Frequently Asked Questions

The cornerstone of rooftop solar is NEM (Net Energy Metering).

After your solar is installed, you will sign an NEM agreement with PG&E.  This sets the terms for your ability to sell your excess solar power back to the grid.

During previous versions of this agreement, homeowners were incentivized to sell power back to the grid during the day, in order to offset their nightly electric bill.  NEM-2 ended on April 14th of this year.

NEM-3 is a "self consumption" policy. Homeowners are incentivized to consume their own solar energy rather than sell it back to the grid.

The big difference is – in almost every case – we will not be sizing your renewable energy system to offset your full electricity usage.  This is because most people do not use more than ~30% of their energy during the daytime hours.  And there is a limit to how much energy you can store in a typical residential battery.

Instead, we will be installing  a smaller solar system – often paired with a battery.  In most cases this will not entirely offset your electricity bill.  But it should still have a decent payback, if designed well.

We are grateful that the people of Berkeley and the greater Bay Area are committed to pursuing decentralized renewable energy in their homes. Thanks to our wonderful community we expect to adapt to this change in policy and continue our decades of work helping people gain renewable energy independence.

At this time, we do not offer any financing. All our invoices must be paid via cash / check. There are some companies that offer solar with no upfront cost, or provide financing themselves. We do not. And we recommend that you take a careful look at the fine print in those contracts. They often have a higher effective interest rate, and they keep the 30% Federal Tax credit. We have found that clients who self-finance by either paying cash, or taking out a "green loan" or HELOC from a local bank or credit union end up with the best return on investment.

Any home is battery ready. How ready is the question. The electrical work required to separate backed up loads and integrate batteries can vary wildly depending on your goals, existing wiring, and site specific variables. Before we give you a quote for a battery system we schedule a site evaluation so we can quote exactly what it will take to incorporate batteries at your home.

You can do anything you want to, it just gets expensive. The more you want to back up, the bigger the battery needs to be. The larger the individual loads, the bigger the battery system needs to be. The more electricity you use, the more battery you need. We have backed up an entire house on 20kWh of battery but one size does not fit all. For instance a large conventional Air conditioner could require 30-40kWh battery system.

Vehicle-to-home charging (V2H) is the holy grail for home energy systems. In theory, incorporating your car’s battery into your home electrical system will give you a huge battery in an outage, reduce your dependence on the grid and help our entire state be more resilient to climate change. However, the reality of wiring an electric vehicle to interact with existing solar and home circuits (in a safe manner) is incredibly complex, and requires compatibility between the specific vehicle, and the home battery System Controller. Enphase is currently developing V2H car chargers that will integrate with their battery system. And many car companies are developing this technology as well. We are closely tracking these developments. Please contact us for up-to-date information, as the situation is constantly changing.

While solar and batteries have been around for over 50 years, true digital home automation is in its infancy. Our biggest concern in this area is lifetime support for the technology. Currently, “dumb” breakers are a time-tested technology that will easily last 40 or 50 years once installed. That reliability is what you want.

Will the new generation of smart panels / smart breakers last more than 10 years reliably? Will the apps be supported and be kept up to date?

Our recommendation in this area is to be very cautious of the shiny new thing – because your main electric panel is not as easily replaced as a smartphone. That said, home automation is starting to mature and we are encouraged by some of the products we see being released, especially by large incumbent manufacturers.

A1 Sun has a working relationship with SPAN and other manufacturers of smart home circuit breaker panels.  We are currently working on pilot installations.  Please contact us for up-to-date information.

We specialize in home energy systems – not in HVAC. That said, we are happy to work together with you and/or your HVAC contractor to plan for the increase in electric loads when sizing your home energy system. And if you would like a referral to a list of trusted local HVAC contractors, please reach out to us.

We are a business that puts quality ahead of volume.