Daylight Power Company, LLC - FAQs about solar PV systems
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What does this term mean? If there are words, phrases or terminology that you are not familiar with, please goto the Terminology page. How does a solar photovoltaic system work? Basically, a solar photovoltaic system takes energy from the sun and converts it into usable electrical energy for immediate use or storage. First, photons from the sun strike the photovoltaic module. These photons interact with the semiconductor wafer sandwich at a layer where, in most solar PV cells, the silicon doped with impurities meets a phosphorus coating. The interaction causes electrons to be displaced in a way that causes an electrical potential difference to build, similar to a battery, where one side of the sandwich is the anode and one side is the cathode. By wiring these cells and modules together, forming an array, a large amount of electrical power is produced. This power is in the form of a DC current that can vary greatly throughout the day. In order to make the power from the array usable for most things, it must be connected to an inverter. The inverter will turn the DC electricity into AC electricity which is compatible with the power from the utility company and can be used right away by appliances or anything which operates on AC electric power. If the array generates excess power, the inverter can be "grid-tied" so that it pumps electricity back into the power grid and essentially spins the utility meter backwards, saving the owner money on their power bill. Other options in a photovoltaic system include the addition of a battery bank, wired between the solar array and the inverter, on the DC circuit with a charge controller, so that batteries can power everything if the power grid goes down. Off grid systems utilize a battery bank to save electricity for night-time and cloudy days. Of course there is more to it, this is only the tip of the iceberg. The complexities of the inverters and the science of the solar cell could fill a book or two, but in a nutshell, that is how it works. How much do solar panels cost? How much does a whole solar photovoltaic system cost? Solar panels can cost anywhere from about 50 cents per watt up to three or four dollars per watt - wholesale. Some common solar panels are roughly three feet by five feet and produce 200 to 250 watts. This is only considering the "crystaline" type of solar panels, because "thin film" solar panels will degrade much more quickly and stop producing energy compared to the 25 year warranty available with crystaline modules. So, the range of wholesale prices for solar panels would be something like $200 to $1000 each. If you purchase many solar panels, there will be a discount and vise-versa if you only purchase a few. The installer or retailer will charge a fee relative to how much work it takes to get the solar panels to you and/or install them. In order for the solar panels to be useful, an inverter must be used to turn their energy into the AC electrical power which is used in our homes and businesses. The cost of inverters varies with the size of the system it supports. A far more substantial inverter is needed to a system with 100 solar panels versus a system with 10 solar panels. So while a 100 module system might need a $9000 inverter, a 10 module system would have a smaller $1500 inverter. Inverters are also available with an assortment of options such as data connections for computers and solar array optimization circuitry. All of these factors need to be considered for specific applications. For the rest of the system is the racking, to hold the panels and then the balance of the the system, which includes everything else, wire, conduit, hardware, nail etc. The cost of the racking and the balance of system will also vary with system size and specific application. It is important to consider all of these factors, and other unforseen expenses, when calculating the cost of an entire solar photovoltaic system. Daylight Power Company, LLC would first give you a rough estimate after inspecting your roof or site, then ask you to choose the best options before finalizing an estimate. Why buy a solar photovoltaic power system? Money. Right now the number one reason to have a PV system installed is because it is an excellent investment! We all know solar PV power is clean and it is good for the environment, but even if that is not a priority to you, owning a solar power system is currently financially rewarding. The Federal and State governments have put incentive programs in place to pay for a large percentage of the initial price tag of a solar PV system installation. On top of that, owners of solar PV systems can sell sREC or (sAEC) credits/certificates for every 1000kW of power generated by their solar system. Then, after all of those financial reasons to own a PV system, you can add the savings you'll get by decreasing your electric bill. All of this adds up to a system that will pay for itself within several years, then deliver profits to it's owners for the remaining life of the solar panels. (Most PV modules come with a 25 year warranty.) Even if you do not plan to keep your home for the next 25 years, a solar array would increase the value of your home. The amount of value added to the home would not only be the investment cost, and not only the amount saved in the electric bill, but also the amount that the system can earn through the sales of sRECs for the years left in the warranty. The sREC values are very inconsistent, please see the Terminology link in the menu bar. The "green", clean energy aspect of owning a solar photovoltaic system is important. The government incentives are there to allow us to be responsible and make the planet habitable for our grandchildren, great-grandchildren and the rest of mankind. Taking on the task of preserving the earth for those who will inherit it is respectable. Making money from the investment is an excellent reward. What system size should I use? The system size should be tailored specifically for you. Things to take into consideration are: your current power usage, what amount of power usage you wish to offset with a PV system, your roof size, type and orientation, if you desire a pole system or a ground system, how much capital you want to invest and a host of other options available to you. There are a few rules of thumb to keep in mind when considering system size: Number one, do not go over your current power usage by much. Why not? Because the cost of building excess in the array will not be earned back. The utility companies are required by federal law to pay you back for excess electricity you have put into the grid, but they are only required to pay you the "wholesale" amount it costs them to generate electricity, not the retail price you pay on your electric bill. Therefore, it is not economical to build a larger system than you need. Also, the utility companies and government incentive programs dissuade the construction of over-size