Friday, December 27, 2019

Energy Savings versus Money Savings

Do energy-saving appliances save money?   Let's crank some numbers and find out.
(annual electric cost, in dollars)

We just got done replacing the last incandescent light bulbs in our house.  These were ceiling cans that the previous owner installed in the trayed ceilings.  They were 75 watt bulbs - six in the living room, four in the bedroom, plus one over the tub, and one over the bar.   They didn't get used a lot in the last decade - nary a one burned out as a result.   But they did let a lot of heat escape into the attic, and when they were on, they got hot. 

The bathroom fixture had a glass cover on it, and this filled up with insects on a regular basis.  Where they come from, I don't know, but they are attracted to the light, and they go in there and die.

We bought replacement retrofit LED lights at Home Depot.  These came with two brackets, one the wire bail type, and another a friction fit.  We used the latter, as we have "naked" cans.  We paid a little more as a result, but they were adjustable from daylight (5000K) to warm white (2700K).   Unless you are running an operating theater, odds are, you'd rather have 2700K lights.  But that is part of the learning curve of all of this, and I am sure kids today are conversant in these color charts and degrees kelvin.   A 100-watt incandescent would mystify them.

We started the move to LED lights not because of energy savings, but because of heat.  In the kitchen, we have a track lighting system with 11 heads that had halogen bulbs.   It was like working under a heat lamp.  Switching to LEDs not only saved energy, but it cut the heat load in the kitchen dramatically.  So there is a double-savings here - you use less electricity to light your home, and you don't need to turn down the AC to keep the house as cool.

Calculating the savings - in theory - isn't hard to do.  A 60watt incandescent bulb can be replaced with an 8watt LED bulb which generates the same amount of light.   Maybe down the road there will be additional savings, as well, as LEDs go mainstream.   In the old days, we used to have 10 Amp wiring for lighting circuits - today the minimum is about 15 Amps.   It may be possible in the future that lighting-only wiring circuits go to lower amperage and thus use thinner copper wires - saving a lot of money on construction costs.  Maybe as little as five amps.  But that's far in the future.

If we assume the average home is illuminated for eight hours a day (morning and evening) and on average has ten lamps lit during this time of 60 watts each, we're talking about 4800 watt-hours a day or 4.8 KW-Hrs of electricity consumed.  In a year, that works out to 1752 KW-Hr of power.  Using the average cost of 13.19 cents per KW-Hr in the USA, this comes to $231 a year for lighting uses, or about 63 cents a day.

For the same scenario, using 8W LED bulbs, the cost drops to $30.81 a year, a savings of about $200 a year, or $2000 over a decade.  I recently bought two standard LED bulbs at Home Depot for $4 apiece.  You can get them cheaper online, and Dollar Tree even had some for $1 for a while.   I found the cheaper kind don't necessarily last as long - the vaunted 10 or 20-year lifespan may be overstated (how can you claim a 20-year design life on a product on the market only a few years?).

The price of incandescents has risen in recent years, while LEDs have dropped in price.  Not long ago, a single LED bulb would run $20 - then they dropped to $10.  Today they are two for $8 and even less online.   No doubt the prices will level off, eventually.  As production of incandescent bulbs dries up, the cost will go up - and has already.   They used to sell for under a dollar, but today they can be a few bucks.

Of course, an incandescent only lasts about 1000 hours, whereas an LED can last ten times a long.  In our scenario, we're burning the bulbs about 3000 hours a year, which may not be realistic.  Like I said, the incandescent ceiling lights in our house were never replaced until today - well over a decade after they were installed.  But then again, they don't get used much.

How long an incandescent bulb lasts depends on a number of factors.  How often it is turned on and off is a big factor.  When you apply power to an incandescent bulb, it is basically a dead-short and there is a huge inrush current.  Once the "filament" heats up, this current drops off.   But it is the on/off switching that blows out incandescent light bulbs, which is why they often were seen to "blow" when switched on.  It is also why those Guinness-Book-Of-World-Records light bulbs that have burned for decades were never switched off and usually installed in public buildings like fire houses and the like.

But assuming normal usage, the cost of incandescent bulbs will pay for themselves handily in lifetime alone.  The $4 bulb I bought today would replace ten incandescent bulbs, and that means an equivalent cost of 40 cents per incandescent bulb - a price I haven't seen since I was in grade school. Assuming an average cost of 80 cents per incandescent (per the USA today article from 2013) and ten bulbs replaced three times a year (per our scenario) we are talking about $8 a year in bulb cost, which means a savings of $4 a year by going to LED.

But the real savings is in the electricity. Now granted, maybe my lighting scenario is a bit overblown.  You can always save energy by turning lights off and maybe in the past a lot of people did this (I know we did).  Now that lighting is cheap, maybe people will be less inclined to turn lights off when they leave a room - that is the problem with efficiency - it defeats itself.

