What are roof top solar systems and their benefits to life and production?
Roof top solar energy is being applied more and more widely thanks to its convenience and, most importantly, its positive impact on the environment. So what is roof top solar energy? What benefits does it bring and how to install it? We will find out in the following article.
Solar energy is energy generated from radiant light and heat from the sun to generate electricity and solar thermal energy, including water heating and solar architecture. Solar radiation, along with secondary solar energy sources, is the most abundantly available renewable energy source. Solar technologies mainly consist of passive energy or active energy depending on how sunlight is captured, converted, and distributed.
Active solar techniques refer to photovoltaic modules (also called photovoltaic panels) and solar thermal collectors to convert sunlight into useful outputs. Active solar technology increases energy supply and is considered a secondary technology, while passive solar technology reduces the need for alternative resources and is generally considered a demand-side technology.
Passive solar techniques include:
- Orienting buildings to the sun.
- Choosing suitable thermal mass materials or light dispersion properties.
- Designing spaces that naturally circulate air.
A roof top solar power system, also known as a rooftop PV system, is a photovoltaic (PV) system with solar panels that generate electricity and are mounted on the roof of buildings, civil or commercial structures. A solar power system consists of photovoltaic modules, mounting systems, cables, solar inverters and other electrical accessories.
Roof top solar systems are typically small compared to ground-based solar power stations. Most rooftop PV stations are grid photovoltaic systems. PV systems on residential buildings usually have capacities between 5 and 20 kilowatts (kW), while those on commercial buildings typically have capabilities between 100 kilowatts and 1 megawatt (MW).
Saving on energy costs
Generating your own electricity from readily available energy means using less electricity from conventional power providers, and you can save quite a bit on electricity costs each month. Many places also trade in electricity generated from the sun to maximize profits from investing in the solar power grid.
Using electricity from roof top solar panels also helps you not be too dependent on conventional power supply, minimizing the impact of unexpected power outages.
Bringing positive impacts to the environment
Solar energy is the least negative environmental energy source of all forms of energy. It does not produce greenhouse gasses and does not pollute water sources. It also doesn’t need too much water to operate, unlike a nuclear power plant, which requires 20 times more water. Solar power generation also does not cause noise pollution, making it easy to install in dense urban areas.
Solar systems can be installed anywhere
Roof top solar batteries can be installed anywhere, as long as the place receives sunlight. Solar panel systems are beneficial for remote areas with rugged terrain, making it challenging to install conventional wiring.
Stand-alone solar systems can provide electricity well to less populated areas, such as mountains or offshore, where traffic is difficult. Not only that, but solar energy can also power spacecraft and boats.
Basic roof top solar panel system installation process with four simple steps
The basic process of roof top solar system installation includes four steps below:
- Mount installation
- Install the solar panels and electrical wiring
- Connect the components of the system
- Start solar inverter
1. Mount installation
First, we will place the brackets for the solar panels. Brackets help keep the system fixed and secure on the roof. The installation orientation of the PV panels (monocrystalline or polycrystalline) also needs to be taken into account for the best energy absorption. For countries in the Southern Hemisphere like Vietnam, installing solar panels in the North direction and slightly inclined from 18 – 36 degrees is recommended. You can use a solar tracker to increase energy conversion efficiency.
2. Solar panels installation and electrical wiring
In this step, you fix the roof top solar panels to the brackets prepared above. Then all we need to do is wire them up. It is recommended to use universal connectors like MC4 as they have a good connection with all types of solar panels. You can wire in the following two ways:
- Series connection: The positive wire of one PV module is connected to the negative (-) wire of the other module.
- Parallel connection: Connect positive to positive and negative (-) to negative (-).
3. Connecting the components of the system (Solar Inverter, Solar Battery, Grid)
This 3rd step will connect the panel to the energy inverter. The positive wire from the control board is connected to the positive terminal of the inverter and vice versa. Then we connect the inverter to the input of the solar cell and the grid to generate electricity.
Next, the solar inverter will be connected to the solar battery, and the positive terminal of the battery is connected to the positive terminal of the inverter and vice versa. Finally, you join the inverter to the grid.
4. Starting the solar inverter
At this final stage, we will start turning on the main inverter switch of the building. Most inverters have a digital display showing detailed roof top solar production and usage data.
Commercial Rooftop Solar Systems
Commercial rooftop solar projects often provide an excellent financial return. Rooftop solar is usually the most straight-forward location for an on-site solar system for a business. A rooftop solar photovoltaic installation is one of the most popular solar system design options for businesses and commercial applications because it typically does not interfere with business operations. Rooftop solar monetizes the roof and can reduce operating expenses by mounting solar photovoltaic panels in a calculated manner based on available roof space and the power consumption history of the business location. Businesses of all sizes, including commercial and industrial organizations, can capitalize on the many benefits of adding solar power to their building roofs. Rooftop solar energy has become a strategic decision that has proven to have numerous benefits for many types of businesses. Commercial rooftops provide an exceptional location to power your business with clean renewable energy. Core Development Group offers customized solar solutions for flat commercial or industrial flat-roof buildings.
