Last updated on March 16, 2021 by qualified builder Aaron Barnett
Knowing when to go off-grid on solar is when you know how to do it. What you really want to know is how do you lesson your actual power consumption so that going 100% off-grid on solar is a no-brainer for you or your family if it suits your situation and your environment.
I will show you the best way to go about being 100%-of-the-grid while saving money doing so.
What are the reasons not to go off-grid?
There are of course pros and cons to consider when thinking about going off-grid. Going off-grid is of course not for every situation. It could be easier to stay on the grid if you have a large power demand, and older larger buildings, especially in cities or when limited by sunlight.
To save money on electricity it’s best to go 100% off the grid while knowing exactly how to reduce your power consumption while making sure you can still use electrical appliances, have hot water, and a warm room.
Before we start it’s important to know that just because you can save money it doesn’t necessarily mean solar is worth it for you, or everyone.
So it is best to consider your situation get the information you need and decide whether to go-all-in or whether to stick to what’s standard if the grid is available to you.
What can make going off-the-grid hard?
Reasons to go 100% off-grid on solar power
It is rewarding to collect your own solar power, just like it is to catch your own fish, build your own table or grow your own food.
DIY is even more rewarding knowing that you’re not only sourcing your own lumber. But you are also powering your power tools straight from your own off-grid solar system running from the current direct sunlight.
A building should look after you not the other way around.
Off-grid, solar is the easiest and most cost-efficient way to power a tiny house, cabin, or a new small build because of the information available already.
Solar power can also off-set grid power usage on large buildings that consume power mostly during the day rather than at night.
Solar makes a way for any building focused on sustainability to minimize overall resource usage and for a city at large if it was more popular.
An off-grid power source like solar might mean you never have to worry about the paperwork required for buying power and maintaining it. One less thing to worry about to be more simple and to do your part to be greener while at the same time reducing your overall power consumption.
Why AC power is not that efficient with solar
High voltage AC power running through power lines, needs to be reduced back down to low DC power inside most of your home appliances for them to operate safely. Every time volts need to be converted, reduced, or amplified 5-20% of electricity is lost, this happens many times before you can turn on your TV.
Energy is also consumed to keep electricity pumping at a high voltage through the power lines and your house even if no one is using it.
When you connect to the power lines the cost of power must also go into the cost to build and maintain the power lines. Factor in the trees that are also needed to build them, and the visual annoyance of power lines in general.
Electricity is also wasted when it travels a distance, even if it’s only a few meters. The voltage drops the longer the distance it travels. That is why electricity is converted to AC as it’s much more efficient at traveling long distances.
When running an off-grid solar system using DC appliances less generated power is needed for the same power output, making solar indirectly attractive only with the right DC set-up, to begin with.
If you’re trying to work out if you can go off-grid or not. Forget about your current KW (Power) usage.
When to go on a solar grid-tie system
If your family home or commercial building is already wired to run on AC, it could be an expensive change switching to DC.
And the convenience of always having power might not be worth switching to solar to save some money or resources.
Especially so if you need constant power in a professional environment or in a busy family home. In these cases, you might be wondering. Should I still get solar panels while staying connected to the grid for convenience?
When it comes to grid-tie solar system assuming a building is running on AC I think the best benefit comes when you minimize the need for battery storage while maximizing how easy it is to get power from solar panels.
You need to know if your electricity is consumed in the daytime or in the nighttime.
If you are using power during the day there is no reason not to go on any type of solar system. If you consume the majority of your power in the day then why not offset that by drawing from solar panels directly. You might only need a small battery to stabilize and average out your power, rather than store it. Or you could stay connected on a grid-tie system.
Likewise, if you only use power in the evenings, and you don’t have an efficient electricity usage plan in your building, it might not be worth collecting a large amount of power and storing it.
Solar at scale is best when it is directly powering in the day without the need for much storage. Solar can do this really well.
I think commercial buildings with low to mid-power draw that have a roof with the sun, and only need power during the day time should consider a large solar system and small battery storage only to stabilize that power throughout the day.
