The value of solar spotlight wattage compared to the old system

[billd766]

I want to put a couple of solar spotlights around the house

 

They seem to range between 45W, 65W and 2,00W.

 

Are the wattages the same value as the non solar wattages, or do they have a different value?

 

I have done several internet searches and they seem to come up with different values.

 

They will be running for 12 hours or more, so what size solar batteries would I need  for a 45W, 65W, 100W or a 2,000W solar spot light?

 

Any help or advice will be gratefully received.

[jvs]

I would not buy batteries but a self sufficient system instead.

Very easy to install and they work very well.

We have a few of them and we are very happy with it.

[billd766]

1 hour ago, jvs said:

I would not buy batteries but a self sufficient system instead.

Very easy to install and they work very well.

We have a few of them and we are very happy with it.

AFAIK the solar charger also saves and stores the charge and effectively is the battery.

 

I think that the number of LEDs on the spotlight side is relevant to the power output of the spotlight. (more LEDs = more light).

 

I also think that the number of LEDs (for want of the proper name) is relevant to the amount of power stored and therefore the length of time that the spotlight will operate for.

 

So the larger the solar panel, the more charge it will hold and the longer the spotlight will work.

 

What does confuse me is the wattage. Does for example a solar spotlight of 65W give the same amount of light as a mains powered non solar spotlight of 45W, 65W, 100W, 500W, 1,000W or even a 2,000W?

Edited December 11, 2023 by billd766
corrected some bad spelling

[Denim]

I have a 45 watt solar  light in every room. Each one has its own small seperate panel on the roof near where the light is mounted. They come on automatically as soon as it gets dark and last through to about midnight. So , if we get a mains power out , at least we have light and can still use the gas cooker etc. Only thing missing is the air con.

 

Having said that , God always has his eye on me. Whenever I spend some of my humble savings on any ' good ideas '  he makes sure to nullify my investment by ensuring there are never again any mains power outs etc. Same as when I wash my car. Might not have rained for weeks and the forecast is good but withing 24 hours of washing and polishing the skys open and there is mud everywhere.  I see him on his cloud surrounded by his favorite angels , passing around the manna , slapping his knee and having a good laugh at my expense.

[asf6]

Wattage relates to power. Light is usually expressed in Lumens. 

[billd766]

12 minutes ago, asf6 said:

Wattage relates to power. Light is usually expressed in Lumens. 

Can you explain the difference and how it relates  to watts?

 

Why do we buy a 100 watt or whatever size light bulb instead of bulbs rated in lumens?

[Crossy]

Solar lights tend to be shown in "equivalent watts" so the idea is that they give the same light as that wattage of regular lamp.

 

My (actual) 10W LED floodlights are rather brighter than my "100W" solar streetlights.

 

Have a look here: -

 

 

[billd766]

36 minutes ago, Crossy said:

Solar lights tend to be shown in "equivalent watts" so the idea is that they give the same light as that wattage of regular lamp.

 

My (actual) 10W LED floodlights are rather brighter than my "100W" solar streetlights.

 

Have a look here: -

 

 

Thank you Crossy.

 

That is the sort of information that I am looking for.

 

A couple of months ago I bought 3 (buy one, get one free) solar spotlights. (The 3 BOGOF lights never arrived).

 

They were supposed to be 100W and possibly they were, but they went flat and shut down in3 hours or less. They were cheap at 582 baht for the 3 including delivery.

 

What I want to do is put a 100W or 200W solar light down the side of the house that we use, plus a 500W or 650W out the back pointing at my MIL house. They need to last at least 12 hours, so I think that it is the size of the solar panel that is important.

 

The are roundtuit jobs and at the moment are sort of covered by 4 foot LED mains strip lights, though the one at the back is not much use for the coverage that I want.

 

Your previous link going back 3 years should give me some useful information for which I thank you and the other posters very much.

[Seeall]

2 hours ago, Denim said:

I have a 45 watt solar  light in every room. Each one has its own small seperate panel on the roof near where the light is mounted. They come on automatically as soon as it gets dark and last through to about midnight. So , if we get a mains power out , at least we have light and can still use the gas cooker etc. Only thing missing is the air con.

 

Having said that , God always has his eye on me. Whenever I spend some of my humble savings on any ' good ideas '  he makes sure to nullify my investment by ensuring there are never again any mains power outs etc. Same as when I wash my car. Might not have rained for weeks and the forecast is good but withing 24 hours of washing and polishing the skys open and there is mud everywhere.  I see him on his cloud surrounded by his favorite angels , passing around the manna , slapping his knee and having a good laugh at my expense.

murphys law?  I call it the damn majicak elf

[jvs]

23 minutes ago, billd766 said:

Thank you Crossy.

 

That is the sort of information that I am looking for.

