10,000 hours life Level three approach requires new luminaires as well as new lamps:

• Can replace incandescent system with HID luminaires, control gear and lamps
• Can replace mercury lamp system with high pressure sodium or metal halide system. It requires capital investment for new luminaires and their installation so there will be a longer pay- back period even though the energy savings can be higher than levels one or two

Energy and Cost Saving Examples Basic parameters for three examples are:

• Energy cost: 7p/kWh
• Lamps burn 10 hours per day, 5 days per week, 50 weeks per year - 2500 hours per annum
• Lighting level will be the same as the present system
• Luminaires replaced on one-for-one basis

Example one

• Present system uses 1000W tungsten halogen lamps 21,000 lumens
• New system will use 250W Kolorarc metal halide lamps - 22,000 initial lumens
• Each tungsten halogen lamp consumes 2500 kWh of energy per year - costs £175 per lamp per annum
• Each metal halide lamp will consume 687.5 kWh of energy (275W circuit watts) - costs £48 per lamp per annum
• Annual energy saving for 100 luminaires is 181,250 kWh
• Annual cost saving of £12,688.00

Example two

• Two 2400mm 100W White fluorescent lamps (17,200 lumens) consume 230W per luminaire - annual energy usage 575 kWh at a cost of £40.25
• Replacement 150W Lucalox HO-T lamp (17,500 lumens) consumes 172W per luminaire annual energy usage is 430 kWh at cost of £30.10
• Annual energy saving for 100 lamps is 14,500 kWh
• Annual cost saving £ 1,015.00 Example three · 700W mercury vapour lamp consumes 750W per 1uminaire and provides 40,000 lumens - annual energy usage is 1875 kWh at cost of £131.25
• Replace with 400W Lucalox lamp which consumes 450W per luminaire and provides 47,500 lumens - annual energy usage 1,125 kWh at cost of £78.75
• Annual energy saving for 100 lamps is 75,000 kWh
• Annual cost saving £5,250.00

Economic Analysis Are future savings worth the investment?

An economic analysis of all costs involved provides a base for decision. As a hypothetical case study, assume a small warehouse lit by 100 only 250W mercury vapour lamps. Colour rendition is not critical and low operating cost required

Standard Lucalox lamps match these criteria

• 250W mercury vapour lamps provide 13,000 lumens
• 150W Lucalox-E lamps provide 14,500 lumens consume less power and give more light