling energy from the utility during this downtime, an off-grid system utilizes battery storage to keep everything up and running through the night.
Precise analysis of 24 hour usage trends will help to develop the most accurate picture of how much power is needed for the overnight period in comparison to the day time, but a safe assumption is that a 100% capacity system will need to be doubled in order to keep up with consumption during the time that power would otherwise be drawn from the grid.