Riverside Public Utilities

All About Solar

Thinking of going solar?

All the help you will need for going solar is right here - we will help walk you through each step of the process. In no time, you will be well on your way to saving money and becoming more energy-efficient by going solar.

When considering solar, there is a lot to think about. We've put together a basic overview to help you on your way to going solar! We've included resources and how solar works, how much it costs, the future of solar, as well as basic laws about solar.

Before you sign up for solar, there are certain things you need to know. For example, solar will not necessarily eliminate your electric bill. Also, when the power goes out, the PV system will stop working. Find out more essential information before signing up for solar.

solar panel installation


Check our frequently asked questions for answers to your solar-related questions.


After you've made a decision to go solar, there are several steps you need to take. Fortunately, after you've decided to go solar, the contractor will be able to handle all of the work!

The Home Energy EZ Profile Report is your online source to obtain your last 12 months of energy use. When moving forward, the actual annual energy used in kWh (kilowatt hours) is the maximum amount of energy production allowed for a solar system on your home. Smaller solar systems may be of any size you choose.

Creating energy efficiency inside the home is an important step before going solar. Reducing your energy needs is typically more cost effective than going solar; and reducing your energy use also means you can install a smaller, less costly solar system. Check out our Energy Efficiency section below to help you get started.

This is a big decision – evaluate your options carefully. Will you own it, lease it or enter into a PPA agreement? They all have different financial impacts and are something for you to consider. The Consider Your Purchasing Options section below will provide additional information on financing options and how they may impact your bottom line.

Qualified contractors are your key to getting the most productive solar energy system for your home or business, talk to three (3) or more contractors before you make a decision! Contractors will evaluate factors that affect your PV system performance such as the roof size, orientation of the system, shading and other factors. Typically, the contractor will complete the paperwork and apply for the City of Riverside Permit and the NEM Interconnection and rebate documentation on your behalf. The contractor will work with you until the utility provides approval for you to turn the system on.

Learn more about contractors from these online resources:

All solar systems that are installed to offset energy use in your home or business are “grid-tied” and must receive a City of Riverside permit and final permit approval before the system may be turned on. The contractor usually takes care of this for you. This is required for you to obtain Permission to Operate.

Once the solar system is installed and the permit is complete, RPU will be notified by the inspector to release the meter and to interconnect the system to the grid. Once the meter is installed on the property, the system will also be interconnected at the same time.

The term “Permission to Operate” is used to indicate an installed solar system has received BOTH (1) City of Riverside Permit Approval and (2) the Net meter has been installed by RPU Meter Shop. The City does not provide an official PTO letter. If you require written PTO authorization, please contact us at [email protected].

Check the Solar Map for status updates.

Once the system is installed, ask the contractor to teach you how to use the solar system production display or website to monitor energy production. Take time to learn how to monitor your solar system's performance and be diligent viewing your energy use at least monthly to verify the system is running and creating the expected energy production. Also, ask your contractor for advice on maintenance or better yet get a maintenance contract to have it routinely checked and cleaned!

Understanding how you use energy is crucial to your start with going solar. We will provide you with a personalized look at your home's energy use to help you see how you use your energy.

Start by learning how much energy you use.

Get a customized Home Energy EZ Profile Report that illustrates your energy use. This tool also provides personalized energy saving tips. Have your account number ready, custom reports require log-in.

Get the biggest bang for your buck!

When you are ready to invest in energy efficiency, be sure to start with the low-cost and no-cost measures to maximize your investment. Let us help you get started. We have developed these 10 Steps to Save to help you get the most out of your time and money.

  1. Program your thermostat $
  2. Seal air leaks around window and doors $
  3. Replace air filters monthly $
  4. Switch to LED lighting $
  5. Plant shade trees $
  1. Seal leaky duct work $$
  2. Install sun screens $$
  3. Upgrade to ENERGY STAR® appliances $$
  4. Fix or replace your old AC system $$$
  5. Invest in solar $$$

Get a rebate from RPU for investing in energy efficiency.