systems. At a certain point of putting too much power into the grid, an over-size system would have to be registered as a power generation plant/facility and so on. Number two, the cost of construction to support the array will not pay for itself like the solar panels themselves do. The racking or other constructs do not generate electricity or money so the cost of these things should be kept to a minimum in order to have the highest return on the entire installation investment. Ideally, the best investment would be the biggest system that can be installed for a reasonable amount and is efficient, but does not produce excess power annually. Does a roof have to be south-facing for a PV array to work? Will my roof work? In the northern hemisphere, where Daylight Power Company, LLC is located, a PV array does have to be facing the south in order to function with any efficiency. This does not mean that all arrays must be facing to exactly true south in order to be viable. In fact, in much of Pennsylvania, a roof pitched at 30º upward and facing 40º West (or 40º East) of South will only lose 6 or 7% efficiency. (If an array was mounted on it and it was compared to a South facing roof with an equal array.) As long as the rest of the system is efficient enough, a 93% efficient roof orientation would function very well as an investment. So it is important to face the array mostly South, but it does not have to be perfect. A North facing array would receive very little direct light from the sun and would not produce much electricity. (In the northern hemisphere.) A completely horizontal, flat roof array, can produce electricity at 90% efficiency. (For some incentive programs, the array orientation and other factors such as shadowing, must be over 80% efficiency. To ensure quality installations, Daylight Power Company, LLC will only install arrays which are well enough over 80% efficiency to compensate for statistical and measurement error but will consider systems such as vertical wall systems (about 70%) as long as the customer is fully aware of the lack of funding from incentives and decreased energy production rates.) (The previously listed efficiency percentages are only for the array and do not account for inverter power loss etc.) Can PV modules work on all roofs? No. Well, the answer is that photovoltaic modules/panels could produce some electrical power in semi-shade or north facing roofs, but it would be very little power. Some systems will not even produce any electricity at all if the modules/panels are not producing a certain level of power. Therefore, it is sometimes not worthwhile to install an array on certain roofs or in certain orientations. An exception to this general rule of efficiency are PV panels which are made specifically for low light areas. Although these special low light modules function where others may not, they still produce much less power than ordinary panels and yield a small return on investment, if any at all. (as of Jan. 2011) If solar panels cannot be installed so that over approximately 80% of the available direct sunlight reaches them, the system will not meet the requirements for some governmental incentives. Daylight Power Company, LLC will not, without great reservation, install a system which is not viable. Will a photovoltaic solar panel array make my roof leak? Will it void my roof warranty? No, if installed properly using the correct mounts a roof mounted array will not create a leaky roof. There are two types of roof mounts available today: penetrating roof mounts and non-penetrating roof mounts. The Non-penetrating roof mounts are basically for flat roofs where a frame can be built to hold weights, such as concrete blocks, so that the array will not move. Penetrating roof mounts are used to hold a solar panel array to a sloped roof. Reputable installers use penetrating mounts which incorporate flashing over the area where a lag bolt is drilled and sealed into roof rafters. Reputable installers will also research the roof manufacturer and roofer to find limitations of warranties etc. Is a roof the only place that solar panels can be installed? & What is a pole system? No. There are currently several other options available for effectively mounting PV panels. A "pole system", or a "pole top system" is a system where an array is mounted on a pole or on the top of a pole. The standard pole top mounting systems hold an array, less that twelve panels in size, about six feet above the ground. Other systems are also available for placing an array directly on the ground, angled to face the sun. There is even the option to mount an array directly to a south facing wall. These systems all share similar factors to consider which are exposure to direct sunlight with little or no shade, wind loading on the structure and financial viability. Does a grid tied PV system work when there is a power outage in the power grid? No, your inverter MUST disconnect the solar modules from the power grid when there is a power outage so that your system is not trying to supply the entire grid and will not electrocute people from the utility company working on the power lines. This may be referred to as "islanding", and your system MUST have an "anti-islanding" mechanism built in. Systems which can function when there is a power outage, or no utility company power at all, are known as "off-grid" systems. What does sREC mean? What does AEC mean? An sREC is the acronym for "solar Renewable Energy Credits". This is also stated as Renewable Energy Certificates in some places. In Pennsylvania and other states the acronym is AEC for "Alternative Energy Credits". The "s" in front of REC or AEC simply notes that the type of alternative/renewable energy is solar as opposed to wind etc. What is an sREC/AEC? An sREC or sAEC is a credit that the owner of a solar PV system gets for every 1000kW or 1MW of electricity the system generates. This credit represents the solar aspect of that megawatt and can be sold to companies which need to show that they finance alternative energy. For instance, if a power-plant uses coal to produce electricity, that power-plant is still required to produce a percentage of alternative, clean energy, and will buy sRECs to fulfill this requirement. These power generating companies will not buy credits directly from producers, they buy these credits in large volumes from groups/people known as "Aggregators". These aggregators will buy small quantities of credits, put them together and sell them bulk to the power companies. The aggregators are the people who will be interested in buying the credits that are produced by single solar PV systems. There are several ways to go about selling your sRECs. There are bidding markets, there are aggregators who will want you to sign up with them as soon as your system is installed. The sREC market is something which you can learn about and decide what to do with your sRECs and how to make the money from each megawatt you generate. Daylight Power Company, LLC can and will help you with you sREC sales.
