Looking for a good solar system for our yurt

We are looking to install a solar system for our 32 ft yurt. We live in southern ontario. We are in need of chraging a nintendo switch (very important to our 10 year old) a laptop, four lights, one fridge and sometimes a one burner hot plate.

We are looking at a Bluetti or Lycan system. Ideally  it is nice to have something that can be charged up by AC power when the solar is not happening.

Thanks in advance for any advice or direction offered.

Alternatively, as I am new, is there a way to go back and read similar posts?

Cheers.

Kevin

Hi Kevin,
Welcome to Permies.

I don't have much knowledge of solar, so I can't help much there, other than I know it is possible to setup a battery bank that can be charged from different sources (solar, generator, grid, etc). This is mostly to bump this for those people who actually know how to do something like that :)

As for similar threads, when you are reading a thread, near the bottom is a list of "similar threads". Sometimes I find it is accurate, and sometimes not so much. You can also use the search bar at the top and put in key words like "Solar". In this case, I don't think the yurt really makes much different other than you probably won't be using a roof mount system :)

The list was easy till you got to "refrigerator".  A refrigerator in general bumps up the system size from small, 12V, to a medium 24V.  I don't think a Bluetti is going to handle that, irregardless of what the ads may say.  Forget about the hot plate completely.  It is NOT going to work on either a small or a medium sized system.  Get yourself a little Coleman propane powered camping stove for that.  I used one plumbed to a 5 gallon barbeque tank for years before finally upgrading to a standard gas stove.

First, you need to understand the concept of the sunhour (sh) which is NOT the amount of daylight you have.  It's a conversion factor for changing watts of panels into kWh of solar power.  Lets say you get 2 sh in winter (clear sunny day) and 5 sh in summer.  We'll use those numbers in the math to come.

My cabin consumption is likely to be similar to what you need.  I have a frig on 24/7, lights, TV, and a laptop.  I might consume ~3.0 to 4.0kWh of power per day, with everything on.  Remember that the inverter being on consumes power to.  A good rule of thumb is that the background consumption of the inverter is proportional to it's size, but also proportional to the quality of design.  I have a quality Schneider XW+6848 inverter that uses 30Wh, or about 0.72 kWh per day.  Cheaper imported inverters, typically the AllinOne types, have far higher consumptions in the range of about 1.4-2.4kWh per day.

So, let's settle on needing needing 3.0kWh of power per day, or 3000Wh.  You divide the power needed by the sunhours.  So, in the winter, you'd need.... 3000Wh/2.0sh = 1500W of solar panels.  In the summer though, you'd need just 3000Wh/5sh = 600W of panels.  Plan for the worst day, not the best, and the system will never let you down.  Plan on installing 1500W of panels.  Grid-tie panels are dirt-cheap right now.  I just got 260W REC panels for 65$ each this year.  That's only 390$ if you buy six of them.  Don't buy little 12V automotive panels.  You pay a hefty price premium for panels designed for automotive.  Don't buy panels online.  Search for panels on Craigslist and go with cash and carry pricing.  Expect to get 2-4W/$ with local pickup.

You might get by with fewer panels if you put them on a single-post rotating array frame like I did.  This frame holds 4 grid-tie panels in portrait, though can hold 6 in landscape.  I made 5.1 kWh in February with just 1000W by rotating from East to West over the course of the day.  My frame adjusts for both azimuth and declination, so I can really maximize my solarization.

You need a charge controller to connect the panels to the battery.  Assume though that you don't get more than 85% of power from your panels with day to day usage.  With 1500W of panels the math is 1500W/25Vcharging = 60A.  De-rated to 85%, that's 51A.  A 50A controller like Epever's Tracer 5415AN would be OK.  You could wire two parallel strings of three panels each into it.  You would write that in shorthand as 3S2P.  With just 1000W of panels, you could go with a smaller (cheaper) Tracer 4210AN controller, but there's less flexibility with the smaller controller.  That has to be wired 2S2P

In a cold climate, Li batteries do not work well.  Lead-acid is less likely to get cold-weather damage if they are kept charged.  CostCo makes a 6V 210Ah golf-cart battery that is still on sale right now for 99$ in the US.  Assuming you don't want to drain a lead battery lower than 50%, then what you get is.... 210Ah X 24V X 50% = 2520Wh, or ~2.5kWh.  That's not much, but it will get you through the night.  You have to decide how much cloudy/rainy weather you need to get through.  Multiply your {(days needed X 3kwh)/24V}/50% to get the size of your battery.  Let's say you need 3 days...  The math is {(3 days X 3000Wh)/24V}/50% = 750Ah.  Those would be a lot bigger batteries than golf-carts.  Expensive, but doable.  Might be cheaper to go with a smaller 400Ah battery like a Trojan L-16, and get a generator to top off after the rains start.

