Water Matters

Renewable Energy for Water Supply
Mr Paul Harris
Wind Energy
Solar Power
Comparison with other renewable energy options
• Will look mainly at solar and wind energy, as I think they are probably most relevant to most of you.
• Happy to try and take questions during the presentation.
Wind Energy
• Regional and temporal variability –
need storage or backup
• Pumping, milling or electricity generation
• Energy payback a few months
• Compatible with other land uses
• 13 W per square metre at 10 kph wind speed maximum input energy
Slide 7
Wind Mills
• Low speed, high torque
• Piston Pump pulsates
Wind Turbines
• High Speed, low torque
• Suit helical rotor
Other Turbines
• Savonius vertical axis wind turbine
• Darrieus Wind Turbine
Wind and Sunshine
Solar Energy http://typesofrenewable‐energy.com
• Original source of all energy (except geothermal and nuclear)
• Generate heat and/or electricity
• Influenced by time of day, cloud and season – need storage/backup
• Photovoltaics have ~ 5 year energy payback but nasty industrial processes
• 1 kW per square metre maximum incoming energy
• Alignment of collector is also a factor
Slide 12
Solar Distillation
• Use the sun’s heat directly
Comparison of Technologies
To generate 1 kW of electricity “continuously” (to lift 7.5 KL per hour of water 14 m vertically OR push the same flow horizontally through 400 m of 50 mm pipe) you need :‐
• 100 square metres of solar panels and 100kWhr Battery Bank • 90 m2 wind generator (2.2 kW) and 100kWhr Battery Bank (but very little land!)
• 860000 m3 storage (12 Ha 14 m deep) and 5000 Ha catchment (Eden Valley) with 10 m drop for micro‐hydro electricity.
• About 17 Ha of oil crop for biodiesel
• About 7 Ha of maize for bioethanol production
• About 10 Ha of 30 y/o woodlot to run a gasifier (Adelaide Hills)
• 13 dairy cattle (housed – about 40 Ha of land) and a 110 m3
digester to make biogas
Slide 14
• Powering a RO unit or pump by solar voltaic panels may be the best option (as solar availability is closely related to stock water demand)
• You will need a bigger RO unit or pump if you don’t have battery storage.
• Look at your own situation, an unusual combination may provide an optimum solution.
Any Questions?