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classradiance

Gods Light

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It is said that just 100 square miles of Solar Panels could deliver enough Electricity to meet Global demand !!

 

Here is the Math for a system if you ever need it, for your own needs as a family.

Start out with just 1 Light when calculating and then add more later when you get used to what you are actually doing.

Basic Electronics Theory is required along with knowledge of Safe Battery Storage and Handling.

Remember that a 12V Car Battery can cause fire if not handled correctly, study safe practice first to easily avoid problems.

 

The same principles as charging a car battery whilst driving where instead of an Alternator you have a Solar Panel.

 

The Solar Panel cables go into a small box called a Charge Controller, which supplies the correct Power to the Battery and then allows an LED Light circuit to go active when the Sun Light drops.

 

woohoo.gif

 

 

Calculations for Home / Boat / Caravan / Shed

1.Add up the hours that each light will be on for to get the Total of Energy Consumed.

2.From that you can Calculate everything you need IE: Solar Panel / Battery / Regulator

------------------------------------------

 

My Calculations

3 Zones (ROOMS)

1 X LED SPOT @ 10W + 2 x LED FLOOD @ 15W

on for (SEE CHART) hours per night

...................

 

-Watt/Hour Chart- - Only ever use 12 volt LED lights -

 

3 Room scenario

 

kitchen/Diner 15W on when required daily average use -- 3 hours = 45wh

Bedroom 10W on when required daily average use - 2 hours = 20wh

front Room 15W on when required daily average use - 8 hours = 120wh

 

Total usage per night in Winter = 185wh/d

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-Load and Battery -

 

House Lights Consumption = 185Wh

185 watt-hours divided by 12 volts = 15.42 amphours taken from system in 1 night

 

Because we can only use half the energy in a lead acid battery without harming the battery,

the minimum battery size is 15.42 amps x 2 = 30.84 amp hours.

the minimum battery size is 15.42 amps x 2 = 30.84 amp hours

or 15.42ah / .5(50%) = 30.84ah or 15.42ah / .3 (30%) = 51.4ah or 15.42ah / .2 (20%) = 77.1ah, choose what calculation will be best for your battery !!

10% discharge

 

I want my system to be reliable if we have four consecutive days of cloudy weather,

4 days of autonomy x 30.84 = 123.36 amp hours for the battery. = 124 + amp hour battery

(Required Battery Bank = 1 x 130 Ah True Deep Cycle

 

 

-------------------------------------------------------------------------------------------

 

-Charging Battery from Panel-

This installation is in a location that gets 5 hours of full sun per day.

Check the charts for this depending on the month in the Season.

To recharge the battery for one day of use we need 30.84 amps in 5 hours = 30.84 / 5 = 6.17 amps from a 12 volt solar panel array.

------------------------------------------------------------------------------------------------------------------------

 

-Solar Panel -

Most load calculations include a discount factor for the inefficiency of recharging the battery.

20% is typical. 6.17 / 0.8 = 7.71 amps.

 

A single 140W solar array that has an Impp (amps maximum power point) of 7.7A would be suitable

 

------------------------------------------------------------------------------------------

 

-Charge Controller Rating in AMPS-

The 140W solar array has a short circuit amp rating (Isc) of 8.2A 8.2A x 1.25 = 10.25A

use a 10.3A or larger charge controller with this array to charge the battery.

 

Cheap example - 20A Unit

For best efficiency to charge use an MPPT Type.

------------------------------------------------------------------------------------------

 

- estimated Cost of mentioned Materials - 20 years / $450. = $500./240 months = £2.08 month = .52 per week ....wow

 

Have seen 140w poly panel on Net for $170 inc delivery

Have seen 130Ah Varta Leisure Battery 12V 130Ah for around $150 inc delivery

20A Charge controller $20 - $60 - mppt prefered of course

3 QUALITY External (For in or out & VERY BRIGHT) LED Lights 2 x 15w/1 x 10w = $60

100m of .75mm twin and earth from wholesalers = $30

Mounting Bracket for Panel = $20

 

Estimated Total = $500ish

 

Also required - Fuse box / switches / bits ..

