Frequently Asked Questions

Transcription

1 Frequently Asked Questions Solar PV Systems How much electricity will my PV system produce? The amount of electricity generated by a solar system is dependent upon several factors, primarily system size, orientation of the system and shading. Typically, a solar system using about 120 square feet of solar panels will generate about 1,500 kwh per year. Will a PV system work with my home? To have a PV system installed on your roof, your property must have a reasonable amount of non shaded, unobstructed roof space during the key sun hours of the day. A southern orientation is ideal, but east and west facing roofs can still capture a portion of the power of a true south facing roof. Your roof can be flat or sloped. Rack mounted systems on the ground are also an option. What size system should I get? The size you choose is a trade off between the amount of money you want to invest and the amount of electricity you want to produce. A fairly large home during peak electricity usage in the summer uses up to 5 kw of electricity at any given moment. Over a year, that same home will use approximately 12,000 kwh of electricity. You can look at your past bills to calculate how much electricity your home typically uses and determine what percentage you want to cover with solar electricity. The only other condition in deciding proper system size is the amount of suitable space available on your roof. To be suitable, it must be unobstructed and not shaded, either flat or sloped, at an orientation other than north. You need roughly 120 square feet of roof space for each kilowatt of PV capacity you wish to install. Starting January 1, 2011 a system's estimated annual kwh output cannot exceed 120% of the total customer usage at that site from the previous 12 months. What is the limit for a system size in relation to customer usage? For all programs, the annual power output (kwh) of a PV system can be no greater than 120% of the total customer usage from the previous 12 months. Any applications that come in over the 120% rule will be declined and asked to adjust system size accordingly. We calculate this at the time of application review by using the previous 12 months of usage. This means that a planned future purchase, such as an electric car, will not be considered when looking at the application and 120% rule. If the building is new construction, we will use the data we have to determine if the kw system is appropriate for the site.

2 To obtain your annual kwh usage, please contact customer service at A representative will give you a number by evaluating your usage over the previous 12 months. You can also request a report that shows your previous 12 months of usage. In what temperatures will a PV system operate? PV systems typically operate in temperatures ranging from 10 to 120 degrees Fahrenheit. PV systems are electronic devices that generate electricity directly from sunlight. Output drops as the system gets hotter due to increasing temperatures on the roof. However, in summer months, the increased daylight hours increase production. What happens at night? Since PV systems require sunlight to produce electricity, your system will not produce at night. We will continue to supply your electricity at night unless you purchase a system with a battery backup. What happens during an electric outage? The PV system will automatically shutdown as soon as it detects an outage on the electric grid. This ensures those working to correct the outage are safe, and also protects the integrity of the electric grid. If you have a battery backup, you can run off of your batteries without any backfeed onto the electric grid. What happens on cloudy days? Since PV systems require sunlight to produce electricity, the bulk of your electricity production will take place under sunny conditions. Output is directly proportional to the amount of sunlight available at any given moment. A system can generate percent of its typical output under bright overcast conditions, but production will continue to diminish as less light reaches your system. Program Rules/Requirements Can I run my PV system prior to having a net meter installed? While you should test your PV system to make sure it is operational, you may not turn on the system until the net meter has been installed. Net metering and billing may not occur until the net meter is in place and the customer is placed on the PV rate. Running a PV system with a standard electronic meter will cause incremental charges for energy that runs back through the meter and onto the grid, thus we recommend testing the system and then moving to full operation when the new net meter is in place and the account is set up on the PV rate. Can I change the size of my system during the application process?

3 You may make changes to the PV system specifications only at Stage 2 Final Submission. At this point in the process, you will be confirming your system information and will have the option to make changes. Keep in mind that acceptable system changes are restricted to +/ 10% of the original system size and that the ultimate system generation cannot exceed 120% of consumption. If you choose to make changes, the Solar*Rewards team will review your changes before moving the application forward. Do I need to be connected to the grid? Yes, to qualify for a Solar*Rewards rebate, you will need to be connected to our grid. While your system generates the bulk of your own electricity during the peak hours of daylight, we will seamlessly supply your electricity at night and on very cloudy days. If you decide to include battery storage, the additional cost for the battery system is not eligible for rebate. Is my solar water heating system eligible for rebate? No, we do not offer rebates for solar water heating systems. Solar water heaters use the sun to heat water, which is then held in a storage tank for future use. They are not used to generate electricity and do not connect to our electrical grid as required by law to qualify for a Solar*Rewards rebate. Will I need approval from my homeowners association? It is a good idea to check with your homeowners association before starting any solar energy projects. How long do I have to complete my solar installation? Your REC price level is set at the time your online electronic application is submitted. In order to remain in the queue, you have 1 month from the submission date to submit the line diagram and Small Generation Interconnection Application. If that deadline is met, your project will be reviewed by the area engineer. Once approved, you will have 9 months from the completion and approval of the interconnection study by the engineer to complete the installation and submit the required documentation. Please note that this includes the all construction, upgrade and design time required by both the installer and Xcel Energy. Can I change installers? In order to change installers, the customer must us directly at nmsolarprogram@xcelenergy.com to request an installer change. This process can only occur once and must be before we have received the Stage 1 documents (Interconnection Agreement and Reservation Letter). The application will remain at the current price until the new application is created. The new installer will need to then create a new application with a new deposit form and fee, as well as a new line diagram. When the new application is created, the installer should us with the new application ID number. Once approved, the original REC price will be applied to the application.

4 Can I move my solar system to a different address if I move or buy another home? We do not allow PV systems that are rebated though our program to be moved from one premise to another. See the next question regarding selling your home. Is my solar water heating system eligible for rebate? No, we do not offer rebates for solar water heating systems. Solar water heaters use the sun to heat water, which is then held in a storage tank for future use. They are not used to generate electricity and do not connect to our electrical grid as required by law to qualify for a Solar*Rewards rebate. REC Payments How do I receive REC payments? REC credits are measured monthly based on the reading from your production meter. For customer owned systems, the credits are subtracted from your electricity bill. Billing Example 1 (Net User): Customer uses 300 kwh PV generates 100 kwh Customer is billed for 200 kwh of net usage Customer receives 100 kwh of REC credits which are credited toward the customer s bill Billing Example 2 (Net Producer): Customer uses 100 kwh PV generates 200 kwh Customer is billed for 0 kwh of net usage Customer receives 100 kwh of excess production at avoided cost rate that month Customer receives 200 kwh of REC credits which are credited toward the customer s bill If the credit on the bill meets or exceeds $50, the customer is sent a check. If the credits are less that $50, they are rolled over to the next month. For developer owned systems, the customer receives the benefits of net metering, while the developer receives a monthly check for the actual production of the system. The rate of pay is dependent on the REC price that each application secures. See the tiered price charts for more information. What is a PV production meter? A PV production meter is a standard meter that is set up for payment rather than for billing.

5 Billing and Metering What does it mean if I see flashing 9's on my residential net meter? When we first set your net meter, it will display all zeros. If your system is generating more electricity than you are using, the meter will move backward, which registers as flashing 9's. Our billing system knows how to correctly handle a negative reading. What does it mean if I see flashing 8's on my residential net meter? The meter is checking the LED display. This is a normal function that the meter runs through periodically. When will the REC payment levels change? The pricing structure is tiered and information regarding this structure can be found on the current pricing web page. A drop in the REC price is tied to MW acquisition in each of the programs and not to a specific date in the future. The best way to know the current price is to check the website for daily updates.