 

A couple of months ago I bought 3 (buy one, get one free) solar spotlights. (The 3 BOGOF lights never arrived).

 

They were supposed to be 100W and possibly they were, but they went flat and shut down in3 hours or less. They were cheap at 582 baht for the 3 including delivery.

 

What I want to do is put a 100W or 200W solar light down the side of the house that we use, plus a 500W or 650W out the back pointing at my MIL house. They need to last at least 12 hours, so I think that it is the size of the solar panel that is important.

 

The are roundtuit jobs and at the moment are sort of covered by 4 foot LED mains strip lights, though the one at the back is not much use for the coverage that I want.

 

Your previous link going back 3 years should give me some useful information for which I thank you and the other posters very much.

The size of the panel is not so important,they are well matched in our lihgts.

[lopburi3]

I needed to replace a normal round opaque gate lamp a few months ago and just about everything is solar (small panel on top - unseen as pole puts it above peoples heads).  They were cheap so ordered one (which also had socket for normal 220v LED lamp).  Have turned LED off and only use with electric LED light.  built in light was dim at best and only lasted 2-4 hours before flashing on/off all night.  As said - was cheap and can use on AC power so nothing lost but fair warning that all is not golden just because it has solar panel, and that panel better have good access to sun most of the day.  

[billd766]

42 minutes ago, lopburi3 said:

I needed to replace a normal round opaque gate lamp a few months ago and just about everything is solar (small panel on top - unseen as pole puts it above peoples heads).  They were cheap so ordered one (which also had socket for normal 220v LED lamp).  Have turned LED off and only use with electric LED light.  built in light was dim at best and only lasted 2-4 hours before flashing on/off all night.  As said - was cheap and can use on AC power so nothing lost but fair warning that all is not golden just because it has solar panel, and that panel better have good access to sun most of the day.  

The house faces South East so the 100W for the side of the house get sunshine for perhaps 6 hours a day and daylight for about 12 hours total, and the 650W would be facing West and get the sunshine  from about noon until around 5 pm and daylight from morning until dusk.

[a340bangla1]

1 hour ago, billd766 said:

Thank you Crossy.

 

That is the sort of information that I am looking for.

 

A couple of months ago I bought 3 (buy one, get one free) solar spotlights. (The 3 BOGOF lights never arrived).

 

They were supposed to be 100W and possibly they were, but they went flat and shut down in3 hours or less. They were cheap at 582 baht for the 3 including delivery.

 

What I want to do is put a 100W or 200W solar light down the side of the house that we use, plus a 500W or 650W out the back pointing at my MIL house. They need to last at least 12 hours, so I think that it is the size of the solar panel that is important.

 

The are roundtuit jobs and at the moment are sort of covered by 4 foot LED mains strip lights, though the one at the back is not much use for the coverage that I want.

 

Your previous link going back 3 years should give me some useful information for which I thank you and the other posters very much.

 

We have a number of 60 W and one 100 W around the house and in the garden. Also some recently bought 5 W post lights. They all work quite well. Usually, when we get up in the morning around 6 - 6:30 most of them are still working, albeit not so bright any more.

[Crossy]

All the lights I bought in the 2020 thread are still going strong after 3 years

 

A lot longer than I actually expected

[KhunLA]

I recently got this one from LAZ/MODI and works quite well.  They are the manufacturer of, and local.  Last 12 ish hrs overnight, sunset to rising.  Facing East, even thought recommended to face West, though does get E & S exposure for 6-8hr and more than enough for full charge of battery.

 

Had for a few weeks, no issues and may pick up a few more, more powerful maybe, as that was just  a tester.

[asf6]

12 hours ago, billd766 said:

Can you explain the difference and how it relates  to watts?

 

Why do we buy a 100 watt or whatever size light bulb instead of bulbs rated in lumens?

Nowadays you can do both. 

In the old days when ordinary consumers mostly bought incandescent lamps, knowing the wattage was enough because you could compare the light given from one lamp to another using watts because all/most lamps used the same inefficient technology. A 100w bulb gave off more light than a 60w bulb and a 60w bulb gave off more light than a 40w bulb. The same went for the old fluorescent tubes, but they were more efficient than incandescent lamps.  

However, nowadays modern lamps/bulbs such as LED lamps are much more efficient than the old technology incandescent lamps but incandescent lamps are still available (and people still buy light bulbs thinking in watts) so manufacturers try to help consumers by adding extra information such as equivalent wattage and/or the lumens given off by the lamp. Wattage still refers to power and lumens to light but you can use the information to compare products and buy something that suits your needs. 

 

For example, a 13.5w LED lamp that I recently bought gives off 1521 lumens and the manufacture states that this is the equivalent of a 100w incandescent bulb.  

