Questions About Solar Electric Systems

1. What are the advantages of solar?
2. Will I still be connected to the grid?
3. Will my system produce more than what I need?
4. What is net metering? Does it mean I can sell electricity to my utility?
5. Will solar reduce my demand charges?
6. How does it work?
7. What determines the output of my system?
8. What parts are included in the system?
9. What impact will the system have on my roof, if any?
10. Will the system be visible from the street?
11. What are the long-term costs of my system?
12. How will I know how much my system is producing?
13. What are the maintenance concerns of a solar system?
14. Where does solar incentive money come from?
15. In which states does solar really make sense?
16. Can 3Phases help finance my solar system?

What are the advantages of solar?

• It’s clean. Solar produces electricity from the power of the sun; no greenhouse gasses or other pollutants are produced in the process.
• It’s renewable. Because the sun rises every day, there will always be a regular supply of free “fuel” for your system.
• It’s reliable. Solar technology has been refined over decades; the modules carry a 25 year warranty, and will likely still be producing energy long after the warranty period, up to a 40 year life span.
• It’s domestic. Since solar produces energy right here at home, not only will you be helping to relieve dependence upon foreign fuels, but you will be supporting North American companies and their workers.
• It’s scaleable. From small household installations to large commercial or municipal arrays, solar systems can be easily sized to meet just about any need.
• It’s local. One of the main challenges that utilities face today is transporting power from the source (a power plant) to the end user, resulting in large expense for transporting power, or transmission and distribution (T&D). The good news about onsite power or distributed generation such as solar, is that it is consumed at the same place it is produced, resulting in reduced need and cost for T&D.
• It produces power at peak periods. The midday hours of the day when the sun is shining most intensely are most often when the electricity grid is under the greatest strain. Utility companies must pay higher rates to acquire energy to supplement their production during these peak hours, leading to higher midday energy rates. Fortunately, these peak hours are also when the solar system produces the most energy.

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Will I still be connected to the grid?

Yes. Your solar electric system will reduce your need to draw energy from the grid, but you will remain connected. Because these systems are designed to be interconnected with the grid, they will stop putting energy into the grid if the grid goes down. (top)

Will my system produce more than what I need?

Your system may produce more than you use on any given day, but solar electric systems are typically designed to reduce, not completely replace, the electricity you draw from the grid. (top)

What is net metering? Does it mean I can sell electricity to my utility?

With net metering, your meter will actually spin backwards when you are producing more power than you are consuming, and you will be given credit for the energy that you put into the grid. When you return to using more than you produce, for example at nighttime, your meter will spin forward again, and you will begin using up the credit generated when you were producing more than you were using. For instance, if, during daylight hours, your system produces 500 kWh more than you actually consumed, then you will enter the evening with a 500 kWh credit that can be used after the sun goes down. (top)

Will solar reduce my demand charges?

Solar cannot be relied upon to regularly reduce your demand charges. Since demand charges are calculated at your single highest usage point during the entire month for each rate period, there is no guarantee that this point of maximum consumption will be covered by output from the solar system. Your high demand peak could come during the time that the system is not producing much output, such as in the early evening or during a rainstorm. Therefore, we typically do not model a reduction in demand charges when we calculate savings from solar. (top)

How does it work?

A solar array uses the sun as source of fuel. When a photon from the sun strikes the cell, the photon’s electrons are stripped away and channeled through the solar module to become DC (direct current) electrical power. Since virtually all equipment and appliances run on AC (alternating current) electrical power, the DC electricity must pass through an inverter, which converts the power from DC to AC. (top)

What determines the output of my system?

Your rated system output is primarily determined by the efficiency of the modules and the size of your system . Final output is then influenced by additional factors such as:

• The weather: While the modules will still produce even when the sky is cloudy or foggy, the panels require direct sunlight to produce any significant level of power. Clouds will cut the level of output significantly. Our projection model, provided by the National Renewable Energy Labs, uses local data to project the average number of kWh output AC per kilowatt AC of system capacity.
• Shading: If the panels are shaded at anytime during the day by trees or buildings, their output will be reduced. As part of the design of your system, we will use a Solar Pathfinder to determine the amount of solar radiation and shade at the array site. The modeled output of your system will be adjusted downward to compensate for shade issues, so that the estimated production will already include a de-rating for shade.
• Season: The elevation of the path of the sun in the sky varies based upon the season; in summer it is at its highest point in the sky, and in winter it is at its lowest. This affects output in two ways: one, the higher the sun is in the sky, the more hours of daylight there will be. Second, the more direct the angle of sunlight on the modules, the more they will produce. If your panels are tilted, they will be set at an angle roughly equivalent to your latitude that maximizes output (for example, 34 degrees in the Los Angeles area) or a lesser angle to make the modules “flatter” which can be more aesthetically pleasing.
• Temperature of the Panels: As the temperature of the module heats up, it becomes less efficient in converting the sun’s rays into energy. The panels require airflow on both top and bottom in order to stay cooled to peak efficiency. Even if your design calls for flat-mount, our installer will leave enough of a gap between your roof and the bottom of the panels to provide airflow.
• Cleanliness of the Panels: The panels should be periodically washed using city water at regular pressure in order to reduce buildup of dust, sand, pollution, and other particulates. We recommend this be done at least quarterly. A regular rain shower will do the trick as well.

