Related Topics:
Maximum Power Point Tracking-
How to use solar panels to power your home devices
Prior to your solar PV panels being installed, all reputable companies will have carried a computer simulation. Into which they will have fed in details of roof pitch, shading and orientation etc. This simulation will then have calculated the output which you can typically expect to obtain on a yearly basis. Provided things don't. Most inverters (box of electronics which converts the DC produced by your panels into AC that can be used in your home) are capable of monitoring the amount of electricity produced. It's. Provided your panels are mounted at an elevation of over 12 degrees from horizontal they shouldn't require any special maintenance. The rain should keep them clean and if you've got a monitoring system you'll. Unless you've got a battery storage System you'll need to be use the electric produced by your panels as it's produced. If you don't it gets sold. In order for your panels to be efficient they need to be correctly fitted and although your supplier will likely have taken care of this for you here's the main check points. In a perfect world you want a south facing roof at the pitch of.
[PDF Version]
-
How to use solar panels for power supply
Before you purchase the components to build a solar power system, you need to determine how much electricity you expect to use. To do this, collect your electric bills from the past several months, and look for your average usage per month and year. Plan to purchase a system that will deliver more power than you. Rigid solar panels for rooftop installation are relatively lightweight and designed to last at least 25 to 30 years. Still, you should ensure that your. Once you know what you need, you can work with a manufacturer or retailer to identify the right components to deliver the electricity you expect to. If you're going for a fixed installation, you'll most likely install your solar panels on the rooftop. Begin by determining the optimal rooftop locations and. The battery or batteries in solar power systems store the electricity your solar panels generate. Depending on the energy delivery you need, you.
[PDF Version]
FAQs about How to use solar panels for power supply
How does a solar PV system work?
Solar PV panels – convert sunlight into electricity. Inverter – this might be fitted in the loft and converts the electricity from the panels into the form of electricity which is used in the home. Generation meter – records the amount of electricity generated by the solar PV system.
Can a solar PV system connect to a domestic electrical supply?
Solar energy, a clean and renewable source of power, is becoming increasingly popular for domestic use. Many homeowners are curious about how they can integrate solar photovoltaic (PV) systems into their existing electrical setup. In this blog, we will guide you through the process of connecting a Solar PV system to your domestic electrical supply.
Can a solar PV system store electricity?
Solar PV systems cannot store the electricity they produce unless you also have a battery fitted to your home (which most don't). In order to use the electricity produced for free, you must use it at the time it is generated – it can't be saved for later in the evening.
Do solar panels need batteries?
Batteries can store the electricity generated by your solar panels for use when the sun isn't shining, like at night or on cloudy days. They are not always necessary, especially if your system is connected to the electricity grid. These are the wires that connect all the parts of your solar system together.
How do solar panels work?
The solar panels and the battery generate direct current (DC) electricity. For solar energy to power your home, you need to run the system-generated electricity through the inverter and convert it into alternating current (AC).
How do solar panels work in the UK?
Installing solar panels lets you use free, renewable, clean electricity to power your appliances. You can sell extra electricity to the grid or store it for later use. There are over 1.3 million installations on homes across the UK – see where the UK solar panel hotspots are. Let's look at how they work and whether they're suitable for your home.
-
Solar power generation sun tracking system
A solar tracking system (also called a sun tracker or sun tracking system) maximizes your solar system's electricity production by moving your panels to follow the sun throughout the day, optimizing the angle at which your panels receive solar radiation.
FAQs about Solar power generation sun tracking system
What is a solar tracking system?
A solar panel precisely perpendicular to the sun produces more power than one not aligned. The main application of solar tracking system is to position solar photovoltaic (PV) panels towards the Sun. Most commonly they are used with mirrors to redirect sunlight on the panels.
What is a Solar Energy Tracker?
It is an advanced sun monitoring system that can rotate the panels to track the movement of the sun across the sky. It facilitates the panel system to trap the maximum sunlight and optimise the energy output. There are considerable advantages to using a solar energy tracker.
How can solar trackers improve energy production?
These efforts emphasize the significance of enhancing solar panel efficiency and energy production with sophisticated tracking and control systems. Recent developments in solar tracker systems include exploring different module geometries, materials, and tracking mechanisms to boost efficiency.
What are the applications of solar tracking system?
