Related Topics:
Country Brief Mozambique Grid-
Solar power storage solutions in Mozambique
Globeleq, Source Energia and Electricidade de Moçambique (EDM) have started construction on the first IPP in Mozambique to integrate utility-scale energy storage with a solar PV plant.
FAQs about Solar power storage solutions in Mozambique
Why is solar energy important in Mozambique?
In Mozambique, the adoption of solar energy systems is particularly crucial due to several key factors inherent to the country's situation. Firstly, Mozambique has a high solar irradiation level, making it an ideal location for harnessing solar energy.
Will Mozambique get a solar power plant in 2023?
Future tenders are expected to be announced in Q4 of 2023, including the selection of two independent power producers for two 30 MW solar photovoltaic power plants and one 50 MW wind power plant. But Mozambique has an enormous challenge that spreads far beyond where the national grid ends.
What is the market for off-grid solar in Mozambique?
The total estimated addressable market for off-grid solar is currently 173 MW, and is expected to grow in line with the growth of the aforementioned sectors. Recent energy policy reforms are also changing the game for off-grid renewables in Mozambique.
Does Mozambique have a strong energy sector?
Over the past two decades, Mozambique has seen steady economic growth, combined with a suite of actions aimed at strengthening the energy sector. The introduction of the Electricity Law in 1997 opened the way to greater participation of the private sector, including the facilitation of Power Purchase Agreements (PPAs).
Will Mozambique achieve universal energy access by 2030?
By 2030, the Government of Mozambique hope to transform this landscape, and achieve universal energy access by the end of the decade. This would require capacity to more than double to almost 6,500 MW. Solar is undeniably the most intuitive renewable technology when it comes to off-grid energy solutions.
Who won a solar power plant in Moçambique?
The first tender under the programme was the Dondo solar power plant which was won by Independent Power Producer (IPP), Total Eren (now acquired by Total Energies), with a tariff of $52.45/MWh, and is supported by Electricidade de Moçambique (EDM) and the French Development Agency (AFD).
-
How to install and connect solar power generation to the grid
For financial benefit. Connecting your solar PV system to the grid allows you to take advantage of the FIT, which gives you a fixed amount of money for each kWh of electricity you generate. On top of these payments for energy generation, you also receive a sum of money for feeding any surplus energy into the grid. By. Your installer should do most of the hard work for you. Once your system is set up, your installation company will supply all of the necessary information. For smaller systems, the installer will generally only need to inform the DNO of your connection within 28 days, providing that your system complies with engineering recommendation G83/1-1 Stage 1. Essentially, this. If you bought your property after 1st October 2008, you should already have one, as the builder or previous owner was legally obliged to provide it. If you purchased your property before this deadline, you may need to. In addition to the tests carried out by the DNO, you will also have to provide your FIT supplier with an Energy Performance Certificate (EPC). This certificate shows the energy efficiency of your property, giving it a band rating from.
[PDF Version]
FAQs about How to install and connect solar power generation to the grid
How do I connect solar panels to the grid?
To connect solar panels to the grid, you need to install a bi-directional meter on your home. This allows energy produced by your solar panels to be fed into the grid when you're not using it, and for you to draw energy back from the grid when you need it.
Can a solar PV system be connected to the National Grid?
While it is possible to have a solar PV system that is not connected to the National Grid, choosing not to connect means missing out on potentially lucrative incentive schemes like the government's Feed-In Tariff (FIT). Here is a list of FAQs on connecting to the National Grid.
Why should a solar PV system be connected to the grid?
For financial benefit. Connecting your solar PV system to the grid allows you to take advantage of the FIT, which gives you a fixed amount of money for each kWh of electricity you generate. On top of these payments for energy generation, you also receive a sum of money for feeding any surplus energy into the grid.
Why do I need an electrician to connect my solar panels?
This allows energy produced by your solar panels to be fed into the grid when you're not using it, and for you to draw energy back from the grid when you need it. It's essential that a licensed electrician performs the connection to ensure safety and compliance with local regulations.
How do you connect solar panels to an inverter?
