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.
A brief introduction to the solar energy service provided by VIVABLAST
VIVABLAST (Vietnam) is a local partner in renewable energy and industry leader in the ASEAN market. With nearly 30 years of experience across all Engineering, Procurement and Construction (EPC) sectors, we confidently bring diversity in technical expertise and top-quality construction. With the latest in solar technology, interest-free accessories, prepaid solutions, and comprehensive coverage across ASEAN, VIVABLAST is one of the best Commercial and Industrial solar companies in Vietnam and is ready to bring the best green energy solution to your project.
Solar systems are installed on the roofs of industrial buildings, sports clubs, cinemas, office buildings, shopping malls or parking lots. They are sustainable and long-lasting, easy to maintain and affordable, helping you reduce your energy costs and reduce your dependence on the conventional grid.
- Solar Panels
- LED Solutions
- Battery Storage Solution
- Solar Farms
- Micro Grids
The high-quality design is one of the prerequisites for a successful rooftop solar power plant project. VIVABLAST Vietnam is one of many companies that specialize in installing rooftop solar power plants and managing projects responsibly and efficiently. We offer a full-service package that includes designing and installing rooftop solar systems on buildings and structures of any type and complexity.
After today’s content, we hope you have gained more helpful information about the roof top solar system: Definition, benefits, and basic installation. If you are looking for a leading solar solution construction company in Vietnam, VIVABLAST is a renowned name with whole experience and expertise. For direct consultation, don’t hesitate to get in touch with us via:
Factors affecting Rooftop Mounting
Some of the factors that can affect the performance of rooftop solar systems are mentioned below:
- Weather conditions
- Time of the year
- Shading from adjacent structures and/or vegetation
- Roof Slope
- The orientation of roof mounts
- Airflow: airflow is better because it helps to cool down the panels which aid in maintaining the voltage levels at an optimum. Higher the voltage, the higher the power and the output energy because
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.
Rooftop Solar Photovoltaic (PV) Installation Market by Deployment (Ground Mounted and Rooftop Mounted), Technology (Thin Film and Crystalline Silicon), Grid-type (Grid Connected and Off-grid), and End-use (Residential, Commercial and Industrial): Global Opportunity Analysis and Industry Forecast, 2021–2030
The global rooftop solar photovoltaic (PV) installation market size was valued at 45.9 billion in 2020, and is projected to reach 84.2 billion by 2030, growing at a CAGR of 6.3% from 2021 to 2030. A rooftop solar photovoltaic installation is a type of electrical installation setup, mounted on the roof that converts solar energy into electricity. Rooftop solar PV systems are distributed power generation system that help in meeting the energy demand of buildings within an existing distribution network. The size of the installation is dependent upon the size of the building and can vary dramatically. The rooftop solar PV systems are small in size and are installed on residential and commercial buildings rooftop.
Growing demand for rooftop solar photovoltaic systems in residential buildings to save a specific share of cost sustained on electrical energy, the demand for which is on a high with technological developments to improve the living standard of the people by offering different electrical power consuming home appliances.
For the purpose of analysis, the global rooftop solar photovoltaic (PV) installation market is segmented into deployment, technology, grid type, end-use, and region. Depending on the deployment, it is categorized into ground mounted and rooftop mounted. On the basis of technology, it is bifurcated into Thin Film and Crystalline Silicon and crystalline silicon is further classified into monocrystalline and multicrystalline. On the basis of grid type, it is classified into Off-grid and grid connected and grid connected is further bifurcated into centralized and decentralized. The end-use covered in the study include residential, commercial, and industrial. Region wise, it is analyzed across North America, Europe, Asia-Pacific, and LAMEA.
Key players operating in the global rooftop solar photovoltaic (PV) installation market are Suntech Power Holding Co. Ltd, First Solar Inc., Yingli Solar, Sunpower Corporation, Sharp Corporation, JA Solar Holding Company Ltd., Kyocera, Shenzhen Topray Solar Co. Ltd., Tata Power Solar Systems Ltd. and Wuxi Suntech Power Co. LTD
Other players operating in the global rooftop solar photovoltaic (PV) installation industry are Aneka Corporation Ltd., Panasonic Corporation, Renesola Co. Ltd., BP Solar International, and Bloo Solar Inc.The global rooftop solar photovoltaic (PV) installation market is studied in accordance with the impacts of the drivers, restraints, and opportunities. The period studied in this report is 2021–2030. The report includes the study of the rooftop solar photovoltaic (PV) installation market with respect to the growth prospects and restraints based on the regional analysis. The study includes Porter’s five forces analysis of the industry to determine the impact of suppliers, competitors, new entrants, substitutes, and buyers on the market growth.
Rooftop Solar Photovoltaic (PV) Installation Market, by deployment
The solar photovoltaic market is majorly contributed by the ground-mounted sector than the roof segment as a result of higher installations setups in the ground-mounted segment across the globe. The higher need for utility-scale is anticipated to continue during the forecast period, with strong demand from the emerging markets such as China across the globe.
Based upon technology the market is segmented into Crystalline Silicon PV, Thin Film PV. The Crystalline Silicon PV sector is leading the market with the highest market share as well as is anticipated to grow significantly during the forecasted period.