- Solar power gives you a great return on investment
- Reduces your business operating costs
- Controls future energy bills and provides a hedge against inflation
- Increases your property value
- Tax credits and bonus depreciation
- Corporate sustainability benefits
Let Core Development Group walk you through the details of commercial rooftop solar, including incentive programs tailored to your area, system planning, installation, inspection, certification, and connection. Get a custom quote for solar for your business.
Financial Return of Commercial Rooftop Solar System
Installing a commercial rooftop solar system is an investment that pays for itself by generating onsite electricity at a lower cost. Core Development Groups tailors customized options for businesses to pay for their commercial solar systems. Depending on incentives and roof details, a target return on investment for a cash purchase is approximately 10%.20% per year with a payback of 5 to 10 years. After the payback period is reached, the commercial solar system will continue to produce electricity for over 25 years.
Businesses can choose a PPA (Power Purchase Agreement) option for the rooftop commercial solar installation, and payments can be structured to be lower than the electricity costs from the local utility company. Under the PPA scenario, businesses can create an immediate monthly savings on their electricity costs. A commercial solar PPA provides an economic hedge against inflation by protecting against energy market spikes and the inevitable rise in utility electricity rates.
Businesses face important choices to install commercial solar systems on their properties. Commercial solar system are innovative and financially focused decisions that have both bottom-line impacts and positive sustainable results.
Commercial rooftops are ideal locations to host clean, renewable energy sources.
Industry-Leading Experience, Knowledge, and Resources
At Core Development Group, we make your sustainable energy goals attainable. With the ever-increasing interest in corporate climate responsibility, businesses today are more focused than ever on effective renewable energy strategies. In the past few years, there has been a lot of discussion on the topic, and we have seen measurable improvement in both grass root and large-scale efforts. Choosing the best renewable technology to implement sustainability goals and knowing which incentive plans are available can be challenging to keep up with. Core Development Group, a nationally ranked renewable provider, has the diverse expertise necessary to offer companies trusted guidance and reliable services towards a sustainable future. Our mission is to help power the world’s companies and communities now and for years to come through sustainable energy development.
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Components of a Rooftop Solar PV System
A rooftop solar PV system consists of several components all of which have to be accommodated on the roofs of different building structures. The components which make up a rooftop solar PV system are:
1] Solar Panels: These devices are commonly made from silicon and are comprised of multiple solar cells which absorb sunlight and use the energy from the sun, photon energy, to generate electricity. Solar panels are often laminated and protected by tempered glass and frames to protect them from any damage which can affect the performance of electricity generation.
2] Inverters: Rooftop solar systems are connected to either micro-inverters or string inverters. These devices convert the DC power from the panel into AC power which can be sent to the grid.
3] DC/AC wiring: These are wires which connect inter-connect panels and which connect panels to inverters. Such cables and wires should not be hanging from the roofs or touching roof surfaces to protect them from degradation and weathering.
4] Mounting clamps: These are usually made from aluminium and stainless-steel brackets and bolts which secure the solar panels to the roof, to the rails and each other. These clamps often vary in design to accommodate the different types of roof materials and orientations.
5] Rails or racking: These structures are often made in parallel orientation to the roof and are made with metals. They are levelled with the roofs so that the panels can be mounted securely and evenly.
6] Mounts: These structures attach the rails to the roofs using bolts or flashings into the rafters or trusses of the roof. These structures also vary in design to accommodate the different roof configurations and styles.
7] Flashings: These are materials such as metal plates which act as a water-resistant seal between the roofs and the mounts to prevent water damage
Different Types of Rooftop Mounting Systems
The mounting of solar panels on rooftops depend on the slope of the roof and for residential building, the roof mounts are aligned with the slope of the roof. For commercial or industrial buildings, the roofs are often flat and there are roof mounts for such systems as well. These are covered below:
1] Steep-Sloped Roof Mounts: Sloped roof requires mounts which need to be penetrated or anchored into the roofs. They are common for residential installations and are classified as flushed mount, shared-rail, and rail-less systems. These systems usually have solar panels oriented either horizontally or vertically with clamps attached to rails. These rails are secured on the roof by using bolts and screws.
a) Flush-Mount Systems: These systems are usually mounted with around 3-6 inches between the solar module and the roof surface. This space between them helps to keep them cool which reduce voltage losses due to temperature effects. Flush-mount systems usually are mounted on roofs which are made from asphalt shingles, tiles, wood shake shingles and metal roofs which make them versatile for residential installations. Such systems are waterproofed through a method called ‘Flashing’ which is the overlapping of materials to prevent the intrusion of water. This creates a watertight seal to prevent water damage to the system.
