There are many things to consider when implementing solar. However, even the most complex, high performing solar array can be broken into a handful of key components.
Learn about different types of solar panels, racking systems, inverter technologies, and battery storage.
Learn about basic design considerations, modeling tools, and financing strategies used to optimize your investment.
Learn about how solar connects to the grid and how you get credit for the energy you produce via net energy metering.
Solar panels are the main component in a solar array, capturing energy from the sun and turning into electricity. They are most commonly made using various types of silicon due to its efficiency, abundance, and durability. There are three main types of solar panels:
Monocrystalline solar panels use wafers that are cut from a single piece of silicon, making them very efficient and generally better for applications with limited space. Monocrystalline panels have a darker color and also be made "black on black" for a more aesthetically consistent appearance with no white grid (see above photo).
Polycrystalline solar panels use wafers that are made up of multiple pieces of silicon. They are slightly less efficient (and therefore less expensive) than monocrystalline panels. Polycrystalline panels are most commonly used when space and aesthetics are not major concerns, or in scenarios where managing costs is important.
Thin film solar panels use silicon or several other elements to create thin, flexible strips that are lightweight and oftentimes semi-transparent. This is the most common type of solar used to power small calculators. These panels are less efficient at generating electricity, but are more versatile for unique applications like building integrated photovoltaics.
Solar panels are built to last for decades. Their efficiency will drop over time, but many solar panels are guaranteed to produce over 80% of their original power after 25 years.
Today, virtually all manufacturers guarantee their solar panels for at least 20 years. However, it is important to realize that this guarantee is only as reliable as the company offering it.
We vet all proposals to confirm that module manufacturers have a positive, long-standing track record, and verify the positive tolerance and performance ratings of their equipment.
Solar racking is the structural equipment that the solar panels are attached to, either on a rooftop or on the ground. Solar racking is made out of steel or aluminum, and is engineered to withstand very high wind and snow loads.
For solar panels on flat roofs, racking systems usually involve a lightweight frame that supports the solar panels at a 5-15 degree angle. The frame is held down with weights, or ballasts. This is called a ballast-mount, and requires no roof penetrations.
For solar panels on shingle roofs, racking systems usually involve penetrating the roof surface and attaching rails or mounting "pucks" to structural roof rafters. Panels are held several inches from roof, parallel to its surface. This is called a flush-mount.
For solar panels on the ground, a metal structure is built to hold up the array. This is called a ground-mount, and is secured to the ground with concrete footers or helical piers.
Hiring an inexperienced installation crew can lead to major headaches and costly damage. Regardless of your roof type, it is imperative that installers are experienced and use quality materials, including flashing and sealant on shingle roofs.
Our installation partners are fully certified with hundreds (if not thousands) of successful solar installations under their belt and customer references available upon request.
The inverter is the brains of a solar array. This component converts the DC electricity generated by the solar panels to the AC electricity we use in our daily lives. Like the solar modules themselves, inverters and optimizers have no moving parts and are built for decades of operation. Inverter/ optimizer selection is a very important part of the design process and can greatly increase the performance of your solar system.
Central inverters, as their name suggests, perform their function at a central location. In this type of system, multiple strings of solar panels (generally 10-20 panels to each string) are wired in series to a central inverter. These inverters come in a variety of sizes, and can be combined to maximize efficiency depending on the size, layout, and other factors of a given solar array. Central inverters are versatile, reliable, and affordable (partly due to the many companies that manufacture them).
While they represent the most common inverter solution, central inverters do come with some drawbacks. First, if a central inverter fails it means none of the solar panels connected to it can produce electricity. Second, central inverters on their own provide limited monitoring capabilities (strings of panels can be monitored, but not individual panels). Lastly, standalone central inverters can be less efficient with solar arrays that encounter significant shade.
Optimizers can be used to mitigate some of the drawbacks mentioned above. Optimizers are attached to every one or two solar panels, allowing users to monitor the performance of individual or pairs of solar panels. Optimizers also enable a safety feature called module-level rapid shutdown, whereby each module can quickly throttle back electricity production in the event of an emergency.
Additionally, optimizers help panels maximize production and work more efficiently with string inverters. For this reason, optimizers are especially beneficial to solar arrays that experience significant or variable shade throughout the day.
Microinverters connect directly to each solar panel (or pair of panels), as an alternative to central inverters with optimizers. Microinverters allow for module-level optimization, monitoring, and shutdown (similar to the optimizers mentioned above), and can make a solar array more resilient by reducing single points of system failure (i.e. one module or microinverter failure will not take down the whole system). Microinverters also eliminate high-voltage DC power runs, which makes a system with microinverters more accessible to electricians who are used to working with AC power.
While they offer several benefits, microinverters do tend to be slightly more expensive (only a few companies manufacture them) and can add complexity to an installation, especially with larger solar arrays. Despite their resiliency benefits, they also introduce more points of failure into the system.
