Author Topic: Electricity getting very expensive in the Workshop  (Read 16078 times)

Offline awemawson

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Electricity getting very expensive in the Workshop
« on: April 26, 2022, 12:29:47 PM »
Today I replaced twelve 6 foot T8 70 watt fluorescent tubes with LED replacements. I have a total of 36 of the 6 foot tubes in the main workshop giving 2500 watts so with electricity having gone up to 29.49 p per kwH this was costing 75 pence per hour just to light - never mind actually using any machines ! My electricity for the workshop had been running at £8 per day (inc standing charge) so something HAD to be done.

The twelve that I have changed were a pilot exercise to check light quality etc, not a cheap exercise though at north of £150 for the LED tubes. If I can scrape any spare cash together I'll certainly do the other 24 as they are pretty good, and apart from access issues over machines were very easy to do - just replace the starter with a 'special' which actually is just a short circuit - then put the new tube in.

These ones are 24 watt so a saving of 66%

The welding shop foundry and woodwork shop probably have another at least 36 tubes between them which is why I've been putting it off - darn expensive this saving money lark!
Andrew Mawson
East Sussex

Offline RussellT

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Re: Electricity getting very expensive in the Workshop
« Reply #1 on: April 26, 2022, 01:21:29 PM »
I used to have a job trying to persuade businesses to use less energy because of climate change :bang: :bang: :bang:.  I think this would have been a good example - if it was used 8 hours a day 5 days a week the investment would be paid for in less than six months - most businesses would have managed that because they could do the investment from the fuel budget rather than needing to ask for funds from the boss.

For your workshop the hours of use will probably make it more difficult to justify, however adding switches and only lighting part of the workshop is likely to be even more cost effective.

Russell

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Offline awemawson

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Re: Electricity getting very expensive in the Workshop
« Reply #2 on: April 26, 2022, 01:48:56 PM »
Yes Russell I have it wired in 'three banks' originally to distribute the load across three  6 amp MCBs each with their own three switches giving switching individually per group of four lights. (Big grid switch by the door)

The bank that I've done is the crucial one - it covers sink, loo, my desk, bench, and the CNC milling machine so that bank can remain one while the other three are in gloom !

Amusingly for some time I've had one tube that for the life of me couldn't get to strike up. and I was convinced that the ballast choke must be O/C - today I even dismantled the fitting to measure the choke (which was fine) only to find one pin on the original fluorescent tube  bent over at 90 degrees  :bang:
Andrew Mawson
East Sussex

Offline tom osselton

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Re: Electricity getting very expensive in the Workshop
« Reply #3 on: April 26, 2022, 04:24:12 PM »
I’ve never regretted installing led lighting in the garage 

Offline awemawson

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Re: Electricity getting very expensive in the Workshop
« Reply #4 on: April 26, 2022, 04:36:33 PM »
Well I've pushed the boat out and ordered another 24 LED tubes - bankruptcy here we come  :bugeye:
Andrew Mawson
East Sussex

Offline vtsteam

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Re: Electricity getting very expensive in the Workshop
« Reply #5 on: April 26, 2022, 05:24:27 PM »
Heck even I switched out my six 40 watt tubes for LED tubes in the larger shed. Lit maybe 200 hrs/yr.  It wasn't obviously the money driving it. I may never reach the payback period.

I just don't like the unnecessary energy usage, the mercury contamination, the slow start and unreliability in cold temps,  the short life and disposal problems of the old fluorescent tubes. It's a vast improvement any way you look at it.

But, I think halogen bulbs give a far better color spectrum than incandescent, fluorescent or LED bulbs -- at least from an artist's perspective.

LED's are improving that way, but you really have to look at the specs to tell if you're getting something pleasant to live with. fluorescent were generally poor that way as well, so for shop use, LEDs are no worse and might be an improvement.

I usually like a warmer light environment, so I go for the ~3000 - 3500 K +-  "soft white" types instead of the "daylight" types at 4000+ K, and look for 90 or better CRI (color rendering index) in the home so there aren't big holes in the color spectrum.

A few years years ago a local coffeehouse changed over to LED fixtures (with non-removable bulbs) -- talked into it by an electrician because their old incandescent ceiling fixtures and wiring were having ground problems. The owner was proud of the change, but after the change customers looked like walking cadavers, and the art shows on the walls might have been painted in gray tones. It was (and still is) an ugly light to sit in.
I love it when a Plan B comes together!
Steve
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Offline WeldingRod

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Re: Electricity getting very expensive in the Workshop
« Reply #6 on: April 26, 2022, 09:59:20 PM »
Another factor if you live in air conditioning country: you pay for the light then you pay to pump out the heat...  a 100 Watt light puts exactly 100 Watts of hear into your room!

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Offline awemawson

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Re: Electricity getting very expensive in the Workshop
« Reply #7 on: April 27, 2022, 02:42:42 AM »
I’ve recently swapped out over 50 “GU10” halogen lamps for LED in the house. The saving with them is far greater than fluorescents as a 50 watt halogen replacement with approximately the same spectrum is only 5 watts. So only one tenth of the cost to run.