b) Shared-Rail Systems: These systems involve 4 rails attached to 2 rows of solar panels. There is one rail in the middle that is shared, and such systems require a lesser number of penetrations which makes installation quicker. The panels installed in such systems can be oriented in any direction and these rails which are clamped with panels allow the accurate positioning on panels in the desired orientation.
c) Rail-less Systems: As the name suggests, the solar panels are directly connected to the bolts and screws in the roof wherein the frames of the panels act as rails. These systems are lower in costs due to lesser manufacturing components and shipping costs but they still need the same amount of attachments as that of a shared-rail system. Panels can be oriented in any direction and are not limited by the rigidity of the rails and the installation time is faster for such systems.
2] Low-Slope Roof Mounts: These roof structures are most common for commercial or industrial buildings where the roof can even be flat. Due to the nature of the roof, PV systems installed on such roofs do not have frames and only have PV laminates. This is because if the panels get soiled through dirty water, snow or any other matter, the flatness or low slope of the roof prevents the particulates from sliding down. If frames are used, the dust and dirt will accumulate near the frames which will increase maintenance requirements and reduce total power output. There are mainly 2 types of low-slope roof mounts and they are:
a) Penetrating Systems: These mounts attach the racking system to a strong part of the roof using structural attachments such as posts, pedestals, standoffs or jacks. The strong parts of the roof comprise of trusses, rafters or purlins which are capable of withstanding the weight of the PV systems.
b) Ballasted Systems: These mounts are not structurally penetrated to the roofs but are designed in such a way that something heavy is placed on the PV system to hold and keep it down. Materials like rectangular concrete blocks commonly known as paving stones are often used. Ballasted systems are useful when the roof is unable to take extra loads or if the geographical location is a windy region. These racking systems are also designed with wind deflectors to keep them stable in windy conditions.
3] BIPV and Solar Shingles: This is the 3rd type of mount systems which involve integrating solar panels into the buildings to avoid any structural attachments. It’s designed as a built-in structure which eliminates the need for mounting systems. However, although it is aesthetic and convenient, these panels tend to operate at higher temperatures due to lower airflow which will affect the overall efficiency of the PV system. It’s also more expensive since it’s not mass-produced like other solar technologies. The concept of BIPV is covered in another article.
Exporting Electricity to the Grid
Owning a grid-tied solar PV system irrespective of whether they’re ground-mounted or roof-mounted can offer opportunities to send your generated electricity to the grid which can lead to 2 types of mechanisms:
Solar Labs makes it easy to create solar design sales proposals in minutes instead of hours. We simplify 3D modeling, financial reporting and allow you to convert more customers with compelling proposals.
1] Net-metering mechanism: Grid-tied solar PV systems such as rooftop solar systems can avail of this type of mechanism where if the generated electricity is in excess, the consumer can export the excess electricity to the electricity grid. Depending on the amount of power exported, the consumer gets credit in return. When it’s time for the billing cycle, the consumer only gets charged for the net power which is the difference between the imported and exported power to the electricity grid. This is why it is termed as net-metering. In this mechanism, there isn’t any selling of power and this mechanism is used to adjust the electricity bill by cutting down bill costs significantly. Over time, the consumer can also generate electricity for free.
2] FIT Mechanism: This mechanism is known as the Feed-in Tariff mechanism where a grid-connected rooftop solar system can sell the generated electricity to the electric utility. The electricity that is sold can be used by the grid elsewhere. Consumers who own such solar PV systems are slowly shifting to this type of mechanism because of the revenue yield. This mechanism also enables the investor of the installer to be paid back. Utilities such as the Public Utility Commission sets a standard rate for the electricity which the utility pays for, and this rate can either be a wholesale ate or a retail rate. In either case, this mechanism has led to the solar payback period being shortened due to higher revenue yield and the installation demand for solar PV systems has increased significantly. The solar PV industry has grown exponentially in the recent decade owing to this FIT mechanism because of the thousands of jobs and revenue that are being generated from photovoltaics alone. This industry has also allowed for reduced transmission losses because of increased localization in production
Best Practices for Designing a PV Roof System
The economic life of a PV array is over 25 years. It is often too expensive to remove current PV arrays, put on a new roof, and then put them back in place for commercial rooftop solar. The perfect time to install a rooftop PV system is immediately following the installation of a new roof or during the construction of a brand-new building.
The most important thing is that the roof system should have an equal or longer life than the expected economic life of PV arrays. The following factors should be taken into account by designers to define a roof system that is as durable as the PV array:
- Roof membranes should be reflective, offer excellent weather protection, and have great thickness.
