Solar Systems – Eagle Track Limited Juba South Sudan

Does South Sudan have a large-scale solar power project?

South Sudan has taken a significant step toward renewable energy with the launch of its first large-scale solar power project. The Ezra Group, a prominent business conglomerate, has successfully developed and financed a 20-megawatt (MW) solar power plant, complemented by a 14-megawatt-hour (MWh) Battery Energy Storage System (BESS).

Why should South Sudan invest in solar power & battery storage?

This project marks a significant achievement for South Sudan, reinforcing its commitment to renewable energy and environmental responsibility. By investing in solar power and battery storage technology, the country is making a decisive move toward energy independence, economic growth, and a sustainable future for its people.

Will South Sudan build electricity distribution networks?

South Sudan is building electricity distribution networks in the mentioned three cities. The administration of each project will be handed over to the South Sudanese side upon completion. The projects are still under implementation.

Why is South Sudan struggling to provide electricity to its citizens?

According to a 2024 sciencedirect.com report, South Sudan struggles to provide its citizens access to electricity despite having abundant energy resources, particularly fossil fuels.

How will a 20 MW solar plant benefit Juba?

The 20 MW solar plant is set to power approximately 16,000 households in Juba. It will also enhance grid stability and reduce energy costs for consumers. The accompanying battery storage system ensures that solar-generated power remains available when needed, stabilizing the grid and improving renewable energy reliability.

Who owns the South America solar photovoltaic market?

The South America solar photovoltaic market is fragmented. Some of the major players in the market include Enel Green Power S.p.A., Trina Solar Limited, Atlas Renewable Energy, Sonnedix Power Holdings Ltd, and Canadian Solar Inc.

Which segment is the largest market for solar photovoltaic in South America?

Moreover, owing the a large number of upcoming solar PV projects, ground mounted segment is expected largest share in the South America solar photovoltaic market over the forecast period. Brazil is one of the largest markets for renewable energy in South America. Solar was the most competitive energy source among all renewables featured in 2019.

What are the key drivers of South America solar photovoltaic market?

South America solar photovoltaic market is expected to grow at a CAGR of more than 11% during the forecast period. The primary drivers of the market include supportive government policies, rising demand for renewable energy, efforts to reduce GHG emissions, and the declining cost of solar PV systems.

Will Brazil dominate the South America solar PV market?

Overall, Brazil's solar power sector is set to experience a decent growth, and is likely to dominate the South America solar PV market during the forecast period. The South America solar photovoltaic market is fragmented.

Which country has the most solar energy in South America?

Brazil is the leader in solar energy in South America as it surpassed 50 GW of installed capacity in 2024. South America continued its steady solar growth over the last half-decade in particular, and overall renewable energy capacity additions in general, through the year 2024.

Which countries have the biggest solar market in Latin America?

Brazil remained the biggest market on the Latin American continent, with other nations like Chile, Colombia, and Costa Rica showing diversity in renewable progress. On the other hand, Chile's massive solar curtailment through the year shows the challenges that still affect the sector on the continent.

What is IoT solar energy?

IoT solar energy systems offer a cost-effective and sustainable approach to accessing energy for personal as well as commercial consumption.

Can IOT power solar energy?

IoT-powered solar solutions revolutionize the way of solar energy generation. Leveraging IoT in the solar installations, and transforming them into smart solar energy plants could significantly improve the overall energy generation capabilities, including monitoring and addressing the gaps in the solar energy systems.

How does IoT based solar power monitoring work?

IoT systems can integrate with energy management platforms to balance energy supply and demand. They can manage how and when to store energy in batteries, or when to feed it into the grid, based on real-time consumption data and predictive analytics. How Does IoT-Based Solar Power Monitoring Work?

Why is IoT important for solar power systems?

IoT enables continuous, real-time monitoring of solar power systems. Sensors and smart devices collect data on various parameters such as energy production, weather conditions, and equipment performance. This constant data stream helps in quickly identifying and addressing issues, ensuring that the solar panels are functioning optimally. 2.

