Solarize Resources

Contrary to popular understanding, a rooftop solar energy system MUST shut-down and stop producing energy if the utility electricity-grid goes out. This national safety requirement protects utility workers from accidental solar energy export when working to restore electrical power for your home. Including a battery in your solar energy system will help you keep all or part of your home's electrical system up and running even in a utility grid outage! Excess solar power produced during the day will be stored in your home battery and be available to use anytime your home needs more power than your solar energy system is producing, when the utility power is out, at night, or when the sun isn’t shining. Coupling a battery with your solar energy system allows your system to create a temporary isolated micro-grid for your home and builds resiliency into your home’s electricity system. When the utility electricity grid comes back online, your system will automatically reconnect and continue having available power from all sources.

Every rooftop can fit a different number of solar panels and generate a different amount of solar electricity. Factors like roof size, orientation to the sun's path in the sky, roof pitch, nearby shading, and roof obstacles all play a role in both how many solar modules can fit on a roof and how efficient those solar modules will be at producing electricity. Solar works on all types of rooftops! The most ideal roof is gabled with a single large unobstructed roof section facing 180 degrees due south at a pitch of between 7/12 and 9/12. On average, a solar energy system built on a rooftop with these conditions will generate about 1/2kWh per square foot of roof space per day based on today's technology. The average home uses about 40kWh of electricity per day. Which means that in ideal conditions you need just 800sqft of rooftop space to provide all the electrical power your home needs.

The average home has enough roof space to generate up to 100% of its electricity needs - but that doesn’t mean it's a good idea to fill your roof with solar panels! Your utilities solar metering policy, the impact of local shading on your roof, how and when you typically use electricity in your home, and your solar energy goals will all help determine the best available system size and design for your roof. A trained solar professional will be able to work with each homeowner and understand the impact of each of these considerations on the final system size and type.

Solar panels only produce about 10-20% of their rated power capacity in the rain. Photovoltaic panels can use direct or indirect sunlight to generate power, though they are most effective in direct sunlight. Solar panels will still work even when the light is reflected or partially blocked by clouds. Rain actually helps to keep your panels operating efficiently by washing away any dust or dirt. If you live in an area with a strong net metering policy, excess energy generated by your panels during sunny hours will offset energy that you use at night and other times when your system isn't operating at full capacity.

Understanding how solar panels mount to your roof is an important part of your solar energy system. Solar panels are connected to your roof through a racking system. Racking systems vary depending on the type of roof you have on your home or business. There are five basic types of rooftop solar racking systems based on the type and style of your roof:

• Asphalt Shingle Roofs with Mechanically attached racking
• Flat Roofs with Ballast-mounted racking 
• Standing seam metal roofs with non-penetrative attachment racked
• Profile metal roofs with penetrative attached racking
• Integrated solar shingles 

Solar rooftop racking systems are often rated to withstand winds in excess of 120MPH, and in many cases can actually protect your existing roof. No matter the type of rooftop mounting system, solar racking manufacturers typically carry product warranties that match the full 25-year warranty on a quality solar panel and are likely to outlast the warranty on an existing roof. Additionally, a qualified solar installer will also typically offer a workmanship warranty of at least 1-year to protect homeowners. 

Millions of homes in the United States have had solar energy systems installed on pitched Asphalt shingle roofs using a lag-bolt and flashing system. This racking system allows your solar panels racking to be bolted to the rafters of the home’s roof. To ensure no possibility of leaks, the bolt-penetrations in your roof should be sealed and weatherized by your solar installation professional by both chemical (caulking) and mechanical (flashing) means. Your solar panels are then attached and bonded to the racking system per the manufacturer's instructions. 

Flat rooftops using a rolled thermo-plastic or rolled asphalt adhesive covering are becoming more popular with modern buildings. Solar panels installed on flat roofs often need no mechanical attachment to the roof itself. Instead, solar panels are set and secured into manufactured trays that are weighted down to the roof using ballast-blocks made of stone or concrete. This technique introduces no holes in the roof and can make future system maintenance easier for your solar technicians.

Standing seam metal roofs are ideal for solar energy system installations. Like an asphalt shingle roof the solar racking system is mechanically attached to the metal roof, but unlike a shingled roof the system will clamp onto the metal seams of the roof material and not need to penetrate or introduce holes into your roof. 

Profile metal roofs are long-lasting but for a solar energy system to be attached to this roof type the solar racking system must screw into the metal of the roof itself in order to be mechanically attached. In some cases, the racking system does not need to penetrate the roof decking or roof structure in order to be firmly and adequately attached. 