- It is better to incorporate a cover board beneath the membrane to help prevent damage and punctures from rooftop traffic.
- Using stiff insulation with high compressive strength improves traffic resistance and prevents insulation damage from the overburdened solar weight.
- A guarantee or a warranty of the roof system that outlasts the life of the PV arrays is beneficial.
Process of Commercial Rooftop Solar Installation
Let’s assume that you decide to place a solar system on your building’s rooftop. What does the procedure look like? We will divide the commercial rooftop solar installation process into:
- Installation and Upkeep
If you are considering installing a commercial rooftop solar system, you must consider a few logistical factors before beginning the project, such as:
- Does your roof have enough room for a system of the right size?
- Is the condition of your roof good?
- Does the roof get sufficient sunlight to generate the required amount of power?
- Are there any rules or restrictions preventing you from installing a rooftop solar system?
Answering these questions will help you and your team create result-oriented planning, and you will be able to identify the best course of action for your building. Depending on your needs and priorities, a rooftop system for your facility can be different than others.
Please clearly communicate the capabilities, limitations, constraints, and expectations to satisfy all the needs of the project and stakeholders. Additionally, there are a lot of financial incentives granted by the federal, local, and state governments and some utilities for the usage of renewable energy.
You can ask your project manager about any funding opportunities available. These incentives can dramatically reduce expenditures and provide more flexibility to your budget.
After completing the evaluation phase, you must move on to the next phase, the design of your ideal rooftop solar system. Your solar contractor will build a system that considers the necessary capacity requirements and safety precautions. Each system can be modified with various parts and configurations to fit your facility’s needs.
PV arrays are typically oriented to capture as much solar energy as possible by keeping panels away from walls and other shading factors. During the arrangement of PV panels, it is essential to consider the access to mechanical components, anchors, catwalks, fire safety, and drainage systems.
The solar system size should fulfill the client’s needs, space limitations, the project’s budget, availability of the sun in the area, energy offset, any future expansion plans, and the deterioration of PV panel performance with time.
Your project can go on to the permitting stage if the design has been approved and complies with all specifications.
You can get permission from the Authority Having Jurisdiction (AHJ) by following a typical application process. AHJs include organizations, governments, and other authoritative bodies that determine which norms and standards must be followed for a project.
You will probably need to work with the local government, utility provider, and fire department to plan a rooftop solar project. You should obtain permits for structural, electrical, and dedicated solar photovoltaic (PV) from your local government to ensure the solar system complies with all state-mandated requirements.
The authorities in the local fire department require a site design including the array layout, the setbacks from the roof lines, the locations of the access pathways, and the location of the utility disconnect to understand the overall structure.
Utility companies must ensure that the rooftop solar system complies with all applicable net metering regulations and electrical safety standards. The remainder of the installation process can begin if the electric utility approves the installation application. After installing the solar equipment, the last phase of solar commissioning and interconnection will occur.
Usually, rooftop solar systems take advantage of being connected to the local utilities’ electric grid. This configuration can reduce the customer’s electricity expenses and offer backup power if necessary.
Depending on the utility, interconnection designs fall into one of three broad groups. Be sure to talk with your utility provider about the best action. The three categories include:
- The customer exports extra energy they didn’t use.
- The customer exports all generation and supply load in a utility power outage.
- The consumer exports the utility of all generated energy from the system.
Installation Upkeep Stage
Once you have secured the necessary permits, you can install the system. Before commissioning, you must perform the final visual inspections to ensure the system complies with all relevant codes. When these inspections are approved, it will be allowed for usage and will be able to start producing power.
Why is Commercial Rooftop Solar System Convenient for You?
No matter where it is installed or how many panels are utilized, solar photovoltaic (PV) technology operates on the same principles. When the size of the solar project expands, there are more general items to install, configure and test before putting a new system online.
When applying for the requisite permissions from local utilities and regulators, larger solar projects make the permitting process and documentation more complex. As a result, many companies turn to commercial rooftop solar contractors who FOCUS on more significant, trickier projects.
Many businesses are setting sustainability goals to play their part in the environmental movement. One of the most important corporate social responsibility initiatives is using renewable energy sources like solar energy.
Going solar benefits the environment and strengthens your brand because it demonstrates to people that your business cares about the environment. This will surely draw clients who share your views and create business prospects.
Commercial Solar Services from Coldwell Solar
Rooftop solar power systems are growing in popularity as a means of generating electricity. With the help of commercial solar rooftop solutions, your business can go solar and save money and the environment. You can have a renewable power supply source at a low cost with careful planning and system execution.
Contact Coldwell Solar if you are interested in a rooftop PV system for your building, and our staff will be able to start the conversation about a sustainable energy solution that is suited to your needs.