How is IoT used in a smart grid environment?

As a result, IoT technology has been used in this work to monitor and regulate solar energy in a smart grid environment. A typical solar module is made up of 6 × 10 photovoltaic solar cells that can produce electricity for residential applications. Additional panels must be installed if more power is needed.

What are some applications of IoT in solar energy?

Here are a few applications of IoT in solar energy: Solar energy systems are usually made of multiple solar panels all connected together to produce energy. For example, in a 1 MV solar farm, there may be around 2,500 solar panels.

How much does an off-grid solar power system cost?

The real cost of an off-grid solar power system varies depending on application but some ballpark figures may help you decide which is suitable for your needs. A 4.4kw power supply, 10kwh AGM battery bank, 4.4kw of solar, 8kw generator suitable for a 3 bedroom property costs in the region of £16,500.

How much does an on-grid solar system cost?

On-grid systems are built to support energy needs but do not serve as your only electricity source. This means they're smaller and cost less than off-grid options. The average cost of solar panels for an on-grid, 5 kilowatt-hour (kWh) system is $15,000–$20,000. An off-grid system costs more than twice as much.

How much does a solar power system cost?

Wind turbines generally cost between $6,000 and $11,000, while a backup generator costs between $10,000 to $20,000. Unless you're installing a small DC solar system, you'll need a backup battery for your solar energy system.

What are the different types of off-grid solar systems?

There are two main types of off-grid solar system, fully off-grid and partially off-grid. Fully off-grid solar systems are not connected to the grid and are ideal for those who want to generate green energy or who require power where there is no connection or where cost prohibits a grid connection.

What is a complete off-grid Solar System?

Complete Off-Grid solar systems include solar panels, panel mounts, batteries, power inverter and everything required to generate, store and deliver off-grid energy. Partially off-grid solar systems are connected to the grid and can either supplement grid electricity or provide a green alternative with the grid as a backup.

Should you install an off-grid solar panel?

An off-grid solar panel installation eliminates fossil fuel usage and allows you to use 100% renewable energy. Frustrated grid-power users: If you experience frequent power outages or grid system failures, an off-grid system might help.

What types of batteries do solar panels use?

Solar panel systems use four main types of solar batteries: lead-acid, lithium-ion, nickel-cadmium, and flow. Each battery type has different benefits and works for different scenarios. 1. Lithium-Ion Batteries The technology underpinning lithium-ion batteries is relatively recent compared to other battery types.

Which battery is best for solar energy storage?

Lithium-ion – particularly lithium iron phosphate (LFP) – batteries are considered the best type of batteries for residential solar energy storage currently on the market. However, if flow and saltwater batteries became compact and cost-effective enough for home use, they may likely replace lithium-ion as the best solar batteries.

What is the most common solar battery?

The most common solar battery is the lithium-ion battery, widely favored for its high energy density, efficiency, and long cycle life, making it ideal for residential and commercial PV systems. In the realm of solar energy storage, lithium-ion batteries have established themselves as the most prevalent choice.

What is the best solar battery?

However, if flow and saltwater batteries became compact and cost-effective enough for home use, they may likely replace lithium-ion as the best solar batteries. Regardless of the chemistry, the best solar battery is the one that empowers you to achieve your energy goals.

Why should you choose a battery for a solar system?

Photovoltaic systems rely on batteries to store the energy generated by solar panels, ensuring a consistent power supply even when the sun isn't shining. The choice of battery type significantly impacts the system's performance, efficiency, and overall cost.

What type of batteries are used in PV systems?

Lithium-ion batteries are the most used type in PV systems due to their superior energy density, longer lifespan, and higher efficiency compared to other battery types. When it comes to energy storage in photovoltaic systems, lithium-ion batteries have emerged as the dominant technology.

What is solar power in South Africa?

