Solar Power Facts
Frequently Asked Questions about solar for your residence or small business
Install solar panels to reduce utility bills and fight global warming. Whether it's called solar, solar panels, solar energy or a residential solar system, here are the basics.
What is a solar panel system?
What is the environmental impact if I use solar power at home?
Do solar panels replace an electric utility?
What are the benefits of having a solar panel system?
How much does a solar panel system cost? What Rebates and Incentives are available?
What size system do I need?
Can I get credit for producing my own electricity?
What is the lifespan of a solar panel system?
What is involved in maintaining and operating a solar panel system?
How can I finance the cost of a solar panel system?
Will a solar panel system require additional insurance?
If you are interested in the details of solar system financing, installation, maintenance and monitoring, Click Here.
What is a solar panel system?
Solar panel systems (or solar energy systems) use Photovoltaic (PV) cells to convert sunlight into direct current (DC) electricity. Solar panel cells are made from silicon and were originally developed to power spacecraft and space stations. The cells are wired together in panels that typically measure about 4 feet by 2 ft by 1.5 inches deep. A group of solar panels mounted on a frame is called a solar panel solar panel array.
To provide electricity reliably and safely, solar panel system components typically include an inverter, wiring and optional battery storage and charge controller. Most solar panel systems convert the DC electricity that is produced by the solar panels into the common household form of electricity, alternating current (AC), by using an inverter. AC electricity can then be used to power your appliances directly, or feed back to an electric utility's grid. The DC electricity can also be stored directly in batteries for later use. In this case, to prevent overcharging or discharging of the batteries, a charge controller is used.
What is the environmental impact if I use solar power at home?
Solar panels have received attention from researchers, businesses and homeowners because, unlike traditional power generation sources, these technologies produce electricity using a renewable source, the sun, without creating noise, emitting pollutants that cause climate change such as greenhouse gases, smog, acid rain, or water resource pollution. Even when the emissions related to solar cell manufacturing are counted, solar panels produce less than 15% of the carbon dioxide from a conventional coal-fired power plant.
As a general rule of thumb, studies indicate that the typical California home using solar power has an environmental impact of removing two cars from the road. Over 25 years, you will have avoided producing more than 500 tons of greenhouse gas emissions. Using solar electricity to power a million homes would reduce greenhouse gas emissions by 4.3 million tons per year, the equivalent of removing 850,000 cars from the road (Source: EPA).
Does a solar panel system replace an electric utility?
Solar panel systems are typically used as either stand-alone systems or grid-connected systems. The role of solar panels in these two types of systems is very different, and the design decisions and performance requirements are very different as well. Stand-alone solar panel systems generate all of the on-site electricity needs of a home. Therefore, they are not connected to any electric utility. Stand-alone systems can provide AC or DC electricity, and typically include batteries to store electricity for use when the sun is not shining. Stand-alone systems are often cost-effective when installed in remote areas where access by electric utilities is difficult and expensive. Grid-connected solar panel systems are typically sized to meet at least 50% of a home's electrical load. These systems are not always sized to meet all of the electricity loads of a house because of the higher up-front costs associated with purchasing a larger system. Solar panel systems can be easily integrated with a utility's electrical grid to provide clean, renewable electricity for homeowners, while still ensuring continuous power supply from your regular utility.
What are the benefits of having a solar panel system?
1. Reduce your utility bill - Solar panel systems can significantly reduce your utility bill. Any energy produced for "free" by the sun and your solar panel system is energy that you don't have to purchase from your utility. This translates into direct savings on your monthly utility bill. In addition to the direct savings, the solar panel arrays also act as a sunshade for your roof, reflecting heat from the sun that would otherwise be absorbed by your house. A shaded roof area can reduce the air temperature of your house, reducing the energy required by your air-conditioner to keep a comfortable temperature in your home.
2. Increase the resale value of your home - Like any home improvement, a solar panel system should increase your home resale value by the amount of the installation. So even if you move from your present home, your solar panel system will have reduced your monthly utility bill and increased the value of your home if you do decide to sell.