The main application of solar tracking system is to position solar photovoltaic (PV) panels towards the Sun. Most commonly they are used with mirrors to redirect sunlight on the panels. Cross-Reference: Design and Implementation of High Efficiency Tracking System
Do you need a solar energy tracking system?
A solar energy tracking system can come in handy for installations set up in locations with an adequate amount of solar energy accessibility. You must consider the installation of a solar tracker so that your panels follow the sun throughout the day.
What are the latest developments in solar tracker systems?
Recent developments in solar tracker systems include exploring different module geometries, materials, and tracking mechanisms to boost efficiency. Single-axis and dual-axis tracking systems are widely used, with dual-axis systems offering greater efficiency and accuracy.
-
Solar power station automatic tracking system
An automatic solar tracking system is an approach for optimizing the generation of solar power and modifying the angles and direction of a solar panel by considering changes in the position and path of the sun.
FAQs about Solar power station automatic tracking system
What is a residential solar tracking system?
Residential solar tracking systems are becoming more popular as homeowners look to maximize their energy efficiency. These systems adjust the position of solar panels throughout the day to follow the sun, ensuring optimal energy capture. This technology can significantly increase the efficiency of photovoltaic panels.
What is a solar tracking system?
A solar panel precisely perpendicular to the sun produces more power than one not aligned. The main application of solar tracking system is to position solar photovoltaic (PV) panels towards the Sun. Most commonly they are used with mirrors to redirect sunlight on the panels.
What is automatic solar tracking?
The main aim of any automatic STS is to maximize the amount of sunlight that the solar concentrator or module will receive, resulting in the maximization of the overall energy outputs of the system. Solar tracking can be performed in two ways: single-axis tracking and double-axis tracking.
Are automatic solar trackers effective?
Currently, research into automatic solar trackers is on the rise, as solar energy is abundant in nature, but its use in a highly efficient way is still lacking. This paper provides a detailed literature review and highlights some key advancements and challenges associated with state-of-the-art automatic solar tracking systems.
Does automatic solar radiation tracker work for photovoltaic panels?
Abstract— This paper concerns the automatic smart solar radiation tracker dedicated to Received : 08 Jan 2023 photovoltaic panels. The proposed tracking system ensures optimum generation of electrical Revised : 21 Feb 2023 power by proper orientation of PV panels while consuming minimal energy.
Why do we need a solar tracking system?
solar energy has become an increasingly important and popular renewable energy source. By using a solar tracking system, we can produce an abundance of energy a
-
Power generated by solar panels in Libya
Libya aims to generate 10% of its power from renewable energy by 2025, following the construction of several large-scale solar photovoltaic plants currently underway.
FAQs about Power generated by solar panels in Libya
Can solar energy be used to generate electricity in Libya?
(Kassem et al., 2020) performed a study analysis of the potential and viability of generating electricity from a 10 MW solar plant grid-connected in Libya. The consequences of that study indicate that Libya has a massive potential of solar energy can be utilised to generate electricity.
Can Libya develop solar photovoltaics?
Libya has a great opportunity to build large-scale solar photovoltaic power. For the scholars, it's considered as an entrant, which can help to develops and adopt this technology. This paper will be valuable as it is a one-step approach for the development of solar photovoltaics application in Libya.
Will Libya generate 10 percent of its energy by 2025?
Libya aims to generate 10% of its power from renewable energy by 2025, following the construction of several large-scale solar photovoltaic plants currently underway.
What are the main energy sources in Libya?
Libya relies fully on fossil fuels to generate its electricity; hence, the Natural Gas and Oil are the key energy sources (Sorensen, 2010). The power stations in Libya are dependent on light and heavy oil, with a growing dependency on natural gas (Asheibe and Khalil, 2013).
Are solar PV systems a good investment in Libya?
In Libya, the solar photovoltaic (PV) systems are encouraging for the future, due to incident solar radiation is greater than the minimum required rate across the country (Hewedy et al., 2017). Based on that from a techno-economics point-view, there is a need to develop substantial energy resource solutions.
How much electricity does Libya produce?
Furthermore, according to the outcomes from the techno-economic; thus, it's detected the maximum electricity generation approximately “22067.13 MWh”. Libya has partnerships with many countries to participate in the desert technology project, contributing to the large power supply system (Hafner et al., 2012).
