Film-Tech Forum ARCHIVE: Projectors that put electricity back into the grid

This is topic Projectors that put electricity back into the grid in forum Film Handlers' Forum at Film-Tech Forum ARCHIVE.

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Posted by Matthew Bailey (Member # 601) on 10-01-2002, 05:35 AM:

Most of us are familiar with solar equipment & other devices that put electricity back into the utility grid.,but what about projectors & other projection equipment? Film platter & projector motors could have a small generator attached or modify the motors so that part of the windings could generate AC or DC sent to a DC to AC inverter before sending it back into the utility grid thus lowering a theatre's electric bills. Also what do you do with the heat from a lamphouse? It could be used to provide hot water to the theatre.

Posted by Steve Kraus (Member # 476) on 10-01-2002, 10:27 AM:

What chu thinkin, boy? Any generator you hook up to a motor, if you put a load on it, will load the motor that much more and draw more power from the line, equal to or greater than the power you get from the generator. The law of conservation of energy requires this. So does the no such thing as a free lunch law. Otherwise you'd have a perpetual motion machine.

Posted by John Pytlak (Member # 331) on 10-01-2002, 02:04 PM:

At the Grandview drive-in I worked at, we always welcomed the heat of those huge Ashcraft carbon arc lamps on cold nights in early spring and late fall.

But we cursed them on hot summer nights.

It wouldn't have been too hard to plumb those water-cooled carbon jaws and projectors to heat the water going to the rest rooms.

------------------
John P. Pytlak, Senior Technical Specialist
Worldwide Technical Services, Entertainment Imaging
Research Labs, Building 69, Room 7525A
Rochester, New York, 14650-1922 USA
Tel: +1 585 477 5325 Cell: +1 585 781 4036 Fax: +1 585 722 7243
e-mail: john.pytlak@kodak.com
Web site: http://www.kodak.com/go/motion

Posted by Steve Kraus (Member # 476) on 10-01-2002, 03:10 PM:

Do the codes still require outside venting of lamphouses? If ozone production has been eliminated then there's no reason that this could not be recirculated during the heating season and pumped outside during the summer.

Posted by John Pytlak (Member # 331) on 10-01-2002, 03:45 PM:

Ozone should be vented to the outside:
http://www.ehs.umaryland.edu/OSH/msds/july00.htm
http://www.ecosensors.com/pg5_0ozonesafetyusgov.html
http://www.ecosensors.com/pg5_2ozonesafetymsds.html
http://www.industrozone.com/health_&_safety_issues.htm

Posted by Stephen Furley (Member # 1277) on 10-01-2002, 03:59 PM:

A fair number of cinemas in the uk, mainly single screen places running small lamps, e.g. 100 or 1600W do not have them vented. One larger example comes to mind, when it was open, the State, Grays, about 2,500 seats I think, had three projectors with Magnarcs, one still carbon, two with 2.5kW xenon conversions, which were not vented, I think these were the largest unvented lamps I have seen. The screen in this place was one of the largest in the country, they could really have used at least 4k. The carbon projector was vented, and I think the two spots and the Brenograph had hoods, but there was quite a strong smell of carbon fumes in the box when they had been running. Why the ducting had been removed from the two xenon projectors I don't know.

The David Lean in Croydon, recently built, very small, maybe 50 seats, has a pair of 100W xenons, and these are vented, so it doesn't always go by size.

Posted by Daryl C. W. O'Shea (Member # 1303) on 10-01-2002, 05:27 PM:

Having a hot booth to return to after falling off the roof a couple of times changing the marquees in mid-January was always nice. Here in the city though, I don't think it actually gets cold enough to classify as Winter.

In the summer-time at the drive-in, onion rings seem to stay pretty warm while sitting on top of the Super Lum-X lamp houses. And like John did, I enjoy the heat of the booth while trying to run a show while it is snowing out in the fall.

