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Q.1:
How do photovoltaics work?
Here's a short answer: Sunlight on photovoltaic modules produces direct current (DC) electricity which is converted to alternating current (AC) by a device called an inverter, which is then wired into your main service panel where it feeds your internal power grid.
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Q.2:
I know people that have broken solar panels for their homes. How is this different and why is this more reliable?
Good question! The broken solar panels you're referring to are likely solar hot water panels, in many cases date back to President Carter-era tax credits, which President Reagan promptly repealed early in his first term. The resulting slack in demand put many solar hot water panel manufacturers out of business, leaving an unfortunate legacy. Photovoltaic technology is completely different, is for the purposes of making electricity, not heating water, and has a 50+year history of reliable performance.
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Q.3:
How long will PV modules last?
Based on manufacturers' in-field experience and reliability testing, PV modules will probably last longer, and are more reliable than just about any other capital investment for your business. In 2003, BP Solar published the results of their analysis of warranty claims and reported that of more than two million modules in service over nearly ten years, approximately one-tenth of one percent were reported faulty, noting "this represents one module failure for every 4,200 module-years of operation." Put another way, if your system has one thousand modules, you may experience the failure of ten modules in 40 years.
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Q.4:
Are there any major advances in technology on the horizon that I should hold out for? (e.g., plastics, nano, thin film, etc.)
Unlike the other major use of silicon – computer chips – photovoltaic technology is not subject to Moore's Law. According to the National Renewable Energy Laboratories, the rate of improvement of achievements in efficiency for crystalline solar cells is less than 1% per year since 1970. Additionally, today’s commercially-available PV products’ efficiency levels were achieved in the laboratory anywhere from 15-20 years ago, indicating the long lag between research gains and commercial product introduction. Net, waiting for a magic solar bullet will probably mean waiting a long time, and paying a lot for electricity in the interim.
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Q.5:
How do I (we/you) determine how large a system I'll need?
The size of the system is usually directly proportional to the amount of power you use. As part of the proposal process Sunlight Electric will perform a site assessment, analyze at least twelve months' worth of utility statements, and raise the question of near-term (3-5 year) expansion and business plans. With that information, taking into account the specifications and limitations of the components, Sunlight Electric will present recommendations for your input and feedback the goal of making sure you feel the ultimate path chosen is ideal.
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Q.6:
Roof-mounted or ground-mounted?
It depends. Roof-mounted tends to be less expensive as they require no support structures and are most often not visible to passersby. On the other hand, ground-mounted systems can usually be oriented and tilted to optimize production. Through understanding your business and your needs, Sunlight Electric will present a solution that optimizes for your business and your needs.
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Q.7:
What happens on dark/cloudy days?
Unlike the early days of solar power when systems had to be sized for peak loads, a grid-connected PV system seamlessly switches to draw from the utility grid when needed. As such, Sunlight Electric uses an annual production target, averaging out sunnier days with cloudy days.
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Q.8:
Do I need batteries?
Is back-up power critical to your business? For most businesses, the answer is “no” and if you don't have a back-up solution today, an ordinary grid-connected PV system will leave you in the same position. However, if you require back-up power or are looking to upgrade your business's disaster preparedness, Sunlight Electric can design a battery storage solution for your PV system to automatically switchover in the event of a power outage. Most customers inquire about batteries and ultimately choose to do without based on cost.
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Q.9:
I have plans for expansion. Can I plan for this now?
We frequently take into account future growth plans when designing your system. The choice of inverter can be influenced by near-term expectations about power usage and in some cases it may make sense to include excess capacity now and simply add more modules later. We'll discuss this with you and explore a variety of options to meet your needs now and in the future.
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Q.10:
What will this do to my roof?
Sunlight Electric PV systems typically weigh no more than 3-4 lbs/sq ft, and most flat roofs have a 20# per sq ft 'dead load' capacity so array weight on the roof is rarely an issue. We can also design a solution to be completely non-penetrating if your municipality accepts our engineering testing documentation, as many have.
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Q.11:
How much do these systems cost and how much money will I save each year? How long will it take to pay back my investment?)
The size of the system is the largest determinant of the price, and the savings rise accordingly. In most cases, the payback period for the investment in a photovoltaic system is roughly 5 years with internal rates of return ranging from 15% to 25%, depending on the avoided cost of energy and the site-specific design and resulting costs.
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Q.12:
What subsidies are available?
Commercial solar buyers benefit from a 30% federal tax credit (though 2019) and accelerated federal depreciation. Combined, these tax benefits typically defray as much as 70% of the out-of-pocket cost of solar. Sunlight Electric will give you the most current information and include that in your proposal with detailed pro forma cash flow statements for a variety of appropriate financing mechanisms. For more details on
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Q.13:
Since the return on investment hinges on selling power to my utility, how can I be confident this will be accurately accounted for?
The power you generate is metered by your inverter and the utility meter tracks power in both directions – both power you buy and power you sell back to the utility. Plus, you can track your production and the power you export via our online monitoring software. Finally, you'll receive a monthly statement from your utility company. All these provide ample reassurance that the accounting will be done, as it has been done for the over 100,000 interconnected photovoltaic systems all across California.
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