Integrated solar shingles may be the wave of the future for rooftop and residential solar energy systems. These shingle-type solar panels not only generate electricity but also act as your roof's primary barrier to the elements. Currently, solar shingles are very expensive and have limited availability.

Solar panels can go on just about any roof, residential or commercial. “Grid parity”, meaning energy generated from solar is the same or less than what it costs from the utility over the warranted lifespan of the solar panels, hardware manufacturers have developed numerous clamping and fastening devices to accommodate solar on just about any roof type imaginable.

Yes. While there are several metal roof types, the most common are standing seam and corrugated, both of which you can put solar on. Standing seam roofs are particularly adaptable for solar due to a special device called an S-5 clamp. The S-5 is designed to clamp (think pinch) the standing seam portion of the roof and therefore requires no actual penetration of the roof.

The short answer is yes, you can put solar panels on a shake roof, however it does present some challenges. Shake roofs are more delicate than asphalt shingle or metal roofs and sometimes made of wood such as cedar. Installing solar on a shake roof requires a lot of attention to detail and extra labor so as to not damage the tiles underneath and around the solar array. It may be hard to find a company willing to install solar on a shake roof and will likely be more expensive. Homeowners with shake roofs may want to consider alternatives such as a ground mount or pergola application.

Same answer as above. It can be done but there are challenges and it will likely be more expensive than installing solar on a traditional asphalt shingle or metal roof. Additionally, due to the delicate nature of tile roofs, it may be hard to find an installer with the requisite skill and equipment. Homeowners with tile roofs may want to consider alternatives such as a ground mount, car canopy, or pergola application.

Yes, solar can be installed on an east- and west-facing roof, however, is not recommended as the first option. East-facing panels will generate more electricity in the morning, because the sun rises in the East, and less in the evening. Likewise, west-facing panels will generate more electricity in the eventing. East-facing or west-facing solar can be beneficial if there is a high electricity demand in the morning or evening hours, however, south-facing and west-facing are preferred orientations for solar.

Because there is not a standard permitting process in the US, a permit to install solar must be obtained from the jurisdiction the property is situated. Each jurisdiction will have its own requirements so the best place to start is by calling your local permitting office to see what is required. 

At a minimum, an electrical permit will be required but additional permits or a structural engineering certifications may be required in some jurisdictions. A grid-tied system, meaning the property is still connected to the utility grid which 99% of rooftop solar installations are, a utility interconnection agreement will be required as well. A reputable installation company will include permitting and interconnection as part of the cost of installation.

Generally, it’s always good for solar panels to be free of dust, pollen, bird droppings and the like, but cleaning solar panels on a regular basis is not necessary. Even when solar panels become dusty or covered with pollen, solar panels will continue to generate close to their maximum efficiency. The next time it rains, the panels will be cleaned off and good as new. 

Importantly, all solar energy systems come with generation monitoring so it’s easy to determine if there’s a drop in production and if a cleaning is necessary. Most solar installation companies offer an optional maintenance service where cleaning the panels is included. For do-it-yourselfers, a standard garden hose and soft cloth will do the trick. NEVER use a pressure washer as doing so could damage the panels.

Solar panels do not cause roof damage themselves, however, a poor installation can cause damage in some instances. Highly qualified installation companies will take great care in determining whether the roof can structurally support the additional weight load of the equipment to avoid roof sagging. Roof leaks from solar installations are rare. Special mounting brackets are used to connect the racking system to the rafters that include flashing and sealant to secure the connection and avoid the potential for a roof leak. 

Customers should carefully consider an installation company’s workmanship warranty, which can vary in length and coverage, to determine how it covers damages to a roof caused by the solar installation.

It's important to hire a solar contractor that is highly qualified and can communicate with your roofing contractor, if possible, about what will void the roof warranty. If a workmanship warranty with the roofing company is still valid at the time solar is installed, they will want to know what type of racking system is being installed and how it is weatherproofed. While it is possible for the applicable part of your roof to be voided, solar panels should not void the warranty if they're installed properly with the correct forms of sealants or flashing.

Another important consideration when installing solar is the current condition of your roof. Solar panels are warranted for 25-30 years and known to keep generating electricity after that. The general rule of thumb is this: if an asphalt shingle roof is over 10 years old, a roof replacement should be considered. 

Solar panel prices are often compared using a metric called the “price-per-watt” which is the total cost of the system divided by the system wattage. For example, a 7kW system (7000 watts) priced at $21,000 is $3.30 per watt. The price-per-watt metric is great for comparing the price of systems that aren’t the same size in wattage, but keep in mind that larger systems will typically have a lower price per watt due to the economy of scale.