-
The largest place for offshore solar photovoltaic panels
The one-gigawatt facility, situated eight kilometres off the eastern coast of Dongying City, represents the largest open-sea solar installation globally and establishes a new template for marine-based renewable energy projects.
FAQs about The largest place for offshore solar photovoltaic panels
What is the largest offshore solar project in the world?
This development signals a significant advancement in solar technology and sets a precedent for the global expansion of offshore solar power. Situated in the open sea region off the coast of Dongying, Shandong Province, this project is claimed to be the largest of its kind in the world.
What are some offshore solar PV projects around the world?
Table 1. Offshore solar PV projects around the world. Refs. Fig. 2. Offshore solar PV 500-kW test project in Shandong, China . Researchers are currently dedicating their pursuits to the exploration of offshore solar PV resources.
Is China's 1GW floating solar PV project a 'first and largest'?
Image: CHN Energy. State-owned China Energy Investment Corporation (CHN Energy) has completed a 1GW floating solar PV facility in the Shandong Province of China. In a statement released on Wednesday (13 November), CHN Energy said it had successfully connected the project to the grid, claiming it is the “first and largest of its kind in the world”.
Where is the floating solar PV project located?
The floating solar PV project is located in the Shandong Province of China. Image: CHN Energy. State-owned China Energy Investment Corporation (CHN Energy) has completed a 1GW floating solar PV facility in the Shandong Province of China.
Which Ocean has the richest offshore solar PV resource?
The findings reveal that the South China Sea has the richest offshore solar PV resource and the least intra-annual fluctuation, despite challenging ocean conditions.
Which Ocean is best for offshore solar PV farms?
The shallow coastal waters of the Beibu Gulf, Yellow Sea, and Bohai Sea offer the best ocean conditions for the development of offshore solar PV farms since they are characterized by relatively lower wind speeds (<9 m/s) and smaller significant wave heights (<1.5 m).
-
Which solar power source in China is the best
is the largest market in the world for both and. China's photovoltaic industry began by making panels for, and transitioned to the manufacture of domestic panels in the late 1990s. After substantial government incentives were introduced in 2011, China's solar power market grew dramatically: the country became the.
FAQs about Which solar power source in China is the best
Is China a good source of solar power?
Since China is responsible for 80% of the world's polysilicon production, with half of the world's polysilicon produced in Xinjiang, many critics of the forced labor usage have stated that it is difficult for many countries to avoid Chinese made solar power solutions.
Is China leading the world in solar power?
Technicians check solar panels in Zhoushan, Zhejiang province. [Photo by YAO FENG/FOR CHINA DAILY] A report by the International Energy Agency, or IEA, on the future of renewable energy production has pinpointed China, and in particular its solar power capabilities, as leading the way for the world in the years to come.
Why is China the world's leading producer of solar panels?
China is the global powerhouse in solar panel manufacturing, driving the industry with unparalleled production capabilities and cutting-edge technological advancements. As the world's leading producer, China commands over 95% of the global market for key components such as polysilicon, ingots, and wafers, essential for solar panel production.
Should China invest in solar energy?
As such, critics argue that investments into renewable energy sources such as solar power are means to increase the power of the central state rather than protect the environment. This argument has been complemented by China's expansion of fossil fuel plants in conjunction with solar energy.
What percentage of China's energy use is solar?
Solar power contributes to a small portion of China's total energy use, accounting for 3.5% of China's total energy capacity in 2020. Chinese President Xi Jinping announced at the 2020 Climate Ambition Summit that China plans to have 1,200 GW of combined solar and wind energy capacity by 2030.
Can China make more solar power?
China can now make more solar power than the rest of the world. Data released by China's National Agency last week revealed that the country's solar electric power generation capacity grew by a staggering 55.2 percent in 2023. The numbers highlight over 216 gigawatts (GW) of solar power China built during the year.
-
How about ground-based solar power generation
Ground-mounted systems offer several advantages over rooftop solar installations:1. Maximized Energy Production: Ground-mounted solar plants can be positioned in areas that receive optimal sunlight, leading to significantly higher energy output. Easy Maintenance and Upgrades:.
FAQs about How about ground-based solar power generation
How do ground-mounted solar panels work?
