The Oil Drum | Tuesday Open Thread

146 comments on Tuesday Open Thread

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DuncanK on March 7, 2006 - 8:14pm

Interesting question.

I'm just in the middle of putting together an energy strategy for my company (small 20 person software development house).

I've grouped energy efficiency into 3 categories:

Easy (read: cheap) "low-hanging fruit" savings

Low-energy light bulbs
Turning off equipment not in use
Configuring all PCs to use maximum power savings settings

Medium term (a bit more expensive):

Replacing Desktop PCs with laptops. Desktops can use anything up to 800W, whereas laptops typically use less than 100W. Laptops also give you backup power during blackouts.
Replacing servers with low-energy CPU models. Also, replace server monitors with LCD ones. These would also reduce the air-con requirements in the server room
Consolidating separate server activities onto fewer actual machines
Reduced voltage Fluorescent circuits saving up to 30%

Long-term, high cost:

Solar PV array on roof to power servers and core lighting
Replace vehicle fleet with hybrids or electrics
Solar water heaters for toilet/showers hot water
Free Company minivan to maximise car-pooling. Employees would have to use their own vehicle (at their own cost) if they 'missed the bus'.

I reckon the easy stuff could knock off up to 20% of current electricity usage, with the medium stuff pushing that up to almost 50%.

As I'm doing the research in my own time, I'd appreciate any other suggestions for efficiency that people might have.

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Mad Maxout on March 7, 2006 - 8:49pm

There is one way to reduce A/C cost of a server farm and make hot water. Adapt the the servers to use water cooling. The water cooling of the CPUs can pre-heat water for the solar to finish heating it or use other otherwise-waste heat. (though not from CPUs.) A server can drain a hundred watts or more just for the CPU itself. 10 servers like that, and you get a kilowatt of "free" heat - and 3600 BTUs removed from A/C load. The watercool interface heatsink costs $50 a pop. $500 for a free kilowatt and removal of 3600 BTUs of A/C. Not low-hanging fruit, but you're not brachiating in the canopy either.

The laptops idea is good too. I use one at home mainly for that reason. Backup for more than an hour is easy. Mine takes 24 volts @ 2 amps at most, so I could go hours on a pair of marine batteries in series. A neat idea for servers: If you need file servers, some networkable hard drives (similar to the USB variation) can work wonders unless I suppose you really load it up. A normal server will be needed for a web site. With Linux, a normal server plus a batch of USB hard drives can make a lovely server setup.

If you want really high-altitude fruit, it's a fact that skinny people need less A/C than fat people. Figure out a way to encourage people to slim down, and you can solve the obesity problem! (assuming peak oil doesn't solve it by famine first!)

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Gets IT on March 8, 2006 - 9:10am

Hard to see it. Seems much more valuable to use the heat as hot air space heating as I do. GB's A/C load at this time of year is zero and minimal, except for 1 month, the rest of the year.

3412 Btu/h = 1 kW @ 100% heat transfer efficiency
reasonable heat transfer @ 60% efficiency
1 kW = 2047 Btu/h

10 computers @ 100 W/ea = 3600 W
@ 60% efficiency = 2160/h Btu useable heat transfer
2160 Btu/h /3412 Btu/h/kW = 0.63 kW saved/hr
@ 0.125 $/kWh
savings rate = 0.07875 $/h

$500.00 material cost
add
$500.00 Labour Cost (unless you DIY as a hobbby or labour of love)
$1000.00 Total Cost

@ 0.07875 $/h = 12698 hrs
12698 hrs/8h/d = 1587 Work days
260 WD/yr = 6 years (@ i=0%)

Evaluating Alternatives
$1000.00 invested @ 5% simple interest/yr
$1000.00 invested in PC water heat X-changer

Even allowing for a fuel cost escallation factor of 25%/yr

Net Values won't be equal for about 10 years.

Even if you install it for free, it takes 8 years.

Problem is; Who keeps a PC for more than 3 years?
At end of 3 years, you must remove cooler and replace it in the new equipment. Another 500.00 every 3 yrs to do that.

Every 5 years? Needs running the PC for 11 yrs.

I haven't seen a 8 yr old PC anywhere, although there is a 5 year old one over in the corner that hasn't been turned on for 2 years now. I don't think I'll turn it into a water X-changer anytime soon. Do they make good air heaters?

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TrueKaiser on March 8, 2006 - 6:30pm

Problem is; Who keeps a PC for more than 3 years?

more then you realize.
contrary to popular belief the vast majority of pc users(all the non-gamers) keep their machines as long as possible.
the parents of a friend of mine still use their amd-k6 350mhz machine.

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Gets IT on March 9, 2006 - 6:50am

You're probably right. I do a lot of CFD work, but did buy a game about a month ago. The first game I bought since CivII 5 years ago. I was intending to put it on a 450 mHz I've had sitting in a dark corner waiting to become dinner for a canibal. Needless to say, it would hardly run the intro screen.

