Design for beginners

mcgivor
mcgivor Solar Expert Posts: 3,854 ✭✭✭✭✭✭
Establishment of base load and reducing it is the most important steps when considering going off grid, once established the design of  the system can proceed. Too often it's the underestimated base load which cause problems such as failure of batteries due to over discharging.

When designing my system I had the luxury of starting from scratch and had to purchase new appliances so my choices were based on the most efficient models. First the refrigerator as the most constant load, I chose a Panasonic inverter model with freezer (medium size 400 liter), washing machine Samsung inverter 7.5 Kg, water pump Hitachi 100 watt inverter, lifting led panel pot lights 5 watts each.  

Each appliance was run independently to establish it's consumption per days use and combined to establish my base line. The next step was the array, charge controller, inverter and battery. Although not sientific I used a 50% rule, assuming everything was 50% of its claimed rating and what I ended up with was 1.5 Kw 24V array, Morningstar 60A PWM controller, 4 Yuassa 130Ah batteries series parallel and a Cotek 2Kw sine wave inverter.

This has worked flawlessly now for over a year, the depth of discharge averages 40 % sometimes dropping to 60 % if the previous day was overcast.Being located in North Eastern Thailand sun is generally not a problem but heat can be so I keep the batteries in a water bath and use ground water to keep the temperature down during hot periods of 40+ degrees Celsius.

Sometimes it can be overwhelming reading all the advice and posts often by unqualified people, study battery charging information from manufacturer sources and never buy the cheapest equipment. 

By the way I am a qualified electrican originally from Canada.  
1500W, 6× Schutten 250W Poly panels , Schneider MPPT 60 150 CC, Schneider SW 2524 inverter, 400Ah LFP 24V nominal battery with Battery Bodyguard BMS 
Second system 1890W  3 × 300W No name brand poly, 3×330 Sunsolar Poly panels, Morningstar TS 60 PWM controller, no name 2000W inverter 400Ah LFP 24V nominal battery with Daly BMS, used for water pumping and day time air conditioning.  
5Kw Yanmar clone single cylinder air cooled diesel generator for rare emergency charging and welding.

Comments

  • mike95490
    mike95490 Solar Expert Posts: 9,583 ✭✭✭✭✭
    Thank you for sharing .  Glad your system is able to keep the batteries up.  inverter fridges are still hard to find in the USA
    Powerfab top of pole PV mount | Listeroid 6/1 w/st5 gen head | XW6048 inverter/chgr | Iota 48V/15A charger | Morningstar 60A MPPT | 48V, 800A NiFe Battery (in series)| 15, Evergreen 205w "12V" PV array on pole | Midnight ePanel | Grundfos 10 SO5-9 with 3 wire Franklin Electric motor (1/2hp 240V 1ph ) on a timer for 3 hr noontime run - Runs off PV ||
    || Midnight Classic 200 | 10, Evergreen 200w in a 160VOC array ||
    || VEC1093 12V Charger | Maha C401 aa/aaa Charger | SureSine | Sunsaver MPPT 15A

    solar: http://tinyurl.com/LMR-Solar
    gen: http://tinyurl.com/LMR-Lister ,

  • mcgivor
    mcgivor Solar Expert Posts: 3,854 ✭✭✭✭✭✭
    Seems a shame inverter refrigerators are not available in the U.S, they are common in Asia and other countries where electricity is expensive as they really compliment an off grid system, the cost was around $350 for a medium sized unit 400 liter including 125 liter freezer. Model Panasonic nrbw415v if you want to Google 
    1500W, 6× Schutten 250W Poly panels , Schneider MPPT 60 150 CC, Schneider SW 2524 inverter, 400Ah LFP 24V nominal battery with Battery Bodyguard BMS 
    Second system 1890W  3 × 300W No name brand poly, 3×330 Sunsolar Poly panels, Morningstar TS 60 PWM controller, no name 2000W inverter 400Ah LFP 24V nominal battery with Daly BMS, used for water pumping and day time air conditioning.  
    5Kw Yanmar clone single cylinder air cooled diesel generator for rare emergency charging and welding.
  • Dave Angelini
    Dave Angelini Solar Expert Posts: 6,731 ✭✭✭✭✭✭
    There are a few in the US. The LG 22 cubic foot is on my list but I will not buy one until there are technicians who are trained with the refrigerant they use.  I know of 2 warranty cases with Samsung where they gave the customer his money back and they bought another brand without R600a.  The linear compressor has a 10 year warranty but there were leaks in the systems and anyone who has reapired refrigeration leaks knows they can be a challenge. 
    "we go where power lines don't" Sierra Nevada mountain area
       htps://offgridsolar1.com/
    E-mail offgridsolar@sti.net