Solar panels systems vary in cost based on several factors. There’s an economy of scale mentioned above (i.e. larger systems cost less than smaller systems).  Some solar power systems may include a battery which adds benefits but drives up the cost significantly. Other factors such as roof pitch, roofing type, travel costs, non-contiguous layout, system warranty and more can affect the price.  

The typical price range for residential solar is around $3.00 per watt. The price for commercial solar varies greatly due to potential system sizes ranging from 50kW to 1MW or more. Always get multiple quotes and compare each contractor’s proposal.

Yes, there’s a Federal Tax Credit for home and business owners. Recipients must have taxable income to apply the tax credit towards, but if they can’t use it all in the first year it can “roll over” for up to 5 years. See our incentives page for more on tax credits

Yes, but the amount you get paid for each unit of electricity (called a kilowatt-hour or kWh) depends on your utility’s metering policy. The most popular compensation policy in the country for how much a utility companesates solar owners for electricity returned to the grid is called net metering. Net metering offers solar owners to offset their electric consumption dollar for dollar. Thirty-seven states plus most US territories offer net metering. 

However, some utilities will only pay the wholesale rate (aka “avoided cost”) for the energy sent to the grid (yes, they immediately turn around and sell it to your neighbor at the retail rate) while other utilities offer something in between net metering and avoided cost. Be sure to ask your solar representative how much your utility will compensate you for electricity that you return to their grid system. 

Yes. Rooftop solar will generate an easily predictable amount of electricity, which is calculated using decades of weather pattern data and site specifics, but the amount your electric bill is reduced by depends on a number of factors such as the size of the PV system, the utility rate plan you’re on, your utility’s metering policy, orientation and tilt of solar panels, shade on the array, times the building is occupied using energy, and more. Bigger isn’t always better when designing PV systems and your solar designer should be able to talk to you about your specific situation and what system makes the most sense for you. 

Some battery storage systems can pair with solar to offer greater electric bill savings by doing what’s called peak shaving or TOU rate arbitrage.

After you identify at least 3 companies you want to get quotes from, do your homework on each of them. As with any industry, there are people working in solar who just want to make a sale and will deceive customers to do so. Watch out for marketing gimmicks (“get paid to go solar”) and high-pressure sales tactics (“sign now or the deal is off the table”). Many companies use those tactics, and even go to the extent of explicitly lying, to trick people into buying overpriced solar that won’t produce as much energy as promised.  

In many cases, out of state companies don’t fully understand how to properly design solar in that state. It’s very different from state to state. Among a myriad of things to know, they especially must understand how metering works at your utility or else you’ll run into big problems with trying to get Permission to Operate (PTO) from your power utility.  

Typically the solar company you hire will handle the paperwork required to get PTO for your solar, so be sure that’s in writing in their contract.

Ask how long the company has been in business, what city/state their HQ is in (you can request a copy of their business license too), ask for references of solar installations in your area, ask for proof of licensure and verify it’s in good standing. Some of the staff should also be NABCEP PV Installation Professional certified. Request a certificate showing their general liability and workers comp insurance.

Do a web search of the company’s name and look for reviews, look for how many complaints they’ve had and if they resolved the complaints. You cannot always trust third-party review sites like BBB, Angies List, etc because those are pay-to-list websites who sometimes ignore serious issues. Google Reviews and SolarReviews.com are good places to investigate a company’s reputation. Glassdoor is a website where employees can review companies they’ve worked for, so you can see what their employees say about them.

Commercial rooftop solar is very similar to residential rooftop solar but designing the system requires someone familiar with commercial utility rate plans. Commercial rate plans are much more sophisticated and accurately projecting savings is more of a challenge. The same can be said for the installation crew, as commercial buildings are constructed a lot different than a house. Solar on a business can be great for sales and marketing because many of today’s consumers prefer shopping at businesses who care about the environment.

Solar shingle products have been attempted by many companies, but no product has become mainstream due to the high upfront cost of these types of systems. Although, they can pay for themselves just like a traditional PV system. Solar shingles or tiles replace the entire roof eliminating the cost of building or replacing a traditional roof, and because the tiles are made of glass, they last much longer than a traditional roof. They also can have better aesthetics compared to traditional solar. The downside is cost and the upside is longevity and aesthetics.

Rooftop Solar is typically roof mounted, hence the name, but the term refers to any on-site solar connected on the customer side of the electric meter. The panels can be mounted in a variety of ways including roof, ground, parking canopy, pergola, awning, on a pole and more. The purpose of Rooftop Solar is to offset electricity that would otherwise come from your power utility.