DAY 27: SOLAR ENERGY; PEAK SUN HOURS EXPLAINED.

Day 27 of #100daysofSolarNuggets

     So we have gone through the basic component of a solar energy system, we’ve discussed solar panels, Inverters, charge controllers and batteries. Before we discuss the nuggets on sizing and designing a solar energy system, there are some basic terminology that we need to introduce and discuss.

We would meet a lot of these terms during the latter part of our nuggets and I believe we should take out time to discuss and understand this terms

The first on our list is PEAK SUN HOURS (PSH)

Peak Sunshine Hours (PSH)

This is simply the number of hours that the Sun’s Irradiance (Power or Energy) from the sun  is averagely equal to 1000w/m². Or in layman terms This is just the length of time when the rays from the sun is strongest, measured in hours.

Why do we use 1000w/m²?  ; This is the standard being used, so you do not need to bother to much about this. 

    The PSH value is very important when designing a solar system, it varies from place to place, so do ensure you get the exact value for your any location you plan to implement.

    Now here I got  the PSH value for Nigeria,

This map represents the yearly average of daily sums of irradiation value for Nigeria.

      From the map we can see that the northern region (the places colored deep red) gets up to an average of 6500watts-hour per m2 per day.

  We divided this value by 1000w/m2 

  6500/1000 = 6.5

This means we have 6 and a half hours when the sun is at it’s best  in the northern region.

 

The places colored blue, gets as low 4000 watts-hour per m2, when we divide that value by 1000w/m2

 4000/1000 = 4

We get only 4 hours of superb sunlight, so when implementing a solar energy system in that region we need to take cognizance of that.

           Now if there is anything you need clarification, please post a comment, or if there is anything you think i might have omitted please do let me know..

DAY 26: INVERTER (TYPES)

     

 Tuesday is finally here and we are back for the second quarter, today we picking up from where we stopped, Types of Inverters.

Enjoy

Day 26 of #100daysofsolarnuggets

Welcome back, today are going to continue from where we stopped on Friday.

Inverters.

We said there were three types of Inverters

.1) STRING INVERTER

.2) MICRO INVERTERS

.3) POWER INVERTERS

Let’s look at the Inverters in detail

.1) CENTRAL INVERTER

This type of inerter is also called string Inverter. This is the most common Inverter type being used.

It is a single (central) Inverter that has all the solar panels connected to it. All the DC Power from all the solar panels are fed into the central Inverter and the Inverter converts it to AC power   for use by the system.

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Features

.1) COST

Of all the Inverter types mentioned, this is least expensive type to deploy.

.2) SHADING

This type of Inverter is also the most susceptible to shading and when this happens the power output from the solar panels decreases.

Since all the panels are connected together in a sequence (series, parallel or maybe both) , If there is shading across any of the panels, the power production of  the affected panel reduces which in turn would reduce the power output of the entire system. #100daysofsolarnuggets

.3) REDUNDANCY

If there is an issue with the Inverter, the entire system would be affected. There is no redundancy in the system.

.2) MICRO INVERTERS

This is a relatively new technology and a lot more efficient then the central Inverter. This type of Inverter is installed on all the panels involved in the system. They are a lot smaller than the central Inverters, they convert the DC power produced by the panels to AC and pass it directly to the system.

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Features

.1) COST

This type of Inverter is quite expensive, since you would be buying Inverters for every single panel being used in your system.

.2) REDUNDANCY

If there is an issue with any of the panels or maybe with a single Inverter, it would not affect the entire system, even in harsh conditions. #100daysofsolarnuggets

.3) EFFICIENCY

This type of Inverter system is very efficient, enabling you get the maximum benefit from your system.

.3) POWER INVERTERS

This type is a compromise between the central Inverter and micro Inverter. The power Inverters are installed on the individual solar panels but they do not completely convert the power from DC to AC, they condition the output from the panels and then send it to the Inverter. The Inverter does the final job of converting to AC.

Features

.1) EFFICIENCY

This Inverter type has a higher efficiency rating compared to the central Inverter but not as much as the micro Inverter.

Power Inverters are a lot more like micro Inverters in features but they are cheaper than micro Inverters.

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DAY: 25 INVERTERS ; THE INTRODUCTION.

Day 25 of #100daysofsolarnuggets

Inverter

Over the course of the program, we’ve discussed on the basic components of a solar system, we have talked about Solar panels, batteries, and charge controllers. 

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Today we would be introducing Inverters.

   Inverters are like the brains of the solar energy system. Their main function is to take D.C. current from the Solar panels or the batteries and convert them to AC current that can be used by our appliance, this is to say that we can’t use our solar system without an Inverter.

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  Things to note.

1.       Inverter does not supply Electric Energy (Power) on it’s own, it merely converts from one form to another (From D.C. to A.C.). The Inverter must be connected to an energy source (Battery) for it to function. If it is not connected to a battery bank it simply cannot be used.

2.       There are inverters and there are Inverter/chargers.

i.                     Inverters: All they can do is to convert D.C. energy from the batteries to A.C. Energy that can be used by our appliances and devices, they do not have inbuilt charges in them to charge the battery bank from an A.C power source.

ii.                   Inverters/charges: They convert D.C. Energy from the batteries to A.C. Energy that can be used by our appliances and devices, they also come with in-built chargers. The chargers enable them to charge the batteries from an A.C. power source (Utility power supply or maybe Generators).

   Inverter/chargers are particularly very useful for solar systems that are also connected to the grid. What this means is that you have the option of charging your batteries with your solar panels and you also have the option of charging your panels with either the utility or your generators.

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3.      Inverter ratings

Inverters are rated in this format 1.5kw 12V, 2.5kw 24V , 6kw 24V,48v and so on

Let me explain in terms of power and voltage..

i.                     Power(Kw)

1.5kw 12V. This means that the maximum power that your system can take is 1.5kw (Please note 1.5Kw is equal to 1500 watts, 1kw =1000watts; kw=Kilo watts).If your system supplies a higher power than yourIinverter capacity, let’s assume 2kw, not only would the extra 500watts of energy be wasted, the higher power could damage your inverter if care is not taken.

ii.                   Voltage(V)

2.5KW 24V.This mean your Inverter works with a 24 Volt system. The voltage rating of the Inverter you buy is depended on the system voltage of your solar system. It is very important that you do not purchase an Inverter with a different voltage rating from your system.

You determine your system voltage from the voltage of your batteries and Solar panels in your solar system.

Some modern Inverters can work with two or more voltage systems for example 7KW 24V, 48V

Now there are three different types of Inverters used in solar installation..

(To be continued).

IMPORTANT NOTICE

This is day 25 and we are through with the first quarter of our online solar class, It has been an interesting journey so far as we have covered the basic of solar energy systems and a few other things.

 Solar Nuggets would be going on a 3 days break, this is to enable everyone that has followed me so far properly revise and understand what we have learnt so far.

 We would resume officially on Tuesday morning as we continue in the second quarter of the online solar class.

Feel free to ask questions concerning any area you do not understand, I would be available to answer any of your questions.