Solar power in South Africa includes photovoltaics (PV) as well as concentrated solar power (CSP). As of July 2024, South Africa had 2,287 MW of installed utility-scale PV solar power capacity in its grid, in addition to 5,791 MW of rooftop solar and 500 MW of CSP. Installed capacity is expected to reach 8,400 MW by 2030.

Who should install solar panels in South Africa?

For peace of mind, homeowners and businesses should always work with accredited solar installation companies. Installers should be registered with the South African Photovoltaic Industry Association (SAPVIA), which promotes high-quality installations across the country.

What is the solar PV market in South Africa?

According to GlobalData, solar PV accounted for 15% of South Africa's total installed power generation capacity and 4% of total power generation in 2023. GlobalData uses proprietary data and analytics to provide a complete picture of this market in its South Africa Solar PV Analysis: Market Outlook to 2035 report. Buy the report here.

What percentage of South Africa's electricity is generated by solar PV?

Solar PV accounted for 15% of South Africa's total installed power generation capacity and 4% of total power generation in 2023.

What are the largest solar farms in South Africa?

TechCentral conducted desktop research into the largest, utility-scale solar power projects that feed energy into South Africa's grid as part of government's renewable IPP programme. These are the 10 largest solar farms, based on installed capacity, in South Africa 1. Xina Solar One | Concentrated solar power

What is the South African Photovoltaic Industry Association (sapvia)?

The South African Photovoltaic Industry Association (SAPVIA) has been actively promoting the use of solar energy in South Africa. Please mouse over the photo panels below for more information on each initiative: The PV GreenCard programme is designed to ensure quality and safety standards are introduced and maintained by all solar PV installers.

What are the major components of a solar photovoltaic system?

The major components of the solar photovoltaic system are listed below. Photovoltaic (PV) Panel PV panels or Photovoltaic panel is a most important component of a solar power plant. It is made up of small solar cells. This is a device that is used to convert solar photon energy into electrical energy.

What are the components of a solar panel system?

The main components of a solar panel system are: 1. Solar panels Solar panels are an essential part of a photovoltaic system. They are devices that capture solar radiation and are responsible for transforming solar energy into electricity through the photovoltaic effect. This type of solar panel comprises small elements called solar cells.

What is solar photovoltaic (PV) power generation?

Solar photovoltaic (PV) power generation is the process of converting energy from the sun into electricity using solar panels. Solar panels, also called PV panels, are combined into arrays in a PV system. PV systems can also be installed in grid-connected or off-grid (stand-alone) configurations.

What is a solar power system?

A solar power system is a simple, yet highly sophisticated assembly of components designed to work with one another—each playing a vital role in the process of converting sunlight into usable electricity. The three primary components of a solar power system are the panels, inverters, and battery storage.

What is a solar power generation block diagram?

Solar Power Generation Block Diagram: The block diagram shows the flow of electricity from solar panels through controllers and inverters to power devices or feed into the grid. The main part of a solar electric system is the solar panel. There are various types of solar panel available in the market.

What is the main part of a solar electric system?

The main part of a solar electric system is the solar panel. There are various types of solar panel available in the market. Solar panels are also known as photovoltaic solar panels. Solar panel or solar module is basically an array of series and parallel connected solar cells.

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.

How do solar trackers work?

This system is commonly used to position solar photovoltaic panels perpendicular to the Sun. You're familiar with PV panels, but do you know about solar trackers? Though less known, they play a vital role in solar energy. They ensure that the panel consistently faces the sun, optimizing sunlight exposure.

How to choose a solar tracker?

You need to consider factors like climate, space, and shading before deciding on solar tracking. These tracking systems offer the most benefits in locations with high latitudes due to the sun's yearly movements. In conclusion, positioning a solar tracker directs the solar panels at an angle toward the sun.

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

Can solar trackers be used with roof-mounted solar panels?

Solar trackers are usually designed to be used with ground-mounted solar arrays, yet in recent years a few solar trackers have been released that are designed to be used with roof-mounted solar panels too.

What are the different types of solar tracking systems?