For professional environments, you might want to stay on the grid so that you have a backup if there’s a chance the system isn’t big enough to cover you fully.
If you do your research there might be things you can do with any leftover power in summer if you size for winter.
Why you should focus on energy efficiency first
For solar to work don’t think about how much energy you currently consume on average. Instead, think about what you actually need power for.
Focus on what you want when it comes to your electricity consuming luxuries. Not the total energy measured in kilowatts you think you need based on your bill.
So instead of focusing on how many Kilowatts you consume every week based on current consumption. Think about how to get the smallest solar system to work in the most efficient way while still being able to run all the electrical appliances you want. Like your fridge, surround sound, microwave, laptop, and of course your power tools.
Run DC power instead of AC
Be more efficient with power by moving away from AC to instead DC power for full-time appliances like the fridge and everything that’s easy to power from direct DC.
Only run an inverter while using appliances that need AC like a vacuum cleaner or a microwave.
An AC inverter consumes the same amount of power as a fridge, even when there is no AC draw. Running primarily DC and only switching the inverter on when running AC appliances will decrease your solar and battery requirements for an off-grid system the most.
What can you run on DC power?
DC power can be stepped up to higher voltages or dropped down to suit a range of all DC appliances. But most DC appliances are made to run on both a 12 or 24v input.
Basically, you want to remove the AC part if you are focused on being more energy-efficient.
For off-grid power decide on a 12v or 24v storage. More on this later.
A DC voltage step-up adaptor is better than an invertor as it lets you manually set the required voltage needed without going to AC first and wasting as much power. These voltage step-up deceives can be used for any appliance that runs on DC and it will come with a range of different plug fittings and adaptors needed to replace any common AC charger. (For less than 80$).
That small box on your laptop wall charger that gets hot is converting AC to DC.
When to use AC power?
DC devices aren’t the answer for everything, although most appliances can be substituted to run directly on DC to save power, some DC appliances cost more than AC appliances to purchase because there is less competition, as the only market is only for RV and marine applications.
If 90% of your power is running on DC you are saving a huge chunk of otherwise wasted power. You don’t want to be a hermit restricted to only DC appliances, however.
Why you should combine solar with gas
Heat is expensive and electricity is ineffective at converting to heat. While heating can be up to 90% of your electricity needs. This includes cooking, hot water, and heating a room.
There is a range of different mixes of gases available with LPG gas being the most common. Whatever you find to be sustainable you could cut out 90% of your need for power storage (Batteries) by also using gas.
Gas is cheap, it also cannot be accidentally spilled which would damage the environment with other fuel types.
Gas like LPG is known to be the one of cleanest burning fuel types available. While being more efficient at producing heat directly rather than converting electricity to heat.
Gas like LPG doesn’t degrade over time and clog up equipment that runs on it, this means less-maintenance than other fuel alternatives.
Three or two 9kg LPG bottles last me half the year in the summertime as less heating is required for water and there is no need for a heater.
For the coldest few months in winter (8-14degres), a 9kg bottle lasts me 2-4 weeks. Mostly from the heater that’s running all the time.
A 9kg LPG gas bottle lasts me 1-3 months on average for a warm room, cooking, and hot water. I pay around $3.6 US per week on average. That’s efficient and even better if you go on a holiday in winter. Or collect your own gas from green waste.
The solar power debate; Is it worth it or not
It’s worth it if you lower your energy consumption by 90% by using LPG gas for heating purposes and then not wasting electricity by running DC instead of AC electricity to further reduce your power needs by 10-40%. You can also factor in that you don’t need to run an AC inverter 24/7 this will save another 30% of your power if you are on a small system.
Also, make sure your lights are 12v LED’s so they are 75% more efficient and don’t put a dent in your battery.
You get the idea you need to be efficient with power.
It is important however that the person intending to live off-grid has no problem with the psychological element of knowing what state the batteries are at and when to prioritize power usage and at what times.
Sometimes you need to go easy on the power. But it’s not that hard when you know how it works.
I do admit that with a family or multiple people it would be a lot harder though to manage if everyone is used to using power whenever they want.