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Leanan on March 7, 2006 - 8:49pm

The last time my employer went on a cost-cutting binge, they removed half the lightbulbs in the building. Just ordered the maintenance guys to remove every other flourescent light tube. Many employees actually preferred that, since it's easier to look at a computer screen in the dark. It was kind of dreary and depressing in the hallways, though. (They don't get any natural light.)

As usual, the main office ordered that all computers be turned off at night. Also as usual, our IT guys said to leave them on. They run antivirus software at night, and send out software updates, and if the computer's not on, it causes hassles.

They also went on an appliance-hunting binge. Space heaters, fans, aquariums, toasters, etc. were banned, and if you still had them after a certain date, they were confiscated. Coffee makers, refrigerators, and microwaves were permitted. This caused a good deal of disgruntlement. I suspect it wasn't worth it. Caused a lot of bad feeling, and a lot of people just hid their appliances and used them anyway.

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Donal on March 7, 2006 - 9:51pm

Thanks, I'm stealing this list for my clients.

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DuncanK on March 8, 2006 - 5:21am

You're welcome. I'm very 'open source' when it comes to info like this. There is so much to learn from each other.

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BeaconBoy on March 7, 2006 - 10:29pm

Duncan

Here's some.

Before changing the water heater try putting in a low flow shower head. This saves water and energy.

Then you can buy a smaller model.

Turn down the thermostat on the Air Con in Winter and up in Summer. Make the office temp more like the outside.

Travel less and use the phone more.

Cheers

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AlanfromBigEasy on March 7, 2006 - 11:22pm

Regarding energy saving idea, please contact me. I cut total power use for a 5 story office building in New Orleans by almost 70%. Nothing high tech, but "different" approachs.

Alan_Drake@Juno.com

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Engineer-Poet on March 8, 2006 - 12:37am

If you aren't going to post it here, mail me a copy and I'll put it up as a guest piece case study at The Ergosphere.

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AlanfromBigEasy on March 8, 2006 - 12:57am

I am a bit short of time, but this is what I wrote. Perhaps a more complete report later.

Each site is different. This one oncluded:

Not just T-8 fluorescent, but high CRI bulbs (extra 50 lumens, higher light quality offsets lower quantity. Used light meter and Illuminating Engineers Society standards. Premium ballasts.
I used 95% reflective computer folded reflectors (Metal Optics)

Single bulb with reflector in hallways for example. 4' of single bulb, 4' space, 4' of single bulb, etc.

Replaced two large 60 ton AC units with 18 residential high efficiency units. 1/3 of 1 floor turned on when someone came in on Sundays, much less air pumping loss. Installed high efficiency gas furnace (condensing exhaust allows MUCH easier installation). Just 10 tons (120,000 BTUs, 34.2 kW) of "bulk heat" plus some heat pumps (others straight a/c) and a few electric strips) provided heat in our mild winters.
Make up air from outside pumped in only when CO2 monitor requests it. Windy day, no requests due to wind driven leaks. This is a MAJOR energy savings !
Reflective film added to windows. Saved 10 tons of a/c. Also keeps heat in in winter.
Plugged holes into building, including gaskets behind switches & outlets. Added insulation to underside of roof with glue-on pins. Added insulation where-ever possible.

Off the top of my head,

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Gets IT on March 8, 2006 - 9:17am

Now that's some good stuff!

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Richard on March 8, 2006 - 2:45am

I think if you make a rule that in the winter the temperature is 18 deg Celcius and in the summer it is 28 deg Celcius and ask people to change their clothing accordingly, you save quite a bit.

Another thought: Why don't you ask the people in the office? In my office, we close the blinds to get the right light for the computer, but we turn up the heating because it gets cold. And we switch on the office lights. A rearrangement of the desks would solve part of that.

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Halfin on March 8, 2006 - 2:05pm

Hope you don't mind me coming to work in a tank top and Speedo because that's the only way I'm going to be comfortable at 28 C, aka 82 degrees Fahrenheit. Otherwise I'll be sweating like a pig. Anything above 72 and I'm uncomfortable. 60s, I'm feeling great. 50s, I'll put on a long sleeve shirt.

That's just me, but in any office you'll find just as many people with problems at the other end of the scale. At 18 C, aka 64 F, they'll have to bundle up like it's Siberia. It's hard to type when you're wearing ski gloves.

In my experience if you don't keep the thermostat pinned right at 72 you get a lot of complaints.

Here's my creative solution to the problem. Set up a heat gradient. Put your heater vent at one end of the building, and the air conditioning vent at the other end. Then one end is consistently warmer than the other, and people can choose their seating according to their temperature preferences. And you only have to heat/cool a portion of the building, for considerable energy savings.

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AlanfromBigEasy on March 8, 2006 - 7:43pm

The key is to lower humidity (down to about 45% RH, below that some complain about dryness, mainly native New Orleanians who develop gills :-). Each person's comfort range broadens as humidity drops, and much more "overlap" of comfort ranges develops.