We offer an array of rebates for energy upgrades you make to your home. Find the energy upgrades that work best for you by visiting our rebates page.

Energy Saving Resources

These resources may provide additional information or tips to help you complete energy efficient home improvement projects or provide information that will help you make an informed decision when purchasing a new appliance or air conditioner.

When going solar, there's quite a lot to think about. We can help you find the basic information you need on solar to help with your decision.

How solar works – a basic overview

Roof top solar is powered by sunlight. When the sun is shining the PV cells convert the sunlight into electricity, and inverters transform this energy from DC power into AC power so it can power everything in your home. Want to learn more? Here is info on the process and the equipment used.

Individual photovoltaic (PV) cells are connected to panels. These solar panels convert sunlight into direct current (DC) electricity. An Inverter converts direct current (DC) into alternating current (AC) for electricity in the home.

Photovoltaic (PV) cells, or solar cells, take advantage of the photoelectric effect to produce electricity. PV cells are the building blocks of all PV Systems because they are the devices that convert sunlight to electricity. When light shines on a PV cell, it may be reflected, absorbed, or pass right through. But only the absorbed light generates electricity. The energy of the absorbed light is transferred to electrons in the atoms of the PV cell.

One of the most important components of any solar unit is the solar power inverter, which converts the direct current (DC) that photovoltaic solar cells produce into alternating current (AC). Types of inverters to consider:

  • Grid tied Inverters – are connected to the electric utility distribution system. The connected solar system allows you to power your home or small business with renewable energy when the sun is shining. Any excess electricity you produce is fed back into the utility distribution system grid. When the solar system is not running electricity from the utility (grid) supplies your needs. Having the utility as your energy back up source eliminates the needs to purchase costly energy storage device, such as batteries.
  • String Inverters - All solar modules are connected in series to a DC electric cable, which is then connected to a single remotely mounted inverter box. The inverter box is typically mounted on a wall by the home’s main AC electrical panel. This creates a very centralized system with a limited amount of labor required to install.
  • Micro-Inverters - Instead of having one inverter for the entire array, a micro-inverter could be installed on each panel or every few panels. The micro-inverters convert the DC to AC right at the module; then, AC wires run from the module to the home’s main AC electrical panel. Each micro-inverter would be handling lower voltage and therefore may not wear out as quickly. Micro-inverters allow the system to be more efficient and therefore produce more energy.
  • When designing a solar system, it’s important to consider what type of inverter will be used with the modules you will install.

  • Traditional String Inverter Method - When set up in the traditional method, a solar array is only as efficient as the least efficient panel. If you have five (5) 200 watt panels, but one of them is shaded or dirty such that it’s only producing at 50% efficiency, then the entire system will only work at 50% efficiency. That means that instead of producing 1,000 watts, the system would only produce 500 watts. Additionally, inverters are currently sized according to the number and type of solar panels on the roof, and if a home owner wanted to add more panels in the future that may require a different inverter with a larger capacity.
  • Traditional String Inverter with Optimizers Method - Adding DC power optimizers to the panels of a traditional string inverter method can solve most of the above string inverter challenges. Power optimizers optimally tune the performance of the solar panel to match the performance of the string inverter to improve overall performance. They are especially useful when the performance of the solar panels will vary widely, such as differences in equipment, shading, being installed facing different directions or widely separated locations.
  • Micro- Inverter Method – In a micro-inverter installation, each panel has a micro-inverter on it. If one panel is dirty or shaded only that panel would be affected. So in the scenario with five (5) 200 watt panels, this time with micro-inverters, one panel would be at 50% and therefore producing only 100 watts, but the other four (4) would still be at 100% producing 200 watts for a total of 900 watts. When micro-inverters are being used and the homeowner decides they would like to add more panels, in theory, additional panels with their own micro-inverter could be added to an existing array without needing to replace anything.

How much does solar cost?

This question is often asked and the answer is – it depends! There is no one answer since each installation is different and each home uses energy specifically to their family’s needs. After you’ve learned more about solar, talk to at least three solar contractors and evaluate your options.