Carefully wire the solar panels together and connect them to the inverter. The inverter converts the DC electricity generated by the panels into AC electricity suitable for use in your home or business. Follow the detailed wiring diagrams provided by the manufacturer to ensure proper connections and prevent potential electrical hazards.
How should solar panels be installed?
Solar panels should be installed at an angle that catches the majority of the sun's rays and securely fastened so they can withstand harsh weather conditions. Once the panels are in place, they need to be connected in either series or parallel, depending on the output voltage required and the kind of inverter to be used.
-
How to connect home solar power generation to the power grid
For financial benefit. Connecting your solar PV system to the grid allows you to take advantage of the FIT, which gives you a fixed amount of money for each kWh of electricity you generate. On top of these payments for energy generation, you also receive a sum of money for feeding any surplus energy into the grid. By. Your installer should do most of the hard work for you. Once your system is set up, your installation company will supply all of the necessary information to your District Network Operator (DNO), who will ensure that you're connected to. For smaller systems, the installer will generally only need to inform the DNO of your connection within 28 days, providing that your system complies with engineering recommendation G83/1-1 Stage 1. Essentially, this. In addition to the tests carried out by the DNO, you will also have to provide your FIT supplier with an Energy Performance Certificate (EPC). This. If you bought your property after 1st October 2008, you should already have one, as the builder or previous owner was legally obliged to provide it. If you purchased your property before this deadline, you may need to.
[PDF Version]
FAQs about How to connect home solar power generation to the power grid
How do I connect solar panels to the grid?
To connect solar panels to the grid, you need to install a bi-directional meter on your home. This allows energy produced by your solar panels to be fed into the grid when you're not using it, and for you to draw energy back from the grid when you need it.
How does a grid-tied solar system work?
By connecting to the grid, you can send any extra energy your solar panels produce back to the grid. This process, known as 'net metering' or 'net billing,' could result in credits on your electricity bill. In a grid-tied system, your solar panels are directly connected to the utility grid.
How to connect solar panels to house?
Here are the detailed steps on how to connect solar panels to house: Step 1: Prepare the mounts that will provide solid support to your panels. You can choose flush mounts or roof-ground mounts, whatever you think is best for you.
Why should a solar PV system be connected to the grid?
For financial benefit. Connecting your solar PV system to the grid allows you to take advantage of the FIT, which gives you a fixed amount of money for each kWh of electricity you generate. On top of these payments for energy generation, you also receive a sum of money for feeding any surplus energy into the grid.
Why do I need an electrician to connect my solar panels?
This allows energy produced by your solar panels to be fed into the grid when you're not using it, and for you to draw energy back from the grid when you need it. It's essential that a licensed electrician performs the connection to ensure safety and compliance with local regulations.
What is a grid-connected solar system?
As the name suggests, a grid-connected solar system is tied to the utility grid. What distinguishes it from other solar setups is that the energy runs in two different ways. When your household requires more energy than your solar system generates, the house draws in energy from the utility.
-
Home Solar Power Ranking
This article provides information on the top five solar panel makers and their product lineups. It also gives tips for choosing the best solar panels for your home, including cost, efficiency rating, wattage output, temperature coefficient rating, energy needs and available space. The article explains how to compare quotes from. The article provides an overview of solar panels and their accessories, including the benefits of using them in homes. It also mentions the competition among companies that offer these. Forbes Home has compiled a list of the top five solar panel makers based on 42 different attributes such as wattages available, customer. SunPower is considered as best overall option while Panasonic Solar is best for warm climates, Q Cells are most popular brand, Canadian Solar. SunPower is one of the best overall options for powering your home with solar energy solutions. They have a network of trusted installers to help you get started.
[PDF Version]
-
What brand of home solar power supply has the best quality
Best Solar Panels of 2025Panasonic: Best OverallREC Group: Best For Harsh ClimatesQcells: Most PopularCanadian Solar: Most PowerfulMaxeon (by SunPower): Best Warranties.
FAQs about What brand of home solar power supply has the best quality
What are the best solar panel brands?