Rooftop Solar Photovoltaic (PV) Installation Market, by grid type
Based on grid type, the market is segmented into grid-connected, off the grid. The grid-connected segment is dominating the market with the greatest market share as well as is expected to grow substantially during the projected period.
The Residential segment is the most significant segment and witnessed significant growth during the forecast period. The market is driven by the fact that rooftop solar photovoltaic systems are little in size, and can be quickly installed on household structures.
Rooftop Solar Photovoltaic (PV) Installation Market, by region
Asia-Pacific will be highest growing region during the forecast period. The government in nations like India, China and Japan is advertising clean as well as green energy. Additionally, they are giving subsidies and incentives on solar PV project. over, the surging demand for power along with the emerging requirement to find alternatives to the promptly diminishing fossil fuels in this region.
Lockdown imposed due to the outbreak of COVID-19 pandemic resulted in temporary ban on import export and manufacturing processing activities across various industries and electrical utilities, which decreased the demand for electricity from these consumers. Regardless of this strength, renewables’ growth is anticipated to decrease. The globe is set to include 67 gigawatts (GW) of renewable power capacity. This decrease reflects delays in construction due to supply chain disturbances, lockdown actions and also social distancing guidelines, along with emerging financing obstacles. According to the International Energy Agency forecast, it expects utility-scale solar PV projects to rebound as most of the projects are already financed and under construction, however setups of roof solar PV for companies and homes might continue to be dispirited in the medium term without strong government assistance.
Key Benefits For Stakeholders
- The report provides an extensive qualitative and quantitative analysis of the current rooftop solar photovoltaic (PV) installation market trends and future estimations of the market from 2021 to 2030 to determine the prevailing opportunities.
- A comprehensive analysis of the factors that drive and restrict the rooftop solar photovoltaic (PV) installation market share is provided.
- Estimations and forecast are based on factors impacting the rooftop solar photovoltaic (PV) installation market forecast, in terms of value.
- Profiles of leading players operating in the rooftop solar photovoltaic (PV) installation market are provided to understand the global competitive scenario.
- The report provides extensive qualitative insights on the significant segments and regions exhibiting favorable rooftop solar photovoltaic (PV) installation market growth.
Key Market Segments
- By Deployment
- Ground Mounted
- Thin Film
- Crystalline Silicon
- Grid Connected
- Off Grid
- North America
- Rest of Europe
- South Korea
- Rest of Asia-Pacific
- Saudi Arabia
- South Africa
- Rest of LAMEA
1.1.Report Description1.2.Key Market Segments1.3.Key Benefits For Stakeholders1.4.Research Methodology
1.4.1.Primary Research1.4.2.Secondary Research1.4.3.Analyst Tools And Models
Chapter 2:Executive Summary
2.1.Key Findings 2.2.Cxo Perspective
3.1.Market Definition And Scope3.2.Key Findings
3.2.1.Top Investment s
3.3.Key Forces Shaping The Market3.4.Market Dynamics
188.8.131.52.Soaring Electricity Prices184.108.40.206.Reduced Dependence On Foreign Oil And Fossil Fuels220.127.116.11.Power Can Be Stored And Can Used At Any Time
18.104.22.168.High Upfront Cost Of Solar Energy22.214.171.124.Low Energy Conversion Rate
126.96.36.199.Rising Electricity Demand In Remote Areas 188.8.131.52.Rising Clean And Renewable Energy Source
3.5.Value Chain Analysis3.6.Impact Of Key Regulations On The Global Rooftop Solar Photovoltaic Pv Installation Market3.7.Impact Of Corona (Covid-19) Outbreak On The Market
Chapter 4:Global Rooftop Solar Photovoltaic Pv Installation, By Deployment
4.1.1.Market Size And Forecast, By Deployment
4.2.1.Key Market Trends, Growth Factors, And Opportunities4.2.2.Market Size And Forecast, 2020-2030
4.3.1.Key Market Trends, Growth Factors, And Opportunities4.3.2.Market Size And Forecast, 2020-2030
Chapter 5:Global Rooftop Solar Photovoltaic Pv Installation, By Technology
5.1.1.Market Size And Forecast, By Technology
5.2.1.Key Market Trends, Growth Factors, And Opportunities5.2.2.Market Size And Forecast, 2020-2030 (Million)
5.3.1.Key Market Trends, Growth Factors, And Opportunities5.3.2.Market Size And Forecast, 2020-2030
Chapter 6:Global Rooftop Solar Photovoltaic Pv Installation, By Grid. Type
PV system (2013)
In the mid-2000s, solar companies used various financing plans for customers such as leases and power purchase agreements. Customers could pay for their solar panels over a span of years, and get help with payments from credits from net metering programs. As of May 2017, installation of a rooftop solar system costs an average of 20,000. In the past, it had been more expensive. 
Utility Dive wrote, For most people, adding a solar system on top of other bills and priorities is a luxury and rooftop solar companies by and large cater to the wealthier portions of the American population.  Most households that get solar arrays are upper middle-income. The average household salary for solar customers is around 100,000.  However, a surprising number of low-income customers appeared in a study of income and solar system purchases. Based on the findings of the study, GTM researchers estimate that the four solar markets include more than 100,000 installations at low-income properties. 
