Advice for getting off-grid (out of spite)?

[Hyperspace Industries]

Well, over here in SA we have a horrendous electric grid, which means that we get frequent power outages. This is annoying my dad to bits (not me of course, since we have had them for as long as I can remember, I’m used to the lights going out), so he wants to install a solar system to power our house.

Any advice?

[Deddly]

Do you have IKEA over there? They do pretty good complete systems and can help you design the setup.

From the topic, it seems you're looking to completely disconnect from the grid, correct? There are several different battery options available to you:

• Lead acid: Big and heavy, but that doesn't matter much in a static system. Relatively cheap, but this kind of battery doesn't have many duty cycles (they'll need replacing much sooner than other technologies). Make sure you have enough batteries so that you're never going to discharge below 50% and they should last a while. 
• Lithium ion: Very popular nowadays. The smallest and lightest option, very long service life (many charge cycles) but also likely to be the most expensive in the short term. Requires an advanced battery management system to prevent damage from overcharging or over-discharging. Note that although these are more expensive to buy than lead acid, they can actually work out cheaper in the long term because they last that much longer.

Those are the two most common choices, but there are some unconventional options that might be worth it if you can get them:

• Nickel metal hydride. These are almost impossible to get in the kind of sizes you will be looking for. But if you can get them, they will last a long time and likely work out cheaper than Lithium ion. 
• Nickel iron. Now these are pretty special. They are big, heavy and quite hard to get, but these batteries will last longer than your house. There are electric cars that used these batteries 120 years ago and the original batteries are still in perfect working order. Unlike any other battery chemistry that I know of, they can be abused through overcharging, complete discharging, freezing... you can overcharge them to the extent that all the electrolyte boils away, refill and you're good to go. You can deep-discharge to 0%, leave them out in the winter and let them freeze solid, bring them in, thaw them out, charge them, and they'll be fine. I certainly wouldn't recommend doing any of this, but it does give some idea of how hardy they are. They need a little maintenance in the form of topping up the electrolyte from time to time, but they're not likely to take any serious damage if you forget once in a while. They have no known limit in the number of charge cycles. I can't think of anything better for a stationary off-grid system. 

The angle of the solar array is different for on-grid and off-grid solutions. If you are actually going off grid, they should be angled for optimum power in the winter. This will give you less total power throughout the year than one optimised for the grid, but it's in the winter when you really need to chase the photons. 

[Nuke]

why not use LiFePO4 batteries. i think they are ideal for power wall scenarios, and dont explode as much as lithium ion. 

Edited May 27, 2022 by Nuke

[Deddly]

10 hours ago, Nuke said:

why not use LiFePO4 batteries. i think they are ideal for power wall scenarios, and dont explode as much as lithium ion. 

True, lithium iron phosphate batteries are good. Very expensive though. 

[kerbiloid]

20 hours ago, Nuke said:

LiFePO4

"LiFe" is clear. But what pun is "PO for" ?

[Deddly]

1 hour ago, kerbiloid said:

"LiFe" is clear. But what pun is "PO for" ?

Phosphate

[Mazlem]

On 5/28/2022 at 11:26 AM, kerbiloid said:

"LiFe" is clear. But what pun is "PO for" ?

Not a pun, it's Lithium-Iron Phosphate, similar voltage ranges as lead acid but much higher capacity, and safer than lithium ion.  Check out Will Prowse's site; he has a ton of videos showing various options out there, how-to videos, links to recommended batteries / solar equipment, etc - https://www.mobile-solarpower.com/

[Maria Sirona]

SA? What is that?

Edited June 2, 2022 by Maria Sirona

[Pixophir]

Hello,

very old time player here, not playing KSP atm but eagerly waiting for KSP2, just browsed the forum in search of a release announcements and found this thread instead.

 

My setting is subtropic, and I am going off grid soon joining quite a few households around here, but my new place is still under construction. It'll probably be autumn until it goes into production.

I opted for bifacial panels (~10 kwp), monophasic inverters, chargers, system  monitoring of a high price sector, 51.2V ~28kwh LiFePO4 battery (LFP from now on, diy), and as a future option charging of a small electric car. This isn't cheap (~22keuro when ordered in february, more today), allthough I am doing it myself so only little extra cost, mainly for the bureaucratic things. DC isn't rocket science, if I may say so :-) The layout is redundant in terms of component failure, otherwise it could be much cheaper. I may join a neighbourhood project in the future, should such a thing ever come into existence.

The most important thing before starting over is to do a thorough review of your necessities, list up all the consumers, the potential your roof/patio cover/garage/whatever has in store in terms of area, azimuth, inclination, geographic setting, shading, prevailing weather and climate. You can't of course go offgrid with solar alone at 70°N because winter and cold. You can easily go off grid with solar alone in South Africa (?) if you're not under a constant cloud of a prevailing wind system ;-), have a well insulated and air-tight house, use a heat pump for heating/cooling and a ventilation system with heat exchanger and recuperation.

Whatever technology and how much of it you choose as a storage depends. When using lithium, I'd recommend LFP because they do not (easily) suffer from "thermal runaway" like some othe Li-Ion tech.  They are temperature sensitive, but have a high round-trip efficiency and needs only very little care, mostly adjusting and monitoring settings and charge states. When going for Lead-acid, have a look at "traction batteries" (OPzS). Leave Gel, AGM and starter batteries alone. All lead acid is environmentally unfriendly and needs quite some love and monitoring, but is extremely sturdy and can also last a long time. But they can easily be destroyed in a short time when discharged deeply or overcharged to a high degree. Also, do not nuy batteries from storage, have yours made for you on demand, by a battery make not on the other side of planet.

