Last time we only powered a single light bulb. Now we are powering more lights, IP cameras and CCTVs.

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Automatic Porch Light
using Solar Power.

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Objective
• Having a porch light that switches on at dusk
and switches off at dawn, automatically.
• Powered by a single solar panel.

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Item 1 – Solar panel 12V 10W
• https://www.lazada.com.my/12v-10w-watt-
polycrystalline-cells-solar-panel-poly-solar-
module-battery-charger-13254147.html
• RM93

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Cheaper – Solar panel 12V 10W
• http://www.lazada.com.my/10-watt-10w-
polycrystalline-solar-panel-12v-ready-stock-
28045065.html
• RM76 – no longer available

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Item 2 – Solar Charge Controller
• https://www.lazada.com.my/dual-usb-pwm-
102030a-solar-charge-controller-12v24v-lcd-
displaysolar-panel-charge-regulator-
models10a-83267837.html
• RM34.70

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Item 3 – 12V 7.2Ah GP Battery
• https://www.lazada.com.my/genuine-gp-12v-
72ah-rechargeable-sealed-lead-acid-battery-
gpp1272-29285514.html
• RM60

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Item 4 – 12V White Light Bulb
• https://www.lazada.com.my/e27-5w-6000k-
led-bulbs-lamp-for-dc-12vwhite-light-
101540546.html
• RM14.20

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Cost
Items Price
Solar panel 12V 10W RM93.00
Solar charge controller RM34.70
GP 12V 7.2Ah Battery RM60.00
12V DC White Light Bulb RM14.20
TOTAL RM201.90
• Not inclusive of labour,
wiring, conduit &
installation charges.

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Calculating The Load
Power for Bulb 12V 5W
• Dusk to dawn = 12 hours.
• 12 hours x 5 Watt = 60WH.
Storage for 12V 7.2Ah Battery
• 7.2Ah x 12V = 86.4WH
• Being a sealed lead acid
battery, you get only 50% of
that power.
• 86.4WH x 0.5 = 43.2WH
(<60WH; inadequate)
• Light were out by around 1am.
https://www.lazada.com.my/
genuine-gp-12v-12ah-
rechargeable-sealed-lead-acid-
battery-gpp12120-
96324854.html (RM129.50)
Power from Panel 12V 10W
• Dawn to dusk = 12 hours.
• Kuala Lumpur Daily Daylight
Average = 6 hours
• 6 hours x 10 Watt = 60WH.
• So 1 solar panel 12V10W
can generate enough power
for one 12V5W bulb.

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The Installation
Solar panel on
roof top.
Wiring from
solar panel to
solar charge
controller.
Solar charge controller.
Solar charge controller.
12V bulb
12V battery

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Connecting Everything – Step 1
1. Connect battery to
solar charge controller.
It will detect the type
of battery.

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Connecting Everything – Step 2
2. Connect solar
panel to solar
charge controller.
It will detect the
type of solar
panel.

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Connecting Everything – Step 3
3. Connect light
bulb to solar
charge controller.

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Connecting Everything – Step 4
4. Click on this
button 4x until
you get this work
mode display.

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Connecting Everything – Step 5
5. Then press on
this button for 5
seconds until it
starts blinking.

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Connecting Everything – Step 6
6. Then click on this + button
once so that it displays “00”.
Then the light will switch on
from dusk to dawn. “24” means
that it will be on 24 hours. You
can set from “00” to “24”.

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Connecting Everything – Step 7
7. Then click on this
button once to save
the setting. Now
you’re done.

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Conclusion
• As expected I couldn’t get the light to run from
dusk to dawn due to the wrong capacity of the
battery and solar panel. I should have bought a
larger battery and a larger solar panel. Wrong
advice received.
• I should cover back the cost of my investment
within 100 days of use. It should last for 2 years.
• The light was bright enough to illuminate the
porch.

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July 2018 – An Update

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Cost of new setup
Items Price
Solar panel 36V 250W RM859.00
2x solar panel 12V 10W (old) RM186.00
Solar charge controller (old) RM34.70
Solar charge controller (new) RM279.00
wifi dongle RM89.00
DC24v stepdown to DC12V RM51.42
1xCentury 12V 60Ah Battery RM215.00
4x12V DC White Light Bulb RM56.80
Power cable RM69.00
TOTAL RM1832.92
• Not inclusive of labour,
wiring, pergola, conduit
& installation charges.
Wifi dongle
allows for remote
monitoring and
control of solar
controller via wifi.

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Current Layout
x2
x8
x4

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Why 2 solar controllers?
• The CCTV needs to run 24/7. The power came
from the Epever Tracer 3210A controller.
• The lights need to come on at dusk and switch
off at sunrise. The power came from the old
PWM controller.
• The IP cameras need the USB ports. So the
power came from the old PWM controller.

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Calculating The Load
Generation
Power from 30V 250W Panel
• 6 hours x 250 Watt = 1500WH.
Power from 2x12V 10W Panel
• 2 x 6 hours x 10 Watt = 120WH
Usage
Power for 4 Bulbs 12V 5W
• 4 x 12 hours x 5W = 240WH
Power for 8 CCTVs 12V 0.5A
• 12V x 0.5A x 24Hx 8
=1152WH
Power for 2 IP Cams 5V1A
• 5V x 1A x 24H x 2 = 240WH
Storage 24V 60Ah Battery
• 60Ah x 24V = 1440WH
Conclusion (just nice)
Generate = 1620WH
Store = 1440WH
Load = 1632WH

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The New Installation
Solar panel on
pergola.
Wiring from
solar panel to
solar charge
controller.
Solar charge controller.
12V bulbs
12V batteries

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The New Installation
Voltage from
solar panel to
solar charge
controller.
CCTV power distributor
12V bulbs
wires from battery

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How much did I save?
• 1620Wh x 30 = 48.6kWh
• Since my bill hovers around
RM200, then the price per kWh is
RM0.516. Therefore
48.6x0.516=RM25.08 per month.
• So it will be 6 years before I get
back my investment.
Cum kWh Block kWh Per kWh Total RM Cum RM
200 200 RM0.218 RM43.60 RM43.60
300 100 RM0.334 RM33.40 RM77.00
600 300 RM0.516 RM154.80 RM231.80
900 300 RM0.546 RM163.80 RM395.60
901 1 RM0.571 RM0.57 RM396.17

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Conclusion: Solar = Expensive Hobby
One of the two IP cameras
supported by solar power