A report released in June 2018 by the Consumer Energy Alliance that analyzed U.S. solar incentives showed that a combination of federal, state and local incentives, along with the declining net cost of installing PV systems, has caused a greater usage of rooftop solar across the nation. According to Daily Energy Insider, In 2016, residential solar PV capacity grew 20 percent over the prior year, the report said. The average installed cost of residential solar, meanwhile, dropped 21 percent to 5000.84 per watt-dc in the first quarter of 2017 versus first quarter 2015.  In fact, in eight states the group studied, the total government incentives for installing a rooftop solar PV system actually exceeded the cost of doing so. 
In 2019, the national average cost in the United States, after tax credits, for a 6 kW residential system was 5000.99/W, with a typical range of 5000.58 to 3.38. 
Due to economies of scale, industrial-sized ground-mounted solar systems produce power at half the cost (2c/kWh) of small roof-mounted systems (4c/kWh). 
2.2. Net-Metering Mechanism
This is an arrangement for grid connected solar power systems. In this mechanism, the excess solar power generated is exported to the electricity grid. The consumer gets credit for the amount of power exported. At the end of the billing cycle, the consumer is charged for the net or difference of power imported and power exported to the electricity grid.  Hence the name, net-metering.
A key point to note here is that there is no sale of solar power in this mechanism. The exported kWh are only used to adjust the imported kWh prior to the bill calculation.
2.3. Feed-in Tariff Mechanism
In a grid connected rooftop photovoltaic power station, the generated electricity can sometimes be sold to the servicing electric utility for use elsewhere in the grid. This arrangement provides payback for the investment of the installer. Many consumers from across the world are switching to this mechanism owing to the revenue yielded. A public utility commission usually sets the rate that the utility pays for this electricity, which could be at the retail rate or the lower wholesale rate, greatly affecting solar power payback and installation demand.
The FIT as it is commonly known has led to an expansion in the solar PV industry worldwide. Thousands of jobs have been created through this form of subsidy. However it can produce a bubble effect which can burst when the FIT is removed. It has also increased the ability for localised production and embedded generation reducing transmission losses through power lines. 
Installers have the right to feed solar electricity into the public grid and hence receive a reasonable premium tariff per generated kWh reflecting the benefits of solar electricity to compensate for the current extra costs of PV electricity. 
An electrical power system containing a 10% contribution from PV stations would require a 2.5% increase in load frequency control (LFC) capacity over a conventional system—an issue which may be countered by using synchronverters in the DC/AC-circuit of the PV system. The break-even cost for PV power generation was in 1996 found to be relatively high for contribution levels of less than 10%. While higher proportions of PV power generation give lower break-even costs, economic and LFC considerations impose an upper limit of about 10% on PV contributions to the overall power systems. 
There are many technical challenges to integrating large amounts of rooftop PV systems to the power grid.
6.1. Reverse Power Flow
The electric power grid was not designed for two way power flow at the distribution level. Distribution feeders are usually designed as a radial system for one way power flow transmitted over long distances from large centralized generators to customer loads at the end of the distribution feeder. Now with localized and distributed solar PV generation on rooftops, reverse flow causes power to flow to the substation and transformer, causing significant challenges. This has adverse effects on protection coordination and voltage regulators.
6.2. Ramp Rates
Rapid fluctuations of generation from PV systems due to intermittent clouds cause undesirable levels of voltage variability in the distribution feeder. At high penetration of rooftop PV, this voltage variability reduces the stability of the grid due to transient imbalance in load and generation and causes voltage and frequency to exceed set limits if not countered by power controls. That is, the centralized generators cannot ramp fast enough to match the variability of the PV systems causing frequency mismatch in the nearby system. This could lead to blackouts. This is an example of how a simple localized rooftop PV system can affect the larger power grid. The issue is partially mitigated by distributing solar panels over a wide area, and by adding storage.
6.3. Operation and Maintenance
Rooftop PV solar operation and maintenance is of higher costs in comparison with ground-based facilities due to the distributed nature of rooftop facilities and harder access. In rooftop solar systems it typically takes a longer time to identify a malfunction and send a technician, due to lower availability of sufficient photovoltaic system performance monitoring tools and higher costs of human labor. As a result, rooftop solar PV systems typically suffer from lower quality of operation maintenance and essentially lower levels of system availability and energy output.
There are solutions on multiple levels to improve the quality of distributed solar OM, dealing with Industrial IoT approaches of automation:Automatic panel cleaning
Automated performance monitoring
- Omnidian residential solar performance insurance partner Omnidian;
- Soltell solar management solution, accessible via SSMP portal;
- Solytic generic solar monitoring Solytic portal;
- Sunreport device-agnostic Cloud solar monitoring Sunreport platform;
The Jawaharlal Nehru National Solar Mission of the Indian government is planning to install utility scale grid-connected solar photovoltaic systems including rooftop photovoltaic systems with the combined capacity of up to 100 gigawatts by 2022. 
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