Frequently Asked Questions About Solar Battery Storage

​​In some cases, yes, particularly if your panel manufacturer is Zinsco or Sylvania. Those panels have been delisted due to fire hazard concerns. We will determine if a new service panel is necessary during our site visit, and let you know the associated costs prior to signing a contract.

Yes, almost always. We will verify during our site visit.

The inverter is integrated within the battery, enabling the Powerwall to convert energy from AC to DC for storage, and vice versa for use in your home.

The Powerwalls (most people need two) are each 46" high by 30" wide, and 6" deep. They may be “stacked” one in front of the other on finished surfaces, or placed side by side, usually along the base of a wall. You will also have two or three other electrical components, each roughly the size of a typical electrical service panel, and a “gutter” to conceal wiring that is 4”-6” high and sits beneath or above the componentry. The electrical components need to be within 6' of your main service panel, on the same wall or opposite wall, so you do need a sizable tract of wall space near your main service panel. The Powerwalls themselves do not need to be within 6’ of your main service panel, but should be as close as possible to ensure a cost-effective installation.

The Powerwalls are rated for indoors and outdoors. To optimize performance, avoid installing Powerwall in locations exposed to direct sunlight or subject to extreme temperatures. If on an exterior exposed south-facing or west-facing wall, you would need to provide shading from a structure or screen. Additionally, while humidity and rain do not pose a risk, Powerwall should not be installed in locations subject to flooding or near water sources such as downspouts, faucets or sprinkler systems. In order to maintain proper ventilation, Powerwall should be kept clear of debris such as leaves and dense brush.

Tesla has undertaken extensive testing to show Powerwall is safe regarding electromagnetic emissions. Tesla Powerwall is designed and certified to government standards for electronic equipment that includes testing for electromagnetic emissions.

Yes, but there are drawbacks. Without solar to recharge your batteries during an outage, your backup time will be limited to last 1-3 days in most cases. For storage clients who do not have solar, we include a Manual Transfer Switch for a generator as part of our installation package to allow you to use a generator to power your home in those situations where the Tesla Powerwall has been fully drained and power is still out.

As a battery customer, you will be moved to a time-of-use rate plan with PG&E. You can charge your battery during off-peak (less expensive) times of day and use that stored energy during on-peak (more expensive) times of day. This usually results in modest savings.

Two Tesla Powerwalls will give you 27 kWh of usable energy. For most users, this equates to 1-3 days of backup power, depending on how conservative you are using the electric loads that are being backed up. Residents who also own a solar panel system, which will recharge their battery during an outage, will receive backup power for a longer period of time—essentially unlimited in sunny conditions.

We will configure your electrical system so that your critical loads will be available during an outage: refrigerator, outlets and lights, and well pump if you have one. Because too many large loads on your critical backup panel could trip the Powerwall if used simultaneously, we do not back up for some non-essential loads. We can back up the electric oven, range, and dryer, but we highly recommend that users not use these appliances during a power outage, as it would rapidly drain the batteries. That said, if you have solar and the sun is shining, you may be more liberal in your overall energy usage. Most large 240V loads such as AC, hot tub and pool equipment, heat pumps, etc. would likely not be available during power outages.

Solar panels recharge your batteries, so you don’t have to worry about this if you have solar panels and a battery. This scenario is more likely for non-solar customers during an extended outage lasting more than 2-3 days. For non-solar customers, during our installation process we will wire and install a manual transfer switch that can be used for a 240v generator. You would be responsible for purchasing the generator and plug specific to your generator.

At a distance of one meter and at 86 degrees F, the noise level is 40 decibels or less. For comparison, a household refrigerator, when “running,” is 50 or 55 decibels.

Two Powerwalls, the recommended amount of storage for most homes, usually costs in the $32K-$35K range. We require a site visit to ascertain the particulars of your physical and electrical situations, after which we will provide a final price.

Yes! Solar batteries are eligible for the 30% federal solar tax credit as long as they have a capacity rating of 3 kWh or greater. Learn more about solar tax credits and incentives.