What is Solar Energy?
Solar energy is simply energy provided by the sun. With the use of technology, man is able to harness the sun’s energy and make it usable to power different equipment(s).
Solar energy is an important source of renewable energy. The amount of solar energy reaching the surface of the earth in one year is estimated to be twice as much as will ever be obtained from all of the Earth’s non-renewable resources of coal, oil, natural gas, and mined uranium combined.
Uses of Solar Energy
Solar thermal technologies can be used for water heating, space heating/cooling, cooking and water treatment, among other thermal uses.
Solar energy is also used in the production of solar electricity and is anticipated to become the world’s largest source of electricity by 2050.
Solar energy plays a part in the revolution of architecture and urban planning, modern buildings are designed to maximise light and warmth.
In agriculture and horticulture, techniques such as timed planting cycles, tailored row orientation, staggered heights between rows and the mixing of plant varieties are used to optimise the capture of sunlight.
Solar energy has influenced the manufacturing of solar-powered modes of transportation such as boats, planes and balloons. A good example would be vehicles currently used in the World Solar Challenge.
Benefits of Solar Energy
1- Saves Cost
Once a solar system is installed, one is expected to recover the cost of installing the solar energy system in about 10 years. Saving can be from saving in electricity bills or as in some countries, solar rebates are offered by Governments.
Solar energy systems also require very little maintenance to ensure that they are in working order hence saving on maintenance cost and the hassle of organizing repairs. One thing you need to note is that you should go for the best solar panels in Tanzania. Low quality versions could cost you more.
2- Protects the Environment
Solar energy production has zero noise and zero emission from the photovoltaic panels, it is the most environmentally friendly form of energy.
Other types of fuels such as coal, oil and gasoline are the leading causes of increased carbon dioxide in the atmosphere. Effects of increased carbon dioxide include global warming and ocean acidification.
In low-income countries, charcoal and firewood are the major sources of fuel which leads to deforestation. Solar energy is a sustainable alternative for such communities by providing them with an alternative for their household fuel needs.
3- Offers Energy Security
Solar energy is a stable source of electricity. Once you have a solar system set up, you will no longer be affected by power cut-outs. All you need is a good solar panel in Tanzania coupled with a solar generator. Raise in utility charges will also not be one of your worries.
Solar power is not only sustainable, but it is also renewable. This means that once you install a solar system, you will never run out of energy because, well, the sun never runs out.
According to National Geographic, Every hour the sun beams more energy onto Earth than it needs to satisfy global energy needs for an entire year.
4- Improve your property value:
Since the world is recognizing the value of solar energy, a home built with a solar energy system is much more valuable than a traditionally powered home. By having a solar energy system set up, should you need to move, your house will fetch a higher price in the market than it normally would prior to installing a solar energy system.
The world is also seeing a shift in the tourism industry where properties that are solar-powered, especially in third-world countries where the power supply is not stable, are preferred by most travellers. Travellers especially those in favour of sustainable tourism, opt for solar-powered properties because of their stable power while leaving no carbon footprints. As a company in the tourist industry in Tanzania it’d be a lucrative idea for you to invest in quality solar panels and generators.
How do Solar Systems work to Produce Electricity
The solar energy production begins when the sunlight comes into contact with a solar panel. Sunlight is a form of energy consisting of invisible particles called photons, that have energy, but zero rest mass. Solar panels collect photons and pass the photons through silicon cells to free up the electrons contained therein and eventually processed to form electricity.
The energy generated by a solar panel comes in a form of Direct Current (DC). The DC current needs to be converted through an inverter to produce Alternating Current (AC) energy which is the form of energy commonly used in homes and businesses.
Since solar energy depends on the sun being out, a solar storage system will come in handy to ensure that you have the energy to use even when the sun is out such as at nights or on cloudy days.
The basic solar components
In order to have a solar electrical system, you need something to capture the sunlight. You need a solar panel. Solar panels are the most important part of the solar energy system. Without a panel, you are not able to collect sunlight which is the key ingredient in the production of solar energy.
For the system to work properly, the entire solar panel must be exposed to the sunlight. This is why you need to make sure you engage with a company that has experience in installing solar panels and solar generators in Tanzania.
Solar panels are made of an array of photovoltaic(PV) cells that are made of semiconductors. Majority of the solar panels use crystalline silicon cells. The PV cells collect and convert sunlight into energy before sending the energy to an inverter ready to be converted into electricity.
