Hello, I have been working for most of the year at several sand and gravel facilities where efforts are being made to save energy by using more energy efficient lighting, and lighting controls. At one of these facilities in particular, I have estimated the replacement cost per fixture at well over one thousand dollar per fixture, including labor and materials. Although I think these efforts are well intentioned, I believe that efforts to correct the power factors of these facilities would be a better way to spend money on energy savings. I say this because most of the power is consumed by induction motors. Does anyone have experience with industrial facilities making power factor corrections?

Power factor correction is an easy savings, if the bill includes a charge for peak VA demand. The best way is to get a recording meter. I borrowed one from a wholesaler and they did a calculation of the proper size capacitor bank and payback.

It's cheaper to install correction on the larger motors, because you can use the existing controls, but you need to do regular testing to make sure they don't fail. If you have VFDs in the building, the bank is better because you can install a filter. Harmonics are a problem with capacitors.

What kind of upgrade to lighting are you looking at?

Do we really have statistics about how much lighting contributes to our overall energy bill. I understand we are generally "over lit" as a culture but without simply dimming the amount of light we want, is there a significant amount to be saved compared to things like heat bills?

Thanks for the info gfretwell. The lighting project is someone elses gig, but as I see it, it is correction of power factor on motor loads where the biggest savings can be achieved. As for how much lighting consumes in power, I think I read it is about 20 percent of all power consumed, which is still quite a large percentage. I will look furthur into measuring the phase shift on the motor loads, and how much can be saved by correcting this. This is actually an interesting subject, and will be interesting to find out how much can be saved in monetary terms.

Over the last few years, I have seen many lighting retrofit jobs, and quite a few within the last month. Warehouse sites converting 400 watt MH hi bays to T-8 &/or T-5 fluorescents with motions. Power consumption reductions are acceptable to the occupants, although I have ne $$ to post.

I have not seen any, nor heard of anyone planning any power factor type conservation efforts.

That's whyI like products like the "Kill-a-watt" and recording meters (dataloggers). They let you see exactly where you're using power.

Yes, there is a tremendous saving in using T-5 fluorescents rather than metal halide. There are also very real savings between T-8 and T-12 fluorescents. We're talking about being able to reduce a power bill from $100 to $60-70- and I'm not making any allowance for reduced maintenance or a lesser load on the air conditioning. Nor am I including the increased productivity that comes from having better-quality lighting.

The first step is to identify just where the power is being used. An office uses far more liighting than a machine shop, while the machine shop has more 'power quality' issues.

Ricker,
We have done several P.F. projects. Fairly straight forward. Any specific questions? Are you sure they pay a penalty for low P.F.?

Jeff

Ricker;

In regards to your post, I have some responses.



First and foremost, I need to make a statement for clarification, per P.F. Correction.

Applying Power Factor Correcting items to Machinery will assist only to reduce the drawn KVA from the Utility - not the drawn KW or KWH.

Please refer to the following example...

ABBREVIATIONS:
VA = Volt Amp (Apparent Power)
VAR = Volt Amp Reactive (Reactive Power)
W = Watts (True Power)
W-H = Watt-Hour (Total Energy Draw)
KVA = Kilo Volt Amps (1,000 VAs)
KVAR = Kilo Volt Amps Reactive (1,000 VARs)
KW = Kilo Watts (1,000 W)
KWH = Kilo Watt-Hour (1,000 W-H)

Example:

Machine "X" runs exactly One (1) Hour per billing cycle.
Machine "X" draws 500 KVA, with Power Factor of 70% (0.70 PF).
This would equate to 350 KW, and 357 KVAR. Billable Consumption is 350 KWH.

PF Correction is applied at the Machine (Capacitor Bank), to improve the Power Factor from 0.70, to 0.90.