Installed costs of solar are coming down, but it is hard to say what your system will cost until you obtain quotes from contractors. Over the years the installed price per watt has reduced down from $10 per watt to typically less than $6 per watt. It is important to talk to at least three contractors to obtain a clear understanding of your installation and the potential costs. This way you can make an educated decision on the purchase of your solar system.

If you’re paying cash or obtaining a loan for your system, be aware there are a number of factors that vary from home to home and installation to installation. These factors affect the initial cost of the solar system. The initial system cost divided by the cost of the energy offset by solar will provide you with an estimated return on your investment.

  • Quantity of Panels
  • Type of Inverter
  • Mounting Design
  • Equipment Options
  • Labor Costs
  • Infrastructure Improvements
  • Monitoring
  • Purchase Option

When you’re leasing your system or entering into a Power Purchase Agreement (PPA) for your system, initial costs aren’t usually a factor. With these purchase arrangements you’ll be evaluating the energy offset costs of the system. See the Purchasing Option section for more information on leases and PPAs.

The initial cost of the solar system may not be the only question to ask. Consider obtaining answers for “What is the cost of the energy (kilowatt hour) produced by the solar system proposed for my home?”, “What is my current cost of energy from the utility?” and “How do they compare?”

Once the system is designed, the contractor will run a program to estimate how much energy the system designed specifically for your home is expected to produce. The same system facing a different orientation on someone else’s home will produce a different amount of energy. Energy, or kilowatt hours (kWh), is what will offset your electric utility bill. Make sure you understand how much energy is produced by the solar system each month and how it will offset your monthly bill. Your Home Energy Analyzer report will show you how much energy you use each month when you enter your account number and run the report.

Due to the angle of the sun and weather conditions, solar systems produce less energy during the winter months than they do during the summer months, so try to understand the monthly generation. Ask your contractor to show you the California Solar Initiative Expected Performance Based Buy Down Calculation (CSI-EPBB) report for the expected performance of your solar project.

Solar Resources

Want to learn more or dig deeper? We’ve compiled some resources for you to do just that! There is a lot of information on the internet, so consider your sources as you endeavor in your own investigation and learn more about solar. The websites below can be helpful:

US Department of Energy produces information on science-based energy upgrades helping homeowners reduce their energy bills. Energy Efficiency Homes and Photovoltaic Technology Basics.

Residential 101

An educational website funded by the US Department of Energy dedicated to educating homeowners about solar power options.

National Renewable Energy Lab Solar Photovoltaic Technology Basics

NREL is a national laboratory of the US Department of Energy, operated by the Alliance for Sustainable Energy, LLE.

What does the law say about solar?

Have you heard of the Solar Rights Act? Or the Solar Shade Act? Yes, there are laws and regulations allowing consumers with rights to install solar if they choose. Here is some helpful information on that subject.

  • You may have questions about whether your neighbors can block access to your solar panels with shading.
  • Additionally, can Covenants, Codes, and Restrictions (CC&Rs) limit your use of solar?
  • State laws in California protect homeowner access to the sun for systems, and these laws have been in place for more than 30 years.
  • Many homes today are part of planned communities that require a uniform and consistent appearance within the development. The California Solar Rights Act and the Solar Shade Act provide important information for homeowners considering to go solar.
  • The Solar Rights Act was created in 1978 (AB 3250, 1978), and it created a legal framework for solar access.
  • The law includes protections to allow consumers access to sunlight (and prevent shading of systems) and limits the ability of homeowner associations and local governments from preventing installation of solar energy systems.
  • The Solar Rights Act sought to promote and encourage the widespread use of solar energy and to "protect and facilitate adequate access to the sunlight which is necessary to operate solar energy systems.”
  • The Solar Rights Act balances the needs of individual solar energy system owners with other property owners by developing solar access rights.
  • The Act limits the ability of CC&Rs, typically enforced by homeowner associations (HOA), and local governments to restrict solar installations. These are the best known and important provisions.
  • The Act also creates the legal right to a solar easement for a landowner to obtain adequate access to direct sunlight for a solar energy system.
  • The Solar Shade Act (AB 2321, 1978) provides limited protection to solar energy system owners from shading caused by trees and shrubs on adjacent properties.
  • The law seeks to prevent a property owner from allowing trees or shrubs to shade an existing system installed on a neighboring property, provided the shading trees or shrubs were planted after the solar collecting device was installed.

