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Energy analysis and reporting, How to waste energy

How to waste energy No. 7: meter reading

A big part of wasting energy is not knowing how much you use, when, where or for what. Most keen energy wasters rely on their energy suppliers not read their meters for them, but here are some top tips for those who want to be proactively bad:

1. Make it difficult to get access, for example by installing meters at height, or leaving the keys to the meter room with an obnoxious jobsworth.

2. Try to have meters installed in positions where you cannot see their dials.

3. Never have a reliable check-reading taken by somebody who knows what they are doing.

4. Do not create a meter schedule; if you have one, don’t keep it up to date.

5. Do not try to find out what each meter serves.

6. If in doubt about units of measurement or scale multiplier factors, make whatever assumptions you like.

7. When a meter is swapped out, dispose of the old one without noting its final reading.

8. Do not train anybody to read meters.

9. Do not appoint stand-ins to cover for sickness or holiday absence.

10. Allow meter readers to be lax about when they take readings, and let them record the date they were supposed to take the readings rather than the actual date and time.

11. Allow meter readers to include or ignore decimal fractions as they feel inclined, if possible being inconsistent between visits to the same meter.

12. Rely on paper returns, and lose them.

Link: Energy management training

 

How to waste energy

How to waste energy No. 6: air conditioning

The hot weather brings with it demands for air conditioning, and with that comes a whole raft of excellent ways for organizations to waste energy. Here are my top ten hot tips:

1. Don’t argue when people ask for rooms to be cooled to 20C rather than the more sensible 27C. Every degree reduction in set-point adds 10-15% to the electricity used for cooling, and you may even hit the jackpot of some people turning on electric heaters as well.

2. Encourage people to leave the windows open with the air-conditioning on. This allows warm air in and expensively-cooled air out, more or less guaranteeing that the air conditioning will have to run flat out without reaching the desired internal temperature.

3. If it is not possible to leave the windows or doors open, minimise the recirculation of ventilation air.

4. Do not take advantage of lower overnight outdoor temperatures to pre-cool occupied spaces.

5. Encourage people to leave idle electrical items running, to increase the heat gains. Desk fans are an excellent example for those who can appreciate the irony: by creating air movement they make the occupants feel more comfortable, while continuously heating the air a little.

6. Believe your IT department and equipment suppliers when they say their kit needs to be housed at 16C (the idea that it might be designed to operate in tropical climates is ridiculous).

7. In computer rooms have the equipment racks all in the same space, so that their warm extract air mixes with the chilled air needed for intakes. Under no circumstances partition the space to separate cold and warm air.

8. If possible, house people and equipment racks in the same space as if they needed and/or could tolerate the same conditions.

9. Do not shield windows from direct sunlight.

10. Always use artificial cooling when increasing the ambient fresh air supply would do the job equally well.

Energy management training

Energy analysis and reporting

Struggling to verify savings?

When people ask me for advice on how to verify energy savings, it is usually because their analysis is not giving the results they expected. Often they have left it too late, developing a methodology after the event or even making it up as they go along. So if you are contemplating an energy-saving project the first plea I would make is this: agree a measurement and verification plan between the interested parties before the project starts. That way, everyone is forced to think about the calculation methodology and (just as importantly) focus on what data will be needed, who will collect it, and even how much uncertainty there is likely to be in the conclusions. It also pays to think about what non-routine changes might occur (patterns of occupation, extensions, demolitions, etc) and agree how those will be factored in if they occur.

Sometimes, fortunately, it is possible to rescue the verification of a project where the “shoot first, ask questions later” approach has been used. To achieve a resolution one needs two things: first a willingness on both sides to accept a retrospective definition of procedure; and secondly, at least some accurate prior consumption data. That consumption data can, however, be sparse, so the presence of a lot of estimates (a common situation) need not necessarily be a problem. The analysis in such circumstances is done using a technique called “back-casting”.

Recall that in a normal evaluation, accurate and complete pre-project baseline data are needed so as to establish the prior relationship between consumption and relevant independent driving factors (such as degree days, hours of darkness, production and so on). A formula is derived, typically using regression analysis, for predicting consumption from those driving factors. After the energy conservation measure (ECM) has been installed, that same baseline formula can be fed with driving-factor data and will yield an estimate of what consumption would have been in the absence of the ECM. The spread between this estimate and actual consumption is a measure of the ‘avoided’ energy consumption.

The back-casting method is different. It turns that logic on its head. Using post-ECM rather than pre-ECM measurements, a formula is developed which relates consumption to driving factors for the improved installation (rather than its original performance). Thus you can say that the analysis “baseline” period follows, rather than precedes, the ECM, which some people find odd. In this scenario, pre-ECM actual consumptions can be compared with what they would have been if the ECM had been active all along, and one would expect those actual consumptions to be higher than the model’s predictions (the opposite of the conventional approach where post-ECM consumptions turn out lower than the baseline model predicts).

