Hi everyone. Thought this was interesting enough to share in detail on this site too. I will update the thread as the test continues. I published this originally on wietforum.nl (in Dutch) and on its sister forum opengrow.com (in English). I hope you enjoy the reading and don't draw any too early conclusions before we do the test with the lights in a reflector.
Peace!
- - - start part one - - -
On opengrow's Dutch sister Wietforum there were questions how e-ballasts really performed. So we took 3 popular e-ballasts for a testride in the Wietforum labs. Our testlocation was at Gavita Nederland. Being one of the market leaders in Horticultural lighting, Gavita does a lot of research on lamps, ballasts and reflectors. They have a great light lab including an integrating sphere, also known as the Ulbricht Sphere.
Here's the three candidates fltr Lumatek, Leuchtek, Bal
The equipment used: Een Voltech PM6000 en een Fluke 34B power quality analyser (not on the picture the Li-Cor Li-250 measuring the light)
The Sylvania lamp in the sphere
All lights were inspected for resonance
The PM6000 results
We haven't concluded all the tests yet but here are a few preliminary results.
This is what we did:
What you read in the table:
First part: Ballast input circuit
U = Line voltage. This was adjusted with a Variac. Electronic ballasts have no problem with changes in the line voltage, output remains the same and conversion efficinecy of the ballast remains intact.
I = TOTAL current, including the extra current due to the power factor in Amperes. Reactive loads such a a magnetic ballast move more current than they actually use. It's just pumped in and out and is a real problem for electricity companies. Professional users need to compensate reactive and inductive loads. A HID ballast must have a pf of more than 0.85.
Pw= Real power, so excluding the extra current as a result of the reactive or inductive load. This is what you see on your bill and what you use for cost calculations.
Ps = Apparent power (including power factor) - this is what goes through your wires.
PF = Power Factor (0.95 = 95% pf)
Second part: Ballast output circuit
U =Lamp voltage
I = Lamp current
Freq = Signal frequency, for E-ballasts in KHz, for magnetic ballasts in Hz.
Third part: Light
Measured in μMol PAR
Fourth part: Lamp efficacy
This is the total light devided by the real output power of the ballast, in μMol/W
Fifth part: System efficiency
The output power compared to the input power, so which percentage is lost in the Ballast (and can generate heat!).
Now you need to know that these lights were tested in an open air environment (inside the integrating sphere). In a reflector the lights get warmer and the lampvoltage and current change. You can really go quite high in the curve but when the light gets too hot the efficacy drops.
Now we see that both the BAL and Leuchtek do not reach their maximum output power, they don't pump out 600 watt. However, in a reflector we expect them to perform differently. The Lumatek performed exactly as specified: 5% more output power in super lumens position, 600 watt output at 100% and 400 watt at 75%, so you can use a 400 watt lamp in there of optimal efficacy without changing the ballast. We will see what it does in a reflector. Dimming the 600 watt light reduces output by almost 50% and reduces lamp efficacy to a bit under a 400 watt comparable bulb. Dimming the Lumatek increased the frequency tot over 110 KHz: We saw no signs of resonance at these high frequencies so they are safe to use (on a recent trade show in Madrid they switched the light from super lumens to 50% at least 700 - 1000 times over a 3 days period: nothing happened to the light). We did come across resonance inspecting the lamp with ballasts using lower frequencies. In this first set-up, the Lumatek performed best in lamp efficacy and system efficiency, and it produced the most light of the three ballasts.
Here's the table:
Publication of this report only with prior written approval from Gavita Nederland BV
Now we are going forward with the second batch of measurements where we measure the cold light inrush, redo the Grolux test and do a test with the lights in (different) reflectors. We used the original lamp leads of the Ballasts. We expect shorter leads to have a big effect, so we will test that too.
- - - end part one - - -
Now there was a question if a more expensive E-ballast would actually pay off, as a grower mentioned that replacing his magnetic ballasts (which he changed every 2 years) with BAL electronic ballasts did not really increasy his yield. There can be all kinds of reasons for that to happen (different reflectors for example) but these were my thoughts about that:
- - - beginning part two - - -
If you have 5% more light on your crop, given that climate, substrate, nutrients and genetics are in order, and you have let's say (to make a really safe calculation) just 2% more yield. Let's say you have 600 watt per square meter to make it really simple and you get like 500 gram per m2. That's 10 grams extra per m2 times 4 grows per year. With the electricity prices and the value of your crop you can easily defend a higher investment in the ballast. I calculated that it pays back within 3 crops maximum .