There are two helpful reports written by the Energy Policy Initiative of the University of San Diego's School of Law about the Solar Rights Act and the Solar Shade Act:

Bringing Solar Energy to the Planned Community: A Handbook on Rooftop Solar Systems and Private Land Use Restrictions. You can download this report as an Adobe Acrobat PDF file (62 pages, 1.0 MB).

There are several things you should be aware of before signing-up for solar. Going solar is a process, and we want to help you get started.

1. Energy Efficiency Comes First

Before considering a solar system, energy efficiency improvements in your home should be considered. Lowering your energy use will assist in lowering the cost of your solar system because a smaller system may be installed. Not to mention, energy efficiency is usually a faster return on your investment!

2. Your Energy Consumption

RPU's Solar Energy Program allows customers to offset up to 150% of their historical 12-month energy use. With your account number in hand, go to the Utility Bill page to obtain your last 12 months of energy use. If you have less than 12 months of energy use, we use the formula of two (2) watts per square foot of living space, including garages to calculate your energy use; this is the maximum amount of energy (kilowatt hour) production of a solar system that will be allowed at your location until you have a 12 month history of energy use to evaluate.

3. Solar Will Not Eliminate Your Electric Bill

Unless you move 100% off the electrical grid with absolutely no connections to your electric utility, you will continue to have electric bills. After you install solar, the utility will continue to standby and supply power when your system is not producing. Even when your solar system is sized to offset 100% of your energy load there will be months where you purchase energy from the utility and months when you over produce and export back. This is because the solar system produces different amounts of energy each month depending on the sun's angle and the amount of available sunshine.

4. When the Power Goes Out, the PV System Stops Working

The solar system typically does stop working when the power goes out. Solar electric systems sold for use in California are designed with a power inverter which automatically disconnects from service if the inverter senses a loss of power from the electric utility. This safety measure protects our crews as they may be working on the system to restore power. The inverter only re-connects the system once utility power has been re-established.

5. Energy Rates and Trends

RPU’s current and historical rates are posted online for your reference.

Have you decided to go solar? There are several financing options. The typical choices include buying, leasing, and Power Purchase Agreements (PPA). In this section, you can find out what these choices are, and how they compare.

When evaluating the cost of energy and considering if purchasing a system is right for you, use the cost of a kilowatt hour (kWh) as your basis for analysis and comparison. A solar system will reduce only the components of the bill that are priced per kWh.

Read all contracts carefully and completely. Each homeowner’s situation is different. Only you can discern which option is best for your circumstance.

It is wise to speak with your tax advisor about the tax implications associated with the various purchase options before you enter into a solar contract.

1. Own, Loan, Refinance

When you purchase a solar system, the purchase of equipment and the installation is paid for up front and you own the equipment.

Ownership can come in a variety of ways – you may pay cash for the system, take out a loan, open a line of credit, or refinance your home.

The US Department of Housing and Urban Development (HUD) offers FHA Title 1 Home and Property Improvement Loans and information on how to finance a home improvement.

You own the equipment and are responsible for the operation and maintenance. You may consider entering into a service agreement for maintenance and repairs.

2. Lease

When you lease a solar system you agree to pay a monthly rent (lease) payment in exchange for the right to use all of the power produced by the PV system. You do not own the equipment.

Leasing a solar system requires a contract, usually for 20 years. Typically there is no large upfront cost associated with a lease, easing the initial burden of ownership. The lease may include an annual price increase, called an escalation, on the monthly payment. Escalations are risky, and may exceed the rate the utility energy (kWh) rate is going up. Ask about pre-paid leases and how that may affect the contract and financial burden.