Types of Solar Panels
i. Monocrystalline Silicon PV (mono-silicon or single silicon)
These are commonly used for residential and commercial installations for both large and smaller scale systems. Their cells use very pure silicon and have a complicated crystal growth process.
They are the most efficient type of photovoltaic cell (14-19% efficiency level), but also the most expensive due to their high silicon content and take more energy to use.
ii. Polycrystalline Silicon PV (multicrystalline, multi-silicon, ribbon)
Polycrystalline silicon panels are also common for both residential and commercial installations. They are also produced from silicon but has slightly lower levels of efficiency (13-17% efficiency level) as compared to Monocrystalline Silicon PV. They have lower silicon levels hence they are less expensive.
Installation of Solar Panels
Solar panels can be roof-mounted or ground mounted. Ground-mounted roofs are an excellent option for high performance and accessibility, however, they require an extra space in your yard for them to be installed.
While roof-mounted panels remain hugely popular, certain factors need to be taken into consideration to make sure you have the right roof for your panels.
Below are a few of the top factors that determine your roof compatibility with the solar panels.
i. Orientation and Pitch:
This refers to the direction to which your solar panel faces. The direction of your roof may have a large impact on the productivity of your roof-mounted panel. Your solar panel will generate the most energy when it gets many hours of sunlight exposure in a day.
The Pitch or slope of your roof influences the arrangement of your solar panels. A steeper roof makes installation of your solar panels difficult while a flat roof requires additional racking to lift the panel to the right angle.
Contrary to common beliefs, solar panels on flat roofs are more flexible and less expensive systems than those mounted on the ground or pitched roof.
ii. The Roof’s Age
It may be wise to replace your roof if it is quite old before installing a solar panel. Solar panels can last for up to 30 years and having to repair your roof in the next 5 years will result in costs that can otherwise be avoided.
In order to repair your roof, your solar installation company will need to unmount and remount the solar panels, and often, this comes at a charge from your installation company.
To maximize the productivity of your solar panel, your roof should have minimal hours of shading so that your panels get enough direct sunlight.
It may be time to trim a few branches off the surrounding trees to allow more sun to reach your panels.
iv. Your Roof’s Material
A strong roof is more suitable for solar panels to be able to hold the panels weight. Metal roof and composite shingles are generally recommended for ease of solar installation.
Other roofing materials such as clay, slate and wood shake shingles are highly breakable and most installers will shy away from working on these types of roofs.
v. The size of your roof
The more roof space, the more panels you are able to install. Most residential solar panel systems are 5kW hence requires about 20 250-watt panels. That is at least 500 sq feet of roof space since each kW requires a space of at least 100 sq feet.
How many panels do you need?
Most solar energy users have more than one solar panel. The number of panels needed, mostly depends on how much power is needed in your home or business or as we have seen in the previous sections, your roof space, can also determine the maximum panels you can install. This is the same with ground-mounting, the space you have in your yard will determine how many panels you can have installed.
The first step in determining the number of panels is to find out how much power you currently use on an average day. A look at your electric bill can help you figure out your average daily power usage. Once you know your average power use per day, speak to your solar consultant to find out how many panels you will need based on your energy consumption.
Other factors such as the weather in your location play a part in determining the number of panels. Weather affects how much solar radiation reaches the ground. A cloudy day won’t be as productive as a sunny day.
It can be difficult to come up with a straight forward answer. We’d advise you to contact us so that we can survey your plot and provide you with expert recommendations.
How long will they last?
Solar panels generally have a life-span of 25-30 years or more. This does not mean your panels will stop working altogether, it simply means their capacity will be reduced. Solar energy systems degrade at varying rates depending on the brand, as well as the climate where they’re installed.
To make your panels last longer, keep your panels clear of damaging elements such as leaves, dirt, dust, bird droppings etc, will allow your panels to produce optimal solar energy. Consult your solar provider if your panels are obstructed or damaged by any of these elements, unless you have proper training and equipment to clean the panels.
Make sure your solar system receive regular maintenance and check-ups for maximum efficiency of your panel’s performance.
Once the sunlight is converted into solar energy, you need something to store the energy. Batteries come in handy when the sun is not shining as they will provide you with a power supply from the batteries’ storage.
There are batteries specially made for use in solar energy systems. These are recommended for solar power use due to their ability to repeatedly charge and discharge as you use energy.
Types of Batteries used in Solar Power
There are three common types of batteries used in solar energy:
- lead-acid batteries
- lithium-ion batteries and
- flow batteries.
Lead acid batteries have large capacities and have widely been used in renewable energy. They are relatively low cost and a good option for people who want to solely depend on solar energy.