 

 

-----------------------------------------------------------------------------------------

-Solar Panel specification-

STK-140P6-A ...... manufactured by 3E

Related power

140W

Open circuit voltage Voc(V)

23V

Short-circuit current Isc(A)

8.2A

Optimum operation voltage Vmp(V)

18.3V

Optimum operation current Imp(A)

7.7A

.......................

 

Thanks to everyone who places information out there on the WEB

Hope the above can inspire you.

Not mentioned above are Switches, Inverters, Distribution, Heating, Health & Safety,

etc ... Caution -12V Batteries can Cause Fire if not Fused or Stored Correctly-

 

- Battery info -

 

Deep cycle batteries are designed to be discharged down as much as 80% time after time,

and have much thicker plates. The major difference between a true deep cycle battery

and others is that the plates are SOLID Lead plates - not sponge. This gives less surface

area, thus less "instant" power like starting batteries need. Although these can be cycled

down to 20% charge, the best lifespan vs cost method is to keep the average cycle at about

50% discharge.

 

Battery life is directly related to how deep the battery is cycled each time.

If a battery is discharged to 50% every day, it will last about twice as long

as if it is cycled to 80% DOD. If cycled only 10% DOD, it will last about 5 times

as long as one cycled to 50%. Obviously, there are some practical limitations on this

- you don't usually want to have a 5 ton pile of batteries sitting there just to reduce

the DOD. The most practical number to use is 50% DOD on a regular basis. This does NOT mean

you cannot go to 80% once in a while. It's just that when designing a system when you have

some idea of the loads, you should figure on an average DOD of around 50% for the best storage

vs cost factor. Also, there is an upper limit - a battery that is continually cycled 5% or less

will usually not last as long as one cycled down 10%. This happens because at very shallow cycles,

the Lead Dioxide tends to build up in clumps on the the positive plates rather in an even film.

 

 

Sizing a system

In sizing a system correctly, the aim is to balance the power going in from the solar panel

with the power going out of the battery over a period of days or weeks (depending on how

it is being used). A 10W panel will give 10W (0.6A @ 16.5V) over an hour under standard

test conditions (1000W/m sq and 25oC – equivalent to one hour of 'peak' sunshine). In the

UK we expect around 4 hours equivalent sunshine in summer and 1 hour in winter. Thus in

Winter a 10W panel will give 10W over a whole day, whereas in summer it will give 40W.

These are fairly conservative figures – some companies use up to 6 hours in summer, but

of course whatever figure you use the panels will perform the same in real life. You can do

the same calculations with the Amps.

 

Let me know if this has helped you or given you an interest in Solar Light Systems - This is free advice and I want nothing for it.

The information above is taken from many books/videos/web sites and my own angle on it all is above where I have built and tested my own Hardware.

 

But more to the point is if in a Catastrophe you required a means to Light the Dark nights without Flame, then the above may help or inspire you to look into the Science of Solar Power.

 

cool.gif

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Welcome, Classradiance! I am definitely coming back to read this when my brain is working. Thanks!

 

MtRider :offtobed:

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Welcome, Classradiance! I am definitely coming back to read this when my brain is working. Thanks!

 

MtRider :offtobed:

 

Sure .. just 20 minutes everyday for 4 weeks of you life, just possibly may be all it took, to light up a room in the darkness because you stopped for 1 minute to read this.

 

I think like this and have changed my life to practice what I preach .. Peace to all and I hope the day never comes huh.gif

It does not hurt to take a little something away from each experience ...

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we are using outdoor solar spotlights (landscaping) at night for room lighting when we just want a 'glow'.

They are even bright enough to read by and safer then candles as we can leave the room and not worry.