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What parts are included in the system?

• Modules: Your system’s primary component is an array of solar electric modules, which capture the sun’s rays and convert it to direct current (DC) electricity.
• Inverters: Your system will include one or more inverters which convert direct current (DC) to alternating current (AC) power. Smaller inverters can be wall-mounted, and larger ones, above 30 kW in capacity, are typically set up on the ground like other large switch gear.
• Transformers: For each inverter, your system will require one transformer, which may often by integrated into your inverter.
• High Voltage Disconnects: Your system will include two high voltage (HV) disconnects for each inverter: one for the DC side, between the panels and the inverter, and one for the AC side, between the inverter and the grid.
• Racking: Your modules will be mounted in rustproof, often aluminum racks to form panels of 6-18 modules each.
• Tilt Kits: Your panels, unless your design specifies flat-mount, can employ tilt kits to angle the modules towards the sun in order to increase their average output. These tilt kits will enable the installers to precisely set the degree of tilt for your panels to strike the best possible balance between output and available space.
• Wiring and Balance of System Components: Your modules may be run in strings into combiner boxes, which will then be wired into through the DC HV disconnect box(es) into the inverter(s).

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What impact will the system have on my roof, if any?

If your system is mounted on your roof, the system will shade the roof deck underneath it, protecting it from harmful UV and infrared rays. Roof mounted systems can be penetrating or non-penetrating, depending upon the needs of the application. Advances in mounting technology are dramatically reducing the the need for roof-mounted solar array’s to penetrate the roof at all. (top)

Will the system be visible from the street?

For most flat-roofed buildings, it is unlikely that the system will be very visible, if at all, from the street, particularly if your building has a parapet of more than a foot or so. Some designs can involve hanging a portion of the array over the parapet, creating a "solar shade" which will be highly visible. We believe that visible solar modules make a powerful statement about your commitment to clean energy, but if your aesthetics or local codes call for minimal visibility that can likely be accommodated. (top)

What about a ground mounted system?

Lately there have been many improvements in ground mounted systems which are either fixed-tilt (locked at a certain angle) or tracking (move to optimize the angle the sun.) A single axis tracking system allows the modules to track the sun from sunrise to sunset. A dual axis tracking system goes further by also tracking the sun during different seasonal position in the sky. Tracking systems in general are 20%-50% more productive than fixed-tilt systems. (top)

How will I know how much my system is producing?

Keeping track of your system performance is easy. Your inverter(s) will come with a display that indicates the current power output of the system. In addition, on partially cloudy days you can actually watch your meter change speed as clouds pass over and away from the sun. We can also install a remote monitoring device on your meter that will you and 3 Phases to periodically verify the output of your system.

If the system appears to be under performing, check to make sure that none of the HV disconnect switches have been thrown to the OFF position. By law, these must be near the panel and cannot be locked, so in essence there is nothing stopping someone from shutting the system off. A part of the regular housekeeping chores should be checking to make sure that all the HV disconnect switches are in the ON position. (top)

What are the maintenance concerns of a solar system?

The inverter is the most fragile component of any solar electric system. The expected life span of inverters is about 10 years, and the warranty period is five to ten years. Otherwise the modules usually require no maintenance other than occasional washing. (top)

Where does solar incentive money come from?

Despite its free fuel source, and long term financial benefits, solar energy is still expensive in the short term. The federal government and many state governments provide incentives for solar energy to make it more affordable. At the state or utility level, these funds usually come from small charges that are approved by the state legislature or public utilities commission and added to all rate-payers’ bills. (top)

In which states does solar really make sense?

3 primary factors drive the economic viability of solar systems. First is the level of state incentives for solar. Second is the strength and abundance of the sun. And third is the underlying cost of energy that a rate payer must pay in his or her area; the higher the cost of the electricity, the more viable solar becomes. Considering these 3 factors, the leading states for solar in the U.S. today are CA, CO, NJ, NV, PA, AZ, and HI. While solar systems can be built anywhere, 3 Phases focuses on opportunities in these states. (top)

Can 3Phases help finance my solar system?

Yes. There are many innovative financing solutions which allow customers to avoid the capital cost of their system and pay for either the equipment or the energy over time. One such solution is 3 Phases Daylight Savings program which provides all the capital up front, and the customer to pays for the energy over a 10 year period. (top)