Light given off 1521 lumens. Old technology 100w power usage. New technology 13.5w power usage. 

The bulb uses 13.5 watts of power but the light given out is equivalent to a 100 watt incandescent bulb. 

 

Edited December 11, 2023 by asf6

[billd766]

8 hours ago, asf6 said:

Nowadays you can do both. 

In the old days when ordinary consumers mostly bought incandescent lamps, knowing the wattage was enough because you could compare the light given from one lamp to another using watts because all/most lamps used the same inefficient technology. A 100w bulb gave off more light than a 60w bulb and a 60w bulb gave off more light than a 40w bulb. The same went for the old fluorescent tubes, but they were more efficient than incandescent lamps.  

However, nowadays modern lamps/bulbs such as LED lamps are much more efficient than the old technology incandescent lamps but incandescent lamps are still available (and people still buy light bulbs thinking in watts) so manufacturers try to help consumers by adding extra information such as equivalent wattage and/or the lumens given off by the lamp. Wattage still refers to power and lumens to light but you can use the information to compare products and buy something that suits your needs. 

 

For example, a 13.5w LED lamp that I recently bought gives off 1521 lumens and the manufacture states that this is the equivalent of a 100w incandescent bulb.  

Light given off 1521 lumens. Old technology 100w power usage. New technology 13.5w power usage. 

The bulb uses 13.5 watts of power but the light given out is equivalent to a 100 watt incandescent bulb. 

 

Thank you for the information.

 

What I am trying to do is to convert the wattage of a LED spotlight into something that I can understand.

 

I do understand that the more LEDs in a spotlight means that it is brighter. Then I need to work out that if the wattage is for example 500 watts and the Voltage is 230V, I can work out the power consumption per hour.

 

What I then need to do is multiply that figure by 12 for the overnight usage and then try to size the solar panel from that.

 

What I think I need to know is how many (I use the term LED as I don't know the correct term) I will need to power each spotlight for 12 hours plus 10 or 20%.

 

The bigger the solar panel theoretically determines how much charge it will hold in milliamps and that I think is the figure that I am looking for.

 

It is easy to get the correct size spotlight but the problem, at least for me, is sizing the solar panel.

[lopburi3]

5 minutes ago, billd766 said:

The bigger the solar panel theoretically determines how much charge it will hold in milliamps and that I think is the figure that I am looking for.

Believe most solar panels charge a battery that holds the power so you need to know the battery capacity for how long they will provide power and the solar panel capacity for charging the battery and then the power required by lamp and the lumen output of the actual lamp (not all LED's need or provide the same power).  As panels will at best be at highest capacity for limited time and even then weather/dirt/dust will make a huge impact - this is really not for the faint of heart.  Signing out.  

[asf6]

2 hours ago, billd766 said:

I do understand that the more LEDs in a spotlight means that it is brighter. Then I need to work out that if the wattage is for example 500 watts and the Voltage is 230V, I can work out the power consumption per hour.

 

What I then need to do is multiply that figure by 12 for the overnight usage and then try to size the solar panel from that.

 

If the wattage is for example 500 watts you can work out the power consumption simply by multiplying the wattage by the number of hours. The voltage is irrelevant to that calculation. 500w x 12 hrs = 6kw hours. 

 

 

.

Edited December 12, 2023 by asf6

[billd766]

4 hours ago, lopburi3 said:

Believe most solar panels charge a battery that holds the power so you need to know the battery capacity for how long they will provide power and the solar panel capacity for charging the battery and then the power required by lamp and the lumen output of the actual lamp (not all LED's need or provide the same power).  As panels will at best be at highest capacity for limited time and even then weather/dirt/dust will make a huge impact - this is really not for the faint of heart.  Signing out.  

Thank you.

 

The solar battery storage is where I am stuck at the moment.

[billd766]

1 hour ago, asf6 said:

 

If the wattage is for example 500 watts you can work out the power consumption simply by multiplying the wattage by the number of hours. The voltage is irrelevant to that calculation. 500w x 12 hrs = 6kw hours. 

 

 

.

But from my electrical training of many years ago to get the power consumption you need the voltage as well,

 

There is a large difference between 115 volts used in the USA, 240 volts as used in the UK and in Thailand where the nominal voltage is 230 volts..

 

In reality, having looked at my clamp voltmeter it is currently 226 volts. During a brownout it can drop as low as 170 volts which buggers up the time calculations enormously.

 

If you know the wattage of the item that you are using and you know the voltage,  you can work out the length of time it takes to burn through 1KWH. That is the way I look at it and I would rather over engineer and have too much battery storage than not have enough and have the light go out earlier.

 

500 watts for a lamp is just a nominal figure. From what I have read so far, it seems that the number LEDs will give the correct brilliance. The more LEDs, the brighter the light.