Most companies provide a guaranteed minimum annual energy (kWh) production for the solar system. Consider various size systems to meet your energy needs. Remember, your energy use changes month to month, and the solar system output varies month to month, but a lease payment is the same each month. Some months you will receive more energy production for your lease payment and other months you will receive less energy for your lease payment.

Talk with your provider about how maintenance and repairs are handled, and what happens if the solar system stops functioning. Before signing the dotted line make sure you understand the terms of the lease agreement and your obligations to ensure a safe and productive solar system installation.

Consider the consequences of the lease contract if you decide to sell your home. Will it be easier or harder to sell? Talk with your lease provider to investigate if the new buyers must qualify to assume your lease and what happens if they don’t qualify.

3. Power Purchase Agreement (PPA)

A PPA is similar to a lease, but the monthly payment is based on an agreed upon price per kilowatt hour (kwh) for each kilowatt hour produced by the solar system rather than a flat monthly charge. You do not own the equipment.

PPAs require a contract, usually for 20 years. Typically there is no large upfront cost associated with a PPA, easing the initial burden of ownership. Read the contract thoroughly. The PPA agreement may include an annual price increase, called an escalation, on the price you will pay for each kilowatt hour (kWh) generated by the solar system. Escalations are risky, and may exceed the rate the utility energy (kWh) rate is going up. Ask if purchase buy-out options are available and how that will affect the contract and financial burden.

Most companies provide a guaranteed minimum annual energy (kWh) production for the solar system. Each month your energy needs and the amount of energy produced by the solar system will change. Compare your monthly needs, and the system's monthly production, to ensure the system size fits your specific needs.

Talk with your provider about how maintenance and repairs are handled. Before signing the dotted line make sure you understand the terms of the PPA agreement and your obligations to ensure a safe and productive solar system installation.

Consider the consequences of the PPA contract if you decide to sell your home. Will it be easier or harder to sell? Talk with your provider to investigate if the new buyers must qualify to assume your PPA agreement and what happens if they don’t qualify.

4. What is the difference between a lease and a power purchase agreement (PPA)?

A solar lease and solar PPA are similar in many ways, but have a few important differences.

Solar Lease vs. Solar PPA Agreement Differences

  • In a lease: the customer leases or “rents” the equipment and is entitled to the benefits of using the system. Some leasing companies will guarantee the minimum production of the system. If the system does not meet its production targets, the company may agree to compensate the property owner. Leases may be for a fixed price per month throughout the term of the lease, or may contain an “escalation schedule” where the monthly payment increases each year.

  • In a PPA: the customer agrees to buy the power generated by the system at a set price per kWh. This price may be fixed over the length of the PPA agreement or may include an “escalation schedule” where the price per kWh generated by the solar system increases at an agreed upon rate each year. The solar company estimates the production of the system installed at the residence, but only bills for the actual kilowatt hours (kWh) the system produces to offset your energy use.

5. Tax Credits

Qualifying installations may be eligible for tax credits to help offset the initial cost of solar system ownership

Federal Tax Credit: The federal tax credit is available, to the system owner, for the purchase and installation of eligible solar systems. For more information on the federal tax credit, please refer to the Go Solar California Tax Credit webpage or consult a tax professional.

Metering, Monitoring, and Maintenance

During your solar decision process, you’ll make metering choices for monthly or annual billing, and you will want to understanding Net Energy Metering. How you will monitor the energy production is important, this is how you verify you’re getting the value you expected from installing the solar system. And, planning for routine maintenance for continued energy production and safe operation of your new solar system must be considered.

Solar System Metering

The solar system installation will offset energy use but will not eliminate your receipt of a monthly electric bill from the utility. Learn more about the changes in your utility bill and how Net Energy Metering (NEM) works.

If the system is financed by a lease or PPA agreement, you will now have two monthly bills related to your energy use – the monthly utility bill plus the lease or PPA agreement payment.