Standard HVAC practice to lower humidity is to supercool the air, then reheat it (4 pipe system or use electric strip reheat). Wonderously efficient !! :-P

I did two things, bought AC evaporators with variable speed motors and attached humdistats to some of them (others were just set on low ALL the time, saved the cost of a humdistat).

And bought some dehumidifers from DEC, most energy efficient on market.

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Mad Maxout on March 8, 2006 - 9:44pm

The heat gradient idea is great. It potentially solves a problem that is the bane of building maintenance people everywhere. Some people (usually women) need it HOT and others (usually men) like it COLD. Add in ethnic diversity (people coming from hot or cold climate places) and that spells big trouble with thermostat wars.

The only alternative is allow fans and in summer keep it at 78F (25.5C) and in winter trun the heat down to 68F (20C) and pass out sweaters. Women would just have to wear pants and long underwear instead of use desk heaters, which are fire hazards.

Where I work, the warehouse floor wasn't heated to the mid-80s only becuse of natural gas prices. The offices are still saunas due to desk heaters. These offices are at least 30C (86F) becuse mostly women work in them - and belong to a hot climate ethnic group. Worse, they refuse to dress warmly if they get cold. They complain instead or use desk heaters.

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Magnus Redin on March 8, 2006 - 5:54am

You probably already have them but sun blinds to keep direct sunlight from reaching the windows is a very good idea.

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Donal on March 8, 2006 - 8:47am

At Bartlett's conference last year, the engineer Wulfinghoff recommended that we start designing buildings with very small windows shaded from the sun.

I see it as a coming design challenge to reconcile this approach with daylighting, clients' desires for natural light/good views and the commercial aspect of extensive storefront glazing.

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Leanan on March 8, 2006 - 11:46am

My building used to have heat, but not air-conditioning. (They eventually were forced to install air-conditioning for the computers.) We used to open the windows to cool the building off in the summer.

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Gets IT on March 8, 2006 - 3:53pm

Lotta' buildings in Houston you can't even open the windows without a large heavy brick.

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kjmclark on March 8, 2006 - 11:29am

Did anyone else find it interesting that almost none of the ideas mentioned involved oil and/or transportation? Employers share part of the responsibility for employee transportation energy, but they almost always ignore that, as if no energy was used in transportation. This "energy expenditure that doesn't exist" phenomenon is one of the reasons I suspect oil peaking will be so difficult for the car-dependent world.

There are lots of excellent ideas already, so I won't repeat those. I'll add one for non-petroleum energy savings and a few for petroleum energy savings.

Buy a small combined heat and power (CHP) genset. Capstone Microturbine and its competitors are good sources. These double as uninterruptable power sources and achieve high efficiencies, well over 90% as CHP systems. This may not seem like an energy saving idea, but when you consider the amount of loss in the electrical transmission grid, decentralized electrical production makes more sense. This should be much cheaper than similar sized solar or fuelcell systems and can run on bio fuels or waste gas.
Charge for parking, and provide everyone with a tax deductable transportation subsidy instead.
Provide covered/enclosed bike parking close to a building entrance.
If/when the business decides to relocate, make sure the new location is close to transit lines, on bicycle friendly routes, and in an area that would allow some employees to walk.
Stop maintaining the parking lot (assuming the business has one.) Over time, remove parking so that there is less to maintain. If possible, sell or build on the land that is now unused parking.

I recommend you broach the last four topics with extreme caution, as you may find severe hostility to any idea that reduces parking privileges. I was nearly fired for making suggestions to improve conditions for nonmotorized transportation, and I work for the EPA!

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Leanan on March 8, 2006 - 11:50am

We were forced to cut our gasoline use for air quality reasons. There was talk of paying people to walk, bike, or carpool, charging people to park in the parking lot, etc. In the end, they just decided to buy cars that don't use gasoline. So we have a fleet of electric vehicles, and natural gas vehicles. And now one hydrogen.

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tom deplume on March 8, 2006 - 12:55pm

In the 90s there was a tax credit available for employers who pay for bus, subway, train fares of employees. Where I worked the credit was more than the price of a monthly bus pass. Don't know if it still exists.

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DuncanK on March 8, 2006 - 10:04pm

Yes, the idea I had was a company minibus.

Here in the Hawkes Bay region of NZ, we have two major towns, Napier and Hastings, which are about 20km apart. Up until last september our office was in downtown Napier, and about 12 of the 18 employees lived in Napier or it's suburbs.

In September we moved into this office in Hastings with a 14 year lease. Now the 12 people from Napier have about a 15 minute commute (much grumbling).

So, a company minibus could be driven by the person who lives furthest away, and he can come along a prescribed route that everyone else can walk to. Employees then have the choice of the free company minibus or use their own vehicle at their own cost.

Of course, some people may need to run errands at lunchtime, so they would need their car, but as petrol prices go higher they'll probably think more about combining those trips to save on fuel.

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