Hi! I'm new to solar and NEED HELP!

[FairyGirl16]

Hi guys!

I don't know if I came to the right place or not.

I am a tad bit frustrated but also excited. We basically built a shack that more or less could even be a room. And I do work from home so it's ideal for me to get out of the house and work in peace.

My idea goal is just to use 600 watt solar panels to power an a/c until that's 5000 BTUs (about 155 watts according to Google), a mini fridge which is 75 watts, and my TV which serves as a monitor for my laptop (shouldn't be too much)

So, I do more or less know how much watts I'll need. I believe 600 watts (two 300 watt panels) should work for what I want to do. But I don't want to spend a whole lot of money. My target spending is $500 or less.

This is what I found on Amazon, so please tell me if I'll be okay buying this equipment. I don't want anything to smoke or explode, lol. I'm very new to solar energy and even learning about "watts" was a real headache for me! I guess I feel overwhelmed, lol.

Here are the links:



Y&H 1000W Grid Tie Inverter Stackable MPPT Pure Sine Wave DC15-28V Solar Input AC90-140V Output for 12V Solar Panel https://a.co/d/gfKw8JA

Feuruetc 12V 15Ah Deep Cycle LiFePO4 Battery, 3000+ Cycles LFP16AH Rechargeable Battery, Maintenance-Free Battery for Golf Cart, Boat, Solar System, UPS etc Rechargeable Lithium Iron Phosphate Battery https://a.co/d/71aGHv9

Solar Panel 600W 2pcs 300 Watt ETFE Flexible Solar Panel Portable Monocrystalline Solar Battery Charger for Car Yacht Battery Boat https://a.co/d/i536pw3

Thanks for helping me! It really means a lot to me. If there are other better products or advice, let me know please!

 

[Hogheavenfarm]

Why would you need a grid tie inverter? Thats for pumping power back into the electrical grid. You will need an inverter, not a grid tie one. For what you want to run, at least a 3000w one. Going to be well over 500$.

 

[Mattb4]

Without spending too much time researching I can tell you rather quickly that you should avoid any flexible panel kit. They all too often have false or misleading ratings.

I also suspect your wattage for the 5000BTU AC is low. I have an old one, and not probably as efficient as new, and it pulls from 4-500w when running the compressor.

The 15ah battery is too small to reliably power much of anything.

Would be handy to know your days watt hours for the mini fridge.

 

[SamDeleted]

If you only plan to use in day light it should be a little easier

 

[FairyGirl16]

Why would you need a grid tie inverter? Thats for pumping power back into the electrical grid. You will need an inverter, not a grid tie one. For what you want to run, at least a 3000w one. Going to be well over 500$.

Thanks for the advise! I'm looking at inverters on Amazon. I'm new to all this so just bare with me please!

 

[FairyGirl16]

Without spending too much time researching I can tell you rather quickly that you should avoid any flexible panel kit. They all too often have false or misleading ratings.

I also suspect your wattage for the 5000BTU AC is low. I have an old one, and not probably as efficient as new, and it pulls from 4-500w when running the compressor.

The 15ah battery is too small to reliably power much of anything.

Would be handy to know your days watt hours for the mini fridge.

Based off Google my mini fridge is 75watts. And I'm considering not using an ac unit (I have a good box fan that cools well).

What battery (affordable) would you recommend that can at least maintain power for a mini fridge 24/7? And thanks! I'll look for other solar panels on Amazon then.

Also, do you know an affordable inverter that can go with all this? Something that doesn't really smoke or burn or something?!

Thanks again!

 

[Mattb4]

For solar panels the first thing you need to know is that they are rated at STC (Standard Test Condition) of 1000w per square meter in sunlight. This means a 20% efficient panel of a square meter size would be rated as a 200w panel. Always look for the size of any panel you are thinking of buying and do the math. Panels can range from 19% up to 23% efficient but not much higher.

As to the battery capacity to carry your mini fridge and other loads. It is fairly easy math also. Amp hour can be converted to watt hour by multiplying the nominal battery voltage. So if you have a 100ah -12v Li battery you can expect at most 1200wh from it. Let's say you are drawing on average 75w from the refrigerator all 24h a day. That is 1800wh. So you would need 2 - 100ah battery to reliably power the frig all day. Watts= Volts X Amps

I know all this sounds complicated but it is worthwhile to sit down and get a firm handle on the basics. In the Video section of the Forum here the owner (Will) has several good beginner system videos you can watch for ideas.

 

[OffgridMatty]

It would be cheaper to run a subpanel from your house grid power into the shack if it's near the house. Then you can run everything you want with out issues.

 

[jasonojordan]

Also if your load is indeed 600w you are going to need more then two 300w panels. 300w is their theoretical max output and you will likely never see that.

 

[Mattb4]

I spent a few minutes looking at solar kits offered on Amazon. I would have to say that none of them are a good deal. There are very few that look legit in terms of honest rated items such as panels and SCC but their prices are steep in comparison to buying your own components. What a minefield out there for beginners.

Almost makes me want to go into business selling a decent quality bargain level setup.

 

[Tomthumb62]

Don’t rely upon Google to get your watt numbers. Get the actual devices and hook them up to a watt meter to get real world readings in your real world situation.