The Utility Bill

Yes! You will still receive a monthly utility bill. The installation of a solar system does not eliminate the monthly utility bill unless your system is “off-grid”. Remember, your solar system energy production is offsetting just the kilowatt hour portion of your bill. If the system is financed by a loan, lease or PPA agreement, you will now receive both a utility bill and a bill from your third party finance agency.

These helpful links provide additional information: Understanding Your Bill points out how to read important aspects of your monthly utility bill; and the current Residential Electric Rate will describe the utility bill structure and monthly charges.

Net Energy Metering (NEM)

Homes with solar installations receive special meters called “net meters” that are certified for accuracy when spinning both forwards and backwards recording both the power used from the utility and the surplus generation delivered back to the utility.

How Does Solar Billing Work?

Customers who install a solar electric system may be enrolled in monthly or annual billing. If not specified, customers are automatically enrolled in monthly billing.

  • Monthly billing is available to all customers with a solar electric system, and this is the default option when a solar system NEM is installed. Customers receive a monthly utility bill for net energy consumption that is due and payable each month, just like you received prior to the solar system installation.
  • Annual billing is available for residential customers and small businesses with a maximum yearly demand of 10kW or less. Customers receive a monthly utility bill showing the charges for all services. Annual billing customers may continue to pay for energy charges monthly, but they are eligible to delay payment of energy charges (kWh) to once every 12 months. All other charges, including the monthly electric basic service charge, and water, garbage and sewer, are due and payable every month.

The monthly utility statement will show the net energy used, purchased from the utility, and you can double check your inverter or online monitoring system produced by the PV system.

If you have questions or would like to change to annual or monthly billing, please contact us at (951) 782-0330.

Additional Information on NEM Rates

For more information on NEM rates, see the RPU Rates page.

Once the system is installed, monitoring the energy production will be your means of verifying the solar system is operating properly. Ask your solar contractor what monitoring system comes standard with your solar system, what monitoring upgrade options are available and if there are any costs involved.

Monitoring is used to track and optimize energy production and to reduce long term operational and maintenance costs. Solar system monitoring is available in a multitude of ways. A simple way of monitoring, if you have a string inverter, is to look at the LCD screen and record the information you see on the LCD screen. Other providers may supply a display device to be located in your home or in your garage. And still others may provide an on-line portal to view near real-time energy production graphs. Investigate what is being offered with your system and the options you have available.

At a minimum, monthly monitoring is recommended. More often is better. With monthly monitoring, a system problem or lower than expected energy production may be identified, investigated and fixed providing you with the anticipated rate of return on your investment.

At the end of the year, pull out your solar system contract. Note the estimated annual energy production for your installed system and if there is a performance guarantee. Compare the estimated annual energy production to the actual production obtained from the inverter or monitoring device. Is your solar system performing as anticipated? If not, contact your solar contractor and ask them to investigate.

Solar systems are low maintenance requiring occasional cleaning, electrical system checks and inverter preventive maintenance checks. Having your system inspected every year or two is recommended. Ask your solar professional for guidance on maintaining your system.

Dirty solar panels are the most common maintenance issue and can significantly reduce the energy production of the solar system. Dust, leaves, twigs, bird waste and soot on or under the solar panels can have a negative effect on the system. Keeping the array clean will boost energy production.

Shading on any portions of the solar array will reduce energy production. Shading of the system was considered by the contractor when your system was designed, and the energy production estimate included existing shading issues. Over time shading on the system may change – trees grow and other obstacles that create shade may occur. Routinely check for shading and investigate if there is an unexpected drop in energy production.

Loose wiring connections, cracked panels or other physical problems with the system may occasionally occur. System maintenance inspections should be performed to ensure safe and reliable operation.

To participate in the Riverside Public Utilities Solar Program, all equipment must carry a 10 year warranty. A solar module has an estimated life of 20 or more years. The solar inverter typically has a shorter estimated life and often is the system component to fail first. Proper care and maintenance of the inverter will help extend its useful life.

Ask the installing contractor about a maintenance contract – talk about cleaning above and below modules, checking all mechanical and electrical connections and wiring, inspection of air ducts and cooling fans and checking expected energy production to actual.