The Future Of Transparent Solar Technology
According to Richard Lunt, the Johansen Crosby Endowed Associate Professor of Chemical Engineering and Materials Science at MSU, highly transparent solar cells represent the wave of the future for new solar panel technologies.
Lunt says that these clear solar panels have a similar power-generation potential as rooftop solar, along with additional applications to improve the efficiency of buildings, cars and mobile devices. Lunt and his team estimate that the U.S. alone has about 5 to 7 billion square meters of glass surface at present. .
With this much of glass surface to cover, transparent solar panel technology has the potential to meet about 40 percent of the countrys annual energy demand. This potential is nearly the same as that of rooftop solar. When both these technologies are deployed complimentarily, it could help meet nearly 100 percent of the U.S. electricity needs if we also improve energy storage. comment
Know Your Codes For Solar Mounting
By Dan Felix, IronRidge training manager
In the realm of solar mounting, codes are alive in that they are constantly being updated to keep pace with an ever-changing industry. These codes protect installers from making dangerous mistakes and from scenarios that have led to failure in previous installations. Therefore, it is critical to keep up with changes that local authorities having jurisdiction have put into place.
Working in the solar industry necessitates understanding more than one type of code, unlike, for example, an electrician who may just need to know the National Electrical Code . Building codes , fire codes and structural engineering codes also come into play when adding solar to an existing structure. Here are a few codes all solar installers should be familiar with when working on rooftop projects.
Why Is There A Gap Between Solar Panels
The solar panel frame and glass are affected by temperature, contracting and expanding all the time. If there is no space the panels will press into each other and could cause damage. Your solar panel warranty will be voided if there is no space between the panels, so make sure there is a gap.
It is tempting to place the solar panels right next to each other to fit as many as possible, but that is not advisable. Solar panels are designed to work under specific circumstances. A solar array can only be a particular distance from a house before performance is affected, and it holds true for module spacing as well.
The panel frame and the glass covering the cell are durable, but they are not designed to bump into each other. Depending on the weather the modules will get quite hot as well, so you want to make sure there is sufficient gap between them.
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How Much Space Should Be Between Solar Panels
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Installing solar panels on rooftops can be challenging. There must be enough space on your roof but you have to make sure there is ample room between each panel too. But how much space is required, and why is it necessary in the first place?
Solar panels must have at least 4 to 7 inches of space between rows because the frame contracts and expands as the weather changes. There must also be at least 12 inches of space between the solar panel and the edge of the roof to comply with building codes and to keep the array secure.
How Big A System
With a 3.5kw system now costing about £6,500 and annual returns of £800 plus, getting solar PV panels installed really is an attractive investment opportunity.
The key to making the numbers work though is maximising the number of panels you can squeeze onto your roof, because regardless of the size of system, you are still going to need things like inverters and cabling to run through the home, so the actual cost of adding an extra panel is not really going to add that much to the final cost of the system.
Most solar panels are 250 watts therefore to get a 3.5kW system you would need 14 panels.
250 watt solar PV panels are all pretty much a standardised size they are around 1.6m x 0.9m and about 5cm thick.
For example the Suntech 250w monocrystalline panel is 1665mm x 991mm x 50mm, whhereas the Sanyo/Panasonic panel is 1610mm x 861mm x 35mm, but broadly speaking they are all in that range. Therefore when sizing your solar PV system we recommend using this to drive your calculations.
With a panel therefore being approximately 1.44m2 in total, to get 14 panels on a roof you need a space of about 20m2. However roof-mounted solar installations must also be more than 30cm away from the external edge of the roof, meaning that actually you will need an even larger space so this needs to be factored in to any roof sizing calculations.
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Great Conventional Alternatives To Solar Shingles
As you can see, the list of drawbacks to BIPV products is significant.
The main reason that homeowners are interested in them is improved aesthetics, but a better alternative for most people is to choose conventional panels that are all-black.
All-black solar panels look sleeker and tend to blend into a roof better. Some manufacturers also offer racking systems with dark frames to match the color of the black panels.
The big benefit of going this route is that youâre using mainstream products, which means youâll have far more product choices, better known product longevity, conventional racking, more choice of inverters, and many more options when it comes to choosing installers and getting repair service in the future.
For some other tips, read our article on how to improve the curb appeal of solar panels .
