Learning solar power for off grid lifestyle

[Okjoek]

I'm interested in learning how to use solar power as a step towards making myself less dependent on the grid and possibly some day making money by supplying to the grid for some passive income. What do I need to know about buying / working with these things? All I know right now is that there's a few components:

 

- The panel themselves that do something with electrons when sunlight is present

 

- A regulator does some kind of voodoo magic of digesting the panels power so the battery can charge with it

 

- Then there's battery banks of which I don't know what people look for for this sort of thing. 

 

- Inverters do something to turn the DC current of the battery into AC for outlets that many household appliances use

 

 

And that's all I really know about this topic from taking Basic+digital electronics in high school. And I think most of that process is the same for wind / water turbines as well. I've been trying to determine what sort of steps I can take to make my lifestyle more suitable to this kind of power system. I strive for simplicity.

 

- I can remove as many "always-on" appliances as possible.

- We already only use LED light bulbs.

- I already hang-dry my laundry.

- I can use a toaster oven and portable cooktop burner in place of the huge conventional household ovens. Dunno if they have microwaves that aren't always powering a display or something.

- Desktop PCs use a lot of power. I could switch to a laptop, but the problem I see with some of these devices is they use AC to DC converters when I would already be using an inverter to convert DC to AC. I'm worried if that would cause    problems. If so maybe a low power desktop running on an APU or GT 1030 would be better than my 75W RX 460.

- For laundry washing I'm curious what kind of energy efficient or modern man-powered systems are available.

- Food refrigeration is a tough one because those things can use a lot of power over time. One idea is to put a fridge in a chest position so that the cold air can't escape all over the floor when the door is open. Other than that it's important to put it in a place where the sun and warm air never reaches. Another curious idea I stumbled upon is using a standalone ice maker and dumping the ide into an un-powered fridge/freezer with a drain hole.

- I can't think of any ways of getting around plumbing. I need a sink, toilet and shower head, there doesn't appear to be any getting around that.

- I'm kind of ignorant as to what needs to be powered for internet use aside from just a modem router.

 

 

Another big question I have is how does one integrate a DIY solar power system with existing home systems working off the electrical company's grid? Thanks in advance for any input, I'm just trying to come up with ways to deal with a crappy economy.

 

[Jurrunio]

How much surface area can you cover with solar panels?

[Okjoek]

41 minutes ago, Jurrunio said:

How much surface area can you cover with solar panels?

Just a suburban back yard with a fairly decent view of the southern (relatively speaking because New York) sun.

Probably something like this (but all grass)

Spoiler

 

[Hackentosher]

Okay the first thing you must realize is solar is no magic bullet to cure the world's energy needs. Next you have to realize that it produces the most amount of power when demand for energy is lowest, and stops producing energy when demand is highest. 

 

With that out of the way, let's talk about the system. So you have your solar panels, most of them produce between 100 and 300 watts each. The most efficient, dense panels I've seen are 175w/m^2. Your solar panel then should probably go to a solar charge controller. What this guy does is take the sometimes unstable output from the panels and smooths it out, setting it to the right voltage as well. This then goes into your batteries. For this, I recommend popping over to https://secondlifestorage.com/index.php to learn more about building a powerwall. Once your batteries have some juice in the, the DC voltage from your panels and batteries is sent to an inverter to turn, say 24v dc into 120v ac that gets piped into your breaker panel. Then you can use the energy as normal.

 

you have to size the system on your energy use in your house. If you use 40kw/h a day, you need to have enough solar to run your house in the day, and charge enough batteries that will power your house when the sun goes down. Now, all of this is pretty damn expensive and not too practical unless you have a lot of land and/or roof space.

 

I hope all this helped, let me know if you have any more questions. If I can't answer them, I should be able to point you in the right direction.

[Okjoek]

35 minutes ago, Hackentosher said:

Okay the first thing you must realize is solar is no magic bullet to cure the world's energy needs. Next you have to realize that it produces the most amount of power when demand for energy is lowest, and stops producing energy when demand is highest. 

 

With that out of the way, let's talk about the system. So you have your solar panels, most of them produce between 100 and 300 watts each. The most efficient, dense panels I've seen are 175w/m^2. Your solar panel then should probably go to a solar charge controller. What this guy does is take the sometimes unstable output from the panels and smooths it out, setting it to the right voltage as well. This then goes into your batteries. For this, I recommend popping over to https://secondlifestorage.com/index.php to learn more about building a powerwall. Once your batteries have some juice in the, the DC voltage from your panels and batteries is sent to an inverter to turn, say 24v dc into 120v ac that gets piped into your breaker panel. Then you can use the energy as normal.

 

you have to size the system on your energy use in your house. If you use 40kw/h a day, you need to have enough solar to run your house in the day, and charge enough batteries that will power your house when the sun goes down. Now, all of this is pretty damn expensive and not too practical unless you have a lot of land and/or roof space.

 

I hope all this helped, let me know if you have any more questions. If I can't answer them, I should be able to point you in the right direction.