Battery storage can add tremendous functionality (not to mention sex appeal) to a residential, commercial, or utility-scale solar installation. In some energy markets, infrastructure conditions and billing mechanisms have created a positive ROI for battery installations. In other markets (like Pennsylvania), Net Metering allows consumers to maximize their solar ROI without batteries. Regardless of where you live, recent technological developments, as well as a precipitous drop in cost, have led to increased accessibility for all consumers.
Especially when coupled with solar, onsite energy storage can help you to maintain critical electrical needs when the grid goes down. However, the relationship between solar capacity, battery capacity, and critical load is complex and requires thoughtful analysis.
Batteries have become a popular marketing tactic for some solar installers. Without a thorough understanding of your needs, a salesperson is simply guessing at what equipment is appropriate.
Solbridge makes sure you know what you’re getting, and getting what you need.
Every solar project is different. Design decisions can be influenced by many factors, including client goals, budget, zoning, permitting, utility requirements, and availability of materials. However, designing a solar system generally starts with a few key considerations.
Most solar systems are sized to offset the energy usage of a single consumer. Whether this is a home, business, or other entity, we build to suit the needs of the host.
Some sites don’t have enough space to offset a consumer’s entire annual consumption. Some sites have more than enough space, with multiple locations that could host solar. We consider client goals, shading and overall efficiency, aesthetics, and more when evaluating potential sites for solar.
As the saying goes, “cash is king!” When possible, paying with cash creates the quickest return on investment. The solar system belongs to you right away, and immediately adds value to your property. Federal tax incentives help you recoup 25-50% of your investment in the first year, followed by steady payback and long-term cashflow.
Financing a solar system with credit, loans, or bonds can create a very favorable scenario for buyers who have limited capital and/or would like to maintain positive cashflow. This strategy still allows you to capture federal tax incentives, which can be used to pay down the basis of the loan (some solar-specific loans encourage this), or leveraged toward another expense/debt. This investment still adds immediate value to your property, and offers the long term-value of ownership without the upfront cost.
Power purchase agreements (or PPAs, for short) come in many shapes and sizes. This strategy involves a third-party (usually a solar developer) who pays for and owns the solar equipment, and then charges the host for the solar electricity produced. Oftentimes this means no upfront cost for the consumer, and no need to maintain the equipment as it belongs to someone else.
PPAs are often used with nonprofit hosts who cannot realize the federal tax benefits available to taxpaying entities. Short-term PPAs involve a transfer of ownership to the host after tax benefits have been monetized by the investor/developer (typically 7-10 years). Long-term PPAs typically remain under the ownership of the investor/developer for multiple decades.
Net metering is a billing mechanism that allows consumers who generate electricity to get credit for the energy they produce, regardless of when they use it. When a solar system is producing more electricity than its host is consuming at a given moment, the excess electricity flows out onto the grid and is used by neighboring consumers.
A net energy meter (installed by the utility company after a solar system is installed) gives you credit for every excess kWh you generate. Over the course of a day, you may produce more electricity than is needed in the afternoon and then use those credits at night. Over a year, you may overproduce in the summer months and use those credits in the winter. Essentially, net metering allows you to treat the grid like a giant battery for your solar system.
The billing mechanisms discussed in this section are very heavily simplified for the sake of general explanation. As mentioned, different markets can have vastly different structures, and thus different financial implications for solar. As such, we make sure our clients understand the laws and practices that pertain to them early in the exploration process, regardless of where they’re located.
The Solar Investment Tax Credit (ITC) is a federal program enacted in 2006 to promote the growth of solar (since then, the industry has grown more than 10,000%). This program applies to both residential and commercial solar installations. As long as you own your solar system, you can receive a discount on the taxes you owe proportional to the cost of your solar investment.
The ITC has been extended at a rate of 26% until the end of 2022, at which time it is scheduled to step down to 22%. So, if you go solar before the end of 2022, you can deduct an extra 4% from your taxes! There is no cap on the value of the credit. The larger your investment, the larger the credit. If you don’t have sufficient tax liability, you can apply the credit to future years as long as the tax credit is in effect.
For commercial entities, accelerated depreciation offers an additional tax incentive that typically equates to 20-30% of the total upfront cost of going solar. Current tax code allows businesses to depreciate 100% of the solar system’s total cost in the first year of ownership. Like the ITC, this relies on your federal tax liability, but can similarly be rolled over into subsequent years until its full value has been realized.
Solar Renewable Energy Credits (SRECs) are part of a state-sanctioned solar incentive system that increases the economic value of a solar investment. As a solar energy producer, you earn one SREC for every 1000 kWh of solar energy your system produces. Your SRECs can then be sold in a state marketplace to accelerate payback. SREC prices fluctuate, and their value is influenced by traditional market forces (supply & demand) as well as state and federal policies. SRECS can be generated and sold by any type of solar producer, as long as you own the solar array.