Find out what owners think of JA Solar, Jinko Solar, Longi, Solaredge and Trina Solar solar pv panels to find the best solar panel brand for you.
What are the best solar panels manufacturers in the UK?
In no particular order, here are the top 10 solar panels manufacturers whose products are available in the UK today: Project Solar: The best manufacturer in terms of warranty (offering a warranty period of 99.9 years). REA Solar: Provides solar panels with high power output. SunPower: Best manufacturer in terms of product variety.
What is the best solar panel in 2025?
Save up to £915 on your electricity bills with solar energy! The best solar panel in 2025 is SunPower Maxeon 6. The best solar panel in terms of warranty is the Project Solar Evolution Titan 445, offering a lifetime warranty of 99.9 years. Over the last few years, it has become increasingly popular to install solar panels for homes across the UK.
What are the cheapest solar panels?
At about £190 per solar panel, Sharp NU-AF solar panels are some of the cheapest solar panels on the market. While they are some of the best solar panels for a lower budget, there are also some disadvantages when it comes to Sharp NU-AF solar panels. For instance, they have a higher performance degradation rate of 0.7% per year.
What makes a good solar panel system?
The quality of the installation and other equipment (such as the inverter) also contribute to how good the solar panel system is overall. Price also varies depending on the solar panel brand and installer. The Which? members we surveyed owned solar PV panels from more than 20 different brands.
What are the most powerful solar panels?
Efficiency Trina's Vertex N solar panel range takes the pick for the most powerful solar panels on today's market, with a power output between 685 - 710W. This makes them a great option for large homes with high energy demands, or even for very small homes with limited roof space, as solar expert Josua Pearce explains:
-
Solar Photovoltaic DC Power Generation
PV systems are most commonly in the grid-connected configuration because it is easier to design and typically less expensive compared to off-grid PV systems, which rely on batteries. Grid-connected PV systems allow homeowners to consume less power from the grid and supply unused or excess power back to the. Off-grid (stand-alone) PV systems use arrays of solar panels to charge banks of rechargeable batteries during the day for use at night when energy from the sun is not available. The reasons for using an off-grid PV system include. Solar panels used in PV systems are assemblies of solar cells, typically composed of silicon and commonly mounted in a rigid flat. A PV combiner box receives the output of several solar panel strings and consolidates this output into one main power feed that connects. When solar arrays are installed on a property, they must be mounted at an angle to best receive sunlight. Typical solar array mounts include.
[PDF Version]
FAQs about Solar Photovoltaic DC Power Generation
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.
How do solar panels make DC electricity?
Solar panels make DC electricity using the photovoltaic effect. Sunlight hits the panels' cells, exciting the electrons in them. This excitement makes the electrons flow, creating a direct current. The cells work this way because they contain layers of semiconductor materials.
Do solar panels produce direct current (DC)?
Solar panels produce direct current (DC). For use in homes or the grid, this DC needs to be converted. Inverters change the DC electricity into usable alternating current (AC) power. This is what makes solar energy practical for everyday use.
What is a photovoltaic (PV) cell?
A photovoltaic (PV) cell, commonly called a solar cell, is a nonmechanical device that converts sunlight directly into electricity. Some PV cells can convert artificial light into electricity. Sunlight is composed of photons, or particles of solar energy.
Does solar PV technology make progress in solar power generation?
This paper reviews the progress made in solar power generation by PV technology. Performance of solar PV array is strongly dependent on operating conditions. Manufacturing cost of solar power is still high as compared to conventional power.
What are the main features of solar photovoltaic (PV) generation?
Abstract: This chapter presents the important features of solar photovoltaic (PV) generation and an overview of electrical storage technologies. The basic unit of a solar PV generation system is a solar cell, which is a P‐N junction diode. The power electronic converters used in solar systems are usually DC‐DC converters and DC‐AC converters.
-
Who installed solar power in China
In June 2024, China activated the world's largest solar power facility, a 3.5-gigawatt (GW) installation in Urumqi, Xinjiang. Built by Power Construction Corporation of China, this plant produces around 6.09 billion kilowatt hours (kWh) of electricity annually. 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 lat. Photovoltaic research in China began in 1958 with the development of China's first piece of. Research continued with the development of solar cells for space satellites in 1968. The Institute of Semic.