Lithium-ion batteries are a little more expensive than lead-acid batteries. They are ideal for those who want to use solar energy but still remain connected to the power grid.
Flow batteries are the latest option in solar batteries. They have a longer life-span but have a complex chemistry which requires additional energy and cost, thus reducing its current popularity. It is, however, foreseen that the solar energy industry will be leaning towards this type of batteries in the future.
How to Choose your Solar Storage
In choosing the battery for your solar energy storage, other than the price, of course, there are important factors to consider such as battery’s capacity & power ratings, depth of discharge (DoD), round-trip efficiency, warranty, and manufacturer.
i. Capacity & power
Capacity is the total amount of electricity in kilowatt-hours (kWh) that a solar battery can store. Capacity alone is not a good indicator without considering a battery’s power. Power is the amount of electricity that a battery can deliver at a given time measured in kilowatts (kW).
A battery can have a high capacity i.e store enough energy but have a low power i.e you are not able to run a lot of appliances at once. However, this will allow you to run the appliances for a longer period of time.
To get extra capacity, you can stack up multiple batteries in your solar system storage since most batteries are designed to be stackable.
ii. Depth of discharge (DoD)
Most solar batteries have an indication of how much you can use the batteries power before you are required to recharge it. Due to their chemical make-up, solar batteries need to retain some amount of charge at all times.
Using a solar battery beyond the indicated DoD will shorten the battery’s useful life. In choosing a battery, one with a higher DoD will allow you to utilize more of your battery’s capacity before recharging.
iii. Round-trip efficiency
A battery’s round-trip efficiency is the percentage of the energy that can be used out of the amount of energy that went into the battery during charging.
For example, if you fully charge your 5kWh battery but find out that you are only able to use 3kWh out of the 5 kWh, then your battery has a 60% round-trip efficiency.
A battery with a higher round-trip efficiency will get you more usage value out of your battery.
iv. Battery life & warranty
A battery cycle occurs when you charge and drain the battery. The battery’s cycle time will gradually decrease over time. As the battery gets older, it will not be able to hold much of its charge as compared to when it was new.
Solar batteries normally have a warranty that guarantees a certain number of cycles and years of useful life. Some manufacturers may also guarantee that the battery will keep a certain amount of its capacity over the course of its warranty.
There is a wide range of battery manufacturers ranging from automotive companies with a long history of battery manufacturing entering the storage market to tech start-ups which boast new and high performing technology.
Your choice of a battery manufacturer will depend on your preference, whether to go for an old reliable brand that may not have the technical flare in their products or to go for a newer high-tech brand with innovative products.
If it all gets confusing, a look at their warranties can help you make a decision on which manufacturer to go for.
We also do offer solar generators as we have partnered with different vendors across the world to make sure that you get the best quality possible.
C. Charge Controller
The strength of sunlight is not fixed, it varies from time to time. On days where the sun is significantly stronger, there is the possibility that the voltage produced by the solar panels can damage the batteries. A charge controller is required to regulate the battery charging process to prevent damage to the batteries and increase the battery life.
D. Power Inverter
A power inverter can be used in two scenarios. When using a solar-powered source of energy, it is useful in converting the low voltage DC to the 120 volts AC for use in homes and businesses.
When you also use power from a utility grid or an AC generator, you will need an inverter to charge your batteries.
Your choice of an inverter will depend on whether you will be using it solely for solar energy use or you will need to use solar power together with grid power.
E. Solar Panel Mount
In order to install solar panels, you will need a solar panel mount to hold the weight of the panels.
Roof-based solar panels are normally made of aluminium rails lines up at calculated angles to achieve the most potential of sunlight capture. Ground-based solar systems use ground mounts which are typically made of concrete.
F. Utility Meter
If you need to install a solar energy system but need to remain connected to the power grid, you will need a utility meter. The meter is used by power companies to measure and regulate the energy collected by your solar panels.
Did you know?
Solar energy has been used by mankind from as early as the 7th century B.C. While the use was not supported by technological equipment as we do in the modern day, still solar energy was used for heat, cooking, light, and to light fires.
From the 7th Century B.C, ancient Greeks and Romans used magnifying glasses to concentrate the sun’s rays onto fuel and light a fire. In extreme cases, solar energy was used as a war tactic such as the case of the Greek scientist Archimedes who experimented with using the reflectivity of bronze shields to focus sunlight and set fire to enemies’ wooden ships.
While it has taken mankind close to 2,000 years to advance the solar technology, it seems we have come upon a strong candidate for the future of energy in the world.