We did the test and we did it at a company that has no interest in promoting a specific light for our industry. They do certified tests all the time to check the performance of lamps for horticultural greenhouse growers. Bear in mind though that many big professional greenhouse growers actually grow with 400 volt fixtures and professional lights, that perform better, use less power and keep their output for a longer time. Here's a little example for you of what I would call a big installation:
6000 GAN Electronic 1000W 400V fixtures on this location. Company uses a total of 23000 fixtures! Efficiency, efficacy, light... that is all crucial in these installation. 5 watt more per fixture is almost 100 KW per hour! That's about (if I do a quick calculation) more than half a million euros electricity costs per year! So you can imagine in professional greenhouse grows the economics are a bit different. The constant light output of these Greenpower CG lamps is guaranteed by Philips for 2 years (Constant Grow light).
There are more differences between the Lumatek and the BAL than the output and efficiency. You see that the PF of the BAL is lower than the Lumatek, the output frequency is lower and without a reflector they do not reach optimal power. That's why we are going to do extra tests with reflectors to see the effect on the output and efficacy of the lamp. So we are not done yet.
As you can see a magnetic ballast does perform well when it gets its optimal voltage and does not show any signs of wear. However...
- it does use more power
- it does create more harmonics, especially when they get old (which give an electricity company easy ways to locate you)
- it had a much lower power factor, especially when you don't change them every year or two years (again, that's a way for an electricity company to locate you) which decreases over the use (depending on the quality of the compensating capacitor)
- it uses more power than an electronic ballast (and dissipates much more heat)
- the lamp performs better over a longer period on the electronic ballast
- the electronic ballast is much safer to operate (remember a light failure will cause a magnetic ballast to draw big amounts of extra current, trying to re-ignite!)
Also remember that one burn-out in two years can already be a catastrophe in your house. A good electronic ballast just shuts down the light when it starts to behave outside it's specs.
Now whether you want to invest $100 or $200 for a ballast depends on a lot of things:
1. How long will they last?
Compared to a magnetic ballast you can easily prove that an electronic ballast has at least a twice as long a lifetime. So you have to value your investment on the long term. You can have all the advantages of the electronic ballast and pay exactly the same for it over time, even if the eballast is twice as expensive as the magnetic. There are quality differences in E-ballasts. Any moving parts (such as fans) cause a risk and there is a lot of difference in the quality of electronic components. They can fail too. Always look at the warranty (many go up to 5 years!). I have seen the stacks of burned out magnetic lights in a large installation... So in any case an electronic ballast is safer and because it lasts longer it may cost about twice as much, just for the investment to be worth it and have all the safety advantages.
2. How well will they perform?
If an electronic ballast and the lamp outputs more light over the period you use them, that's a very easy calculation to make. However.. if the e-ballast under-performs you will get about the same light and yield, only work safer and use less electricity and cause less distortion on the power grid (harmonics, power factor). So in any case that would be a safer situation, and much easier to operate and install (think about the switching and the fuses). When you look at the BAL you see it is outperformed by the magnetic ballast (IN THIS TEST!! We still have to to the test WITH the reflectors!!!). However, the magnetic ballast will not perform that well over it's lifetime and the lamp will fade faster too on a magnetic ballast. So that equals it a bit.
In case of the Lumatek you see less power consumption and, more important, more light! So do I get more than $100 profit from more light over the life time of the ballast? You betcha!
My best advice at this moment would be to buy the e-ballast that outputs the most light most efficiently and see the difference over let's say one or two years. You will want to buy the newest and greatest again in two years I suppose
. If you read the data well, the Lumatek outputs 10-14% more than the BAL with the same lamp. So I can see your friend doesn't see a lot of difference using the BALS at this moment with the current data available.
There are however differences between professional grows and home grows. First of all look at the voltage you get at your ballast. In many houses mains voltage can be up to 10% less than what is specified, depending on the time of day, industry nearby, wiring etc etc. With a magnetic ballast that's easily 10% less light (10% more is 10% more light)! An electronic ballast doesn't care, it outputs exactly the same with a lower or higher input voltage.
Good reading is the Advance HID guide, you can find it on the advance or Philips site (Advance is a Philips company)
Peace!
