INTRODUCTION:
Solar Measurement Parameters: Measurement must put ahead in every aspect of engineering work solar energy was not exempted. There are parameters need to be observed for proper and accurate solar radiation, location and direction. Before installing solar electricity the following parameters need to be observed.
It gives you details view where to installed PVC for high radiation collection, which produces the high output.
Solar Constant:
Is the amount of solar rays received per unit time of collector area, at the mean distance of the earth from the sun on a surface, normal to the sun. It is expressed in Cm2 /min.
Irradiance:
Define as the amount of solar energy felled on a surface or total amount of energy passing through an area. This gives a hint of how much of solar energy is present for the collector in an area.
In solution:
Is refers to solar irradiance received on a horizontal surface, such as the ground solar flux.
Is the sun trine at an angle?
Example:
Find the irradiance of a 9500kg of sunlight striking a 1m2 surface in 2 hours. The irradiance at any points on the surface is given by.
Irr = 9500/m2 x 2 x3600 = 6.84x104 Kw/m2.
How can the above solar parameter be observed? By using an instrument designed to carry out the solar observation. Some instrument will be discussed below:
The pyranometer:
Is an instrument used to measure the total flux? From the direct rays, as well as the rays scattered by the entire hemisphere viewed by the instrument.
Note: total flux is sola called Global flux.
Shading Range Pyranometer:
Is an instrument that records only solar flare excluding direct sunlight that his scattered component of the sunlight, so that when this record is subtracted from the reading of standard pyranometer, the result is a measure of direct solar flux.
Pyranometer
It refers to an instrument used to measure, direct solar flux plies and a very small amount of sky included in its field. It is mounted in a manner; it can track the daily and seasonal motion of the sun.
Moving Shadow- Bar Pyrheliometer: It used to measures both direct scattered and total isolation. It was a moving shadow bar to modulate the incoming direct component of sunlight.
Sunshine Recorder: Is a device designed to records the capacity of sunstone at a per specific region, with the aimed to give the suitable location for solar energy production for powering electrical devices.
Sunshine Recorder:
It comprises glass sphere keep in a spherical bow I together with a metallic groove which keeps the record card. Sun rays refracted and focused accurately on the record card under the glass sphere, making burnt signs on the card. To measure sunshine duration, length of the burnt signs has to be observed, the card is calibrated to allow measuring hours and minute of the day.
The sunshine recorder glass sphere was silvered inside and was put before the camera lens while the axis of the device is being placed parallel to the earth's polar axis. It used double convex lens about 90mm.
Operation of pyranometer:
It consists of Thermopylae which makes it small less heavy low cost and continues generating of voltage output, and it is an active device because it does not require any external source control.
It operates by detection of incoming solar radiation and totally received by a horizontal dark surface, over a huge wavelength range. This makes an increase in of temperature that measured via thermocouples join in series. It consists of the hot junction that collects radiation and passive (cold) junction that serves as a heat sink.
The higher performance pyranometer is made up thermoelectric with two dissimilar semiconductors devices.
Temperature and heat are they similar?
No, the temperature is the measure of the degree of hotness or coldness of the body while heat means a total energy of molecular motion in a matter it depends on the speed of the molecules cooled cosmos. IPAC. Catechu temperature scale.
Ok = 273.15 + OC
OF = (5/9) x (OF -32)
OC = (9/5) x OC +32
To know the energy you will utilize over a period of time multiply power by hour example 40W, 2Hour is 40 x 2= 80WH.
Solar Power Introduction:
The world experiencing consequences of climate change which seriously affecting human resources.
As are a salt of this, now a lot of countries are investing in solar energy to overcome the effect of climate change. This led to manufacturing the electric car, solar vehicles and so many electronic devices such as mobile phone and calculates. Field of electrical wiring also not left behind in a small explanation.
What is the component you need for solar election there is a lot of components, procedure and guides line to installed solar power in our homes firstly, there is a need for the solar panel, which has the photocell, that accepts solar rays, radiation as a Direct current (DC) source, it can be used inverter before they use solar power.
Before mounting the solar panel, you must estimate the load required in your resident. This will give how many solar panels require to meet require load in the residential building.
Suppose, you want to supply solar electricity to power 20buibs of 15w and you need, to use it for 6 hours daily.
Solution
P total = 15x20 = 300w
P daily = 300x 6 = 1800w
Assuming 6 hours/ day of sunshine each day therefore, hourly = 1800/6 = 300W
Despite the effort of giant countries, to invest in advancing research in renewable energy such as solar energy up to now the components are expensive, but we hope few years ahead, everybody can benefit with solar electric everywhere in the world.
Factors must be observed before installing the solar panel that is solar array configuration.
Solar valuation.
Site Location
Availability of solar ray's radiation.
Collector
Tracking and other met logical conditions solar photovoltaic cell power generation profile.
Temperature
Wind
Moisture
Relative humidity,
I hope we are together we still talking about solar panel only this is the sign of solar electricity consist of a lot of procedures before it reaches final subcircuit, be patient just follow us. Also, there is a solar array configuration as follows.
Series connection for grid-connected inventor or 24v
Parallel connection. Charge controller
V1
V2
V3
PVC PVC PVC
Series solar panel connection gives out high voltage, which current will be the same, as following At its output two terminals are observed.
