Welcome some "perfect" solar setup suggestions

[Hardknocks]

My wife and I started living off grid over 8 years ago - we have really only ever had enough solar to light our house with DC lights, charge our computers with small or cheap inverters and watch TV-
We started with a few Harbor Freight panels and cheap - not much has really changed it's always been make shift and mismatched - we would like to be able to run fans a blender a 300 watt washing machine and a dishwasher we have a solar refrigerator so we don't need that - would a clothes dryer or a window AC be too much to ask as well...? If have a great system in this lower mid range size (we are not a large house hold we heat with wood, make our coffee on the stove and don't have a microwave, no central air) what do you use i.e. how many panels? charge controller? batteries? and inverter? or if you had it to do over again what would you get?
What voltage would you use and why?

 

[Stupid Monkey]

A lot depends on what sort of mounting options you have, and how long they can get in the sun.

Anything is possible, just depends on budget.

First add up your expected usage, eg fridge likely to be about 1kwhr/day lights, how often washing machine is on. Add it all up and add 40% for sizing.

Say that gives you 5kw hrs - then in good sun in summer a 1000w of panels should do that.
Then factor in daysof autonomy you need (most people want 3) and times that 5kw hrs and that gives you the size of battery you need.

Will gives this setup to run an AC

Ultra Sized Systems: Run an Air Conditioner

If you want to power an air conditioner, you are going to need a massive solar power generation system. This will require a VERY large vehicle. 28 foot+ minimum. Lets estimate the power consumption...

www.mobile-solarpower.com

 

[tictag]

As @Stupid Monkey says, planning such a system requires a bit of investigation and some basic maths:

ENERGY OUT
Add up your expected daily usage e.g.

Item Power Time Energy
Washing Machine 300W 0.5hr 150Wh
Dishwasher 250W 2hr 500Wh
Phones
Computer
...
TOTAL e.g. 850Wh

ENERGY STORAGE
Multiply your expected daily use by the desired number of days autonomy e.g. 3 days, and you end up with your storage requirement e.g. 2,550Wh (850Wh per day x 3 days = 2,550Wh) or 213AH at 12V (2,550wh / 12V = 213AH) or 106AH at 24V (2,550Wh / 24V = 106AH).

In this example, if you plum for lead acid batteries, those shouldn't be regularly discharged below 50% DoD, so 4 x 100AH 12V batteries would about cover you. Li-ion is a far superior battery technology but also costs significantly more, a single 110AH 24V LiFePO4 battery would cover you.

ENERGY IN
You generally want to replenish your expected daily usage every day so, as a basic calculation, you'll need to generate 850Wh over 5 hours good sunshine per day. One 170W panel would do (850Wh / 5 hours = 170W) or 2 x 100W panels would give you a little more than you need. But you also need to consider your latitude from the equator. I live in England at 55o so I tend to assume 80% efficiency in Summer, 20% in Winter. Spec your panels accordingly.

Once you have your system requirements, you can then go and look for a product solution that meets your needs. Options exist from completely DIY kits from the cells up to all-in-one units, all of which Will covers in his videos.

Clear as mud?

I hope this helps,
David.

 

[tictag]

Hmmm, my ENERGY OUT table didn't quite work, but you get the picture, right?

 

[Steve_S]

Your potential energy generation depends on where you are located and how many sun hours you get over the course of the seasons. Basically you need to plan your panels needs & generation capacity to match the worst times of the year for generation I your area. The basic guideline of 3 days autonomy without any generation (dark cloudy days & no genset running) is the most common people figure on, some go for 5 days but your talking more battery & panel of course.

As for the AC unit, some are quite efficient and not bad while others will eat your batteries and spit out chunkies. You need to know what the surge is (on start) and what it uses while running, a kill-a-watt meter is great to figure that out. Mini-split heater / ac units have seriously improved in the past couple of years, the prices have dropped quite a bit and these tend to be gentler on solar powered systems. A Dryer... ok, any resistive device is a strain on any solar system, conventional tumble dryers can be atrocious power pigs almost as bad as electric stoves with coils. Sure you can solar power it all but at a cost of equipment. Conservation is always cheaper than generation and storage.