Back-casting is no less valid as a method, but it enjoys one big advantage in that you only need two firm meter readings predating the ECM. They should be as far apart in time as possible, and you need to be able to retrieve driving-factor data spanning exactly the entire period between the meter readings, but if those conditions are met, your model formula can tell you what the expected consumption of the installation would have been over that entire period if the ECM had already been in place, and hence how much more was actually used in the absence of the ECM. This back-to-front approach is attractive because regular meter readings are generally easier to assure after the project than before.

Link: Energy management training

How to waste energy, Human factors

How to waste energy No. 5: motivation and awareness

People are your greatest asset in the battle against energy efficiency. Here are my top tips for disengaging your workforce:

1. Focus on trivial behaviours like leaving phone chargers plugged in.

2. Position climate change as a key consideration in order to maximise time-wasting and unproductive debate. Remember also that a message of fear will paralyse rather than stimulate action.

3. Over-promise with slogans like “together we can save the planet”.

4. Give away branded mugs, coasters and other merchandise to enrage anyone bothered by waste of resources.

5. Do not canvass people for their opinions or ideas: remember the best instrument of communication is a megaphone.

6. If you do an opinion survey, use on-line techniques to be certain of reaching only those with computer access.

7. Use multiple-choice questions to be sure of missing responses you did not expect (obvious missing options also infuriate and alienate people).

8. Mount a high-profile launch event before you are ready with follow-on activities.

9. Appoint energy champions and leave them to sink or swim.

10. Be slow responding to staff suggestions.

11. If a suggestion does win an award, do not implement it.

12. Give individual cash awards: they can be wonderfully divisive if they are perceived as having gone to an undeserving winner.

13. If payouts are a share of savings, be ready to reduce the share for really successful ideas.

14. Don’t forget everybody loves to be awarded a T-shirt with an energy-saving slogan on it.

15. Have a poster campaign.

Link: Energy management training

Energy technologies

Voltage reduction: the short answer

I am somewhat conscious of taking my life in my hands in this issue, but as so many readers have asked me what I think about voltage “optimisation” (or reduction, to use a more accurate term), let me answer the question with the following three guidelines, which apply to everything from heating and lighting to motive power:

1. If the equipment is regulated in any manner, don’t expect voltage reduction to save energy.

2. If it is unregulated and you don’t mind reduced output, voltage reduction will save energy.

3. If it is a thermal application used on an intermittent cycle, voltage reduction will have a perverse effect, increasing energy consumption.

Link: Energy management training

Energy technologies, How to waste energy

How to waste energy No. 4: compressed air

1. Use compressed air for dusting off overalls, sweeping the yard and other cleaning duties. This not only wastes energy but blows debris into people’s eyes.

2. If you have individual applications that require a higher pressure, run the entire system to satisfy them rather than fitting local boosters.

3. Set overall system pressure as high as you can (check that the safety valves are lifting frequently). As a rule of thumb, every 2 psi increase in operating pressure requires an additional 1% energy.

4. For low-grade duties such as tank agitation, use clean dried compressed air at high pressure rather than fitting local blowers.

5. Locate air inlets in the hottest place possible – remember every 6C increase in temperature adds 1% to the electricity consumption.

6. Never clean your air filters and avoid fitting low-loss types.

7. Make sure you do not dry the air.

8. Allow all your compressors to run in parallel, sharing the load however small.

9. Do not shut the system down if the premises are closed at night; but if you do, empty the air receiver at the end of the day so that it needs to be repressurised in the morning.

10. Leave air-receiver drain cocks cracked open.

11. Bypass the air receiver so that the compressors have difficulty matching the load and need to start and stop frequently. This is a marvellously inefficient mode of operation, and abrupt swings in pressure will also help to maximise the number of leaking joints and fittings.

12. Maximise pressure drops in the distribution system by undersizing all pipework.

13. Ignore leaks: fixing one probably causes another to appear somewhere else. If you have a routine for tagging and repairing leaks, do not repair any that people find. As well as wasting energy this will discourage people from reporting air loss.

14. When specifying new equipment, give preference to models that continuously vent air. Use air tools if electric equivalents are just as good.

15. Look for opportunities to use compressed air inappropriately. Dusting off overalls may not waste enough; try using it for cooling motor bearings that are running hot, or to cool people working in hot locations.

16. Do not recover free heat from compressor exhausts if it is possible to use heat from a boiler system (or better still, electric heaters) instead.

Link: Energy management training

Energy technologies, How to waste energy

How to waste energy No. 3: lighting

1. If your light fittings are the type with translucent diffusers, fill them with dead flies.

2. Avoid replacing tungsten-filament light bulbs with LED equivalents. Although it is now illegal to sell most general lighting service (GLS) filament lamps, one can still buy “rough service” equivalents which have the great advantage of being even less energy-efficient.

3. Keep your external lighting on 24 hours a day. This encourages a culture of not caring about leaving things running when idle, and will help waste many times more energy than is used in the lights alone.

4. Also keep your internal lights on continuously, not least because doing so will increase the demand for air conditioning.

5. Provide excessive light levels in working areas and try to ensure that corridors and stairwells are even brighter (this removes one of the vital cues that prompt people to turn lights off when they leave empty rooms).

6. Be careless when specifying automatic lighting controls. Choose the wrong sensor technology, so as to maximise nuisance switching. This has a dual benefit – it encourages people to override the control, and it also antagonises them so they won’t cooperate with other energy-saving initiatives.

7. In shared workplaces, paint over any labels identifying which switch controls which zone.

8. Choose automatic lighting controls with remote control handsets that cannot be understood without training. Then lose the instructions and the remotes.

Link: Energy management training

Energy technologies, How to waste energy

How to waste energy No. 2: automatic control of buildings

1. Set your frost-protection thermostat at too high a temperature.

2. Override your time control to run the plant continuously.

3. Set heating controls for maximum air temperature. The aim should be to make it so hot that occupants are forced to keep the doors and windows open, increasing the heat loss.

4. Alternatively, place a baked-potato oven under the space temperature sensor. This will hold the heating off and encourage people to bring in electric heaters.

5. If you have adaptive optimum-start control, set the timings as if it were a conventional time-switch (i.e. with start of occupancy at the same time you would previously have asked the plant to start up).

6. Also if you have adaptive optimum-start control, set a target temperature above the daytime control setpoint. The control will add more and more preheat every day because it never achieves the target temperature.

7. If you have air conditioning, set it to cool to a lower temperature than your heating, so that the two systems run simultaneously providing perfect comfort at infinite cost.

8. If you have humidity control, set it for the narrowest range conceivable. This will ensure you are nearly always either humidifying or dehumidifying.

9. Remove or jam the linkages on valve and damper actuators.

10. Do not commission your building energy management system; do not document the control philosophy or agreed settings; and as a backstop, lose the operating manuals.

Link: Energy management training

Energy technologies, How to waste energy

How to waste energy No. 1: motor-driven equipment

1. When a motor fails, have it rewound by a cowboy outfit, as this will reduce its efficiency.

2. If you need to replace a motor, use the cheapest and least efficient unit available (preferably oversized). Efficiency standards of new motors are being continuously improved, so you may need to shop on eBay.

3. Shift motors slightly on their mounting plates so that any drives and couplings are misaligned.

4. Ensure that drive-belts are slack. On multi-belt drives it can help to remove some belts. If possible, use the wrong kind of belt for the pulleys fitted.

5. Change pulley ratios to drive fans and pumps at higher speed: on centrifugal fans and pumps, a 20% speed increase adds over 70% to the load.

6. Neglect lubrication of bearings and gearboxes.

7. Allow equipment to run continuously, whether it is needed or not. This has the added advantage of accelerating wear and tear, and reducing your power factor.

8. When the driven equipment is decommissioned, at least leave its motor behind, energised and running.

9. In dirty environments, do not clean any debris off motor cooling air inlets. The extra resistance to air flow will increase mechanical losses in the motor and, as a bonus, accelerate its failure by causing it to overheat.

10. In situations where the mechanical output of a fixed-speed motor is controlled and regulated, run the motor below its rated voltage in order to increase the motor current and associated copper losses.

Link: Energy management training

Energy technologies, Human factors

Duty-standby rotation

One of my clients, who operates computer data centres, asked his monitoring and targeting software supplier to conduct some pilot analyses using daily data. Cusum analysis of one particular circuit, which was feeding computer-room air cooling (CRAC) units, threw up an interesting observation: energy performance had been toggling between good and bad on the first of every month. This fact had been masked by the weather and variations in the quantity of energy consumed in the equipment racks, but once revealed, it was traced to the fact that they were alternating two banks of CRACs on a monthly cycle. In situations like this, it pays to change the regime so that preference is given to the more energy-efficient plant. This has the secondary advantage that the standby set will have more maintenance life left in it when the lead set fails. Cusum analysis is very good at providing insights like this, which is why I give it prominence in my training courses on monitoring and targeting.

The other place one finds opportunities for instant savings is multi-boiler heating systems, where, too often, the firing sequence is deliberately rotated to give each boiler the lead and even out the wear. Apart from making no sense in terms of risk management (when one fails, all the survivors will be equally clapped-out) it also misses the opportunity to favour the unit with the highest combustion efficiency, and thereby consume less fuel for a given output of useful heat. Anyone unfamiliar with combustion efficiency and the opportunities that it offers can read up in the A to Z guide at www.vesma.com.

Combustion tuning is a good (and frequently-overlooked) opportunity for nearly all fuel users.

Link: Energy management training