Posted by Scott Norwood (Member # 30) on 10-01-2002, 07:12 PM:

I've worked in a booth with a pair of Kinoton FP-30s with 2kw bulbs without ventilation and, surprisingly, the booth didn't get very hot at all. These aren't "normal" 2kw xenons like one would use in a Christie or Strong lamphouse, however; they are physically smaller. Also, Kinoton machines have one switch to control both motor and lamp, so there was only one lamp running at a time.

I've also run several booths with two machines with 1kw and/or 500w lamps without ventilation; heat wasn't a major issue there, either. Of course all of these use modern (supposedly) ozone-free xenons.

I will soon have a carbon arc Super Trouper followspot (essentially the same thing as a Strong "Utility" lamphouse) running unvented in a large theatre, although it won't be run for more than a few minutes at a time (and, then, only occasionally) and will be on a theatre balcony, not an enclosed booth.

I'm not necessarily trying to suggest that any of these setups is optimal, just that the smaller lamps can be run unvented without adverse consequences for the operator, though lamp life probably suffers.

Posted by Wes Hughes (Member # 981) on 10-01-2002, 09:53 PM:

It has always been my understanding that even "ozone-free" lamps still produce some ozone.

Posted by Frank Angel (Member # 248) on 10-01-2002, 09:57 PM:

First generation xenons, besides being as sensitive to vibrations as nitroglycerin, also produced dangerous levels of ozone, and those were the days of single screen booths. Imagine what the levels would be today with a dozen or more lamphouses running all day long?!

Newer generations of xenon lamp design have corrected much of those early problems, which unfortunately has led manufacturers to used the term "ozone free" quite loosely. Even the most modern xenon bulbs are not ozone free, and yes, a single bulb will give off low levels of the gas that is said (by someone) to be harmless, but that's looking at one bulb at a time. Given the nature of multiplex operation, rarely is a single bulb fired in most booths -- there are many of them and the ozone accumulation can be significant if it is not properly vented by a properly designed ventilation system.

Some years ago a civil suit was filed in Brooklyn against Cineplex-Odious and the management of the Alpine Theatre here because the venting system was inadequate and always in bad repair with management refusing to address the problem. The union projectionists were getting very ill. OSHA became involved and found very high levels of ozone as well as even more toxic gases. The case was settled, and the ventilation system was upgraded.

When a large multiplex is designed with a common booth, the idea of ozone-free bulbs becomes a real issue; proper ventilation needs to be part of the design, not an afterthought.

I believe that in NYC the building code for projection booths still requires that if the booth is going to have a ventilation system for the general booth area, it must be a separate system from the projectors which must always be vented. I think that is still on the books, but then again, the requirement for a licensed projectionist to be present in the booth at all times is also still on the books, but its a reg that management pretty much laughs at.

Frank

Posted by Joe Redifer (Member # 3) on 10-01-2002, 10:05 PM:

I have 5 1600w lamps and 1 2000w lamp, all with ventilation and the booth gets incredibly hot!

Posted by Gordon McLeod (Member # 33) on 10-02-2002, 04:08 PM:

Ozone is still produced during Lamp ignition by the spark gap and some hv flyoff

Posted by David Graham Rose (Member # 1450) on 10-04-2002, 03:08 PM:

The laws of conservation of energy states;

Energy can not be created, only tranformed from one form to another.

Therefore, by definition, a motor can not act as a generator with any gain in energy. However in the past, cinemas have used motor/generators to provide d.c. power from an a.c. supply instead of using a rectifier.

Posted by Gerard S. Cohen (Member # 994) on 10-04-2002, 03:54 PM:

David said:
<<Therefore, by definition, a motor can not act as a generator with any gain in energy.>>

True, but there is ongoing research into conserving energy in motor vehicles by utilising the energy of the moving mass during decelleration and braking to generate potential energy stored in batteries. Normally, braking produces heat and is wasteful of the energy it took to overcome inertia at starting and accellerating.
Almost since the invention of motorcars, magnetos, generators and alternators have been used to recharge the battery, driven by the gasoline engine itself. Driving similar generators from the wheels
on decellerating would be a further conservation, if storage of electrical energy permitted the use of electrical motors part time during the use of the vehicle.