- - - start part one - - -
On opengrow's Dutch sister Wietforum there were questions how e-ballasts really performed. So we took 3 popular e-ballasts for a testride in the Wietforum labs. Our testlocation was at Gavita Nederland. Being one of the market leaders in Horticultural lighting, Gavita does a lot of research on lamps, ballasts and reflectors. They have a great light lab including an integrating sphere, also known as the Ulbricht Sphere.
Here's the three candidates fltr Lumatek, Leuchtek, Bal
The equipment used: Een Voltech PM6000 en een Fluke 34B power quality analyser (not on the picture the Li-Cor Li-250 measuring the light)
The Sylvania lamp in the sphere
All lights were inspected for resonance
The PM6000 results
We haven't concluded all the tests yet but here are a few preliminary results.
This is what we did:
- We tested the 3 ballasts with the Sylvania Grolux en de Philips Greenpower CG, both 600 watt popular lights in The Netherlands.
- The Sylvania performed very well. Actually we were a bit surprised with the performance as it was way above specs. We will do the Grolux test again with another lamp, to be absolutely sure that this was a good test and the results were not affected by the lamp. All ballasts were tested using the same lamp of course.
- We measured these lamps exactly as the manufacturers do, in an integrating sphere without reflector.
- Lumatek dimmable on super lumens position
- Lumatek dimmable on100%
- Lumatek dimmable on75%
- Lumatek dimmable on 50%
- BAL
- Leuchtek
What you read in the table:
First part: Ballast input circuit
U = Line voltage. This was adjusted with a Variac. Electronic ballasts have no problem with changes in the line voltage, output remains the same and conversion efficinecy of the ballast remains intact.
I = TOTAL current, including the extra current due to the power factor in Amperes. Reactive loads such a a magnetic ballast move more current than they actually use. It's just pumped in and out and is a real problem for electricity companies. Professional users need to compensate reactive and inductive loads. A HID ballast must have a pf of more than 0.85.
Pw= Real power, so excluding the extra current as a result of the reactive or inductive load. This is what you see on your bill and what you use for cost calculations.
Ps = Apparent power (including power factor) - this is what goes through your wires.
PF = Power Factor (0.95 = 95% pf)
Second part: Ballast output circuit
U =Lamp voltage
I = Lamp current
Freq = Signal frequency, for E-ballasts in KHz, for magnetic ballasts in Hz.
Third part: Light
Measured in μMol PAR
Fourth part: Lamp efficacy
This is the total light devided by the real output power of the ballast, in μMol/W
Fifth part: System efficiency
The output power compared to the input power, so which percentage is lost in the Ballast (and can generate heat!).
Now you need to know that these lights were tested in an open air environment (inside the integrating sphere). In a reflector the lights get warmer and the lampvoltage and current change. You can really go quite high in the curve but when the light gets too hot the efficacy drops.
Now we see that both the BAL and Leuchtek do not reach their maximum output power, they don't pump out 600 watt. However, in a reflector we expect them to perform differently. The Lumatek performed exactly as specified: 5% more output power in super lumens position, 600 watt output at 100% and 400 watt at 75%, so you can use a 400 watt lamp in there of optimal efficacy without changing the ballast. We will see what it does in a reflector. Dimming the 600 watt light reduces output by almost 50% and reduces lamp efficacy to a bit under a 400 watt comparable bulb. Dimming the Lumatek increased the frequency tot over 110 KHz: We saw no signs of resonance at these high frequencies so they are safe to use (on a recent trade show in Madrid they switched the light from super lumens to 50% at least 700 - 1000 times over a 3 days period: nothing happened to the light). We did come across resonance inspecting the lamp with ballasts using lower frequencies. In this first set-up, the Lumatek performed best in lamp efficacy and system efficiency, and it produced the most light of the three ballasts.
Here's the table:
Publication of this report only with prior written approval from Gavita Nederland BV
Now we are going forward with the second batch of measurements where we measure the cold light inrush, redo the Grolux test and do a test with the lights in (different) reflectors. We used the original lamp leads of the Ballasts. We expect shorter leads to have a big effect, so we will test that too.
- - - end part one - - -
Now there was a question if a more expensive E-ballast would actually pay off, as a grower mentioned that replacing his magnetic ballasts (which he changed every 2 years) with BAL electronic ballasts did not really increasy his yield. There can be all kinds of reasons for that to happen (different reflectors for example) but these were my thoughts about that:
- - - beginning part two - - -
If you have 5% more light on your crop, given that climate, substrate, nutrients and genetics are in order, and you have let's say (to make a really safe calculation) just 2% more yield. Let's say you have 600 watt per square meter to make it really simple and you get like 500 gram per m2. That's 10 grams extra per m2 times 4 grows per year. With the electricity prices and the value of your crop you can easily defend a higher investment in the ballast. I calculated that it pays back within 3 crops maximum .