Ground-mounted solar panels maximize energy production With rooftop solar panel systems, the characteristics of your roof directly impact the production of your system. If your roof isn't at the right angle, doesn't face south, or has obstructions like chimneys or skylights, your solar panels won't generate maximum electricity.
Why should you choose a ground-mounted solar system?
With a ground-mounted system, you can choose the orientation of your solar panels to increase energy production. Ground-mounted systems also tend to operate more efficiently because they have more air circulation beneath the panels, allowing them to stay cool. It's easy to maintain ground-mounted solar panels
What is the difference between ground-mounted solar panels and on-roof solar panels?
Ground-mounted solar panels and on-roof solar panels differ primarily in their installation locations and associated benefits and challenges. Ground-mounted solar panels are installed on the ground, typically in open spaces, and offer greater flexibility in orientation and tilt, which can maximise energy production.
Are ground-mounted solar panels right for my home?
We'll go over the details to help you decide if they're right for your home. Ground-mounted solar panels operate like a typical rooftop system but are generally more efficient. Ground-mounted solar panel installations cost about $42,140 after the federal tax credit.
What are ground-mounted solar panels?
Ground-mounted solar panels are installed on the ground instead of on a building's roof. They allow optimal placement to maximize sun exposure, resulting in higher energy production. Ground-mounted systems are highly versatile and can be adjusted for the best tilt and orientation.
Are bifacial solar panels better than ground-mounted solar panels?
Ground-mounted solar panels are more efficient than roof-mounted solar panels, as achieving the best angle and direction is easier when no roof is in the way. This setup also enables the installation of bifacial solar panels, which can turn more sunlight into power.
-
How to change the voltage parameters of solar panels
What is VOC? VOC is the maximum voltage of an open circuit produced by a solar panel. Open Circuit Voltage (VOC) and is a product of the forward biases of the solar cell. You cannot go by the volts rating on the solar panel box because a 12v solar panel will produce as much as 18v-22v. However, you can use a. The first thing to do is double-check your calculations before you buy solar panels and your solar regulator. Your goal is to keep the voltage from the panels at 2/3s of the average maxim voltage of the controller. For example, if. A VOC solar charge controller is a device that limits the amount of energy that passes through it. We often see these in solar array systems where a solar battery storage system is in place. They are sometimes called step.
FAQs about How to change the voltage parameters of solar panels
How do I change the voltage on my solar charge controller?
You can do this by adjusting the voltage setting of the charge controller. The voltage setting determines how fast your solar cells can recharge. You can change these settings Via PC software, or on your charge controller. It is recommended that you follow the manufacturer's recommendations to get the most from your solar energy system.
Can you reduce solar panel voltage?
And that would cause problems. So can you reduce your solar panel voltage? The easiest way you can reduce your Solar Panel's Voltage is by using either an MPPT Charge Controller or a Step-Down Converter (aka Buck Converter). Other solutions are to use resistors or modify the solar cells' connections via the junction box.
How do I use a solar charge controller?
While solar panels can be connected in parallel to provide maximum output voltage, a basic charge controller may only accommodate a maximum input voltage of 12 or 24 volts. To use a solar charge controller, you need to set the voltage and current parameters. You can do this by adjusting the voltage setting of the charge controller.
How do solar panels increase voltage?
The overall system voltage is increased by connecting solar panels in series. When a grid-connected inverter or charge controller requires 24 volts or more, solar panels in series are typically employed. Solar cells are comprised of silicon that has been carefully processed to absorb as much light as possible.
What is a solar system voltage?
Generally, the system voltage is 12V, 24V or 48V. The system voltage value can be 110V and 220V for medium or large charge controllers. The maximum charging current refers to the maximum output current of solar panels or solar array.
What is the voltage output of a solar panel?
In solar photovoltaic (PV) systems, the voltage output of the PV panels typically falls in the range of 12 to 24 volts. However, the total voltage output of the solar panel array can vary based on the number of modules connected in series.
-
6v solar panels in series
To wire your solar panels in series, simply link the positive MC4 connector of the first solar panel to the negative MC4 connector of the next one, and continue this pattern for the remaining panels.
FAQs about 6v solar panels in series
How many volts does a 6 panel solar array use?
The above diagram shows a six-panel array using 5 Amp, 20 Volt panels wired in a series-parallel configuration of 3-panel series strings wired in parallel (3s2p). First, we need to find the volts and amps of the series wired strings of solar panels.