FAQs about Who installed solar power in China
How much solar power does China have?
As of at least 2024, China has one third of the world's installed solar panel capacity. Most of China's solar power is generated within its western provinces and is transferred to other regions of the country.
Did China install more solar in 2023?
Between March 2023 and March 2024, China installed more solar than it had in the previous three years combined, and more than the rest of the world combined for 2023. Solar capacity first surpassed wind in 2022, and the gap has grown significantly larger, thanks to the massive expansion of distributed solar.
Did China break its own record for new wind and solar power installations?
China broke its own records for new wind and solar power installations again last year, official data showed on Tuesday, accelerating from a breakneck pace set in 2023 as the country looks to peak its carbon emissions before 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.
Where is solar power generated in China?
Most of China's solar power is generated within its western provinces and is transferred to other regions of the country. In 2011, China owned the largest solar power plant in the world at the time, the Huanghe Hydropower Golmud Solar Park, which had a photovoltaic capacity of 200 MW.
When did China start making solar panels?
China's photovoltaic industry began by making panels for satellites, 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 world's leading installer of photovoltaics in 2013.
-
China s solar photovoltaic power generation company
Here are some of the top solar photovoltaic power generation companies in China:Trina Solar LimitedJinkoSolar Holding Co., LtdLONGi Green Energy Technology Co.
FAQs about China s solar photovoltaic power generation company
What are the largest public listed companies in solar industry from China?
This is the list of the largest public listed companies in the Solar industry from China by market capitalization with links to their reference stock. $10,000 in September 2023 would now be $32,767 by following this algorithm daily at market close. Use AI to boost your investing & swing trading, now! 1. Trina Solar Co. Ltd 2.
Where is solar power generated in China?
Most of China's solar power is generated within its western provinces and is transferred to other regions of the country. In 2011, China owned the largest solar power plant in the world at the time, the Huanghe Hydropower Golmud Solar Park, which had a photovoltaic capacity of 200 MW.
Who are the top solar panel manufacturers in China?
The following are the top solar panel manufacturers in China as of 2024. Jinko Solar Co., Ltd., now officially known as Jinko Solar Holdings Co., Ltd., was established in 2006 and is headquartered in Shangrao, Jiangxi Province, covering an area of over 500 acres.
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.
When did China start making solar panels?
China's photovoltaic industry began by making panels for satellites, 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 world's leading installer of photovoltaics in 2013.
Does China have a solar industry?
And despite all the turmoil, the Chinese solar industry has the manufacturing capacity to meet the demand. Discover all statistics and data on Solar energy in China now on statista.com!
-
Power generation of solar power stations in China
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 Power generation of solar power stations in China
Does China have a potential for solar PV power station installation & generation?
The results of this study indicated that China, as one of the fast-growing countries in the global south, shows outstanding potential for solar PV power station installation and generation potential.
What is the potential of solar power generation in China?
Chen et al. developed a comprehensive solar resource assessment system based on the GIS + MCDM method in 2019. This system was applied to the assessment of the potential of PV power generation in the countries under the “Belt and Road” initiative. The results showed that the PV potential of China is 100.8 PWh.
What is the PV power generation potential of China?
The PV power generation potential of China is 131.942 PWh, which is approximately 23 times the electricity demand of China in 2015. The spatial distribution characteristics of PV power generation potential mainly showed a downward trend from northwest to southeast.
Where is solar power generated in China?
Most of China's solar power is generated within its western provinces and is transferred to other regions of the country. In 2011, China owned the largest solar power plant in the world at the time, the Huanghe Hydropower Golmud Solar Park, which had a photovoltaic capacity of 200 MW.
Why is China a global leader in solar photovoltaic power generation?
growth and success in the solar photovoltaic power generation market. As the world's largest energy consumer, China's commitment to renewable energy and its pursuit of a more sustainable energy future have positioned it as a global leader in solar photovoltaic power generation, playing a crucial role in the f
How much solar power does China need?