There are two types of solar tracking systems based on their movement: single-axis and dual-axis. A single-axis tracker moves your panels on one axis of movement, usually aligned with north and south.

What is solar photovoltaic (PV) power generation?

Solar photovoltaic (PV) power generation is the process of converting energy from the sun into electricity using solar panels. Solar panels, also called PV panels, are combined into arrays in a PV system. PV systems can also be installed in grid-connected or off-grid (stand-alone) configurations.

What is a photovoltaic system?

A photovoltaic (PV) system is composed of one or more solar panels combined with an inverter and other electrical and mechanical hardware that use energy from the Sun to generate electricity. PV systems can vary greatly in size from small rooftop or portable systems to massive utility-scale generation plants.

What are the components of a photovoltaic system?

A photovoltaic (PV) system consists of several key components that work together to convert sunlight into usable electricity. These components include: Solar panels, also known as photovoltaic modules, are the primary components of a PV system. Each panel contains numerous solar cells made from semiconductor materials like silicon.

What is a solar power system?

A solar power system is made up of a variety of components that turn sunlight into useful electricity. Photovoltaic (PV) panels are at the heart of any system, absorbing sunlight and converting it into direct current (DC) power.

How does photovoltaic (PV) technology work?

Photovoltaic (PV) materials and devices convert sunlight into electrical energy. What is photovoltaic (PV) technology and how does it work? PV materials and devices convert sunlight into electrical energy. A single PV device is known as a cell. An individual PV cell is usually small, typically producing about 1 or 2 watts of power.

What are the different types of photovoltaic systems?

There are three main types of photovoltaic systems: These systems are directly connected to the electrical grid. The electricity generated by the solar panels flows into the grid and can be utilized in conjunction with the grid to satisfy the energy demands of the end user.

How many solar panels do I Need?

To produce 1,000kWh per month, you would need a large solar panel system of at least 12kW or more which is likely to require 16+ panels. It should be noted, however, that the average home only uses 2,700kWh per year, which would only require 4-5kW (approx. 10 panels). Every household has different electricity needs.

How many solar panels does a 2 bedroom house need?

A 2 bedroom house requires 4 to 8 panels, a 3 bedroom house needs between 8 and 13 panels, while a 4 or 5 bedroom household in the UK will need 13 to 16 solar panels, on average depending on household energy consumption and the wattage of the panels.

How much energy does a solar panel use?

In this chart's estimates the solar panel's output used is 350W, which is the standard for many high efficiency panels. Although these numbers provide a helpful guide, remember that they are general estimates. The exact number for your home's energy requirements may differ. More on that later.

How do I calculate how many solar panels I Need?

To calculate how many solar panels you need, the only piece of information you need to find is your annual electricity usage, which your energy supplier will usually share with you each year. If you have an online account with your supplier, you may also be able to find your annual consumption that way. Otherwise, get in touch with the company.

How many solar panels are needed for a 5kw Solar System?

If you're wondering how many panels are needed for a 5kW solar system, then the answer is between 8 – 13 panels, (either 350W or 450W). This, however, is only an estimate on paper, a home running only on solar power may need an even more powerful system to compensate for weather disruptions, family growth or property expansions.

How many watts can a solar panel produce a year?

Most home panels can each produce between 250 and 400 Watts per hour. According to the Renewable Energy Hub, domestic solar panel systems usually range in size from around to 1 kW to 5 kW. Allowing for some cloudier days, and some lost power, a 5 kW system can generally produce around 4,500 kWh per year.

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 does solar energy cause wind?

Solar energy causes wind through the process of heating different areas and creating air pressure gradients. According to Gay-Lussac's Law, as heat increases, so does pressure. Consequently, areas that are more heated have higher pressures, leading to air moving from areas of high pressure to low pressure and causing wind.

What is solar wind & how does it work?

What is solar wind? The solar wind is matter that is blown from our sun, out into the whole solar system. This stream of material is coming out of the sun all the time – about a million tonnes per second. It's gusty, and changes with time, but it also comes out at a speed of between one and two million miles per hour.