How many volts are in a series solar panel?
This diagram shows three, 4 amp, 24-volt panels wired in series. Since series wired solar panels get their voltages added while their amps stay the same, we add 24V + 24V + 24V to show the total array voltage of 72 Volts while the Amps remain at 4 Amps. This means there are 4 Amps at 72 Volts coming into the solar charge controller.
How many solar panels are connected in a series?
A set of two solar panels connected in series Series Voltage: V1 + V2 .. + Vn 12V + 12V = 24V. (Voltage is additive in series connection) Series Current: I1 = I2 .. = In 10A = 10A = 10Ah (Current is same in series connection). Now, we have two sets of series connected solar panels. If we connect these two set in parallel: Parallel Voltage:
How many volts does a 4 panel solar array use?
Finally, you wire the 2 series strings in parallel to create a 4-panel solar array with a voltage of 28 volts (the lowest voltage rating of the 2 strings) and a current of 11 amps (6A + 5A).
How many Watts Does a pair of solar panels generate?
After wiring our two panels in parallel, we manage to generate around 555-560 watts of power, a noticeable decrease from our series configuration. Now, let's look at a combination of series and parallel wiring, which allows us to effectively bring together four panels. We start by wiring two sets of panels in series.
Can a 12V solar panel be connected parallel?
Only the same rated solar panel can be connected in series, parallel or series parallel connection. A 12V solar panel can only be connected in (series, parallel or series-parallel) with another 12V solar panel. A 12V solar panel should not be connected (in series, parallel or series parallel) to a 6V or 24V solar panel.
-
How do solar panels simulate sunlight
A solar simulator (also or sunlight simulator) is a device that provides illumination approximating natural. The purpose of the solar simulator is to provide a controllable indoor test facility under laboratory conditions. It can be used for the testing of any processes or materials that are, including, , , ,,.
FAQs about How do solar panels simulate sunlight
What is a sun simulator for solar panel testing?
This is where sun simulators come in. PV Sun simulator for solar panel testing. Sun simulators are special machines that copy the sunlight spectrum and intensity that panels would get in real sunlight. Solar companies use these simulators to check how much power a panel can produce, how efficient it is, and other important factors.
How do I choose a solar panel simulator?
•Large Area vs. Small Area Simulators: Large area simulators cover the entire solar panel, while small area simulators, zoom in and fixate light onto selected solar cell's areas for detailed examination. When selecting a sun simulator for solar panel testing, several critical factors must be considered to ensure accurate and reliable results.
Why do solar panels need a sun simulator?
Sun simulators give a consistent light source, making it easier to test and improve new ideas quickly. This means that new solar technologies can be developed faster and brought to the market sooner. Accurate performance prediction is very important for solar panels to be successful in the market.
How do solar simulators work?
Solar simulators consist of several key components that work together to emulate sunlight. These components include a light source, optical filters, and a collimation assembly. The light source, often a lamp, emits light that closely matches the solar spectrum, encompassing ultraviolet (UV), visible, and infrared (IR) wavelengths.
What is a one sun simulator?
One Sun simulators are widely used in solar panel testing to evaluate solar cells' electrical performance and efficiency under realistic conditions. By simulating one sun irradiance, these simulators enable manufacturers to assess the performance of solar panels in real-world scenarios.
What is the difference between a solar simulator and a sun simulator?
AAA solar simulators provide the highest level of spectral accuracy, closely matching the solar spectrum, while one sun simulators replicate the irradiance levels experienced under typical operating conditions.
-
How about opening a solar power store
In this article, we'll guide you through 9 essential steps to launch your solar power business, including a comprehensive checklist to ensure nothing is overlooked. Curious about the details?.
-
Solar Trough Power Station China
Chinese scientists have announced a plan to build an enormous, 0. 6 mile (1 kilometer) wide solar power station in space that will beam continuous energy back to Earth via microwaves.
FAQs about Solar Trough Power Station China
When was CSNP Royal Tech Urat 100MW parabolic trough concentrated solar power project connected?
CSNP Royal Tech Urat 100MW Parabolic Trough Concentrated Solar Power Project was successfully connected to the gird at 22:49 p.m. on January 8th, 2020.
Which CSP project uses parabolic trough system?
