Thinking of going solar
I have reading alot about solar systems. I live in a 40′ 5th wheel RV. Now This is what I was thinking of buying…..
6 – LG 305 watt solar panels ( 305 watt output each total 1830 watts ) ( around 75 amps output )
Magnum 5000 watt 24 volt inverter
Schneider (Xantrex) XW-MPPT-60-150V Charge Controller
4 – 6 volt 480ah Royal AGM batteries.
( Plus 3 – 30 amp fuse boxes and a junction box for the solar panels
My question is…………..
I am Trying to figure out how many hours per will I be able to runs some devices on solar
I run about 500KWH per month or 16.6 KWH per day. I know I will not be able to run
all my devices in the RV all day but least teh refer ( 5 amps ) and window A/C unit
5 amps and maybe a 12 amp heater. ( not all day ) or at the same time.
Thanks.+
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Replies
Ron,
The output of your 1.8 kW PV system will depend on the angle of your PV array and your geographical location.
In Seattle, your PV array will give you between 46 kWh/month (in December) and 229 kWh/month (in July).
In Phoenix, Arizona, your PV array will give you between 197 kWh/month (in December) and 278 kWh/month (in May).
So you may want to park your RV in Arizona... at least in December.
Ron,
You also should check whether your 5,000-watt Magnum inverter can really handle the start-up surge of your air conditioner by calling the inverter manufacturer.
It makes no sense to use an off-grid PV system to run an electric-resistance heater. My guess is that you probably won't be able to use your air conditioner either.
Well from what I have seen you can seen you can run a 5,000 BTU window A/C. It's about 500 watts.
here is just 1 example of many I have read thus far............
https://www.youtube.com/watch?v=NcqjIMHV45E
~500 watt air conditioners can sometimes have 5000+ watt start up requirements. Modulating "inverter drive" ductless air conditioners don't have this issue, since the drive motor for the compressor is direct-current, not alternating current, and the compressors themselves are scrolls rather than reciprocating. It's just a whole-lot nicer to the battery inverter.
Even though a 3/4 ton mini-split has ~2x the maximum cooling power of a cheap window air conditioner, it can modulate down to 2000 BTU/hr or less while tracking the cooling load, so it has fewer starts/stops too.
And, if you got a heat pump version rather than a cooling-only version, it will deliver 3-5x the amount of heat for the amount of power used as your 12 amp resistance heater. The 115V versions aren't quite as efficient as the better 230V versions, but they're not terrible. Watch out- many low-end 115V mini-splits are not inverter-drive and would have the same start-up issues as window-shakers. This 3/4 Gree is available through a national box store chain at about $850, and would probably fill the bill:
http://www.greecomfort.com/wp-content/uploads/2014/08/Rio-Submittal-RIO09HP115V1A-V2.pdf
Max power it's pulling 2x that of a 5000 BTU window shaker, but at low speed it's less, and much higher efficiency, and when it's modulating at low speed 3500/BTU/hr (cooling) it will beat the SEER & HSPF ratings on efficiency, and would be approaching 2x the efficiency of a pretty-good window shaker, getting 1.5-2x hours of cooling out of your PV/battery/inverter system, and 3-4x the amount of heating out of it than a resistance heater.