The truth is I don't care about the world's energy needs although it might sound selfish I just care about my energy needs and ways I can make a long term investment. That and I've kinda gotten bored after I learned how to build a PC and some other electronics hobby might help keep me entertained and learning about new stuff.

 

I'm unsure how exactly to determine the amount of power we use. I have a job, but my mom pays the power bills. I will note she was happy with the last power bill because it was only 104 USD she claimed. 

 

After that IDK exactly what specs to shop for in components. Solar panels seem fairly straightforward once I know how much energy I need, but can I just pick any old charge controller and Inverter off Amazon? And what kind of batteries would be suited for this? Car batteries don't really sound like the best choice, but what options are there for this application? These are some of the first questions going through my head. Thanks for that forum too it looks like I might be able to learn from people who are experienced and passionate on a forum like that.

[Hackentosher]

4 hours ago, Okjoek said:

The truth is I don't care about the world's energy needs although it might sound selfish I just care about my energy needs and ways I can make a long term investment. That and I've kinda gotten bored after I learned how to build a PC and some other electronics hobby might help keep me entertained and learning about new stuff.

 

I'm unsure how exactly to determine the amount of power we use. I have a job, but my mom pays the power bills. I will note she was happy with the last power bill because it was only 104 USD she claimed. 

 

After that IDK exactly what specs to shop for in components. Solar panels seem fairly straightforward once I know how much energy I need, but can I just pick any old charge controller and Inverter off Amazon? And what kind of batteries would be suited for this? Car batteries don't really sound like the best choice, but what options are there for this application? These are some of the first questions going through my head. Thanks for that forum too it looks like I might be able to learn from people who are experienced and passionate on a forum like that.

I only talked about the world's energy needs because the inherent problem with pure solar power is applicable to all scales. 

 

Before you start designing any system, you need to define your constraints. Figure out how much power your house uses, on average, every day. 

 

Again, for panels, you need as much power as it takes to run your house's day time operations and charge the batieres. Think of all the things consuming energy in your house, when you use them, and how much power you consume. For example, the average home air conditioning unit consumes about 3500w, and where I live, it's probably running around 10-16 hours out of the day. Determine how many hours it's on durring the night gives you the minimum amount of battery capacity you need to run your house at night. 

 

As for solar charge controllers, you want an MPPT controller that supports the battery chemistry you're using (pretty much lithium vs lead acid). If you're using lead acid, you just have to wire up your batteries and that's about it. Leaf acid has a lot of limitations though, so many people use lithium batteries. These systems are much more complex in their wiring and monitoring. Lithium ion systems need a bms to keep all the cells balanced, prevent over charging prevent over discharging, and allow for over current protection. Most people build their lithium power walls from old laptop batteries, I suggest checking out jehu Garcia and hbpowerwall on YouTube. 

[Okjoek]

On 5/15/2018 at 7:28 PM, Hackentosher said:

I only talked about the world's energy needs because the inherent problem with pure solar power is applicable to all scales. 

 

Before you start designing any system, you need to define your constraints. Figure out how much power your house uses, on average, every day. 

 

Again, for panels, you need as much power as it takes to run your house's day time operations and charge the batieres. Think of all the things consuming energy in your house, when you use them, and how much power you consume. For example, the average home air conditioning unit consumes about 3500w, and where I live, it's probably running around 10-16 hours out of the day. Determine how many hours it's on durring the night gives you the minimum amount of battery capacity you need to run your house at night. 

 

As for solar charge controllers, you want an MPPT controller that supports the battery chemistry you're using (pretty much lithium vs lead acid). If you're using lead acid, you just have to wire up your batteries and that's about it. Leaf acid has a lot of limitations though, so many people use lithium batteries. These systems are much more complex in their wiring and monitoring. Lithium ion systems need a bms to keep all the cells balanced, prevent over charging prevent over discharging, and allow for over current protection. Most people build their lithium power walls from old laptop batteries, I suggest checking out jehu Garcia and hbpowerwall on YouTube. 

I started watching Garcia DIY vids like this

and it's painfully clear to me that it's a bit more complex than I thought. If I'm going to get into this stuff I need to start at much smaller scale and ambition of projects to iron out my inexperience. I should try an experiment like just powering an LED bulb or my phone charger I think.

 

The lightbulb in my room's lamp says 9.5W.

My Phone charger uses about 18W I think.

 

[Pixel5]

the thing with living off solar is not to limit yourself with everything you buy or do, if you have the funds to build a good solar system you want to size it so you can cover your needs as good as possible.

 

sure you can try to downscale on some things, if i hear $104 power bill that sounds ok at first but considering new york has an electricity price half as high as i do and you spend about the same money that means you consume twice as much energy and i already dont consider myself someone who saves power where he can so you got room for substantial savings.

 

you want a solar system to be no hassle to work with and possible start small and only power a few things and build it expandable.