We did the test and we did it at a company that has no interest in promoting a specific light for our industry. They do certified tests all the time to check the performance of lamps for horticultural greenhouse growers. Bear in mind though that many big professional greenhouse growers actually grow with 400 volt fixtures and professional lights, that perform better, use less power and keep their output for a longer time. Here's a little example for you of what I would call a big installation:
6000 GAN Electronic 1000W 400V fixtures on this location. Company uses a total of 23000 fixtures! Efficiency, efficacy, light... that is all crucial in these installation. 5 watt more per fixture is almost 100 KW per hour! That's about (if I do a quick calculation) more than half a million euros electricity costs per year! So you can imagine in professional greenhouse grows the economics are a bit different. The constant light output of these Greenpower CG lamps is guaranteed by Philips for 2 years (Constant Grow light).
There are more differences between the Lumatek and the BAL than the output and efficiency. You see that the PF of the BAL is lower than the Lumatek, the output frequency is lower and without a reflector they do not reach optimal power. That's why we are going to do extra tests with reflectors to see the effect on the output and efficacy of the lamp. So we are not done yet.
As you can see a magnetic ballast does perform well when it gets its optimal voltage and does not show any signs of wear. However...
- it does use more power
- it does create more harmonics, especially when they get old (which give an electricity company easy ways to locate you)
- it had a much lower power factor, especially when you don't change them every year or two years (again, that's a way for an electricity company to locate you) which decreases over the use (depending on the quality of the compensating capacitor)
- it uses more power than an electronic ballast (and dissipates much more heat)
- the lamp performs better over a longer period on the electronic ballast
- the electronic ballast is much safer to operate (remember a light failure will cause a magnetic ballast to draw big amounts of extra current, trying to re-ignite!)
Also remember that one burn-out in two years can already be a catastrophe in your house. A good electronic ballast just shuts down the light when it starts to behave outside it's specs.
Now whether you want to invest $100 or $200 for a ballast depends on a lot of things:
1. How long will they last?
Compared to a magnetic ballast you can easily prove that an electronic ballast has at least a twice as long a lifetime. So you have to value your investment on the long term. You can have all the advantages of the electronic ballast and pay exactly the same for it over time, even if the eballast is twice as expensive as the magnetic. There are quality differences in E-ballasts. Any moving parts (such as fans) cause a risk and there is a lot of difference in the quality of electronic components. They can fail too. Always look at the warranty (many go up to 5 years!). I have seen the stacks of burned out magnetic lights in a large installation... So in any case an electronic ballast is safer and because it lasts longer it may cost about twice as much, just for the investment to be worth it and have all the safety advantages.
2. How well will they perform?
If an electronic ballast and the lamp outputs more light over the period you use them, that's a very easy calculation to make. However.. if the e-ballast under-performs you will get about the same light and yield, only work safer and use less electricity and cause less distortion on the power grid (harmonics, power factor). So in any case that would be a safer situation, and much easier to operate and install (think about the switching and the fuses). When you look at the BAL you see it is outperformed by the magnetic ballast (IN THIS TEST!! We still have to to the test WITH the reflectors!!!). However, the magnetic ballast will not perform that well over it's lifetime and the lamp will fade faster too on a magnetic ballast. So that equals it a bit.
In case of the Lumatek you see less power consumption and, more important, more light! So do I get more than $100 profit from more light over the life time of the ballast? You betcha!
My best advice at this moment would be to buy the e-ballast that outputs the most light most efficiently and see the difference over let's say one or two years. You will want to buy the newest and greatest again in two years I suppose
. If you read the data well, the Lumatek outputs 10-14% more than the BAL with the same lamp. So I can see your friend doesn't see a lot of difference using the BALS at this moment with the current data available. There are however differences between professional grows and home grows. First of all look at the voltage you get at your ballast. In many houses mains voltage can be up to 10% less than what is specified, depending on the time of day, industry nearby, wiring etc etc. With a magnetic ballast that's easily 10% less light (10% more is 10% more light)! An electronic ballast doesn't care, it outputs exactly the same with a lower or higher input voltage.
Good reading is the Advance HID guide, you can find it on the advance or Philips site (Advance is a Philips company)