Anyone want a big pile of halogen bulbs and 6 foot tubes just ask!
Andrew Mawson
East Sussex

Offline hermetic

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Re: Electricity getting very expensive in the Workshop
« Reply #8 on: April 27, 2022, 04:09:01 AM »
Hi Andrew
  What are the current/induction implications of keeping the ballast in circuit? I must admit that offhand I don't know, but it would seem to be slightly counter productive, given that the driving current for the led's should be less than the tube current but perhaps enough to create some ballast losses? As my 8ft tubes fail I am replacing them with two 4ft led tubes held in the centre with terry clips and removing the ballasts, and it looks like they are producing similar light levels to the 2x8ft tubes they replace. I have found that 2x4ft led tubes can be had for much less than 1x8ft led tube! I am spoilt by the fact that when I put the lights in I used plug in ceiling roses and chain suspension, and that combined with my low ceiling means that they are really easy to get down, I imagine yours are a lot higher?
Phil
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Offline awemawson

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Re: Electricity getting very expensive in the Workshop
« Reply #9 on: April 27, 2022, 05:11:14 AM »
Phil, yes the main workshop is high giving access issues, and the rows of lights are wired in plastic conduit running between beezer boxes on top of each light, the lights being chain suspended. This makes taking an individual light down quite difficult.

As for the ballast issue - I don't know the answer. I suspect that the current limit for the leds doesn't rely on the reactance of the ballast, as it would seem from the instruction sheet that it can be totally eliminated (with dire warnings regarding being a competent electrician!)

Turns out that I would need a further 41 LED tubes to replace all the 6 foot 70 watt fluorescent tubes that I have distributed between the welding shop, the foundry, the wood workshop and a Portakabin. This would be  a further 'investment' of £553.50 so that's NOT going to happen. I console myself with the fact that their use, unlike the main workshop, is pretty intermittent.

Scary to think that with the original 77 (total) 70 watt tubes there was 5,390 watts off lighting if all were on at once, which of course was actually never the case.
Andrew Mawson
East Sussex

Offline vtsteam

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Re: Electricity getting very expensive in the Workshop
« Reply #10 on: April 27, 2022, 08:11:37 AM »
I pulled the ballasts out of mine and wired direct to the tube holders. My tubes came with stickers to put on the fixture warning of the changed connection. Got a lot of electronic parts and copper wire for the scrap bin.

Of course I only had three of them!
I love it when a Plan B comes together!
Steve
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Offline Muzzerboy

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Re: Electricity getting very expensive in the Workshop
« Reply #11 on: April 27, 2022, 08:33:18 AM »
Last time I looked, the light output per W of drive was actually very similar for fluorescent and LED. Something like 100 lumens per Watt is typical for both modern LEDs and fluorescent tubes. On the face of it, replacing all of your tubes won't actually reduce your bills in the short term. They even claim very similar life for tubes and LEDs, possibly even longer for tubes. And yes, tubes lose output with time as they age and their voltage increases. But so do LEDs - they age and wear out too before finally failing.

Don't get me wrong. I'm an electronics engineer and I use LED lighting. I prefer to avoid glass tubes and mercury vapour for batten lighting. But being an engineer, I like to get my data right too!

The way the light output is defined / measured may differ between the 2 technologies but by and large, the numbers are going to be reasonably meaningful.

Here's some of the readily available options:
LEDs:
https://www.screwfix.com/c/electrical-lighting/light-bulbs/cat8350001?calclightbulbtechnology=led&cm_sp=managedredirect-_-lighting-_-ledbulbs
Tubes:
https://www.screwfix.com/c/electrical-lighting/tube-lights/cat2690010

Offline awemawson

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Re: Electricity getting very expensive in the Workshop
« Reply #12 on: April 27, 2022, 09:04:46 AM »
On the face of it, replacing all of your tubes won't actually reduce your bills in the short term.

For these tubes the electrical consumption has reduced by 66% for an illumination that subjectively is better so I'm not sure what you're on about !
Andrew Mawson
East Sussex

Offline Muzzerboy

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Re: Electricity getting very expensive in the Workshop
« Reply #13 on: April 27, 2022, 01:05:10 PM »
Sorry I wasn't getting at you but I don't see the 66% improvement anywhere. The lumens per watt seems like a useful figure of merit.

What figures are you looking at here? I agree LEDs are a better solution but don't see how you'd save 2/3 of your electricity costs.

Offline vtsteam

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Re: Electricity getting very expensive in the Workshop
« Reply #14 on: April 27, 2022, 01:27:16 PM »
Seems odd to me. I agree with Andrew that the light level seems equivalent or better with the LED tubes than it was with the fluorescents. So much so that I now am using a single tube in each fixture instead of two.  The Parmida brand tubes I use are rated at 2200 lumens on 18 watts.