But the bottom line is, based on these simple calculations, we could be saving over $200 a year by switching to LED bulbs. Perhaps. Again, maybe my assumptions about light usage are over-the-top. For a family of four, maybe less so - everyone wakes up in the morning, turns on a light bulb, goes to the bathroom, turns on another light bulb, while Mom is in the kitchen turning on several light bulbs.  Then in the evening, the process repeats - only for yet more hours.  Ten bulbs, eight hours a day?  Not far-fetched.

And of course, to a lot of people, long-term savings that are not readily apparent in real-time are hard to fathom.  I recounted before the not-too-bright waitress at a local restaurant, lamenting that the toll to get on our island was $6 (now $8) and that she would have to wait until payday (seven days away!) to buy a $45 annual pass.  How broke do you have to be not to have $45 for a parking pass?   She certainly could afford the numerous tattoos and piercings she had.  And as we left the restaurant, we saw her smoking out by the dumpster.  But it illustrates how people look only to the immediate and not the long-term, even when the long-term is a week away.

But it begs the question - has switching to LED bulbs actually saved us energy?  This is harder to quantify, as the big energy hogs in any home are the air conditioning or heat pump, hot water heater, refrigerator, and other "major appliances".   Sure, you can switch to gas heat, but that is just replacing one form of energy with another.

The big savings for us has been installing double-pane vinyl replacement windows, to replace our single-pane wood-framed windows that came with the house circa 1969.   It is hard to point to a particular utility bill as going down, but we notice less heat coming off the glass in the summer, and fewer drafts and cold in the winter.

I recently plotted our energy usage for the last decade.  This isn't easy to do, as all I have are utility bills, which don't indicate the KW-Hr used - only the dollars consumed.  And Georgia Power only logs my energy usage for the last three years.  I have dollar amounts logged on quickbooks, but that doesn't tell me how much energy was used.  And the cost of energy has changed over time.  It is hard to find actual utility rates for all of 2009-2019.   Most give rates from earlier years, some from later.  Others are nationwide averages, others state-by-state.   Taking the KW-Hr and dividing by bill amount gives one number, but might not be the actual KW-Hr rating (taxes and fees might be added).

Overall, it seems that the cost of electricity is pretty consistent, around 10 cents a KW-Hr, closer to 11 or 12 these days.   Looking at some of the charts, I can see it fluctuates over time.   So we'll just use dollar amounts to save time.  The difference in calculation isn't too significant, compared to other things, like the weather.

With the change of the seasons, utility bills fluctuate.  So you have to look at annual cost to get an idea of year-to-year changes.  In fact, I can look at our utility bill and plot out our life experiences. For example, two years ago, we spent a few months travelling to Alaska and back.  Our home was unoccupied for nearly four months - during the most expensive part of the year, cooling season.   The house cools down at night, and takes a long time to heat up during the day.  Some months, our utility bill was under $50 - which alarmed me, as I thought the power had been shut off (a neighbor checked for me, and everything was fine).

When we first sold the New York house, we took a long trip to Newfoundland (I suggest strongly you go - allot at least a month, if not more).   We hope to go again maybe next year.  This year, it is the Isles de la Madeleine.  I becha didn't know they even existed!  I didn't, until I looked at a map and said, "hey, let's go there!"   So we're going.

Anyway, this makes it hard to look at the raw data and say, "look, here's where there is big savings when we installed the new windows" or "here's where the big savings kick in from the LED lights!" because they were installed over a period of several years.  The first two years in the chart, this was a vacation home, and we spent far more time away than in later years.   That means no hot water heater running, the HVAC set at 85 degrees, few lights on, and so on and so forth.

This last year, we replaced the HVAC system, and before the old one died, it was running 24/7 with a low charge, for nearly a month, just trying to keep up with the cooling load.   So for one month (July) we had the highest electric bill of all time - over $450.   This sort of skews the average a bit and illustrates why it is hard to look at actual bills to see savings.

If you filter out some anomalies, it does look like our electric bills have gone down.

Again, the first two years in this chart, we spent a lot more time in New York - leaving in May sometimes.  We also built the new Studio in 2011, which added quite a lot of electrical load (70A service) including an electric kiln that costs several dollars per firing.  In 2018, we left early for a trip to Alaska, which reduced our electric bill considerably.   But looking at the monthly bills over a decade, I see that weather is a big factor - cold winters generate big bills, as do hot summers.

Putting in the insulated windows helped a lot, and the LED bulbs contributed a small amount - probably along the lines I calculated above - maybe $200 a year.   Not a lot of money, but something, anyway.  Of course, over time, these cost savings will level out, as the efficiency will not continue to improve.   And as electric rates go up (thanks in part to an unfinished nuclear power plant that we are still paying for - that bankrupted both Toshiba and Westinghouse!) over time, costs will go up, of course - but not as much as they would have, if we had the old incandescent bulbs, old HVAC system, and single-pane windows.

