2014 League of Minnesota Cities CITY OF ST. CLOUD LED LIGHTING Steve Lawrence & Blake Redfield
City of St. Cloud LED Street Lighting Goals Reduce electrical costs Reduce maintenance costs Provide high quality roadway lighting Reduce glare to the motorist Improve pedestrian and residential security Reduce street light outage times Minimize light trespass onto private properties Become more dark skies compliant
LED Street Light Installation Considerations Quality of light & fixture Complexity of the LED light source Cost effectiveness of fixtures Implementation process Complete Staggered Ownership methods Organization purchasing fixtures Allow outside investors to purchase & reap benefits of energy (cost) savings When to get aboard the LED street lighting world
LED Lighting Basics
Driver: Converts AC to low voltage DC Door: Protects against weather, insects, creatures Surge Suppressor: Protects Driver from Voltage Surges Terminal Block: Electrical Connection to AC Power Source LED Light Engine LED: Small Solid State Device that Emits Light Door Clamps: Secures Door Fixture Clamps: Secures Fixture to Pole Labels: Provide certifications and model numbers Body: Provides support for LED circuit board and cooling for the LED s *Note: Some fixtures use mirror arrays to direct the light rather than an LED lens LED Lens*: Directs Light for even Distribution and Various Distribution Types
Efficacy Lumens of light / Watt of electricity Efficiency of driver Spectral efficiencies Cool color temperatures Higher output levels Lower color rendering indexes Warm color temperatures Lower output levels High color rendering indexes P-N junction temperature efficiencies LED efficiencies drop as temperatures rise above normal levels Delivery system efficiencies Lens losses Reflective losses Aiming losses System losses can exceed 30% of potential light output when any of the components have losses or are not matched to the system 2
Department of Energy s Projections of LED Efficiencies 1
LED Efficiencies since 2005 2005 2015 2025 60 lm/wt Baseline 190 lm/wt +315% 266 lm/wt +443% Average of 10.3% increase per year for 20 years.
The St. Cloud LED Street Lighting Story 2010 awarded ARRA funds for LED lighting projects Developed test methodologies for street lights Developed plans and specifications for light fixtures that passed our test criteria 2010-2011 installed lighting systems on Kilian Boulevard and Riverside Drive
Kilian & Riverside LED Street Light Project Location
Street light style along Kilian Blvd & Riverside Drive
Problems Encountered when Reviewing Decorative LED Street Lights Photometric files did not always match real world testing Shadows were a major problem at the base of light poles Electrical power consumption measurements were not consistent Thermal management varied considerably from fixture to fixture Quality of the fixture materials and ability to do maintenance varied from fixture to fixture Was the LED color temperature correct with the manufacturer s claims?
Solutions for Reviewing LED Street Light Fixtures Develop a standard battery of tests that every street light sample would go through Develop a test lab for performing the battery of tests Develop an evaluation methodology for each of the LED fixtures Develop visual photometric modeling that would better illustrate the light outputs of the LED fixtures than traditional modeling Make fixture reviews as objective as possible
Test Deck
Konica Minolta Light Meter & Self Aligning Shoe
Data Collected & Inputs from Testing / Review Measure footcandles at 64 points on test deck Measure CCT at 64 points on test deck Measure thermal temperature of heat sink unit 80 & 90 degree cutoff level measurements Rate workmanship Rate quality of materials Rate finish/coating Rate electrical component replacement Rate diffuser replacement Rate product standards Rate warranty Rate driver components Rate LED components
Data Input and Report Form
Two Dimensional Photometry Model from Test Deck
Three Dimensional Photometry Model from Test Deck
Predicting Light Levels from Pole Height
Color Temperature Distribution
LED Upgrade Statistics Original Lighting Kilian Boulevard 110-70 watt twin HPS fixtures on 12 poles Riverside Drive 50 100 watt HPS fixtures on 9 poles Minnesota Boulevard 28 100 watt HPS fixtures on 12 poles Updated LED Lighting Kilian Boulevard 55 66 watt single LED fixtures on 12 poles Riverside Drive 50 35 watt LED fixtures on 9 poles Minnesota Boulevard 28 66 watt HPS fixtures on 12 poles Reduced power consumption 51% from 15,500 watts to 7,560 watts. Entire project cost was approximately $263,000.
LED Fixture Statistics Kilian Boulevard Sternberg Old Town Series 3500K CCT 3300 lumens Type V Dist. 66 Watts Qty: 55 Riverside Drive Sternberg Roadway Series 3500K CCT 1130 lumens Type III Dist. 34 Watts Qty: 50 Minnesota Boulevard Sternberg Old Town Series 3500K CCT 3160 lumens Type III Dist. 66 Watts Qty: 28
Conclusions of Kilian & Riverside LED Lighting Project Positives Significant decrease in electrical costs Significant reduction in maintenance Much better quality of light Much better light levels Negatives A couple of residents along Kilian Boulevard complained about losing the twin fixtures from an aesthetics standpoint A couple of residents along Kilian Boulevard complained that the light is now too bright
Additional LED Test Equipment
Color Checker
Light Fixture Lift Tower
Spectrum Analyzer
The Future of LED Street Lighting in St. cloud
City of St. Cloud Develop has developed a cost analysis on a 100% LED changeout program over a 40 year timeframe Five year phase in plan LED expected light fixture life of 20 years Assume 1% annual increase in electrical costs Assume 2% annual increase in maintenance costs Assume 5% annual increase in LED efficiency Assumes cost reduction in light fixtures over time Assumes significant maintenance reduction costs Creates an $18.5 million dollar savings in 40 years
$1,400,000.00 $1,200,000.00 $1,000,000.00 Total of Maintenance & Electrical Costs without LED replacement LED Street Lighting Program City of St. Cloud Period of 40 years Total Projected Savings in 40 Years with Proposed LED Upgrades: $18.5 Million $800,000.00 $600,000.00 $400,000.00 Maintenance Costs without LED Upgrades Electrical costs without LED upgrades Total of LED replacement, Maintenance & Electrical Costs Electrical Costs With LED Replacement Program Electrical Costs Without LED Replacement Program Maintenance and install costs with LED Upgrades Maintenance Costs without LED Upgrades* Total of Maint & Elect. With LED Upgrades Total of Maint. & Elect. Without LED Upgrades Electrical costs with proposed LED program $200,000.00 $0.00 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 Years Maintenance and installation costs with LED replacement
Other St. Cloud LED Street Lighting Projects
Parking Ramp LED Upgrade
Smart Dimming Park-N-Ride Lot
Central Maintenance Building LED Street Lighting and Exterior Lighting Upgrade
St. Cloud Water Plant LED Exterior Lighting and Street Lighting Upgrade
Articles Cited 1,2. U.S. Department of Energy, Energy Efficiency of LEDs, PNNL-SA-94206, March 2013