Perhaps this research, and the frequent announcement that such a vehicle's production is imminent, is what suggested Matthew's posting of this thread?

Posted by Daryl C. W. O'Shea (Member # 1303) on 10-04-2002, 04:50 PM:

Our solarcar drive motor uses re-gen to charge the lithium-ion batteries during 'braking', however it is only about 60% efficient (which is great considering the cells are only 17.5% efficient).

As for a projector, I don't think regenerating electricity for a few seconds off of the fly wheel would be worth the equipment expense.

Posted by Tim Reed (Member # 137) on 10-07-2002, 07:47 AM:

How can you put electricity 'back into the grid'? Isn't there phasing to take into consideration?

------------------
Better Projection Pays!

Posted by Mark J. Marshall (Member # 1409) on 10-07-2002, 08:27 AM:

There is a company offering a 1 million dollar prize to the person who produces a working over unity device.

--> http://www.seaspower.com

Posted by Steve Kraus (Member # 476) on 10-07-2002, 01:09 PM:

Yes, you can put electricity back into the grid and yes you must be in phase. If your voltage is higher than the grid (or you lead a tiny bit in phase) power will flow back out. Let me modify that to refer to the EMF that *would* produce a higher voltage when not online since obviously while connected your voltage would be the same as the grid.
If you tie it all together and your generator or sine wave inverter doesn't go up in smoke as you produce more and more power your meter will start to go slower and slower as you cover more of your own load. When you generate more than you're using and start exporting it to the grid the meter will begin to revolve in reverse (if a conventional disk motor meter and not physically prevented from doing so). This is not cheating the power company as it represents power you are selling them.

I think in the USA Federal law requires the utility to accept power from wind and solar generation and possibly (not sure) from co-generation systems. But they are not required to pay you retail rates for it which is what happens when the meter goes backwards. They'd install other metering for this purpose and give you wholesale rate credit.

Posted by Tim Reed (Member # 137) on 10-07-2002, 06:59 PM:

>:/ You've got to be kidding me! Really?

Posted by Steve Kraus (Member # 476) on 10-07-2002, 09:56 PM:

Here is a completely trivial case of a coasting projector generating a wee bit of power. This is how I have my projector motors wired, as I've previously described, with two switches. The wall switch will feed the motor and the Dolby Digital motor start relay; the base switch does not so the motor can be run with no concern of triggering the delayed DD switchover.

If you run the motor via the base switch (wall switch off) and then switch back to the normal position, the coasting motor will generate sufficient voltage to backfeed and lift the relay. This is seen by looking at the CP500D, which will sit in DD even with nothing running and only default to SR when it gets a contact closure on one or the other motor relays. Motoring at more than a low speed and as you switch off you see the CP switch briefly into SR then back to DD.

Posted by Frank Angel (Member # 248) on 10-08-2002, 03:41 AM:

There is a bill before Congress this session that will DEREGULATE the electrical power industry; if it passes, you can kiss selling electricity or anything else back to them goodbye, either at retail OR wholesale prices.

Posted by Jeffry L. Johnson (Member # 453) on 10-08-2002, 05:14 PM:

The courts are deciding the fate of net metering in Ohio.