There are two other factors to consider with LED lighting.   The first is lighting creep.   When we remodeled the garage, we added a lot more lights (like a LOT more lights - three times as many) and it is super-bright out there.  With LED lighting, you can add lights to a circuit without worrying about over-amping it.  When we relamped the kitchen track lighting, we added some additional "heads" to the circuit.  When we relamped the studio, we added several more.   I suspect we are not the only ones to be subject to lighting creep, at least for work areas.   Why live in the dark, when LED lights are so cheap and use so little electricity?

But a far bigger savings will occur for commercial users, not residential ones.  When I was at GM, we had a pair of guys who did nothing but replace fluorescent bulbs throughout the factory -  22 acres under one roof.  They started in one corner of the factory with a scissors lift, replacing bulbs, and worked their way across to the other corner - it took a couple of years to do.  Sort of like how the Golden Gate Bridge is perpetually being painted.  When they were done, they started over again.  You could not wait for a bulb to "burn out" as they would burn out randomly all at once all over the plant.  Besides, fluorescent bulbs loose a lot of their lighting power over time, so you have to "throw away" a "perfectly good bulb" long before it flickers out.

Now consider the same scenario with LED lights.  The pair of guys might be replaced with no one, other than the plant electrician who might replace the few lights that fail due to infant mortality, and then, 20 years down the road, they start replacing them all, probably hiring an outside contractor for that purpose, as it is only a one-time job.   More "jobs lost" - not to "automation" or "robots" or "AI" but to technology in general.  It is no different than the many gas stations converting their service bays - with a "mechanic on duty" to replace fan belts, batteries, and blown tires (which were quite common back then) and do annual "tune-ups"- to convenience stores selling lottery tickets, 20-ounce beers, and potato chips.

Again, jobs lost not to "robotics" or "automation" but just to better technology.   We've had the hamster now for nearly five years, and it has no need of a "tuneup" or will need one for maybe another five years - maybe more.  Simple fluid changes (and even those mostly limited to oil) are all that is needed.  Spark plugs?   They last over 100,000 miles.  Some cars likely go to their graves today with the original plugs in them.   Times have changed.

You could say the same for so many other things as well.  Appliance repair man?  Maybe for factory warranty service.  But the Maytag repair man is doubly lonely today, as no one bothers to pay $100 for a service call on a $400 appliance.  It is just easier and cheaper to buy a new one, particularly if your old appliance is more than eight to ten years old.   A sad reality, perhaps, but reality nevertheless.

Or take house painters.  How many were put out of a job by vinyl siding?   A good housepaint job might last five years, vinyl siding might last ten or twenty.  And even newer paints last longer than the old lead-based paints of yore, that peeled and cracked with the seasons.   Yet we don't hear Bill Gates warning of us of the evils of vinyl siding.   I don't put much stock in his warnings about "AI" which isn't all that intelligent, quite frankly, artificial or not.  And besides, he isn't even a programmer, just a guy who got lucky.

But once again, I digress.   But maybe not by too much.  LED lamps are just an example of new technologies that last forever (or at least a lot longer than older ones) and create all sorts of ancially issues, such as plastics do.  Plastic - the modern wonder material!  It never rusts, never degrades, never comes apart (well, it does, actually, but that is the subject for another posting).   The problem with plastic?   It never rusts, never degrades, never comes apart.

Technology changes the world, and we have to change with it.  And Trump is tapping into this fear of change, with his unhinged rants about light bulbs and toilets.   The bottom line is, of course, that LEDs are here to stay - they've won the technology war.  No one is going back to incandescents, unless they really are unhinged, just as no one is going back to carburetors and points ignition.

It is a rant that resonates with some, but perhaps not many - for very long.   It has been my experience that rednecks might resist change and new technologies, but often end up embracing them wholeheartedly over time.  Go to a tractor pull sometime and ask yourself how these folks figured out how to harness five supercharged big-block chevies into one transmission  - without the R&D resources of a major corporation behind them.   And they rarely break, too - under full load!

When I bought my 1948 Willys Jeep from some "mudders" in rural Illinois, they had put a 350 cid engine from a junked 1970 Chevy in it.  It was a masterpiece of redneck engineering, to be sure.   But they weren't so dumb as to stick with the stock breaker-point ignition.   It had an electronic ignition distributor out of a later-model car.  They ain't stupid.

I suspect the same will be true of these other modern technologies. Often the poorest and least educated are the most enthralled by the latest smart phone or jumbo-sized television.  Trump may make inroads with some government conspiracy theorists (who believe the CIA is monitoring their brainwaves through their water-saving toilets), but in the long run, it will be viewed as the ravings of an old man whose time has come and gone, much as John McCain, with his "hey you kids! off my lawn!" or Joe Biden with turn-of-the century terms like "Malarky".

Like I said, maybe that sort of rant had currency a decade ago, when LEDs were $20 apiece and people felt they were being "forced" to convert to the new technology.   Today, LEDs are on a par with incandescents (and actually cheaper to buy, by half, as I illustrated above).   Trump's rant is sadly out of date, as is the rest of his thinking.

Light bulbs are dead.  Long live the LED!