I use this one:

Poniie PN2000 Plug-in Kilowatt Electricity Usage Monitor Electrical Power Consumption Watt Meter Tester w/Extension Cord https://a.co/d/1IHQB9n

Plug in your device, such as your mini fridge and check the meter after 24 hours to know a more realistic use amount. For more accuracy, measure over 3-7 days. And keep in mind it will be higher use in summer months, so if it’s summer where you are, this is a good time of year to measure.

Fwiw, we use an apartment fridge (bigger than a mini but smaller than full size) in our mostly uninsulated camp trailer (HOT in summer) and we use about 1100Wh in 60-80F and 1900Wh in 80-100F temps. If your shack is well insulated, that will help a good amount to reduce power usage.

 

[FairyGirl16]

For solar panels the first thing you need to know is that they are rated at STC (Standard Test Condition) of 1000w per square meter in sunlight. This means a 20% efficient panel of a square meter size would be rated as a 200w panel. Always look for the size of any panel you are thinking of buying and do the math. Panels can range from 19% up to 23% efficient but not much higher.

As to the battery capacity to carry your mini fridge and other loads. It is fairly easy math also. Amp hour can be converted to watt hour by multiplying the nominal battery voltage. So if you have a 100ah -12v Li battery you can expect at most 1200wh from it. Let's say you are drawing on average 75w from the refrigerator all 24h a day. That is 1800wh. So you would need 2 - 100ah battery to reliably power the frig all day. Watts= Volts X Amps

I know all this sounds complicated but it is worthwhile to sit down and get a firm handle on the basics. In the Video section of the Forum here the owner (Will) has several good beginner system videos you can watch for ideas.

Thank you!!!

 

[jasonojordan]

Another reliable meter you can plug your 120v devices in to check draw is this:

https://www.amazon.com/gp/product/B000RGF29Q/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

 

[Rednecktek]

Blurb time!

Well, I'll start the default answer to these questions and we can work from there. Here's you To-Do list:

1: Power audit! This will give you some important information on how big your inverter needs to be as well as how much battery capacity you'll need. There is a link in the FAQ section (I think, or someone here will post it shortly) so fill in the blanks and see what it comes up with. You'll probably need some sort of Kill-A-Watt to get accurate measurements. Are you going to be running a 12v system? 24v system? 48v system? What are the specs on your solar panels? VoC? Vmp? Being as this is a new build, throw together a wish list of what you want and estimate on the high side.

1a: Where do you live? Speccing out a system for Scotland is a LOT different numbers than Arizona due to the amount of light you actually get. Someone here can post the link to the PVwatts.com or JCR Solar Uber-Sun-Hours calculator sites to help figure out how much you'll have to work with. That will be a box in the Power Audit form.

2: Parts list: You don't need a make & model list, just a parts list to start from for reference. You'll need an inverter, a MPPT charge controller, fuses, shunt, buck converter, batteries, wire, etc. Once you have a basic list it can be fine tuned to make & models after that. If you're looking at the All-In-Ones check for correct voltage outputs (120v or 240v Split Phase for North America, 220v Single Phase for European type areas) and make sure it has enough capacity for a little bit of growth and fudge factor.

3: Budget!: Steak is great but doesn't mean anything if your wallet says hamburger. Figure out what you're able to spend now vs what you'll have to cheap out on now and upgrade later.

4: Tape measure! Figure out where you're going to stick all the stuff you'll need. A dozen 3000AH batteries sounds great until you're sleeping on the floor because there's no room left for a bed. Is there a compartment that can house all this stuff? Will the server rack batteries fit? Are you going to have to make space? Physics can be pretty unforgiving.

5: Pencil out what you think you need and throw it at us so we can tell you what you've missed (because we ALL miss stuff the first go-round ) and help figure out which parts and pieces you're going to want to get.

Well that's the thing about solar systems, there is no 1-Size-Fits-All answer. Your system will need to be designed to fit YOUR needs. When you design and built the system, it's not going to be the perfect system for me, or Will or 12vInstall or anyone else, but it Will be the right system for You and that's the goal.

As for where to get started, let me throw my standard blurb in here to help point you in the right direction. There's going to be a lot of math and research involved, but that's going to be a LOT cheaper than just buying parts off of someone's list and finding out that it doesn't do what you need.

Don't panic on the Power Audit, you'll actually be doing that a few times. When you do the first pass put in ALL the Things that you might want. AirCon? Sure. Jacuzzi? Why not. MargaritaMaster-9000? Go for it.

The second pass will be the "I Absolutely Need This To Survive" list that isn't going to have much on there.

The third pass will be the "This is what is realistic" audit that you'll use to design the rest of the system.

The Power Audit is going to tell you 3 primary things: 1: How big does your inverter need to be to power your loads? 2: How much battery bank do you need to last $N number of days with krappy weather? and 3: How much solar panel will I need to install to refill those batteries in a 4 hour day (the average usable sun hours rule-of-thumb).

Once you know what you Want and what you Need and what your budget can Afford there will be somewhere in that Venn diagram where those three things meet.

After that, THEN you can start looking at parts.

Yes, it's a long drawn out process, but it's worth it in the end. Not every house has the exact same floorplan, not every vehicle is the same make & model, and not every solar system is designed the same.