We found that the total installable capacity is at least 44,614.6 GW for China as a whole, resulting in an annual electricity generation potential of 72.7 PWh. However, the spatial distribution of solar PV potential does not match the electricity demand in China.
-
Wind and solar power price comparison
In this article, we'll dive into a detailed cost comparison of wind and solar power, examining key factors like: – Upfront installation and equipment costs – Ongoing operation and maintenance expen.
FAQs about Wind and solar power price comparison
How much does solar energy cost vs wind energy?
However, there are other reports that detail the potential cost of solar energy vs wind energy specifically. Those reports indicate that (some information is paraphrased): From group.met.com ' it about $2.19 per watt to install solar energy, while wind power costs only $1.50 per watt'
How do wind power and solar energy compare?
Let's explore how wind power and solar energy compare in this regard. Wind power has a relatively low environmental impact. The process of generating electricity from wind turbines produces no greenhouse gas emissions or air pollutants.
Why is wind power cheaper than solar?
For large scale systems, wind power breaks even and produces power cheaper than an equivalent solar system. Big wind farms make cheaper power than large solar installations. Wind farms generate more power in less space and need less maintenance for each megawatt they produce. Wind turbine upkeep costs $3,000 to $5,000 [$2,500 to £4,200] yearly.
Is solar energy better than wind?
Wind power currently outpaces that of solar when it comes to overall share of electricity generated. For homeowners, solar energy is a far more practical option. What it really comes down to, however, is location. In the world of energy, there is no one-size-fits-all solution.
How much does solar energy cost?
Those reports indicate that (some information is paraphrased): From group.met.com ' it about $2.19 per watt to install solar energy, while wind power costs only $1.50 per watt' Data provided by regenpower.com might indicate that (paraphrased) wind energy costs about 20.3 cents per kWh, and solar energy costs 4.6 cents per kWh
Should you choose wind or solar energy?
Consumers and energy providers look at cost when deciding between wind and solar. That includes the cost of initial setup, maintenance, and ongoing operation. The cost of wind power has decreased significantly over the years. It is often considered more cost-effective than solar energy, particularly in regions with strong and consistent winds.
-
Solar power generation storage power station use
As a thermal energy generating power station, CSP has more in common with such as coal, gas, or geothermal. A CSP plant can incorporate, which stores energy either in the form of or as (for example, using ), which enables these plants to continue supplying electricity whenever it is needed, day or night. This makes CSP a form of solar. Dispatchable is particularl.
FAQs about Solar power generation storage power station use
Can solar energy be used as a energy storage system?
Existing compressed air energy storage systems often use the released air as part of a natural gas power cycle to produce electricity. Solar power can be used to create new fuels that can be combusted (burned) or consumed to provide energy, effectively storing the solar energy in the chemical bonds.
Should solar energy be combined with storage technologies?
Coupling solar energy and storage technologies is one such case. The reason: Solar energy is not always produced at the time energy is needed most. Peak power usage often occurs on summer afternoons and evenings, when solar energy generation is falling.
What is a solar power station?
A solar power station is a facility that generates electricity by converting sunlight into electricity using solar panels, which consist of multiple solar cells. These stations can range in size from a few kilowatts to hundreds of megawatts and can be installed on the ground, rooftops, or walls to harness direct sunlight efficiently.
What are power system considerations for energy storage?
The third part which is about Power system considerations for energy storage covers Integration of energy storage systems; Effect of energy storage on transient regimes in the power system; and Optimising regimes for energy storage in a power system.
Can energy storage devices be used in photovoltaic power plants?
Furthermore, the placement of energy storage devices within photovoltaic power plants have also been discussed. From this review, the following conclusions can be drawn: At present, Lithium-Ion is, by far, the most used technology.
How can energy storage help a large scale photovoltaic power plant?
Li-ion and flow batteries can also provide market oriented services. The best location of the storage should be considered and depends on the service. Energy storage can play an essential role in large scale photovoltaic power plants for complying with the current and future standards (grid codes) or for providing market oriented services.