2. Noor Phase II CSP Project (200 MW) in Morocco uses the parabolic trough CSP system. The Project won the 2019 China International Sustainable Infrastructure Award, the 2020 China Power Quality Project (Overseas) Award, and the Social Responsibility Award Certificate issued by the Moroccan government.
What is the biggest solar project in Southeast Asia?
Dau Tieng Photovoltaic Solar Power Project (500 MW) in Vietnam is the biggest solar project in Southeast Asia and the world's largest semi-immersed photovoltaic project.
Does China have a solar power station?
The operation of the solar power facility makes China the eighth country to have a large solar thermal power station. It is also a milestone for the company's solar-thermal energy development after more than 10 years of development.
How many kilowatts a year will China's solar power plant power?
After the project is put into operation, annual power connected to the grid is expected to reach 3.65 billion kilowatt hours, it said. The company's Delingha 50 megawatt solar thermal power plant in Qinghai, which is also China's first large commercial parabolic-trough concentrated solar power plant, was put into operation in 2018.
Which CSP project in Morocco uses a parabolic trough system?
The Project won the 2019 China International Sustainable Infrastructure Award, the 2020 China Power Quality Project (Overseas) Award, and the Social Responsibility Award Certificate issued by the Moroccan government. 2. Noor Phase II CSP Project (200 MW) in Morocco uses the parabolic trough CSP system.
-
How to attach flexible solar photovoltaic panels
There are two main methods of mounting flexible solar panels: peel-and-stick adhesive and screw-in. While screw-in provides more security, it risks damaging the panels if not done correctly.
FAQs about How to attach flexible solar photovoltaic panels
How to install a flexible solar panel?
Apply a generous and even layer of adhesive on the back of the flexible solar panel. Make sure you cover everything, from corner to corner. Carefully align your panel with the marked positions on your mounting surface. Precision at this stage will make the difference between a professional-looking job and a clumsy DIY project.
What do I need for a flexible solar panel?
You're going to need the flexible solar panels-refer to our top picks on our “/flexible-solar-panels” page. You'll also need a high-quality adhesive, a measuring tape, a clean cloth, and your personal protective equipment (PPE), such as gloves and goggles. Make sure your work surface is flat and stable.
How to install solar panels?
Wipe any dust, dirt, or grime off your mounting surface. Let it dry completely before moving on to the next step. Use your measuring tape to choose the spot where you'll mount your panels, mark it if necessary. Remember, solar panels need maximum exposure to sunlight, so place them accordingly. Attention to detail is key here.
How thick should a solar panel adhesive be?
The thickness of the adhesive should not be less than 4 mm, and the width should not be less than 10 mm. If possible, apply adhesive on the center of the back of the panel to enhance installation liability. How do clouds and shadowing affect solar panel output efficiency?
Are flexible solar panels better than rigid solar panels?
Traditional rigid solar panels have their place, but in some scenarios, flexible solar panels are distinctly advantageous. Imagine you're decking out your RV or remodeling your boat – you'd prefer the smooth contour of flexible solar panels over the boxy rigidity of traditional panels.
Can a solar panel fly off a roof?
Panel may fly off the roof when driving vehicle at high speed. Clean the roof before applying primer. Leave it for 2-3 minutes after applying to make sure it is installed properly. Apply force evenly to the whole panel instead of pinpoints to prevent damage to solar cells. Apply adhesive around the panel after installation.
-
Make money by selling solar panels
The most common solar PV installation in UK homes is a 3.5kWp system, capable of generating approximately 3,000kWh of electricity each year in optimal conditions. This amounts to around 75% of a typical household's electricity consumption, meaning that a solar system can make a home largely self-sufficient, dramatically. A large portion of potential solar panel earnings comes from the government's generation tariff, which is part of the Feed-In Tariff (FIT) scheme. Under the generation part of this. On top of the generation tariff, you also receive a fixed rate of 4.5p/kWh for any surplus electricity that you feed back into the National Grid. This. It's important to remember that all the solar PV earnings you make must be offset against the cost of installing and maintaining your solar system. Installation cost ranges between.
-
Cook Islands production of solar photovoltaic panels
Renewable energy in the is primarily provided by and biomass. Since 2011 the Cook Islands has embarked on a programme of renewable energy development to improve its and reduce, with an initial goal of reaching 50% renewable electricity by 2015, and 100% by 2020. The programme has been assisted by.