 

if you want to start with something you could buy some components for a few hundred bucks to get started and learn how this stuff works.

[Julian5]

On 17/5/2018 at 11:58 PM, Okjoek said:

I started watching Garcia DIY vids like this

and it's painfully clear to me that it's a bit more complex than I thought. If I'm going to get into this stuff I need to start at much smaller scale and ambition of projects to iron out my inexperience. I should try an experiment like just powering an LED bulb or my phone charger I think.

 

The lightbulb in my room's lamp says 9.5W.

My Phone charger uses about 18W I think.

 

To be honest with you Garcia DIY's videos are MUCH more complex as he makes the parts himself and is trying to replicate the Tesla powerwall with smaller more "fragile" 18650 batteries which require balance leads etc. A 12v battery bank can much more easily replicate this with off the shelf parts for a similar price. As previously said you will need to carefully design the system to your own needs so its essential to understand how much power you need and when. After that, you can start looking at solar panels, charge controllers, batteries and inverters suitable for your power load.

[d3sl91]

I currently live in Madagascar. The power goes out occasionally, and is very expensive. As I write this, the power has been out for 2 hours. 

Because power is expensive, and not always available - many people in villages use solar panels to power a light, charge their phones and maybe power a radio or small TV. In the cities, most have solar as a backup option for when the power does go out. 

It is actually very, very easy to get started with an independant system. Many folks around here have zero knowledge about electricity and how it works and yet they have them. When it gets hard, is when you build the entire system yourself from scratch, and/or you are trying to power a whole house and integrate with your grid power. You can pick up multi function solar charge controllers that will have, all in one unit, a solar charge controller to charge the batteries, an inverter to convert from DC to AC. They will also often times have 12V connections, as well as USB. This, plus some panels and a battery will get you started. 

Example unit: https://www.amazon.com/dp/B075ZJMM6H/ref=twister_B07BD29KM9?_encoding=UTF8&psc=1
 

I would also recommend looking up various Ham Radio resources. Many, many hams are running their equipment on solar power - either as a portable field option, or as an emergency preparedness setup. 
 

[Mira Yurizaki]

Throwing in some two cents, but the first thing I would do if I want to go off the energy grid is to consolidate just how much electricity I really need before even considering what kind of solar power system I should get. The less electricity that's being used, the fewer things that are needed for the system.

[Pixel5]

17 hours ago, M.Yurizaki said:

Throwing in some two cents, but the first thing I would do if I want to go off the energy grid is to consolidate just how much electricity I really need before even considering what kind of solar power system I should get. The less electricity that's being used, the fewer things that are needed for the system.

yea this is something were OP has much room for improvement, with the power bill he talked  about and the electricity price where he lives they probably use about 5000kWh a year, maybe a little more.

[Mira Yurizaki]

1 hour ago, Pixel5 said:

yea this is something were OP has much room for improvement, with the power bill he talked  about and the electricity price where he lives they probably use about 5000kWh a year, maybe a little more.

This topic does remind me how the founder of the Soylent drink wrote about how he lives off a solar charger and a car battery (among other things). Though his computer at the time was a NUC and two USB monitors and says if he wants more computing power, he just SSHes Amazon cloud thing.

 

Though the rest of the article is really hippy stuff. That was the only thing I found actually interesting and practical (And maybe his kitchen setup)

[Ahoy Hoy]

Putting the odd panel on your roof to cut down a little off electricity bills or as some said earlier to help during power outages. But going for 100% solar power is not worth it. To make it work you spend an awful lot of money ruin your backyard and lower your living standards by not using basic things like washing machines and the oven.

[Pixel5]

20 hours ago, Ahoy Hoy said:

Putting the odd panel on your roof to cut down a little off electricity bills or as some said earlier to help during power outages. But going for 100% solar power is not worth it. To make it work you spend an awful lot of money ruin your backyard and lower your living standards by not using basic things like washing machines and the oven.

if you are not able to use a washing machine you are going solar wrong, its easily possible to do this.

[Mihle]

Money wise, your kWh price have to be quite high for it to ever be worth it. I bet it isn't where you live.

[Meic]

On 5/15/2018 at 4:42 PM, Okjoek said:

One idea is to put a fridge in a chest position so that the cold air can't escape all over the floor when the door is open.

Before you try this one...

 

The fridge's compressor needs to be upright to function. If you put a fridge on its back, the coolant will drain out of the reservoir and the fridge will stop working. I would guess it would also burn out its motor. 

[Pixel5]

On 4.6.2018 at 11:04 AM, Meic said:

Before you try this one...

 

The fridge's compressor needs to be upright to function. If you put a fridge on its back, the coolant will drain out of the reservoir and the fridge will stop working. I would guess it would also burn out its motor. 

yes this would absolutely happen.

 

also Air is not holding very much energy anyways so letting the cold air out is not a big issue, if you want the fridge to be more efficient fill all the extra space up with water bottles, that way you dont lose so much cold air when you open the door because there simply is less air in the fridge.