Just have to remeber to put them outside during the day but some I have in windows and on bright sunny days that is enough to charge them for the few hours they are needed.

Like what you posted - lots of info to make you think a bit.

:AmishMichaelstraw:

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we are using outdoor solar spotlights (landscaping) at night for room lighting when we just want a 'glow'.

They are even bright enough to read by and safer then candles as we can leave the room and not worry.

Just have to remeber to put them outside during the day but some I have in windows and on bright sunny days that is enough to charge them for the few hours they are needed.

Like what you posted - lots of info to make you think a bit.

:AmishMichaelstraw:

 

Hi A H

New Technology has allowed the LED to become more radiant whilst using less Power.

If you are using Wind Turbines / Solar Power / Water Turbines the end result is the same where you are always only creating a Voltage output which can be Stored in a Battery.

REMEMBER THAT IF A 12V BATTERY NEEDS CHARGING THEN THE VOLTAGE OF THE GENERATOR (Solar/wind/whatever)

MUST BE MORE THAN 12V TO CHARGE IT - AND TO CONTROL THAT YOU USE A CHARGE CONTROLLER CIRCUIT.

 

LEDs require only small amounts of power which is why it is totally possible to now light every room in your home using only Car Batteries as

the Electrical Power source. Place your average room usage in the above calculations to see what size system you need and then you can cost it accordingly. You will not regret it.

 

Remember to always store Batteries in a safe manner - see my YOUTUBE where the light in my kitchen is only 12 WATTS (4 x 3W LED's)

You can see from my Link these lights are incredibly bright.

 

You may see that some systems are 24V or 48V. The reason for the increase is because when you are trying to deliver a voltage/amps to a destination source (the cable is acting as the Resistance) so simple OHMS law COMES INTO EFFECT.

When calculating cable lengths which are to carry a known Amperage at a known Voltage over a known distance which is the (Resistance) . . if you get it wrong then the Cable gets hot enough to catch Fire. So always study the relationships between Resistance / Amps / Voltage.

It is not hard at all and there are many learning sources out there on the WEB at the moment.

 

My link

post-9265-084964100 1350124029_thumb.jpg

Edited by classradiance

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if you get it wrong then the Cable gets hot enough to catch Fire. My link

 

 

Nothing works !!! - Just as an update to the above

Also - if you get the calculation wrong then the correct voltage is not delivered to the end of the cable !!

 

example. your Light is 10W and requires 12V.

Your cable is .75mm diameter copper twin & Earth Cable and its Length is 18 meters from Battery to where the Light will live. (But it will not work or is very Dim)

 

According to the Charts - you can only deliver 12V over 9 meters, which means that the Voltage at the end of your 18 Meter Cable is around 6V -

 

The 12V Light has a Demand for 10Watts/12V = .83 Amps also shown as (83 mA - this is the amount which allows the light to work correctly)

 

But our long cable can only deliver 6V - So 6V x 83mA = 4.94 Watts (that is half the power that is required for the light to work correctly)

 

So the answer to get around this could be to double the cable diameter or double the voltage going up the 18 meter cable - hence you have 24V & 48V systems for smaller cable diameter usage that can go further distances but still deliver the Power required.

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we are using outdoor solar spotlights (landscaping) at night for room lighting when we just want a 'glow'.

They are even bright enough to read by and safer then candles as we can leave the room and not worry.

Just have to remeber to put them outside during the day but some I have in windows and on bright sunny days that is enough to charge them for the few hours they are needed.

Like what you posted - lots of info to make you think a bit.

:AmishMichaelstraw:

 

From Philbe...I have a handful of them pointed out my covered porch window, handy at any time for the same reason...they give off light without needing batteries. I also showed my mom how to put hers into a canning jar for stability, that she could just set on her porch and porch steps. They charge all day and are there for free lighting at night. We also have some in our camp trailer as well as strand that I can hang under the awning for additional light. Not to say we don't have alot of "puck lights" that are LED's ... LOL

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