Why is solar wind constantly released from the Sun?

In this outer atmosphere, temperatures are extremely high, causing plasma to expand so much that it breaks free from solar gravity and is released into space. An artist's illustration of solar wind streaming out from the Sun. The solar wind is constantly released from the Sun's outer atmosphere.

How does the solar wind change over time?

The solar wind varies in density, temperature and speed over time and over solar latitude and longitude. Its particles can escape the Sun's gravity because of their high energy resulting from the high temperature of the corona, which in turn is a result of the coronal magnetic field.

Why do we need solar and wind energy?

By providing clean, renewable, and increasingly affordable energy, they help reduce greenhouse gas emissions, protect natural resources, and support a thriving green economy. While challenges remain, advancements in technology and policy support continue to make solar and wind energy more viable than ever.

How fast does the solar wind travel?

The solar wind travels faster than the speed of sound. During events like solar flares and coronal mass ejections, when larger than normal amounts of solar energy are released from the Sun, the speed of the solar wind increases, reaching speeds of over one million miles per hour.

What happens if a solar panel fails?

It's also possible that one solar panel in your pv array failed. As the pv modules are connected in series, one failing pv module will shut down the entire system. If your solar system is not delivering sufficient power for which it is rated for, the resulting situation is called a low power situation.

Do you have problems with your solar panels?

Nearly seven in 10 owners had had no problems with their solar panels in our survey of over 2,000 owners.* The most common – and most serious – problem owners face is with the inverter. In some cases inverter problems mean you don't get any usable renewable electricity. It can also be a pricey problem to fix.

Why do solar panels need to be replaced?

Rare manufacturing defects may require panel replacement. Micro cracks in solar panels can lead to power loss over time. Cracking in the back sheet of the panel can cause moisture ingress and panel failure. Hotspots in cells can lead to burn marks and potential fire hazards. Shattered glass in panels can be caused by hotspots or impacts.

What happens if a solar panel cracks?

Cracking in the back sheet of the panel can cause moisture ingress and panel failure. Hotspots in cells can lead to burn marks and potential fire hazards. Shattered glass in panels can be caused by hotspots or impacts. Moisture ingress and delamination of back sheets can cause leakage and inverter trips.

How do I care for my solar panels?

Here's how to proactively care for your solar panels and safeguard your clean energy investment: Depending on your location, dust, pollen, or leaves might accumulate on your panels. A seasonal, gentle rinse can help maintain their efficiency. Think of it as giving your panels a refreshing shower.

Why is my PV system not working?

These two conditions which may require troubleshooting are: Zero output is a common problem and in nine out of ten cases, it is due to a faulty inverter or charge controller. It's also possible that one solar panel in your pv array failed. As the pv modules are connected in series, one failing pv module will shut down the entire system.

What are the components of a photovoltaic system?

The components of a photovoltaic system are: In Grid Connected systems there are, in addition: Solar panels transform solar energy into electrical energy through the photovoltaic effect. There are two main types: Monocristalline solar panels: They have homogeneous, dark blue, almost black cells that work best with perpendicular sunlight.

What is a solar photovoltaic (PV) energy system?

Solar photovoltaic (PV) energy systems are made up of diferent components. Each component has a specific role. The type of component in the system depends on the type of system and the purpose.

What are the components of a solar panel system?

The main components of a solar panel system are: 1. Solar panels Solar panels are an essential part of a photovoltaic system. They are devices that capture solar radiation and are responsible for transforming solar energy into electricity through the photovoltaic effect. This type of solar panel comprises small elements called solar cells.

What are the components of a PV system?

In addition to PV mod-ules, the components needed to complete a PV system may include a battery charge controller, batteries, an inverter or power control unit (for alternating-current loads), safety disconnects and fuses, a grounding circuit, and wiring. (See 36 cells.

What is a PV cell & how does it work?