Prior to applying the PF Correction, the Power flowing through the Meter is:...
KVA (Apparent Power): 500.00 KVA,
KVAR (Reactive Power): 357.0714 KVAR,
KW (True Power): 350.00 KW,
KWH (Total Energy): 350.00 KWH

With PF Correction applied, the Power flowing through the Meter is:...
KVA (Apparent Power): 388.885 KVA,
KVAR (Reactive Power): 169.5038 KVAR,
KW (True Power): 350.00 KW,
KWH (Total Energy): 350.00 KWH.

The remaining 187.567 KVAR is "Bounced" between the Capacitor Bank and Machine "X".

PF Correction does not dramatically reduce KW draw - it only stores KVAR.

If your Facility draws excessive Reactive Power, the billing statement will reflect "Penalties" and is billed accordingly.
Reduction of drawn KVAR would reduce the $$$ billed as Penalty, but not the consumption of True Power - that will still remain as a 350 KWH usage on the Billing Statement.

So, as you can see, the KWH Meter still records 350 KWH.
To reduce consumption, the Equipment its self must be addressed.

With that in mind, on to the Lighting!



Lighting upgrades for medium and large size Facilities will eventually have a payback - sometimes having a payback within 2 or 3 Years.
The savings is not just KWH Consumption per Lighting; it also includes reduced overhead costs for Maintenance, reduction of Generated Heat, and compensation from the Utility Company for reduced usage.

Area controls (Occupancy Sensors) work great with High Efficacy Lighting, to reduce Consumption and overhead issues.
Additionally, Lighting upgrades to Luminaries > 10 Years old, may be a "2 for 1 swap".
Example; (1) 8 Lamp T5HO Hi-Bay Linear Fluorescent Fixture could replace (2) 250 Watt HPS Hi-Bay Fixtures.

The T5HO Fixture draws 438 Watts (Lamps = 432 W, Ballasts = 6 W);
The HPS Fixtures draw 540 Watts (Lamps = 500 W, Ballasts = 40 W).

Reduction in demand Wattage is 102 Watts.
Heat generated is apx. 50% of the Two HPS Fixtures.
Illumination is slightly higher from the T5HO Fixture, than the Two HPS Fixtures.

Applying Occupancy Sensors for dimming and/or shut-off will further reduce consumption and generated Heat.


Lastly, just FYI, take a look at the Interior Lighting Compliance Standards - Nonresidential Compliance Manual - AKA: "CCR Title 24, Part 6", via the following link:

Nonresidential Compliance Manual
For California's 2008
Building Energy Efficiency Standards

Per Utility Billing; take a look at a single Month's usage, to see where fees are applied, and at what levels.

Ask the Facility's Management (Accounting Admins) if you may view a Billing Statement. This will demonstrate the Billing of Consumption per type of usage, Demands, Transmission and Generation surcharging, Penalties, and all other related items.

Billed amounts in excess of $10,000.00 per Month are very common for the Projects I deal with.

Feel free to post any questions you might have, regarding my reply.

Hope this reply is of assistance to you.

Scott

While I am not saying that the power savings from lighting is not worthwhile, it is my understanding that the power company bills based upon apparent power, and that by reducing reactive power, that the apparent power is reduced. I will have to review my electrical theory book on this before going furthur. I do know that the motor loads at these plants far exceed the power consumed by the lighting. Thanks all, I will revisit this on the forum after reading more.

ricker...

The typical PUC stipulates that Pocos charge for real power, period.

Then, for the big users, penalties are imposed for poor utilization of Poco assets:

Power Factors below 90
Peak Power surges -- like tanning saloons --
Seasonal Power surges -- like farm pumps --
Time of Day Power peaks -- like massive air conditioning loads
etc.

Power breaks are given for night time users such as an electric steel melter willing to run only on the night shift...

Power breaks are given for users willing to have the Poco cut them off entirely during energy peaks...
etc.

PG&E is rolling out a program to clip air conditioning demand by residential users. It responds to central control by interrupting just the air conditioner power circuits.

Because of all of the possibilities you simply have to have the customers bills in hand.

Now, with net billing on solar, it gets even more complicated. Pretty soon juice will be sold like airline seats.