  • mcgivor
    mcgivor Solar Expert Posts: 3,854 ✭✭✭✭✭✭
    R 600a is nothing new and used extensively and will most likely become the norm in the future with climate change and as always fear of the unknown raises concerns, when Japanese cars first arrived in the U.S.the fear was they were too small and wouldn't last, wrong. All news is bad news and sure there may have been some warranty issues but only raised because of being in the spotlight as a new technology.   
    1500W, 6× Schutten 250W Poly panels , Schneider MPPT 60 150 CC, Schneider SW 2524 inverter, 400Ah LFP 24V nominal battery with Battery Bodyguard BMS 
    Second system 1890W  3 × 300W No name brand poly, 3×330 Sunsolar Poly panels, Morningstar TS 60 PWM controller, no name 2000W inverter 400Ah LFP 24V nominal battery with Daly BMS, used for water pumping and day time air conditioning.  
    5Kw Yanmar clone single cylinder air cooled diesel generator for rare emergency charging and welding.
  • Dave Angelini
    Dave Angelini Solar Expert Posts: 6,731 ✭✭✭✭✭✭
    Well it may not be new to you but I live in the little state of California and Samsung gave the customer their money back after they tried to fix it 3 times. Samsung said they did not have any technicians who were legal and trained here. Do you know different?
    "we go where power lines don't" Sierra Nevada mountain area
       htps://offgridsolar1.com/
    E-mail offgridsolar@sti.net

  • mcgivor
    mcgivor Solar Expert Posts: 3,854 ✭✭✭✭✭✭
    Not sure but from what I've discovered is that R 600a is not common in the US and being isobutane, a flammable gas, there seems to be a sense of fear associated with it. The amount is so small that it would have to be contained in a small space to reach the flash point ratio with air. Because it is not a new technology in Thailand there are technicians who are qualified. At least Samsung did the right thing and gave the money back albeit probably without compensation for inconvenience. 

    Not being an expert on refrigeration perhaps I'll be disappointed with my choice but so far so good. My choice was based on energy efficiency and green technology.
    1500W, 6× Schutten 250W Poly panels , Schneider MPPT 60 150 CC, Schneider SW 2524 inverter, 400Ah LFP 24V nominal battery with Battery Bodyguard BMS 
    Second system 1890W  3 × 300W No name brand poly, 3×330 Sunsolar Poly panels, Morningstar TS 60 PWM controller, no name 2000W inverter 400Ah LFP 24V nominal battery with Daly BMS, used for water pumping and day time air conditioning.  
    5Kw Yanmar clone single cylinder air cooled diesel generator for rare emergency charging and welding.
  • BB.
    BB. Super Moderators, Administrators Posts: 33,433 admin
    Iso Propane should not be a safety problem in the modern world... At least one fridge had 80 Grams (2.8 Oz) of Iso Propane. Not a large amount at all. Most leaks are very small and will not build up a flammable/explosive situation.

    They did invent/use Freon all those decades ago to remove Ammonia and flammable refrigerants from normal use. There there is a question about Freon and Holes in the Ozone layer (and the Freon patents expiring just as ozone holes because an issue--And now they seem to not be an issue any more?).

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset