Energy Efficiency of Lifts
Up to 80% stand-by consumption!
Jürg Nipkow, Swiss Agency for Efficient Energy Use
www.energy-efficiency.ch
Lifts are considerable electricity consumers in
buildings – especially commercial.
In a Swiss research project (2005) energy consumption (kWh) and
division into drive and stand-by energy have been investigated.
33 lifts of different types and manufacturers were measured and
analysed. A projection of energy consumption by a standard usage
was caculated.
Final report ¾ www.electricity-research.ch
*
671
688
513
Residential building
300
300
279
211
196
165
157
119
116
107
100
100
77
100
62
55
49
42
40
37
33
0,000
26
25%
*
10,000
5,000
17,700
*
353
40%
*
15,000
Residential building
4,350
Standby consumption
340
%
standby
83%
Travel cycle consumption
20,000
Commercial building
Total
kWh
p.a.
950
* Cable traction with recuperation converter
25,000
16
Energy consumption of typical rope lifts:
Type of
Capaci- No. of No. of
building
ty kg
stops
cycles
p.a.
Small
630
6
40,000
apartments
Office block/
1,000
8 200,000
medium size
apartment
block
Hospital,
2,000
12 700,000
large office
block
Energy consumption
by travel
Energy consumption
byshown
number
ofcycle
travel cycles
kWh/a
330
Total electricity consumption of the approx. 150,000 lifts in
Switzerland was projected as 280 GWh p.a. or 0.5% of the
country consumption. In certain buildings, lifts may account for
up to 10% of the electricity consumption.
www.swiss-energy.ch
313
Energy consumption figures
11
source: Schindler
Travel cycles (1,000 p.a.)
Proportion of standby to overall energy consumption, by type of building
Residential building
Office
Hospital (visitors’ lift)
Hospital (visitors’ lift)
Car parking
Car parking
Office
Car parking
Hospital (lift for beds)
Office
Shopping centre
Office
Office
Residential building
Office
Office
Office
Residential building
Car parking
Frequency converter
Residential building
Cabin door lighting
Residential building
Operating console inside cabin
Vehicle lift
Operating console at each floor
Residential building
Floor display
Residential / surgery
Control device
Residential building
Typical shares of the different components to stand-by
consumption – example with switch-off of cabin lighting
facility:
% of stand-by consumption, by type of building
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Residential building
Composition of stand-by consumption
Energy saving measures
Technology
No lights on or doors under power when not in use
•
No hydraulic drive unless with counterweight or energy
storage
•
Efficient drives: adjustable speed drive, frequency
converter, PM-motor, gearless drive, recuperation
converter
•
Optimisation of counterweight: 20% instead of 40…50%
of nominal load, according to average load
•
Efficient lighting: FL & CFL instead of halogen lamps
Planning and dimensioning
•
A minimal number of lifts in a building reduces cost,
required space and power/energy needs
•
Lower travel speed needs less power: 0.63 metres per
second is sufficient for up to 6 and more storeys
•
Lift control: collective instead of taxi operation saves
travel cycles
•
Lift system architecture: suspension type and guide
elements influence friction losses
Typical power input while travelling down - up (rope lift, empty)
Up:
no recuperation,
would be < 0 with recuperation
Down:
hoist counterweight
4000
3000
Acceleration
2000
Breaking
1000
Door
Stand-by
Reduce stand-by power, develop sleep mode
•
power [W]
•
Door
Breaking
Door
0
0
4
8
12 16 20 23 27 31 35 39 43 47 51 55 59 63 67 70 74 78 82
time (seconds)