The PV cell is the part of the PV panel responsible for transforming solar radiation into electrical energy thanks to the photovoltaic effect. The generating power of solar panels is DC electricity that is suitable to store in a battery system. Still, we will usually need a power inverter to use it.

How does a solar PV system work?

PV system disconnects Typically, a solar PV system comes with two safety switches or disconnects. The first one is the DC disconnect/switch, which can interrupt the flow of the DC current between the solar module (source) and the inverter by opening the circuit. In some cases, it is integrated into the inverter.

Can a PV system tripping a RCD in wet weather?

If not, I will have to assume that tripping the RCD in wet weather has a different source and the PV system has nothing to do with it. The solar panels produce DC voltage, that is then converted to AC and stabilised before being applied to your mains. As such the technician is correct that the panels are not directly connected to the mains.

Why is my RCD tripping when it rains?

We have had no history of our RCD tripping until solar panels were fitted last month. Since then our RCD frequently trips when it rains. The technician who fitted the PV system told me it couldn't be anything to do with that, as the solar cell wiring was entirely separate from the house wiring which the RCD was protecting.

Can a solar PV share a 30mA RCD?

This is isolate the tripping problem from the household circuits. It is not ideal the solar pv sharing an RCD as the solar pv will have residual current and this coupled with any residual current already existing on the household circuits could well be enough to cross the tripping threashold of the 30mA RCD.

What happens if a shared PV system is tripping?

The issue with the PV being fed from the shared isn't just nuisance tripping. It will also affect disconnection times. If there is a fault of one of the circuits which are protected by the RCD, say for example the sockets, then the RCD will operate yet the PV system will still be feeding power to the circuit.

Why does my inverter keep tripping?

You can't supply the inverter through the RCD. It will cause the RCD to trip Start with switching the DC breaker off at the inverter so the panels aren't supplying the inverter with any power and then wet the panels again and see if the RCD trips. If the RCD does trip then this is definitely an AC problem.

Why does my solar meter trip?

You have an “upfront” RCD straight after the meter so any fault on your domestic or solar electrics could cause it to trip. Or there could always have been a residual leakage just under the trip sensitivity of the up front RCD hence the added leakage from the inverter now producing the trips.

How many Watts Does a 150 watt solar panel produce?

A 150 watt solar panel will produce 150 watts an hour or 750 watts a day with 5 sunlight hours (150 x 5 = 750). With more sun hours, more watts. However it isn't that clear cut. 150 watts is the peak output for a 150W solar panel. It is the maximum power the module can produce when the sun is high above the horizon.

Is a 150 watt solar panel a good choice?

A 150 watt solar panel is an ideal choice for camping, RVs and small homes. It isn't as costly as largo panels but offers plenty of power. But exactly how much power can you expect? Will it be enough for your appliances and other electronics? That is what we will find out in this guide.

What is a 150 watt solar system?

A 150 watt complete solar system is ideal for small homeowners facing low light problems in their locations. The system includes a 150 watt solar panel, solar inverter, solar battery, mounting structure, connecting wires and other fixing gadgets like nuts and bolts.

How much battery do I need for a 150 watt solar panel?

For a single 150 watt solar panel, you'd need about 12v 70-100Ah lithium or 12v 140-200Ah lead-acid battery. The exact value will depend on the amount of peak sun hours your location receives. To calculate the size of a battery pick the highest number of peak sun hours your location receives.

Can a 150 watt solar panel run a refrigerator?

A 150 watt solar panel can run several light bulbs, fan, laptop, TV, radio and movie player. However the solar panel cannot run a refrigerator, microwave, sump pump and other large appliances. How Much Power Can a 150 Watt Solar Panel Produce? The answer seems simple, right?

How many watts can a solar panel use?

You can also use any number of appliances as long as the total watts is 700 watts or whatever your solar panel has produced. Or you could use several light bulbs and turn on the fan while using your laptop or watching TV for instance. You can connect several 150W solar panels to increase amps or voltage.