But with LPG, you never have to worry about not being in a warm room, or not having hot water, or being able to cook.
The power needed for lights, charging your phone, running a laptop, microwave TV, vacuum, surround sound, and even power tools are nothing really. You really don’t need that much power or need a very big solar system.
Anyway, you do have to consider if your house is already set up on AC power and if it’s worth the change. Or if the limitations of how much power can be drawn at once are possible for you and your family.
You also have to consider if you can find an electrician that understands DC power to wire your house to be more efficient when it comes to power consumption.
Auto electricians know how to wire 12v DC, you could also look for someone that specializes in marine electronics a marine electrician will know how to wire an efficient DC system as a requirement for many boats.
If you want to know how to get the most energy-efficient building possible. It makes the best sense to set up an off-grid solar system from the beginning on a new build, mostly for a small cabin, or a tiny house.
You can now even charge and run all your power tools on DC using cordless power tools, as Makita and Dewalt have a battery charger that can charge from a 12v car battery or your solar bank.
What happens when power gets low for me.
If there has been no sun (Literally) for more than 3-4 days and the battery is dropping below 75% (This only has the chance of occurring during a 3-4 month period each year) I don’t use my power tools, vacuum, or microwave until the sun shows again.
When I go easy on the power I still have unlimited heating, a fridge, lights, phone charging, and am able to run my laptop as much as I want.
If a storm hits or if the weather is bad like this I’m not going to need to use power tools outside anyway. I properly won’t turn on the 32inch LCD on the wall as my computer monitor if the weather is forecasted as bad again for the next few days additionally, so I will just use my standard laptop screen.
I will just use my DC Jobsite radio instead of the AC but that’s mostly for convenience anyway. Solar life is kinda fun, I might have to eat a raw meal if it’s too wet to cook outside though. I just haven’t built a rain shelter yet. Being solar is really not that hard, and you learn to work around it.
Don’t get a solar system bigger than what you need
A large solar system can be more expensive but a smaller solar system is relatively cheap, what you want to do is optimize your setup for how your solar system works. So that you don’t actually need that much electricity, to begin with.
You might be shocked to find out why you don’t really need that much power, but you just need to find the cheapest and easiest way to get that small amount of power you need.
Don’t install a huge solar system so that it covers your current energy consumption without reducing it.
Solar doesn’t mean you are saving money or helping the environment, solar might mean having to deal with the drawbacks and maintenance required with solar.
Largely through the eco-friendliness and the cost-saving factors of solar are dictated largely by how small your system is because of a reduced power requirement.
How to have an energy-efficient off-grid system?
- Use gas or a wood-burner for all your heating: This includes hot water, and cooking. gas can be clean, renewable, and cheap while reducing your electricity needs by 90%.
- Avoid AC power conversion 90% of the time: Use primarly DC power directly and further half your energy requirements.
- Set up a small off-grid solar system: Basically find the easiest way to get the small amount of power you need by following the 2 steps above.
- Keep your solar syetem small: To reduce set up costs of solar.
- Get the biggest solar panels you can: You get the best value from the biggest panels, small RV solar panels can be expensive so focus on how many watts you need rather than how many panels.
- Buy online: Its cheaper to buy a solar system and all the componants online. Before finding somone to wire it.
Wind turbine vs. Hydro vs. Solar
What’s great about Hydropower?
Hydro is the cheapest and lowest maintenance way to get free energy 24/7. There are ways to take a small amount of running water through a pipe to power an entire house. You basically just need to get a large DC motor and run it in reverse and it will generate power.
The biggest upside to hydro even is that with a constant flow of water and enough pressure to turn a generator it will generate power all the time.
Even if you only have a 50-watt motor hydro can generate more power than a much larger solar system, and because it will run 24/7.
Batteries love constant power, as they will discharge less often giving them a longer life. With constant power, you will have less need for battery storage as well making the system cheaper.
You also have to be cautious about the environment, you want a flowing water supply big enough that you only take a small portion of the flowing water. If you block or dam a stream it can have a negative effect on the environment and stream life.
