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Top Solar Energy Myths

Ever heard how scientists estimate that more than enough solar energy strikes the earth every hour to power our whole society for an entire year?
But despite the tremendous source of energy staring many of us in the face every day, some keep debating the merits of solar power and other renewable energies, asking the same questions over and over again.

How effective is solar energy?

Is it more expensive?

Where and how does solar fit in the larger energy grid?

Many of the arguments against solar are based on outdated or incorrect information. That’s why we’re setting the record straight on some of the most common solar energy myths.

1. Myth: Solar energy is too expensive and isn’t economically viable for most people.

Fact: The claim that solar energy is too expensive is out-of-date and continues to be proven wrong. The average cost of solar panels fell 75 percent between 2009-2014 alone, and some analysts predict the cost of PV modules will drop 25 percent by 2018. The result is that in many regions around the world and parts of the US, electricity from solar is as cheap – or even cheaper – than electricity from coal, oil, or natural gas.

So it’s no surprise that clean energy is one of the world’s fastest growing industries, and already makes up more than 20 percent of the world’s electricity generation. Bonus: when you use solar energy to do things like power homes or schools, you’re helping protect humans from higher carbon emissions, unnecessary air pollution, and the devastating impacts of climate change.

2. Myth: Carbon dioxide isn’t the main cause of global warming. What about solar variations?

Fact: There is a consensus from 99 percent of climate scientists that human activities are the cause of the global warming we’re seeing now.
Scientists know our climate is changing, primarily due to carbon pollution from the burning of dirty energy like oil, natural gas, and coal. Changes in the radiation the sun emits – known as “solar variation” – affects the climate, too. But scientists take this into account and weigh the contributions these changes make to our climate, which today are minimal to negligible compared to those from carbon pollution. It’s clear that man-made carbon dioxide pollution is overwhelmingly responsible for the global warming we’re experiencing now.

3. Myth: Clean coal is the answer. Why invest in solar when we have clean coal?

Fact: There’s no such thing as “clean coal.” Solar power, on the other hand, is a real, clean energy technology that is viable today.

In reality, “clean coal” is a false solution. Coal is a dirty fuel no matter which way you look at it. The coal mining process blasts away mountaintops and leaves toxic slurry ponds behind. Burning coal results in pollutants that are harmful to human health, like mercury and smog. As if this weren’t enough, worldwide, more carbon pollution comes from the burning of coal than any other fuel.

4. Myth: Solar power isn’t worth it because it won’t work in locations that are cloudy or cold.

Fact: Solar power works even in cold or cloudy places. Because of the way the technology works, solar panels are just as effective—and usually more effective— in cooler temperatures as in hot ones. And while it’s true that clouds can affect the efficiency of solar panels, they can still produce enough power to be viable sources of electricity. Germany, for example, is a country that is not particularly warm or sunny, but is nevertheless the world leader in solar energy.

5. Myth: Solar panels are unreliable.

Fact: The opposite is true. Most solar panels produce electricity for over 20 years or more as their parts do not wear out easily. In fact, many of the first solar systems installed over 40 years ago are still active today.

Additionally, using solar power diversifies our energy sources, making the entire grid more dependable. We have more tools available to make solar and other variable renewable technologies more reliable than ever, such as larger and more integrated grids, better resource forecasting, and more use of energy storage technologies.

The Future:

What will need to be replaced in the next 30 years are aging fossil fuel infrastructures like outdated coal-fired power plants. If we make the switch and rely on renewable sources of energy like the sun, we can save billions of dollars by avoiding not only the costs of replacing these plants, but also the increasingly higher costs of climate change in areas like healthcare expenses and damage from extreme weather.

  • Global solar PV capacity has increased from 3.7 gigawatts in 2004 to 177 gigawatts in 2014. That’s nearly 48x the solar in just 10 years! With so much progress in such a short time, the future of solar power looks bright.
  • Solar power presents shining opportunities. It employs over 2.5 million people around the world!
  • Renewables are the answer to climate change, and a clean energy future is becoming more of a reality every day!