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Guidelines For Designing And Installing Your System
You can hardly fail to notice the surge in solar panels which are popping up on roofs all over the place. But how can you tell the good from the bad? The efficient from the inefficient? The thing is, if you dont have any knowledge of how solar power works, then you run a high risk of falling foul of the many con artists out there.
Its a sad fact of life, but even in Sydney people exist who would like to part you from your cash with no conscience about the job they perform. To safeguard yourself, the very first thing you should do when speaking to a solar power salesman is to ask to see the Clean Energy Council Solar Design accreditation of the designer for the system he is trying to sell you. Ideally, the person visiting your home should have some evidence of internal or external training in system design. If the system they are selling you is itself of a good quality, then its pretty likely that youre dealing with a reputable company who will also install the system correctly.
Solar Panels
Weve covered choosing the right solar panel in our other guides, the Detailed and Brief guides to choosing a solar module. It should also be noted that it is necessary to take into account the voltage and current windows of the inverter when choosing the modules. Your professional installer can assist with this.
How far should the solar panels be from the edges of the roof?
Roof clearance
Dissimilar metals inducing Galvanic corrosion
Shading
Industry Knowledge is so important
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Exclusion Zones And You
If an installer uses SunLock, Radiant or other high quality roof mounting systems you can be very confident they are motivated to do good quality installations. Someone using SunLock isnt suddenly likely to get lazy and forget about its exclusion zone and someone using Radiant is likely to leave at least 20cm between panels and roof edges anyway as that is good practice. A possible exception to this is if a less conscientious installer is only using a high quality mounting system because the customer requested it.
If you are concerned about exclusion zones then it is best to bring it up with your installer before they put a system on your roof. You can check if an exclusion zone is required and if not, how much space from roof edges they are going to leave anyway. Note that if you push for as much solar panel capacity on your roof as possible, you may end up with panels that are closer to roof edges than is ideal. The customer isnt always right, but they often get what they ask for anyway.
Solar Pv Now Has A Solid Footing In The Residential Market And The Building Codes Have Caught Uphere’s What You Need To Know
Glenn MathewsonIssue 292 – July 2020Paths for fire and rescue.
Synopsis: In this installment of Know the Code, code-expert Glenn Mathewson details the commonly encountered issues with the nonelectrical code provisions for solar PV. These provisions include creating safe pathways for first responders and emergency egress, leaving adequate air space for plumbing vents, determining structural loads, and sealing and flashing penetrations and other connections.
Big changes usually happen slowly, and often it takes time for society to catch up to the implications that result. Consider how ride-sharing apps started as an off-the-wall idea, but now there are entire parking-garage levels at major international airports dedicated to the services. I think similar things have happened with rooftop solar.
The Uniform Solar Energy Code was published in the 1970s. Back then, it was all about solar-thermal systems that heat water for space heating and domestic hot water. Though those systems are still available and used and mentioned in codes, the idea never really took off in the U.S. Meanwhile, solar photovoltaics , which turn sunlight into electricity, have grown into a leading technology.
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Space Between Solar Panel Rails And Support
Solar panel rails should have 12 to 16 inches of space between the first support and the end of the rail. Too much space between the rails and the panels could bounce, dangerous during a heavy storm or strong wind gusts. Two rail pieces must also have a rail splice for stability and support.
Space for roof rafters is 16 inches on the average roof, while the standoffs have a 48 inch space between each post. If you are going to install four PV modules measuring 65 x 39 inches each, the combined dimensions will be 160 inches.
Each panel has to be fastened to two rails, and the rail has to be long enough for all the panels. In other words the rail must be at least 160 inches long. If the rail is too long you can cut if off anyway, and it is easier to deal with than being stuck with s short rail.
Solar panel brackets have to be bolted with correct flashing. This will keep the rail from moving and exerting pressure on the other parts. The clamps must also be the right size and number to ensure a proper fit. Remember, your panels are resting on these mounts, so they have to be as sturdy as possible. We strongly recommend the Relmon Z brackets as they are sturdy and well built.
Tesla Solar Roof Shinglecons
- Compared to almost every other brand on the market, Tesla solar power shingles will have a significantly higher cost at anywhere between $50,000 and $100,000 for most homes, including the price of PV tiles and Powerwall batteries
- While traditional installations may take about three days or less, a Tesla solar roof installation could take up to two weeks
- If you are using an electric car, and plan to recharge it with your Tesla solar roof installation, you will require an additional one or two Powerwall batteries
- Tesla roof installation will require a complete removal of your existing roof, which could be an unsavory prospect if your roof is still in good condition and doesnt really need a replacement
Tesla solar shingles cost at present is $21.35 per square foot. This means, if you are looking to install a Tesla solar roof on a 3,000 square foot home, it could cost you somewhere around $60,000.