3. Healthy Environment - By using a renewable power source, you're helping reduce the impact of global warming and climate change. You will avoid producing hundreds of tons of greenhouse gases during the solar panel system lifetime.
4. Energy Independence - Solar power can provide electricity in the event of a power outage or disaster. You will also decrease your use of foreign oil and minimize utility company price increases.
How much does a solar panel system cost? What Rebates and Incentives are available? The cost of a solar panel system depends on the system's size and the types of components. See this table for a list of average solar equipment costs and incentives for grid-connected solar panel systems without a battery backup in the US. To see solar power state rebate information, use the link for your state here.
The actual cost of a solar panel system will depend on whether the system is integrated into the roof-top material or mounted on top of an existing roof, the system configuration (i.e. standardized systems offered by some solar panel retailers generally cost less), equipment options, installation costs, and the solar panel manufacturer.
What size system do I need?
In California, the average residential customer uses 6,500 kilowatt-hours (kWh) of electricity per year (California Energy Commission). Only a qualified installation professional can provide an accurate estimate for your home or small business. Click Here to receive a FREE solar home evaluation from local professionals.
The rated output of solar panel modules is assessed using the full hours of sunshine per day where one full sun hour is defined as being exposed to a solar intensity equal to 1,000 watts per square meter. Full sun hours do not indicate the number of hours that the sun is shining in a day, but rather is an indication of the intensity of the sun. Also important to note is that not all of the sunshine that strikes a solar panel cell will be converted into electricity. Typically, 15% to 25% of the energy produced is lost because of inverter and wire losses.
Can I get credit for producing my own electricity?
Yes. The energy that is produced by a solar panel system will first serve a home's electrical load. Then, if the solar panel system produces more electricity than the home needs at any given time, your utility credits the excess electricity at the same price you would pay for electricity from the utility - in effect turning the electrical meter backwards. This is called "Net Metering," and the credit will appear on the monthly utility bill. Should the home need more energy than the solar panel system is producing at any given time, the customer can be assured that the utility will provide the electricity that the home needs. Often, homeowners find that they receive credits during expensive peak daytime hours, and then use more utility power during less expensive evening hours.
What is the lifespan of a solar panel system?
Solar panel systems last a long time depending on the amount of active use, or the amount of sunshine converted into electricity by the solar panels. Most systems are only in use for 6 to 8 hours per day. Manufacturers will usually provide from 10 to 20 year warranties for the solar panels, and a 5- to 10-year warranty on the balance of system components. Solar panels have been reported to last 30 to 40 years.
Solar panel systems last a long time depending on the amount of active use, or the amount of sunshine converted into electricity by the solar panels. Most systems are only in use for 6 to 8 hours per day. Manufacturers will usually provide from 10 to 20 year warranties for the solar panels, and a 5- to 10-year warranty on the balance of system components. Solar panels have been reported to last 30 to 40 years.
What is involved in maintaining and operating a solar panel system?
Without any moving parts, maintaining a solar panel system is relatively simple. For grid-connected systems, minimal maintenance is required, including keeping the panels free of any debris such as fallen leaves, bird droppings, etc. For stand-alone systems, the batteries usually require the most maintenance. Your solar panel system retailer will provide instructions about simple maintenance that you can do yourself.
How can I finance the cost of a solar panel system?
Yes, lenders are often very willing to lend to quality homeowners who improve the value of their homes with solar panel systems. We do not recommend using credit cards to pay for your solar installation due to the typically higher rates. Typically, the best rates and tax deductions are available when tapping the equity in your home, although some finance companies will provide unsecured loans at competitive rates for loan amounts up to $100,000.
There are also solar lease and Power Purchase Agreement (PPA) financing programs. In the case of leasing, be sure to understand any balloon payments and your options at the end of the lease term. With a PPA, you will likely need 30% of the total cost as a down payment.
Will a solar panel system require additional insurance?
Typically, homeowners will be required by the utility company to provide proof of insurance coverage for their system. However, most standard homeowner insurance policies provide adequate insurance protection and meet the minimum requirements stated in your utility interconnection agreement.