Credit: @Climatereality #ClimateHope

How Energy is Created from the Sun using Solar Panels

The sun supplies more than enough energy to provide earth with all of its energy requirements, but technology is required to harness this energy and convert it into a usable form. Solar panels (photovoltaic modules) are used to do this. Just like the solar panels on rooftops and handheld calculators, even spacecrafts, these solar panels or so-called photovoltaic cells are made of two layers of semiconductor material, usually silicon.

pd pannel

When sunlight hits the solar cells they create an electronic reaction. The voltage produced can drive a direct current with one side of the cell receiving a negative charge and the other receiving a positive charge. When a circuit connects the two sides, an electric charge is formed.

Connecting a number of solar cells electrically to each other and mounting them in a frame make a solar panel (photovoltaic module). The modules are connected together in strings and the direct current generated is carried through wiring to an inverter, which converts the current to alternating current (AC).

 

Source: deaarsolar.co.za

Battery Characteristics - Factors to consider

The choice of batteries possibly the biggest decision to be made if planning a solar power system of any size.
Unless you are looking at a very small system, possibly using a truck battery, upgrading your battery capacity is likely to be difficult and expensive. If you are using a 24 volt battery and decide you need more storage,you will either need to replace the battery for a larger one or connect a second battery of the same size in parallel with the first.
When connecting batteries in parallel however, it is important that the batteries are similar. For this reason it may not be advisable to add to the battery after you have been using the system for a while, by which time there would have been some reduction in battery performance.

Measurement of Battery Capacity

The capacity of a battery or cell is measured in amphours. A 100 amphour battery in theory can supply a current of 1 amp for 100hrs before becoming fully discharged (although a battery should never be discharged below 20% of full capacity, and on a regular daily basis should not be allowed to go below 60% of full capacity)
As the efficiency of a battery, and therefore it's amphour rating varies according to how quickly it is discharged, a standard discharge time is used when quoting a batteries capacity.
If a battery is quoted as having a capacity of 100 amphours (c10), that infers that the it will supply 100 amphours when discharged over a 10 period.
100 amphours (c100) would indicate that the battery will supply 100 amphours when discharged over a 100 hour period. For a particular battery, the c100 rating would be expected to be significantly higher than the c10 rating.

If two batteries are connected in series, the total amphour rating will be same as each individual battery (which should be the same size).
If two batteries are connected in parallel, the total amphour rating will be the sum of that of the two batteries.

Factors Influencing Size of Battery Required

Don't underestimate the size of battery required. It can be frustrating to have a system where the battery size does not give you enough stored electricity to get you through a dull day and also finding that your battery rapidly becomes fully charged on a sunny day and further output from your panels cannot be used.

Factors to Consider:

  •     What is your daily usage in Kw Hours. This is a little tedious to calculate but necessary.
       
  • How reliable is your sunshine - do you generally get clear sun most days or is it much less reliable.
       
  • How long do you expect your system to cope without sunshine.
       
  • Do you also have a wind turbine, and if so, how reliable is the wind.
       
  • How efficient and convenient is your backup system. If you have an efficient diesel generator that starts automatically when required, this will reduce your need for battery storage.

You will also need to consider when you might use any appliances that have a high power requirement. The highest power requirement in a solar powered home may be the washing machine, using something approaching 3 Kw when it is heating water. A battery that is not fully charged may be able to run low energy lighting for many hours but may not be capable of providing 3Kw without the battery voltage dropping to the point that the inverter cuts out for protection.

Drawing a high current causes the battery voltage to drop, possibly returning back to it's original level as soon as the appliance is switched off.
With a larger battery, together with having more electrical power stored, the voltage drop resulting from drawing a particular current level will be less, possibly enabling more of the battery's capacity to be used.

Another fact to consider is that, although we are talking about batteries that are designed for deep cycle use (they are expected to cope being regularly drained and then recharged), the greater depth to which they are discharged, the shorter their life is likely to be. Deep cycle batteries can generally cope with regular discharging down to approximately 60% of their capacity and occasional discharging down to 20%.
Therefore, all else being equal, a larger capacity battery should have a longer life.