-
Solar power supply How does light come from
Solar power, also known as solar electricity, is the conversion of energy from into, either directly using (PV) or indirectly using. use the to convert light into an. Concentrated solar power systems use or mirrors and systems to focus a large area of sunlight to a hot spot, often.
FAQs about Solar power supply How does light come from
How do solar panels generate electricity?
Electricity is generated from energy from the Sun by solar panels. These are made up from individual solar cells (also called photovoltaic cells). Light from the sun passes through the glass cover of a solar cell. The sunlight hits layers of semiconductors, giving extra energy to electrons in the semiconductors.
How the sun can be used to generate electricity?
Find out how the sun can be used to generate electricity. Electricity is generated from energy from the Sun by solar panels. These are made up from individual solar cells (also called photovoltaic cells). Light from the sun passes through the glass cover of a solar cell.
How does solar power work?
Solar power works by converting energy from the sun into power. There are two forms of energy generated from the sun for our use – electricity and heat. Both are generated through the use of solar panels, which range in size from residential rooftops to 'solar farms' stretching over acres of rural land. Is solar power a clean energy source?
How do solar cells convert light to electricity?
The conversion of light to electricity in a solar cell is a process underpinned by the photovoltaic effect. When sunlight, composed of photons, strikes the solar cell, these light particles transfer their energy to electrons in the cell's semiconductor material, typically silicon.
Where does solar energy come from?
Solar energy is derived from the sun, which emits an enormous amount of energy continuously. This energy travels through space and reaches the Earth, where it can be harnessed for various uses. Most commonly, solar energy is captured and converted into electricity using solar cells.
How is solar energy converted into electricity?
Most commonly, solar energy is captured and converted into electricity using solar cells. These cells are designed to absorb sunlight and convert it directly into electrical power without any moving parts, making them highly reliable and low-maintenance.
-
How long does it take to fully charge after converting to solar power supply
Divide the energy required to fully charge the battery (in watt-hours) by the adjusted solar output (in watts) to obtain your estimated charge time. Charge time = 1412Wh ×· 326W = 4.
FAQs about How long does it take to fully charge after converting to solar power supply
How long does it take to charge a solar panel?
If your solar panel is rated at 100W, under ideal circumstances, it would take about 6 hours to fully charge the battery. Identifying the energy output of your solar panel is crucial to estimate how long it will take to charge a solar battery. Peak Sun Hours: What Is It and How It Affects Charging Time?
How long to charge a 12V battery with 300W solar panels?
The duration to charge a 12V battery with 300W solar panels depends on the battery capacity and the solar panel current. For instance, at 6 peak hours and 25% system losses (efficiency is 75%), a single 300W solar panel can fully charge a 12V 50Ah battery in roughly 10 hours and 40 minutes. Let's understand it in detail,
How long does it take a solar battery to recharge?
So if you have a total battery capacity of 2.4 kWh, it would go from nearly flat to fully recharge in around three peak solar hours (0.8 * 3 = 2.4). If your battery is measured in Amp hours, such as this 12V 200Ah Lithium Iron Phosphate Battery, you can convert to kWh by multiplying the voltage by the Amp hour rating and dividing by 1,000.
How to calculate solar battery charge time?
Output power (W) = total watts (W) x conversion efficiency of the solar system x (1 – charge controller's power consumption rate) Substitute the data to get the output power of your solar panel is 1615W, and then finally divide the solar battery charge by the output power of the solar panel to get the charging time, i.e.:
What is the battery charging time calculator?
The Battery Charging Time Calculator is a web-based tool that estimates how long it takes a solar panel to charge a battery completely. Users can enter the size of the solar panel (in watts), the size of the battery (in ampere-hours), the voltage of the battery, and the peak sun hours in their area into this calculator.
How long does a 200W solar panel take to charge?
Assume you are using a 200W solar panel and an MPPT charge controller. Solar output = 200W ×— 95% = 190W 4. Divide the discharged battery capacity by the solar output to get your estimated charge time. Charge time = 960Wh ×· 190W = 5.1 hours