Solar Power FAQ

Answers to Frequently Asked Questions

Solar Energy

What is a solar electric (PV or photovoltaic) grid-tied system?

A solar electric system converts the sun’s energy into electricity by producing direct current (DC) in the PV panels. The DC current goes to an inverter, which changes it to alternating current (AC) which then synchronizes with the utility (PG&E) grid.

The electricity produced by the system goes back through the meter to the grid, providing you a credit for the solar-produced electricity. At the end of the year, PG&E sends a True-Up Energy Statement showing net energy usage. Everything else remains the same as before your solar installation, except for saving money and knowing your electricity is from a clean, renewable source.

Do grid-tied solar electric systems work during power outages?

In order for a grid-tied solar PV system to work during a grid power outage, it must utilize a battery in conjunction with the PV. For more information about batteries, read this Primer.


What is net (or two-way) metering?

In a grid-tied solar electric system, electricity can flow through your meter in either direction, depending on the amount of electricity your system is producing and how much electricity you are using. When your system is producing more electricity than needed, the surplus goes back into the grid, providing you credit. At other times, you draw power from the utility grid, in which case you are “buying” electricity. Net metering keeps track of the difference between the electricity produced by your system and the grid-supplied electricity you use. You still have access to all the power you need.

How am I charged or credited for electricity use?

You receive a monthly bill from PG&E for the previous month’s electricity usage. Sonoma Clean Power customers receive a monthly bill or credit for the generation of electricity, calculating the month’s net usage from the grid or net production to the grid. The monthly bill includes a nominal charge from PG&E for connection to the grid, which shows the year-to-date balance for the distribution portion of your electricity usage. Once a year you receive a True-Up Energy Statement from PG&E for the balance of your electricity usage.

Is payment received for excess electricity produced by a solar installation?

It is important to give Solar Works your accurate electrical usage data so we can design a properly sized solar electric system that meets your needs. With a grid-tied solar electric system, PG&E credits solar customers for up to 100% of the electricity used, but does not pay for excess solar production over the course of a year. Sonoma Clean Power may pay customers for excess production, but not at full retail rate. More information: (SCP).  

What is Time-of-Use (TOU) metering?

TOU metering is a rate plan that bases the price you pay for electricity on the time of day and the time of year it is used. You pay less during off-peak and partial-peak hours and during winter months. TOU metering benefits solar electric system owners by allowing you to “sell” excess solar-produced electricity at peak rates and “buy it back” at off-peak rates, thus reducing your energy costs even more.

What is the difference between PG&E and Sonoma Clean Power?

PG&E and Sonoma Clean Power work together to provide clean power at competitive rates. PG&E is responsible for the infrastructure, including transmission lines, that carry electricity to residents and businesses. Sonoma Clean Power (SCP) buys power generated by renewable sources (solar, wind and geothermal) and PG&E delivers that electricity to your home or business via the PG&E-maintained grid. Get more information at

Solar Design

What is a good solar installation site?

Clear and unobstructed access to the sun is best for a solar electric system, as shading from buildings, trees, or other vegetation can inhibit system performance. However, new shade mitigation technology enhances solar production on sites that may have been considered unsuitable for solar in the past due to shading. If a roof is not appropriate for an installation, the system may be mounted on the ground, or on a trellis or carport. In our experience, Solar Works can find a solar solution for almost any site.

What size solar electric system do I need – and how many panels?

Our designer determines the optimal system size based on many factors, including each customer’s goals, the amount of electricity used, the time of day it is used, and the attributes of the solar array. The most accurate way to measure system size is in kilowatts (kW). For example, a typical 6.6 kW residential system has 20 panels, with each panel rated at 330 watts.

How long will a solar electric system produce?

Solar Works uses high-quality panels with a 25-year limited warranty. Although panels have a useful life expectancy of 30 years or more, it is normal for panels to slowly reduce output as they age. Inverters have warranties of 10, 12, or 25 years, depending on the manufacturer. Solar Works provides a 1-year, no fault warranty and 10-year workmanship warranty to ensure no additional costs to our customers during warranty coverage years.

Where are solar panels placed?

The most cost effective option is to mount panels on a southerly-oriented roof.  We recommend there be as many years as possible remaining in your roofing material to avoid added costs of needing to remove solar panels to re-roof. Depending on our assessment of your roof’s condition, we may recommend replacing it before installing a solar electric system. Panels can also be mounted on a trellis, carport or freestanding support structure.

Solar Economics

How much does a solar electric installation cost?

Many factors determine cost, as pricing is specific to each project. Considerations include: Size, mounting system, roof material and pitch, wiring runs, and other installation details. One of the greatest variables in cost is the quality of specified equipment. Solar Works uses only materials and components we submit to a rigorous vetting process, which may result in a slightly higher upfront cost. But we know from decades of experience that installing top quality products is far more cost effective in the long term.

What is the Return on Investment (ROI) for a solar electric system?

Typically, the ROI for purchasing a system is from 4 to 12 years. Factors affecting the ROI include: Electricity usage, system size, available rebates and tax credits, future electric rates, any shading issues, system output and performance, and other variables. Our comprehensive proposal contains detailed information about the financial benefits of investing in solar

Will the cost of installing a solar electric system decrease in the future?

The most cost-effective time to invest in a solar electric system is now. Although prices of solar components have dropped dramatically over the past 10 years, they have stabilized in the last year, and prices are expected to continue at this level – or quite possibly increase. Costs related to labor, energy and business operations will not decrease, so it’s best not to wait to install a money-saving, quality system.

What about cost-reducing solar incentives?

Federal and State Tax Incentives are available including:
California Incentive Programs
Residential Renewable Energy Tax Credit
Business Energy Investment Tax Credit

The US government currently offers a 30% investment tax credit as part of the Inflation Reduction Act.

Five-year accelerated MACRS depreciation is also available to businesses that install renewable energy systems. Consult your tax advisor to discuss your eligibility.

In California, solar electric systems are exempt from property taxes. (CA RTC, Section 73) Although the value of your home or business will increase with the investment of a solar electric system, property taxes cannot be raised.

Solar Electric System Installation Process

Our complete residential solar electric installation process

Click here for a PDF of our complete residential solar electric installation process from contract to savings.


John Matheny

John Matheny, Solar Works Operations Manager, and his
wife buy the majority of their food from local farmers and artisans to reduce
environmental impact and support the local economy and community.