#### Ice Rink Installation

An ice skating rink had metal halide lamps in their arena and considered plasma lamps as a replacement. The facility had dimensions of 231ft x 148ft for a total floor space of 34188sq ft and had a ceiling height of 30ft. The target floor lumination was 700 lux, necessary for ice skating competitions and public ice skating sessions. The lighting simulation showed a requirement of 44 units of 700 watt plasma lamps, model PSH0731B to achieve the illumination targets. The metal halide lamps have had a substantial operating cost due to the equipment and downtime needed on the ice rink to replace the bulbs and ballasts so the decision to switch to plasma lamps was easy.

#### Luminaire Positions

#### Simulated Illumination Levels

#### Initial Fixed Costs

400w Metal Halide Lamps: | 700w Plasma Lamps: | ||||||

Part | # of Units | Cost | Total Cost | Part | # of Units | Cost | Total Cost |

Bulb | 109 | $50 | $5450 | Luminaire | 44 | $1500 | $66000 |

Ballast | 109 | $60 | $6540 | ||||

Fixture | 109 | $100 | $10900 | ||||

Subtotal | $22890 | Subtotal | $66000 | ||||

Installation Labor Costs | 109 | $80 | $8720 | Installation Labor Costs | 44 | $80 | $3520 |

Initial Cost | $31610 | Initial Cost | $69520 |

Installation labor costs is calculated at $80 per fixture, which takes into consideration the time to install, lift equipment and the wiring involved in installing these fixtures. The cost to install the lamps were higher given the environmental considerations. Initial fixed costs came out to be $69520 for the plasma lamps compared to $31610 for metal halide lamps, a difference of $37910. Note, the plasma fixtures prices are high estimates and are available at a lower price. The metal halide lamps are current retail prices.

#### Energy Costs

400w Metal Halide Lamps: | 700w Plasma Lamps: | ||

Watts per Fixture | 460w | Watts per Fixture | 730w |

Color Rendering Index | 60~65 | Color Rendering Index | 80~85 |

# of Units | 109 | # of Units | 44 |

Power Consumption | 50140w | Power Consumption | 32120w |

Cost per kWh | $0.15 | Cost per kWh | $0.15 |

Hours per Day | 12 | Hours per Day | 12 |

Days per Year | 365 | Days per Year | 365 |

Annual Power Consumption | 219613kWh | Annual Power Consumption | 140685kWh |

Annual Energy Costs | $32941 | Annual Energy Costs | $21102 |

Annual Energy Savings | $11839 |

The ice skating rink required the lights to be on for 12 hours a day, every day of the year. The 460w figure for the metal halide lamps include the power used by the ballast. The annual energy savings is obvious with plasma lamps. A total of $11839 is saved annually, which pays off for the price difference in the initial fixed costs within 3.2 years. But wait, there's more! Plasma lamps require less maintenance because the bulbs do not dim with age and the parts last longer, see the below chart for details.

#### Maintenance Costs

400w Metal Halide Lamps: | 700w Plasma Lamps: | ||

Bulb Life | 10000 hours | Magnetron Life | 30000 hours |

Ballast Life | 30000 hours | ||

Hours on per Year | 4380 | Hours on per Year | 4380 |

Hours per 10 Years | 43800 | Hours per 10 Years | 43800 |

Bulb Replacements in 10 Years | 4.38 | Magnetron Replacements in 10 Years | 1.46 |

Ballast Replacements in 10 Years | 1.46 | ||

# of Bulbs Replaced | 477 | # of Magnetrons Replaced | 64 |

# of Ballasts Replaced | 159 | ||

Replacement Parts Cost | $33419 | Replacement Parts Cost | $19272 |

Bulb Replacement Labor Costs | $19096 | Magnetron Replacement Labor Costs | $2569 |

Ballast Replacement Labor Costs | $6365 | ||

Ten Year Labor Costs | $25462 | Ten Year Labor Costs | $2569 |

Ten Year Parts Cost | $33419 | Ten Year Parts Cost | $19272 |

Ten Year Energy Costs | $329419 | Ten Year Energy Costs | $211020 |

Ten Year Total Operating Costs | $388301 | Ten Year Total Operating Costs | $232870 |

Annual Total Operating Costs | $38830 | Annual Total Operating Costs | $23287 |

Annual Total Savings | $15543 | ||

Price Difference Payoff Time | 2.42 Years |

Though metal halide bulbs might be rated for 20000 hours, lumen depreciation within the first 10000 hours drops by 30%. Bulb orientation can also have a substantial effect on the bulb life and brightness. We used a figure of $40 per part replacement for the labor costs due to the difficulty in doing maintenance on an ice rink. Once we factor in the maintenance costs, the savings are even greater. Total costs to operate the plasma lamps annually is only $23287 compared to $38830 for metal halide. This is an annual savings of $15543, which means the initial price difference of $24710 between plasma and metal halide will be paid off in just 2.43 years!

Keep in mind these energy costs are calculated under the assumption energy prices remain the same during the 10 years. History has proven that energy costs will always rise with time so the payback time might be quicker than the figures shown above. 477 metal malide bulbs and the 28000mg of mercury that those bulbs would have contained were saved from the landfills by going with plasma lamps. Note the lower color rendering index of 60~65Ra with the metal halide lamps compared to 80~85Ra with the plasma lamps. The savings and benefits are obvious.

#### Picture of Final Installation