Now the inverter.  Do NOT get a cheap square wave or modified wave inverter if you run anything with an electric motor.  That includes refrigerators, freezers, pumps, compressors, and power tools.  Get a good quality sine-wave inverter.  There are two types, high-frequency transformerless inverters, and low-frequency transformer based models.  HF is cheap to make but they don't have any starting surge.  LF is more expensive, but can start your power tools under load.  Take a circular saw and press the blade into a 2X4.  Then press the start button.  You'll see the difference.

I've seen complaints that the smaller 1000W inverters would not run a refrigerator.  A 2000W 24V sine-wave inverter is a better choice.  Samlex makes a nice sine-wave 2000W inverter, though it HF.  Schneider makes the LF 4024, which I have in my workshop.  It can run a 1.6hp air-compressor, but it costs 3X the price of the Samlex.  But, I'd never expect the Samlex to run a compressor.

So, what is this going to cost....
six panels 400$
50A charge controller 250$
four 6V batteries 400$
HF inverter 650$
1700$  
Buy some steel to make a nice array frame, sink it in concrete, and wire it all up.  Add another 300$ for steel concrete mix, and good copper wire.  Call it 2000$ total.  Price goes up though as the size and quality goes up.  Factor that in proportionally.

HI Kevin,
Those boxed systems with the lithium packs are designed around portability for which you will pay a hefty price for the capacity they can deliver. Lithium batteries go for 3-4 times the cost of lead acid for the same capacity.  The solar panels they sell to go with their packs are also about 3 times as expensive as regular panels. For your situation I would steer you towards using a propane burner for cooking, a small fridge, an agm battery pack a 2000 watt pure sine wave inverter with charger, some safety disconnects and 350 - 700 watts of solar. Price wise with solar would be more then a base bluetti and less than a lykan with a lot better room to grow. Using a base system like that you will have to incorporate a generator element into the system but for 3 hour stretches only depending on your actual usage it can be for winters only with the occasional run in spring or fall. If you could be regimented about when you run a generator you could even incorporate that electric hotplate.  It all depends on you and how well you use the system. I do sell gear and design systems and I'm in Ontario if you want to chat. I sent you a purple moosage
Cheers,  David

Michael Qulek wrote:The list was easy till you got to "refrigerator".  A refrigerator in general bumps up the system size from small, 12V, to a medium 24V.  I don't think a Bluetti is going to handle that, irregardless of what the ads may say.  Forget about the hot plate completely.  It is NOT going to work on either a small or a medium sized system.  Get yourself a little Coleman propane powered camping stove for that.  I used one plumbed to a 5 gallon barbeque tank for years before finally upgrading to a standard gas stove.

First, you need to understand the concept of the sunhour (sh) which is NOT the amount of daylight you have.  It's a conversion factor for changing watts of panels into kWh of solar power.  Lets say you get 2 sh in winter (clear sunny day) and 5 sh in summer.  We'll use those numbers in the math to come.

So, what is this going to cost....
six panels 400$
50A charge controller 250$
four 6V batteries 400$
HF inverter 650$
1700$  
Buy some steel to make a nice array frame, sink it in concrete, and wire it all up.  Add another 300$ for steel concrete mix, and good copper wire.  Call it 2000$ total.  Price goes up though as the size and quality goes up.  Factor that in proportionally.

I like how you started with compassion of 12 and 24 volt systems.   I went 24 volt a few years back and what a difference! I only had 1kW up there but I saw 6.5kWh collected on most days in the summer and that panel array is mounted flat too so not exactly the right angle!  
Keep up the great work and good advice!

My favorite aspect of solar is its totally scalable and expandable!
( also Solar coffee just taste like, freedom!? lol)

Runing the Outback Solar FlexMax60 MPPT Solar Charge Controller and Giandel 24v 2000w inverters!
2 x Renogy AGM 200aH make up a 24vdc bank

I really like that tilt able ground mounted panels holder shown above. Any chance you could share the dimensions and perhaps some more detailed construction helps?  

Michael Richards wrote:I really like that tilt able ground mounted panels holder shown above. Any chance you could share the dimensions and perhaps some more detailed construction helps?  

I've got two broad designs, single row, and double row.  Here are some pics of my SR v1.4 design and some more pics of my v4.0 DR design.  Pay attention to the trusses on the back side.  I think they are really important to give structural rigidity so the panels don't get flexed in high winds.  Look closely at the cantilevered trusses on the inside struts of my v4.0 design.  I am very proud of those.  Got the idea while driving down the highway and driving next to a big semi carrying roofing trusses to a building site.  I thought to myself, I could do that!

I sink a 8' long 3.5" schedule 40 steel pipe into 36" of concrete, then slip a 4" pipe over it, with the frame welded onto the top of the 4" pipe.  Most of the members are full-channel unistruts, with diagonal re-enforcement either half-channel unistruts or 1/2" rebar.  I custom scale the frames to each set of panels I buy, so there are no real plans as such.