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Hybrid PV Reducing Grid Dependence Stanhope Jonsson solar solu;ons 24/7 Copyright Stan Jonsson 2105 1 Grid Interac;ve PV Systems •  Net Metering –  Power generated by the solar PV system feeds the load first –  Excess power is fed back into the grid Copyright Stan Jonsson 2105 2 Grid Interac;ve PV Systems •  Feed in Tariff (FIT) –  Queensland Solar Bonus Scheme: 44c/kWh FIT •  Commenced July 2008 and guaranteed (?) un;l June 2028 for exis;ng customers who maintain their eligibility. •  Changed to 8c/kWh FIT in July 2012 guaranteed un;l June 2014 •  Reviewed in July 2014 and currently varies with electricity provider – Ergon +/-­‐6c/kWh Copyright Stan Jonsson 2105 3 Stand Alone PV Systems •  General –  Usually installed in remote areas that are not serviced by the electricity grid –  Two basic system types – DC Coupled . . . . Copyright Stan Jonsson 2105 4 Stand Alone PV Systems •  . . . and AC Coupled Copyright Stan Jonsson 2105 5 Hybrid PV Systems •  GENERAL •  The Hybrid PV system is an AC coupled PV system that uses the Grid as a generator •  Points to Consider –  Generally bacery sizing reduced to +/-­‐ 6 – 8hr autonomy –  Assessment of night ;me load for accurate bacery sizing –  Bacery loca;on in a typical domes;c residence •  Temperature / bacery life –  Convert exis;ng grid interac;ve system to a hybrid system? –  Start again with a new system? Copyright Stan Jonsson 2105 6 Hybrid PV Systems •  Conver;ng an exis;ng grid interac;ve PV system to a Hybrid PV system –  Is exis;ng PV array large enough to provide day;me load plus charge bacery to provide night load? –  Loss of FIT as zero export in Queensland –  Ergon / Energex approval –  Will my exis;ng grid inverter be able to work in unison with the new bacery inverter? •  SMA Frequency Shif – Ac;ve Power limita;on Copyright Stan Jonsson 2105 7 Hybrid PV Systems •  Star;ng from scratch – installing a new Hybrid system –  Load assessment -­‐ day & night –  Roof area -­‐ orienta;on & pitch •  System design -­‐ PV array to provide day;me load + charge bacery •  Bacery sizing – DOD (depth of discharge), autonomy (days of back up with no solar input) •  Bacery inverter -­‐ kW ra;ng –  Loca;on of inverters, bacery –  Ergon / Energex approval Copyright Stan Jonsson 2105 8 Hybrid PV Systems •  System Sizing – example –  From Ergon account – average daily consump;on = 12kWh –  Es;mated night load = 3kWh • 
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TV on for 6hrs, rated 180w = 6 x 180 = 2 lights on for 6hrs, rated 15w = 2 x 6 x 15 = Boil kecle, rated 2400w for 6mins = 6/60 x 2400 = Computer on for 4hrs, rated 180w = 4 x 180 =
Fridge/Freezer, rated 200w, es;mate 2hrs = 2 x 200 = Addi;onal we can use
Total night use (6pm to midnight) = Copyright Stan Jonsson 2105 1.08kWh 0.18kWh 0.24kWh 0.72kWh 0.40kWh 0.38kWh 3.00kWh 9 Hybrid PV Systems •  System Sizing – example con;nued –  PV array sizing (assuming North orienta;on and 22° pitch roof) • 
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Average PSH (peak sun hours) for Toowoomba = 4.2PSH System efficiency – cable losses, conversion losses, dirt on panels = 85% Customers load = 12kWh PV Array sizing = 3.5kWp 14 x 250w solar modules –  Bacery sizing • 
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Night load = 3kWh Bacery autonomy using sealed lead acid (Gel) = 50% Bacery efficiency = 90% Bacery Size = 6.7kW or 321Ah at 48volt 8 x Sonnenschein SH12V2.0 (12v / 165Ah) in series parallel Copyright Stan Jonsson 2105 10 Hybrid PV Systems •  System Sizing – example con;nued –  Bacery Inverter kW ra;ng •  From es;mated night load we consider the power ra;ng of all appliances that can be used during the 6hr period •  TV 180w, lights 30w, kecle 2400w, computer 180w and fridge 200w = 2.99kW •  We require a bacery inverter that can provide a constant load of 2.99kW •  SMA SI3.0M Sunny Island bacery inverter rated –  3kW for 30 mins –  3.5kW for 5 mins –  5.5kW for 3 seconds –  Grid inverter •  PV array required = 3.5kw •  SMA SB3000TL single phase inverter Copyright Stan Jonsson 2105 11 Hybrid PV Systems •  Bacery Technology – residen;al installa;ons –  Flooded Lead Acid • 
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Good cycle life & warranty Reliable technology High maintenance Spark Hazard – gassing when charging –  Sealed Lead Acid – VRLA (valve regulated lead acid) •  Good cycle life & warranty •  Reliable technology •  Low maintenance –  Absorbed Glass Mat (AGM) – VRLA •  Reasonable life cycle & warranty •  Reliable technology •  Low maintenance Copyright Stan Jonsson 2105 12 Hybrid PV Systems •  Bacery Technology – residen;al installa;ons –  Lithium – various technologies •  Good cycle life & warranty •  Rela;vely new for solar installa;ons -­‐ however will soon (?) be the standard •  Reliability – Dreamliner Aircraf –  Safe & reliable PROVIDED certain precau;ons are met when charging •  Low maintenance •  High DOD (depth of discharge) •  Bacery Temperature –  Importance of maintaining a cool environment to ensure bacery longevity Copyright Stan Jonsson 2105 13 Hybrid PV Systems •  Baceries – Cost -­‐ Lithium –  Quote from Damien Moyse from ATA •  “we need the cost (of baceries) to come down probably by around 50% for there to be a cri;cal mass for large numbers of people to go off grid” Sanctuary magazine, Issue 30, Page 64 –  Quote from Deutshe Bank report published March 2015 •  “using conserva;ve assump;ons and no incen;ves, our model indicates that the incremental cost of storage will decrease from 14c/kWh today to 2c/kWh within the next 5yrs” •  NOTE: current per kWh cost of >$500, es9mated by 2020 to be $200 (ReNew Issue 128) Copyright Stan Jonsson 2105 14 Hybrid PV Systems •  Cost Es;mates –  Refer back to our sizing example: • 
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12kWh daily load, 3kWh es;mated night load 3.5kWp PV array, 3kw grid inverter 320Ah / 48v bacery SI3.0M 3kw bacery inverter Approximate Total Net Cost (supplied and installed) = $ 22,000 Es;mated 14yr payback assuming 3% annual increase in electricity price –  Consider es;mated drop in bacery pricing by 2020, or sooner? •  Same system with a Lithium bacery pack •  Es;mated cost (supplied and installed) = +/-­‐ $ 15,000 & hopefully much lower •  Es;mated payback within 10yrs assuming 3% annual increase in electricity price Copyright Stan Jonsson 2105 15 CONTACT DETAILS Daniel Rodda Toowoomba Solar Centre P: 0427 654 637 E: [email protected] Stanhope Jonsson solar solu;ons 24/7 P: 0427 118 944 E: solar@solarsolu;ons247.com.au Copyright Stan Jonsson 2105 16