I have a question that is not answered here. Will you answer my question? YES! Email your questions to: info@daylightpowerco.com. Of course we will do our best to answer all questions related to photovoltaic systems and installations. Questions are the only way to build the FAQs page and Daylight Power Company has access to resources that are not available to everyone. Plus, taking the time educate everyone may help our company's recognition, reputation and assist the entire industry. How much money can I get from government incentives, tax rebates and grants to build a PV system? (In PA) Up-date: As of August 19, 2011 PA Sunshine rebates are no longer guaranteed and all applications are put on a "wait-list". If projects which have reserved a rebate are cancelled, then grant money will be freed up for applicants on the "wait-list" to receive. As of January 1, 2011 the highest percentage you can save on a solar photovoltaic module system is 65%. The 65% is from a 30% federal personal tax incentive plus the Pennsylvania state rebate of up to 35%. The PA state rebate will only rebate up to $7,500 for residential systems. The lesser of 35% or $7,500 for residential systems on homes that meet grant criteria based on income. The PA Sunshine Program issues rebates based on the cost of an installed system and on what incentive level "Step" the program has reached. For each "Step" the program advances the rebate amount decreases (See the rate schedules on the Pennsylvania Department of Environmental Protection's PA Sunshine Solar Program page.) For businesses which install a (commercial) PV system the maximum is much higher and PA will rebate up to $52,500 or 35% of the installed cost of a system. The federal 30% tax incentive is for personal tax credit and it has no limit for systems installed after 12/31/2008 but before 12/31/2016. For official and up-to-date information use the links on the Web Resources page. Can I get government incentives for a solar PV array on my home/business/vacation house/investment property? (In PA) In order to be eligible for a federal tax credit of 30% the installed cost of a solar electric system, the home served by the system does NOT have to be that taxpayer's principal residence. However, the Pennsylvania state rebate for residential systems requires that the solar electric system is on the primary residence of the owner. Therefore, the PA incentive is not available for vacation homes and investment properties, but the federal incentive is available for non-primary residences. It is also important to note that the PA Sunshine rebate is available to businesses and therefore owners of business properties can benefit from the program if they install a solar electric system on a commercial building/property. For official and up-to-date information use the links on the Web Resources page. How will a PV solar array affect the value of my home?A solar PV array will increase the value of a home in several ways. First the value of the installed system and the value of the panels themselves should be considered. Add to this the value of energy savings that the system provides over its life expectancy, which will be under warranty for at least 25 years. Then add the large value of SAEC/sREC credit sales. This will be between $200 and $700 for every MWh the system generates. For example, a 5kW capacity solar PV array (20 PV modules of 250 watts each) would produce about 6 sRECs per year; earning in the range of $1200 to $4200 per year. By the time the home is going to be sold, this sREC credit value will be known. Finally the added value of an environmental house can be added. Although it's not easy to put a price on the "green" factor, it would help attract and sell a home. "Solar PV Array" might be added to property search engines in the near future, similar to the way you are able to search for homes with fireplaces or garages. Altogether, to calculate the quantifiable increase in value, the home seller would: 1 • Multiply the years remaining before the warranty expires by the energy saving per year : (25 - age) x (utility bill savings/yr) 2 • Repeat this for the value of sRECs/SAECs credits: (25 - age) x (average sREC sales profit per year) 3 • Add the value of the solar system after depreciation then add the values from 1 and 2 This would give a good estimate of the increased appraisal of a home. There are also other possibilities, like having home buyers sign over the rights to the sREC credits to you, so that you continue to collect that income. The entire sREC/SAEC system is new, and there is an uncertainty to agreements regarding it, but the sale of credits and the Alternative Energy Portfolio Standard, which established the credits, will be around until at least 2021.
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