MWRA Sustainable Energy in Water sports Energy Efficiency & Renewables on the Water

1. MWRA Sustainable Energy in Water sports Energy Efficiency & Renewables on the Water

2. Understand drivers for energy use on the water Options for Energy efficiency Options for Renewable energy Objectives

3. Typical energy use of a standard 100w light bulb in a sitting room Turn off the light when we’re not in the room Use a more efficient source say a 20w CFL. Still the same light delivered. If the sitting room is too bright lets put in a 10w bulb Then we install renewable energy Principles Of Energy Efficiency 1000 hrs a year 100w or 100,000 watt hours or 100 kwh (€17) 700 hrs a year 100w or 70 kwh (€12) Increasing Effort, Savings, investment 700 hrs 20w or 14 kwh (€2.40) 14kwh 7 700 hrs 10w or 7 kwh (€1.20)

4. Simple stuff first • Turn it off when not in use. • Maintain systems • N.B De-ice freezers! • Properly tensioned alternator belt • Good electrical contacts & wiring • Add cold items to fridge if possible • Buy efficient: get certification/ data not salesmen.

5. Luminous Efficacy (circuit) Understanding how much energy we use

6. Deep Cycle Lead acid batteries • Typically are 70% efficient & Lose ~1%/week • Can use up to 80% power (50% for starting batteries) • Repeated excess discharges reduces storage and efficiency. • Limited max charging rate - ~10A charge (110 AH) • Ideally suitable for smoothing out charge & use patterns. • 110 AH leisure battery =>110 x 12.5V = 1375 Watt hours • Deep Cycle 80% recoverable => 1100 Wh or 1.1kWh • Or 1 amp for 120 hours (x0.8) ~ 100 hours • 5 amps for 20 hours….10 amps for 10 hours… etc

7. Other Energy Uses: Reduce where possible

8. Renewables • Prior to installing renewables – bring down load first • Energy efficiency much cheaper than renewable energy • Estimate load and use of all appliances • Estimate occupancy & pattern of use: • Blue water cruising Vs Weekend use. • Coastal (diesel available) Vs Ocean • Size storage (batteries) Vs use & generator capacity

9. Renewables • Solar Panels: Three types • Not all solar panels are the same: • Cost Vs Efficiency must be noted • Solar charge controller required. • Prices tumbling (20% - 30% per annum) • Great for trickle charging – keeping batteries healthy

10. Renewables • Wind Generators: • Wind proportional to Cube of windspeed – high windspeeds necessary • Necessary to mount as high as possible off deck (wind speed proportional to height off ground). • Clear air if possible (rear mount generally) • Intermittent (Battery sizing important) • Use wind power curve to evaluate • Typical outputs for costal marine would be 25% of rated capacity (15-20% inland)

11. Renewables • Tow Generator • Needs 4kts to have reasonable output • Good for long cruising passages • Reduces boat speed – useful when excess wind present • Pointless under power. • Issues with chaffing • Harness electricity off propeller (engine off) • Reduces boat speed • Need to gear up (pulley(s)) • Need to balance forces on prop shaft • Only worthwhile for blue-water cruising

12. Summary • Do an Energy Audit – Power rating and usage time • See what can be reduced in time (switch off!) • Any maintenance requirements – healthy battery etc. • See what energy efficiency upgrades can be done • Interior lights • Navigation lights • Re-fridgeration • Renewables • battery trickle charger (10 W solar) • Light loads for weekends etc 60W solar + backup engine • Heavy loads: consider wind + solar combination

13. Motive Power • Biofuels • Solar powered boats

14. Paul Kenny B.E C.Eng MIEI • Senior Energy Consultant • T: 052 74 43090 • F: 052 74 43012 • E: info@tea.ie • W: www.tea.ie • Tipperary Energy Agency • Craft Granary • Church St • Cahir • Co. Tipperary • Ireland