V. VT = V1 + V2 + V3.
Parallel solar panel connection. It gives out high current, and it has two parallel terminals, one for a started panel other for another end as follows:
Diodes used to block reverse voltage to the solar panel in the dark condition.
Note:
Series connection arrangement positive connected to negative of next panel and negative terminals to another panel terminal (positive).
Parallel connection arrangement:
Positive to positive of next solar panel and negative to negative of next solar panel. On the solar panel, there is a diode that prevents returning back of the energy stored by the backup batteries at night because diode was a unidirectional component.
Also among the solar power components, we have array DC Disconnect is used to disconnect solar power delivery from solar panels.
System meter. It was responsible for monitoring utilized and remaining with your system. This can give hint, how to manage your energy. Charge controller (C.C).
It controlled the batteries from overcharging, which can easily make it weak within a short period. It also blocks delivery of battery charge at certain, point, battery charge from reaching empty level charge controller has it's upper voltage limit depend on the rating of charge controller make sure you did not exceed upper voltage limit to avoid burning it. It consists of different voltage rating such as 12v, 24v. 48v and 6-60v. Also, it has 1-6A. To calculate it 3 powers: watt/ volts. An e.g. 900w/24v = 37. 5+25%
25% stand as tolerance or surplus, do not just use exact value.Backup Battery:
Is used for backup purposes it is clear during night or darkness, the solar cell cannot deliver DC source to the connected load battery is used to stored energy and can utilize it in the absence of sunshine, it can be converted to AC battery rated as Ampere hour (AH)
Volt X AH/100 = Watt Hours
24V X 210AH/100= 50.4WH
Inverted: is an electronic device designed to change direct current (DC) to Alternating current (AC). It receives the voltage from batteries and inverts output to AC. It has its power source to carry-out its operation.
The rating of the inverter, depending on the design of the load to power it. It rated in KVA like 16KVA and it produces sine were output or pulse width modulation.
Most AC motors use modified sine wave it has the standard frequency of either 50H2 or 60H2 AC output voltages is 240VAC at the distribution level the duration of an inverter can prolong by adding many batteries. Also increasing more equipment within inverter rating decrease running time of the inverter, this is opposite generator operation.
Procedure for adding batteries to inverter there is two basic types of connection of batteries
Series connection
Parallel connection
Series connection, the voltage will be high while the amperage remains the same.
Merit:
It gives a high output voltage.
Demerit:
It one battery dies, other can not de live output to an inverter.
Regular change of death battery.
Parallel connection of batteries; it produces additional ampere-hour (ah) rating of the battery the voltage remains constant.
Deficiency
If one battery discharges the other batteries will also discharge through it.
This lead to the fast discharge of the battery bank.
It leads to overcurrent within battery pack its cause fire outbreak
The remedy of the Deficiency
Diodes can be used to isolate the discharged battery from affecting others batteries.
Automatic southing can also use to isolate discharged battery.
Application of Inverter:
It converts DC from either batteries or fuel cell to AC power.
It uses as uninterruptible power supplies (ups)
It rectifier AC to DC.
It used an electric motor speed control
It used as inverter compressors in the refrigerator or air conditioner, to regulate system performance
It used as grid-tied inverters.
Under solar panel series connection:
What will happen, if the solar panel with distinct nominal voltage connected but with the same concentrating?
Suppose we have 3 solar panels in series with distinct nominal voltage, 7,9,10 the array delivers 26 volts at 3.0A, or 26x 3 = 78w.
What will be the result, if solar panels connected in series with distinct nominal voltage and distinct current rating?
In this case, the amperage output will be the same with the least rating of the solar panel, which lead to reduce in arrays efficiency. This is just a way of resources.
Parallel solar panel connection, if all the panels have the nominal voltage rating e.g. 6 volts and identical 4. 0A, the amperage output of the solar panels will increase which voltage remain Constance.
If solar panels connected in parallel form, with different nominal voltage and distinct current rating, it will give output according to the lowest voltage panel, this leads to a huge reduction of solar panel output in short form a series connection produces high voltage output and constant amperage within the whole connection.
But parallel connection produces huge current output and constant voltage within the whole connection.
Example:
A Series Parallel solar Amoy comprises 4 rows 5 column of the solar panel each rated 25v and 5A are connected to charge a bank of solar batteries.
Find the output current, voltage, and power.
Assuming 255AH capacity battery was charged by solar Energy,
how long it takes the battery to change?
ii. Who can long battery deliver 5A constantly to a load?
Solution:
Data
Voltages: 25v/4 raws
Current: 3A/5column
P total=?
V total= V1 + V2 + V3 + V4
= 25+25+25+25
= 50+50
= 100V
I total = I1 + I2+ I3 + I4 + I5
= 5+5+5+5+5+5
= 15+15
= 304
P total = VT IT
= 100x 30
= 3000w
= 3.0kw
How long batteries take to charge with 255AH?
255AH/30A= 8. 5 Hrs
How long battery powered load 5A?
Series-parallel connection.
References:
www.hko.gov.hk
www.pvcdrom.pveducation.org
www.kippzone.com