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How To Find Out If Solar Panels Are Too Heavy For Your Roof
While solar panels are a great additionto your roof if your roof can support them, you need to do some calculations inorder to determine whether placing solar panels on your roof is safe ornot.
So how do you find out if solar panelsare too heavy for your roof?
Solar panels and equipment weigh 2-4 pounds per square foot of equipment to find out if your roof is strong enough to support them, you need to find out your roofs weight capacity, figure out how many square feet of solar panels are going to be installed.
Once you know this square footage,multiply the number by four. This end number is the number of pounds of solarpanel equipment you have, and you ensure that this number is well below theweight capacity of the roof to install them safely.
Installing solar panels can be a greatinvestment in your home if it is undertaken with consideration and forethought.Keep reading to find out why figuring out your roofs weight capacity is vitalto safely fitting solar panels to it.
Plumbing Vents In The Way
Another thorn in the side of effective solar-panel arrangement on roofs is all the other stuff up therenamely, plumbing vents. The drain, waste, and vent system in a house is pretty incredible, but rarely honored as such. It transports the most filthy stuff through and out of our homes, cleans itself, and seals itself from the air we breathe using nothing but gravity, water, and atmospheric pressure. But to work properly, the vents that terminate on the roof have to breathe. Though there may be gas vents and dryer vents on roofs, there are usually many more plumbing vents, and often they are scattered around. Even my small 1950s ranch has three plumbing vents through the roof. Solar contractors have had to dance panels around these vents as their industry grew but not anymore.
The code now recognizes that plumbing vents may be in the way, but they can actually share the space with solar panels. A complete rewrite of IRC section P3103.1 regarding rooftop DWV terminations now specifically allows solar panels to be placed over the top of plumbing vents. Of course, there are limitations, but they speak directly to the issueair getting in and out of the vent. The vent, when protected from snow closure by the panel design, can be cut down from the minimum height of 6 in. to a height of only 2 in. above the roof.
A quick slide down a bank of solar panels and off the roof is likely just as deadly as braving the smoke-filled path through the house.
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Structural Loads On The Roof
Since panels first were placed on roofs, many building departments have asked about the sufficiency of the existing roof to carry the new loads, and this is a very valid question. U.S. housing stock was built over more than two centuries of trial and error and renovation. There is no shortage of surprises that can be found in the attics of homes, and Im not talking about whats in the dusty boxes. There is no guarantee of what the roof can hold, so section R324.4.1 makes a statement that the roof shall be designed and constructed to support the loads imposed by such system in accordance with Chapter 8. Chapter 8 provides prescriptive roof construction methods from the code, so this statement is not directly requiring engineering of the roof structure. Subsections clarify that the roof must support the dead load of the roof including the weight of the panels plus the local snow load. Alternatively, where the snow load is less than the minimum required roof live load , the roof must support the dead load of the roof and the live load.
Fully Transparent Solar Panels
As described in the beginning of this report, researchers at MSU have already achieved a breakthrough to produce fully transparent photovoltaic glass panels that resemble regular glass. Researchers estimate the efficiency of these fully transparent solar panels to be as high as 10% once their commercial production commences.
Its vital to understand here that when it comes to solar panel windows, efficiency of the panel is not the be all and end all. In practical terms, a less efficient solar window only means that the window has to be larger in size compared to the more efficient panel in order to generate the same amount of electricity.
Once fully transparent solar panels get integrated into large windows in buildings, their lower efficiency is bound to be overcompensated .
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Solar Clamp Size Guide
Most solar panels are 1 to 2 inches thick. Top mount clamps are ideal because they can handle panel thicknesses ranging from 0.9 to over 2 inches. The clamps will secure the panels so make sure that is the right specs for your system.
If you buy a solar panel kit it should include all the clamps required to assemble the system. But if you are installing the panel piece by piece, check your solar panel instructions for the recommended clamp size. This is a critical part of the installation so you have to use the right size. A good choice would be the UI AI Solar Panel Clamp Set which should be fine for most setups.