LTO is another upcoming lithium technology. NiFe (as said Nickel Iron, good old Edison battery) have a terribly efficiency, but can last longer than a human lifetime. They are very expensive, if available at all. Oth, they can be discharged until they switch polarity. They only need little brewery every now and then, refill water or change the electrolyte.

There is more upcoming technology, like sodium batteries, but for a beginner it is probably best to go with the main stream and use either LFP or OPzS. When they die in 20 years or so things may look different.

You asked for a dvice, but this is far too general. A lot of things play a role, besides some electricity which can potentially kill and a high component value which could probably go up in smoke, there may be regulations, scarcity of material these days.

Question: do you diy or hire an installer ?

Have you thought of a system to just get over the grid failures instead of going completely off ? Because off is off, usually utility companies do not allow such systems to be connected to the rgid because of multiple failure modes they can introduce. For a mere UPS like system with a set of panels and a battery/inverter combination to get over the failures you will need an installer and proper documentation, but it may be much cheaper than your own power plant.

Edited June 2, 2022 by Pixophir

[kerbiloid]

6 hours ago, Maria Sirona said:

SA? What is that?

Like Finland, but SA.

Mirrored by equator.

[Ben J. Kerman]

15 hours ago, Maria Sirona said:

SA? What is that?

I think you would call it Etelä-Afrikka.

[Hyperspace Industries]

On 6/2/2022 at 2:26 PM, Maria Sirona said:

SA? What is that?

South Africa.

On another note, sorry for not checking this thread, forgot to follow it.

As for some other questions by others:

1. We are planning to hire an installer, my dad knows some people.

2. We do have a generator, but it’s a load of trouble to start, petrol is not cheap, and well, my dad wants to just stop paying eskom (the electricity provider) out of sheer spite.

[Pixophir]

13 minutes ago, Hyperspace Industries said:

1. We are planning to hire an installer, my dad knows some people.

Good idea. They know better what to do in your setting, geography and regulatory environment than some random guy from the internet could possibly without more detail.

13 minutes ago, Hyperspace Industries said:

2. We do have a generator, but it’s a load of trouble to start, petrol is not cheap, and well, my dad wants to just stop paying eskom (the electricity provider) out of sheer spite.

I'm somewhat on your side. But let me comment, 'sheer spite' alone might not be the best criteria. As said, we're talking about a lot of money, and a constant obligation to maintain and repair things. In principle a photovoltaik installation runs or doesn't. If it does, fine.  If not and you don't know where to look you become dependent on installers. There are also details to observe, and things to maintan, cables, connections, batteries to monitor, and components might need replacement in a few years, etc. That'll all cost your time if you DIY or your money if you must call an installer.

Think it over, also alternatives like a solar powered UPS, or a setup that allows you to feed into the grid, with compensation or without, if that exists over there. I read SA is actually pushing small pv installations.

[JoeSchmuckatelli]

5 hours ago, Hyperspace Industries said:

wants to just stop paying eskom (the electricity provider) out of sheer spite

Can be done. 

Will be expensive. 

Return on investment often measured in decades and you are likely to be 'upside down' forever. 

You're getting good technical advice above - but if I can offer my $.02: if you can afford it, spend some of that on a lawyer to inform you of the regulatory impact of the choice / decision. 

Mind you, I know nothing about SA law, but I have heard of jurisdictions that require homes to be hooked up to the grid where available.  In many places the 'sell back to the provider' isn't optional (it's required) and the rate scheme is completely in favor of the utility company. 

The technical difficulties are often easier to solve than the legal, FWIW. 

Edited June 14, 2022 by JoeSchmuckatelli

[Pixophir]

@Hyperspace Industries, I had some time today and performed a short search on PV in South Africa.

From what I get there is a strong case for small private installations connected and feeding surplus into the grid, not just as a means to secure personal power supply of households, but also as a stabilizing element for the grid as a whole. It seems to me that the municipalities are the ones to ask for the detailed how-tos of such a system. Haven't found out if there are subsidies.

There also seem to be financial benefits, tax exemption, etc., even to a degree that some money can be made with a private installation that feeds surplus into the grid. Get all the information you can, from other installations in your area, from the administration of your neighbourhood/municipality/whatever, your tax advisor if you have ... before you start.

In principle this sounds like the best of both worlds to me, far more than I can expect here in Spain where the utility bill can not go below 0. You will definitely want a certified installer for such a thing, and if there's money to be made you will probably want the PV as big as affordable, meaning use all the available/permittable area. I would, in this case, also advocate for a smaller storage, just to get over an outage and not too much more. You want to sell the energy, not to keep it in the pockets. Your house-inverters should not charge from the grid, but from solar alone. Such systems usually have a galvanic separation between the inhouse-energy and the grid connection (different inverters/chargers), so that in case of a grid failure the inverters that feed into the grid can switch off but the in-house supply remains stable. This is extremely important !

In the end, even an electric car can be charged from solar alone if the system is large enough.

My advice: grab your dad, talk him out of the rebellous aspects, tell him about the good in people who dedicate their personal efforts for the wellbeing-of-all(tm) and all that, you get it :-) And that he can draw some satisfaction out of the fact  that you'll be selling energy to the ones who have been fooling you for so long ;-)

Edited June 16, 2022 by Pixophir
Autocorrect corrected and missing word made unmissed