[lopburi3]

15 minutes ago, billd766 said:

But from my electrical training of many years ago to get the power consumption you need the voltage as well,

Wattage is the power consumption - volts x amps determines the watts so the same regardless of voltage for the same 500w light.  

Edited December 12, 2023 by lopburi3

[bluejets]

I don't really see the need to run battery operated spotlights for 12 hours at a time.

That would really be "some" battery, especially at 2000w as they tend to run up around 40 to 80v dc.

If you need to run that amount, fit mains lights, unless of course you are out in the never-never.

Other than that, probably best to go and buy a couple and try them out, navigate away from the el-cheapos naturally.

You'll find most are over-rated on what they say the performance would be.

Just don't expect to get what is written on the pack, either run time or life expectancy.

 

As an added note on the latter, one used to see ridiculous claims on thousands of hours life....all been removed down under here at least...never see it on the box anymore.

Always said it was crap.Maybe the LEDs would hold out but the drivers tend to shit themselves and replacing any part is not even considered anymore.

[billd766]

35 minutes ago, lopburi3 said:

Wattage is the power consumption - volts x amps determines the watts so the same regardless of voltage for the same 500w light.  

That should mean that it will consume 6 KWH per night and need at least a battery storage of 25,000 milliamps from the solar charger.

 

I am screwing myself into an ever decreasing circle now.

[billd766]

8 minutes ago, bluejets said:

I don't really see the need to run battery operated spotlights for 12 hours at a time.

That would really be "some" battery, especially at 2000w as they tend to run up around 40 to 80v dc.

If you need to run that amount, fit mains lights, unless of course you are out in the never-never.

Other than that, probably best to go and buy a couple and try them out, navigate away from the el-cheapos naturally.

You'll find most are over-rated on what they say the performance would be.

Just don't expect to get what is written on the pack, either run time or life expectancy.

 

As an added note on the latter, one used to see ridiculous claims on thousands of hours life....all been removed down under here at least...never see it on the box anymore.

Always said it was crap.Maybe the LEDs would hold out but the drivers tend to <deleted> themselves and replacing any part is not even considered anymore.

 

Thank you for that information.

 

I am/was trying to cut back on my electricity bill which is the reason for looking at solar power.

[Elkski]

2 hours ago, billd766 said:

Thank you.

 

The solar battery storage is where I am stuck at the moment.

650 watt solar spotlight.  Thats as much power as a small microwave.    Watt equivalent amd battery Ahrs will help you determine gow ling it will run.  

You need to think in terms of lumens. 800 to 1000 lumens is starting to be pretty much light but only for a short distance like 4- 5 meters. 

[billd766]

2 hours ago, Elkski said:

650 watt solar spotlight.  Thats as much power as a small microwave.    Watt equivalent amd battery Ahrs will help you determine gow ling it will run.  

You need to think in terms of lumens. 800 to 1000 lumens is starting to be pretty much light but only for a short distance like 4- 5 meters. 

I wanted it to cover an area of about 10 x 15 metres but I have given up on that idea now.

[Elkski]

I have never used these large rated somar lights.  All the small ones ive seen look so dim its not really a light    but my mom does have a few that look like a flame fie a couple hours most nights.  Im a fan and installer of low voltage lighting using LED bulbs. 1 300 watt transformer can run 20 12 watt lights.  80% of 300 is recommended.  Some of these pathway lights are only 3 watts.   Led replacement bulbs run 7 watts and look like 60 watt bulbs and they now make 12 v versions that use the E26 base.  So you can switch your old 220v lamps to 12v. 

I should add that this Chinese co is selling 12v lights on Amazon named sunvie.  They are very low cost and i have installed about 40 amd they are working well adter 4-5 months.   I did take the lens out and added silicon caulk to the glass sealing surfaces because no way are they rated ip65. This nearly tripled the cost i charged but still under 15$ each light.   I've been using landscape lights and LED ones since their early days.  They have come a long way. 

One additional feature about LED landscape lights, specifically these Sunvie, is they onky use 5v for the lights.  So they work with 10.5 volts.  Maybe lower.  Usually your supposed to keep the wire voltage drop to less than 5% .  Even 3%.   But I have a long run installed with 9 12 watt spots. The voltage drop on this 12 guage wire is right at 2 v.   Just tidied up some wiring a few days ago and all is working fine.   With the incandescent, or halogen bulbs you couldn't do this with out having to tap up to a higher voltage to keep the end of string lights on.  This put extra volts on the close lights and shortened their life.  

Edited December 12, 2023 by Elkski

[Elkski]

https://integral-led.com/en/content/what-are-lumens

[billd766]

1 hour ago, Elkski said:

https://integral-led.com/en/content/what-are-lumens

Thank you for that useful link. I have bookmarked to read later.