Incentives in Ohio

Database of State Incentives for Renewable Energy (DSIRE)

Net Metering

Last DSIRE Review: 07/18/2002

Incentive Type:  Net Metering Rules
Eligible Technologies:   Solar Thermal Electric, Photovoltaics, Landfill Gas, Wind, Biomass , Hydro, Renewable Transportation Fuels, Fuel Cells, micro turbines
Applicable Sectors:   Commercial, Industrial, Residential
Limit on System Size:  no limit
Limit on Overall Enrollment:  1% of peak demand for each retail electric provider
Treatment of Net Excess:  New rules pending. See summary for details.
Utilities Involved:  Investor-owned utilities only
Date Enacted:  1999
Authority 1:   Ohio Revised Code 4928.67 (SB 3)
Authority 2:   Case No. 01-0573

Summary:

Enacted in 1999 by the State General Assembly as part of an electric utility restructuring bill, Ohio's net metering rule requires investor-owned utilities to offer a net metering option to customer-generators who own qualifying systems. Qualifying systems include wind, solar, biomass, landfill gas, hydropower, fuel cells and microturbines and must be intended primarily to offset part or all of the customer-generator's requirements for electricity. There is no cap on system size but the total installed capacity is limited to 0.1% of each utility's in state customer peak demand.

When the rule was enacted, the Public Utilities Commission of Ohio ordered utilities to purchase excess generation from their customers at a full retail rate. However, in June 2002, the Ohio Supreme Court ruled in favor of the utilities that this exchange was unreasonable and illegal, in Case No. 01-0573. While it is not yet decided how excess generation will be handled under this new ruling, it is likely that the utility will purchase excess generation from the customer at avoided cost, or that it will be credited to the following month for a period of up to three months.

Net metering system must meet safety standards of the National Electrical Code, the Institute of Electrical and Electronics Engineers, and Underwriters Laboratories. Utilities cannot require the customer-generator to comply with any further safety and performance standards.

Contact:
Kurt Waltzer
Ohio Environmental Council

Columbus, OH
Phone: (614) 487-7506
E-Mail: kurt@theoec.org

Posted by Bill Enos (Member # 440) on 10-09-2002, 05:42 PM:

No less practical than all this would be a collection syatem in the seats to collect gas from farts and pump it into the gas main serving the heating plant.

Posted by Daryl C. W. O'Shea (Member # 1303) on 10-09-2002, 06:15 PM:

One more reason why you should sell salsa with your nachos!

Posted by Craig Hanham (Member # 1010) on 10-09-2002, 06:33 PM:

As for selling power back to the company as mentioned above when you produce more than you are using the meter runs backwards, meaning a lower consumption rate over time. There are a few housholds in this country that do this with wind and solar cell generation. At night when the batteries are charged, surplus goes back to the grid.
It has required a bit of specil wiring and a meter change.
The power is not sold back to the utility, per se, but there is a huge reduction in the households bill.
As for using a projector for re-gen, forget it, as above conservation of energy.
The only way it can work is for motor vehicles, and more spectacularly trains.
Consider the case of an electric train travelling downhill. Lots of tonnage braking = kinetic generator.
I have seen an electric train dead heading a loco as it can provide back to the grid 15-20% of the power used in moving the train as a whole on flat ground.

Posted by Steve Kraus (Member # 476) on 10-09-2002, 09:11 PM:

Ah ha...a train analogy that didn't start with me.

Yes, depending on the electrification system and the type of equipment on the locomotive some use regenerative braking to slow or hold speed in check on downgrades without the use of regular brakes. The train going down the hill can quite literally help the train going up the hill by feeding power back to the catenary.

Otherwise they typically have dynamic braking where the energy is burned up as heat in resistance grids. This is also a common feature on most but not all diesel locomotives. Most diesels use an electric transmission (engine drives generator; traction motors turn wheels) so this comes quite naturally with only a bit of added equipment although some flatland lines do without to avoid the expense.

I believe the Acela train can feed dynamic braking-produced power into its DC link (the bus between the rectifiers and the AC traction motor inverters) as this bus also feeds the HEP ("hotel" power for the cars) inverter. Thus, free HVAC and lights aboard the train while coasting! IIRC it goes into dynamic automatically as it coasts across phase breaks (gaps in the overhead catenary) so there's no interruption in HEP and the lights don't go out in the cars.