With hydro you don’t need much water, what you need is a good amount of head, like usual.
So the higher the highest point of your inlet pipe and the lower the bottom, the more pressure you can generate to get power from.
Think about how much head you need. Not how much water you need. A stagnant lake won’t work by itself.
What’s about wind turbines?
Wind turbines can be limited. If there is too much wind they will turn off so they don’t cook themselves, while not generating any power. Likewise, if there isn’t enough wind they won’t engage to generate any power. So you really have to consider your area’s average wind conditions for wind turbines. But they do work at night-time.
Wind turbines also have fast-moving parts that can be prone to wear-and-tear.
Technology is involving, one solution that is out there is directing wind hitting a roof to funnel into a gutter style turbine.
I think the best usage of wind turbines in an off-grid system, is secondary to solar. If a charge controller has the option for a small turbine that engages when the solar panels turn off at night time. It would help complete a solar battery charge every night for longer battery life.
This is because the drawback of deep-cycle lead-acid batteries is that they have a really hard time getting the last 2% of their charge on solar alone.
This is because only a very low amount of power 10-20 watts can be accepted safely at the end to complete each full charge, if you have large battery storage it can only take 10-watts at a time to trickle in. However, batteries need this low amount of power for longer than the sun shines.
The more times you complete a full charge the longer the batteries last. Or the longer the battery is discharged the shorter the battery life will be, You should never discharge a lead-acid battery by more than 50% as well.
Deep cycle lead-acid batteries can last 3-5 years even with this problem, but I think they could double their life possibly with a small wind turbine, completing their charge properly every day. This might make the cheaper deep-cycle lead-acid batteries last longer like the expensive lithium batteries.
Why is solar the best off-grid choice?
Solar is cheap, reliable, and has no moving parts, plenty of information is available on the internet, and it is easy to install and buy.
Solar can be all you need even with cheaper deep-cycle lead-acid batteries. If you use lithium batteries expect the batteries to last twice as long as they reach full charge easier. They can also be discharged more meaning you only need half the AH storage. But they cost a bit more and are more complicated if you switch your system off and don’t use them for a while if you go on holiday.
Did you know that in deep cycle batteries is already recycled? Keep in mind you can sell the lead from your old deep cycle batteries as you recycle them. And you should make sure to recycle them as lead is toxic if it’s put in a landfill.
How long should a solar system last
The power generated by each solar panel will decrease as they age, but it’s pretty irrelevant. Mostly because solar panels don’t have that much trouble getting power to begin with. A slow slight reduction won’t have an effect for a really long time, even then you can just get 1 more in 20 years for less than $200 online.
Even though solar works the weak point is not the panels themselves the ability to take that power and convert it to storage is not optimized fully yet for household applications, although the solution might be quite simple with an addition of only a small 10-20 watt wind turbine.
How long can you expect a solar system to last
What could improve in the future
It makes a lot of sense that the technology will only get better, but don’t wait for it.
As I mentioned before if all solar charge controllers took a small supplement turbine by default it could increase the battery life of cheaper lead-acid batteries with no real advance in technology.
The technology is already there, I think we can just expect a transition.
A grid-tie solar system might be the best way to benefit from solar if you use power in the daytime and you need constant power in a professional setting.
Meanwhile in a modest home, tiny house, RV, or cabin. If you use LPG gas for all your heating needs, and you run a direct low volt solar system for what cant be powered by gas then you only need 5-10% of the electricity you would normally consume.
Owning off-grid solar is a very reliable way to get the remaining power you might need in a small residential house or a remote rural area in the most effective way – that is off-the-grid.
Some people pay for it. To make life easier, but that’s their business.
You could instead consume less energy, by optimizing the way your energy is consumed by design. At whatever scale.
To bring this to an end I have never paid a power bill, going solar is fun, and rewarding, and I have saved money doing so. My solar system owes me nothing and neither does my tiny house.
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My name is Aaron, and welcome to Bangingtoolbox.
As a qualified builder and DIY’er, my goal with Banging Toolbox is to provide the #1 building and DIY resource on the internet for my readers.
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