PHOTOVOLTAIC SOLAR ENERGY TRAINER DL SOLAR-D1 Manual

Transcription

1 PHOTOVOLTAIC SOLAR ENERGY TRAINER DL SOLAR-D1 Manual

2 DL SOLAR-D1 Contents 1. Solar energy: our commitment 5 to the environment 1.1. Basic principles and concepts 6 Mechanical work, energy and power: 6 definitions, laws and units Transformation of mechanical energy 7 History of energy-conversion technology 8 Electrical energy and power: definitions 8 and units Heat energy: definitions and units Energy from the Sun Electricity directly from the Sun 15 Photovoltaic effect and photovoltaic cells: 15 history and definitions How does a photovoltaic cell work Solar energy received on land 16 surface Positioning of solar panels 16 Standard Test Conditions (STC) and its 21 ap lication 1.5. Characteristics of a solar cell DL SOLAR D Basics of the Solar Trainer Identification of the components of the 26 trainer Current, voltage and power measurements 42 Exercise 1: Measuring the mains voltage 44 Exercise 2: Measuring the load current, 44 voltage, power and energy 2.2. Irradiation and Temperature 47 Measurements Exercise 1: Setting the solar panel to the 48 most irradiated position Exercise 2: Changing the inclination of the 49 solar panel Exercise 3: Changing the azimuth of the 50 solar panel Exercise 4: Covering the solar panel with 51 different materials 2.3. Solar Irradiation throughout the 52 Day Exercise 1: Obtaining the solar irradiation 52 data 2.4. Solar Panel Voltage-Irradiation 56 Curve, Current-Irradiation Curve and Resistance of the Solar Panel Exercise 1: Obtaining the solar panel 56 voltage-irradiation curve Exercise 2: Calculating the inner 58 resistance of the solar panel 2.5. Current-Voltage Characteristics of 60 the Solar Panel Exercise 1: Obtaining the solar panel 61 current-voltage curve 2.6. Solar Panel Electricity Delivered to 67 the Mains Grid Exercise 1: Measuring the electricity 68 delivered to the mains grid 2.7. Solar Panel Supplying Load 72 Exercise 1: Measuring the electricity 74 produced by the solar panel and delivered/taken from the mains grid Exercise 2: Measuring the electricity 77 produced by the solar panel, delivered/ taken from the mains grid, and the loading of DL 9017 lamps Appendix 82 Index 84

3 1 to Solar energy: our commitment the environment Basic principles and concepts Energy from the Sun Electricity directly from the Sun Solar energy received on land surface Characteristics of a solar cell

4 1 Key words 1.4. Solar energy received on land surface Positioning of solar panels a) In northern hemisphere, solar panel should be oriented towards the south (S). b) In southern hemisphere, solar panel should be oriented towards the north (N). This is known under name of azimuth. In an ideal case, on the northern hemisphere an azimuth should be changed from south-east in the morning to south-west in the ev ning tracking the path of the Sun trough the day. includes both, azimuth and angle of inclination, represented by and angle of latitude below. Optimal angle of inclination (α) is equal to latitude Solar panel is positioned in point A oriented to the north on the earth surface under angle of 0, parallel with the earth surface. Sun rays target to point on the panel surface under the angle 120. This is far away from ideal angle of 90. How can we correct this value? Obviously, we have to decre se it, as shown in figure below. = Orientation from north (N) to south (S) in northern hemisphere Orientation from south (S) to north (N) in southern hemisphere Angle of inclination in fact is the latitude of a point A where the solar panel is placed Inclination and azimuth of solar panel in northern hemisphere Inclination and azimuth of solar panel in southern hemisphere. 16 DL SOLAR-D1

5 Solar system. The Earth has third position from the Sun. Notice: all planets rotate around the Sun on the same plane, named plane of the Ecliptic Oscilation Earth axis around the cone. Summer on the north hemisphere. Unfortunatly, the Earth does not rotate around its axis perpendicular to the plane of the Ecliptic. Its axis is incli $ %& & '* +# Earth axis is inclined under average angle of Changing of sezons through the year is due to oscilati /0 1 2! 304! 30"5 6! 304 & Sun rays target the Arctic area (N) under the angle. At the same time, the Antarctic area (S) is hiden in the shade. 6! 30" 1 Sun rays target the Antarctic area (S) under the angle. At the same time, the Arctic area (N) is hiden in the shade. 7 & 1 ning an optimal angle of solar panel. Fortunately, an answer is very simple. The explanation is provided on the next page. Interesting facts TDJMMBUJPO &BSUI BYJT BSPVOE UIF DPOF 8JOUFS PO UIF OPSUI hemisphere. In geography, the latitude of a location on the Earth is the angular distance of that location south or north of the Equator. The latitude is an angle, and is usually measured in degrees (marked with ). The equator has a latitude of 0, the North pole has a latitude of 90 north (written 90 N), and the South pole has a latitude of 90 south (written 90 S). Solar energy: our commitment to the environment 17