Also you might consider that the illumination is directional on an LED tube, even a frosted one, while it isn't on a conventional fluorescent tube. So the lighting is more effective in the downward direction. Thus effective light levels may be higher.

By reducing the number of tubes there is an additional savings.
I love it when a Plan B comes together!
Steve
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Offline vtsteam

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Re: Electricity getting very expensive in the Workshop
« Reply #15 on: April 27, 2022, 01:44:36 PM »
Checking for similar daylight fluorescent tubes I get 3,000 lumens average on 40 watts. That's 75 lumens/watt.

For the Parmida tubes it's 2200 lumens on 18 watts, or 122 lumens/watt. That's about 40% savings based on specs.

But also this is kind of academic, since in reality you are replacing a 40 watt bulb with an 18 watt bulb, so the electrical savings is exactly that ratio. Watt cost per lumen is kind of an arbitrary figure compared to watt cost per tube in any tube replacement scenario.

And you can't even assume that the light level is lower. In reality the LED light is effectively brighter because of the directional nature, and while that won't create an additional savings in itself, in my case, using half the number of tubes definitely does.
I love it when a Plan B comes together!
Steve
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Offline awemawson

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Re: Electricity getting very expensive in the Workshop
« Reply #16 on: April 27, 2022, 02:29:46 PM »
@Muzzerboy

In my view it's extremely simple (like me!)

I am replacing fluorescent tubes that consume 70 watts with LED replacements that consume 24 watts. So my electricity consumption will be 24/70 or 34% of what it was. 100% reduced by 34% is a 66% reduction.

As the LEDs are giving me subjectively slightly better illumination than I was getting before then the only down side is the capital cost. These particular units are guaranteed for 3 years.
Andrew Mawson
East Sussex

Offline vtsteam

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Re: Electricity getting very expensive in the Workshop
« Reply #17 on: April 27, 2022, 02:56:14 PM »
Once again, theory meets reality.
I love it when a Plan B comes together!
Steve
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Offline WeldingRod

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Re: Electricity getting very expensive in the Workshop
« Reply #18 on: April 27, 2022, 05:31:23 PM »
You definitely want to bypass the ballast!  Don't waste power making it hot!

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Offline chipenter

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Re: Electricity getting very expensive in the Workshop
« Reply #19 on: April 28, 2022, 01:44:15 AM »
I fitted Gu10 downlighters over my working area over four years ago , I have had one failure recently two of the LEDs fell of , replacement was £3.99 for four on offer , over the lathe and mill are 12 volt downlighters even older no problems so far , as they are at head height they don't burn my head .
Jeff

Offline awemawson

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Re: Electricity getting very expensive in the Workshop
« Reply #20 on: May 01, 2022, 03:45:56 AM »
Yesterday I replaced the remaining 24 tubes in the main workshop - some amazingly inaccessible over various machines - in fact the four that span over the Beaver CNC lathe one needed to walk on top of the machine enclosure. To my great surprise the wife volunteered which probably a very good thing as she must weigh about half of what I do !



. . . only another 41 to go in various other outbuildings and workshops but in all likelihood I'll leave them as they are 'occasional use' only.
Andrew Mawson
East Sussex

Offline vtsteam

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Re: Electricity getting very expensive in the Workshop
« Reply #21 on: May 01, 2022, 11:38:18 AM »
Andrew how is the light level? Does it feel brighter in there now?
I love it when a Plan B comes together!
Steve
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Offline awemawson

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Re: Electricity getting very expensive in the Workshop
« Reply #22 on: May 01, 2022, 12:16:42 PM »
Yes very much so Steve for several reasons I think:

A/ The LEDs are actually brighter

B/ Although most of the fluorescents were less than a couple of years old a significant few weren't

C/ The fluorescent tube were pretty grimy so not allowing all the light out

D/ I was greatly inhibited from turning on lights, putting up with a bit of gloom. But much less so now!

Andrew Mawson
East Sussex

Offline vtsteam

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Re: Electricity getting very expensive in the Workshop
« Reply #23 on: May 01, 2022, 01:30:53 PM »
Same here.  :thumbup:
I love it when a Plan B comes together!
Steve
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Offline Jo

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Re: Electricity getting very expensive in the Workshop
« Reply #24 on: May 01, 2022, 04:05:55 PM »
I keep thinking about replacing my fluorescent tubes with LEDS but they still provide a very useful low wattage workshop heater especially useful  at this time of the year when I have turned off the night storage heater out there.

I may have mentioned that I am the proud owner of a 4KW solar array which means that in spring/summer/autumn all power use in my workshop is "free"   :ddb: The painful bit is winter when the sun is not that strong so there is not a lot generated  :bang: but at that time of the year I need to heat the workshop so a few extra watts of funded warmth is not going to be sneezed at.


On a slightly different usage of the LED in the workshop: I have a couple of the smallest LED flood lights mounted on the end of a goose neck with a 6" tarpaulin clamp on the other end for securing them. Very handy for over illuminating areas when the need arises  :dremel:

Jo


So many engines to build and yet so little time.