Credit: solar-facts.com

 

 

Battery Bank Tutorial - Series and Parallel

What is a bank of batteries? No, it's not some kind of financial battery establishment. A battery bank is the result of joining two or more batteries together for a single application. What does this accomplish? Well, by connecting batteries, you can increase the voltage or amperage, or both. When you need more power, instead of getting yourself a massive super tanker of a battery, you can construct a battery bank.

The first thing you need to know is that there are 2 ways to successfully connect two or more batteries. The first is Series and the second is Parallel. Lets start with Series

Series
Series adds the voltage of the two batteries, but keeps the same amperage rating (also known as Amp Hours). For example, these two 6 Volt batteries joined in series now produce 12 Volts, but still have a total capacity of 10 Amps.

To connect batteries in a series, use a jumper wire to connect the negative terminal of the first battery to the positive terminal of the second battery. Use another set of cables to connect the open positive and negative terminals to your application.

Never cross the remaining open positive and open negative terminals with each other, as this will short circuit the batteries and cause damage or injury.

It is best to be sure the batteries you're connecting have the same voltage and capacity rating. Otherwise, you may end up with charging problems, and shortened battery life.

Parallel
The other type of connection is Parallel. Parallel connections will increase your current rating, but the voltage will stay the same. In the diagram above, we're back to 6 Volts, but the Amps increase to 20. It's important to note that because the amperage of the batteries increased, you may need a heavier duty cable to avoid the cables burning out.

To join batteries in parallel, use a set of cables to connect both the positive terminals and another set of cables to connect both the negative terminals of both batteries to each other. Negative to negative and positive to positive. You then connect your load to ONE of the batteries, but both drain equally.

It is also possible to connect batteries in what is called a Series/Parallel configuration This may sound confusing, but we will explain below. This is the way you can increase your voltage output and current rating. To do this successfully, you need at least 4 batteries

Series Parallel

If you have two sets of batteries already connected in parallel, you can join them together to form a series. In the diagram above, we have a bank that produces 12 Volts and has 20 Amp Hours.

Don't get lost now. Remember, electricity flows through a parallel connection just the same as it does in a single battery. It can't tell the difference. Therefore, you can connect two parallel connections in a series as you would two batteries. Only one cable is needed, a bridge between a positive terminal from one parallel bank to a negative terminal from the other parallel bank.

It's alright if a terminal has more than one cable connected to it. It is necessary to successfully construct these kinds of battery banks.

In theory, you can connect as many batteries together as you want. But when you start to construct a tangled mess of batteries and cables, it can be very confusing, and confusion can be dangerous. Keep in mind the requirements for your application, and stick to them. Also, use batteries of the same capabilities. Avoid mixing and matching battery sizes wherever possible

Always remember to be safe, and keep track of your connections. If it helps, make a diagram of your battery banks before attempting to construct them. Good luck!

Credit: batterystuff.com

 

 

vfsvWhat is a bank of batteries? No, it's not some kind of financial battery establishment. A battery bank is the result of joining two or more batteries together for a single application. What does this accomplish? Well, by connecting batteries, you can increase the voltage or amperage, or both. When you need more power, instead of getting yourself a massive super tanker of a battery, you can construct a battery bank.

The first thing you need to know is that there are 2 ways to successfully connect two or more batteries. The first is Series and the second is Parallel. Lets start with Series

- See more at: https://www.batterystuff.com/kb/articles/battery-articles/battery-bank-tutorial.html#sthash.GiX3sDKo.dpuf

What is a bank of batteries? No, it's not some kind of financial battery establishment. A battery bank is the result of joining two or more batteries together for a single application. What does this accomplish? Well, by connecting batteries, you can increase the voltage or amperage, or both. When you need more power, instead of getting yourself a massive super tanker of a battery, you can construct a battery bank.

The first thing you need to know is that there are 2 ways to successfully connect two or more batteries. The first is Series and the second is Parallel. Lets start with Series

- See more at: https://www.batterystuff.com/kb/articles/battery-articles/battery-bank-tutorial.html#sthash.GiX3sDKo.dpuf