6 1 :! 30!! 30!! ; < Sun rays target equator (B) under same angles, J Bs and J Bw, during the summer and winter periods. This is the explanation why we have the same weather in equatorial area in all sezons. Compare angles J As and J Aw between Earth surface and sun rays. J As < J Aw This means that the sun rays target point A under angle # 6 < rays target point A in the winter under angle far from # Because of that, we have to correct conclusion from previous page Summer on the north hemisphere Optimal angle of inclination (α) is equal to latitude corrected with corrective angle. : & & & * These values depend on latitude and season. is represented by the 8 &!" # Latitude!+# '+# '+# * # * # *+# *+# 3 # 3 # JOUFS PO UIF OPSUI IFNJTQIFSF Table-3 Corrective angles 18 DL SOLAR-D1 In Winter In Summer # # 8+# 9+# 8! # 9! # 8!+# 9!+# 8' # 9' #

7 1 Example 7 - a) during the winter season Result: b) during the sommer season w corrective angle w w corrective angle s s s Interesting facts Described determination of ideal panel orientation with azimuth 180 strictly to the south on the northern hemisphere and to the north on the southern hemisphere is suitable for the panels installed on the fixed objects, for example roofs, like in example 7. Twice in the year we have to adjust angle of latitude depending on the season using values from the table 3, corrective angles. But can we determinate the orientation of moveble objects? Take a look at the picture right. From our own experience we know: The Sun heats on the best way if we turn strictly against it. Early in the morrning azimuth is less then 180 and panel is oriented almost to the east against the Sun. In the noon azimuth is equal 180 and panel is oriented strictly to the south against the Sun. Finally, in the ev ning, azimuth is great then 180 and panel is oriented almost to the west against the Sun. Simply, the best orientation of the panel is Solar energy: our commitment to the environment 19

8 1 R h 2 ] R i 2 ] Januar 54 February March 94 April May 158 June July August September 111 October November 54 December Annual sum 1179 Table-4 Monthly ir adiation for the panel positioned horizonta ly (R h ) and inclinated (R i ) Example 8 Imagine your home somewhere in Central Europe on the latitude 2 a) positioned horizontal y b) positioned under the best angle a 2 R h = 158 kwh/m 2 R i 2 a) E h b) E i c) E i E h Result: a) E h = R h a E h = 158 kwh/m 2 2 E h = 474 kwh b) E i = R i a E i 2 2 E i c) E i E h E i E h = 6 kwh Dailly sum of global irradiation per month R h - hori onta ly positi ned panel (α = 0 ) R i - panel positi ned optimal y under angle of inclination (α = 36 ) 20 DL SOLAR-D1

9 1 Standard Test Conditions (STC) and its ap lication 2 These conditions are optimum and seldom experienced other than for a few hours at midday in very sunny regions, especially at higher altitudes. Hence it is also called peak power. Sun peak hours 2. For example, six peak sun hours means that the energy received during total daylight hours equals the energy that would have been received if the irradiance had been 1 kw/m 2 for six hours annual average sun s peak hours h p - peak sun hours [h] Sun peak hours within a 24-hour day Solar energy: our commitment to the environment 21

10 1 Example 9 2 large photovoltaic panel per day in southern Spain. This panel is label ed by manufacturer 5.7 kw peak power. How much energy can we produce using P p = 5.7 kw Result: h p a 2 E d E y E d = P p h p E d E d = kwh/per day E y = E d E y = kwh/per day E y = kwh R 2 an ual y a 2 Result: E ty = R a E ty = 2 2 E ty Ey = 100 E ty = = % Example 10 one kwh in France is US cents. P p = 5.7 kw Result: h p = 2.5 h price = US cent/kwh S E d = P p h p E d = 5.7 kw 2.5 h E d = kwh/per day E y = E d E y = kwh/per day E y S = E y price S S S 22 DL SOLAR-D1

11 2 DL SOLAR D Basics of the Solar Trainer Irradiation and Temperature Measurements Solar Irradiation throughout the Day Solar Panel Voltage-Irradiation Curve, Current-Irradiation Curve and Resistance of the Solar Panel Current-Voltage Characteristics of the Solar Panel Solar Panel Electricity Delivered to the Mains Grid Solar Panel Supplying Load

12 2.6. Solar Panel Electricity Delivered to the Mains Grid Objective of the exercise Measure the electricity delivered to the mains grid. Required equipment Introductory examples If the grid tie converter uses 2 W of electricity, how much electricity 2 Calculation area: Calculation area: DL SOLAR D1 67

13 2 5. If the solar panel with capacity 2 kw has 2 Sun peak hours daily in ave- Calculation area: Exercise 1: Measuring the electricity delivered to the mains grid Note * If PV panel produces no power then DL9013G takes power from the grid Circuit diagram of exercise 1 68 DL SOLAR-D1

14 2 Note DL 9021 module contains AC wattmeter, and solar panel produce DC power. Therefore, we can not measure the solar panel power directly. The power is calculated by multiplying voltage and current measured with DL 9021 module Connection scheme of exercise 1 Irradiation (W/m 2 ) Current (A) Voltage (V) Delivered electricity (W) 1. Find the position in which the solar panel provides highest irradiation. the mains grid. the table DL SOLAR D1 69

15 2 6. Draw the delivered electricity-irradiation graph. 70 DL SOLAR-D1

16 2 Questions for evaluation - 2. If the subsidized price of electricity produced by the solar panel is Calculation area: DL SOLAR D1 71