Solar energy at home.

[Osvaldo de Garay]

Since several years ago, I use solar cells to get free electrical energy, partially feeding my home. Here some pics. 27 solar cells, 10W each, 18 oriented to south east to capture morning sun and 9 to north east to capture evening sun. The voltage regulator is self designed, two buck converters with discrete IC's, and a 180Ah 12V batt. My ham 2m rigs are powered from it, the compressor of my refrigerator, part of indoor lightning and a Becker Brescia german auto radio from 1961.

 

[Osvaldo de Garay]

The voltage reg is the black box with ammeter and voltmeter. It is composed of two buck regs operating 180° out of phase. The box with the heat sink is a rectifier from mains, in case of several cloudy days. I do not return energy into grid, nor I will.

 

[mhardy6647]

Nice. Using electricity as a resource looks ever more sensible when one "makes one's own".

Egocentric aside, strictly FWIW. We've got a couple of moderately sized roof mounted arrays at this point. Despite the fixed angle (and we're relatively far north, so that's more of a liability than for more equatorial folks) and the weather here (winter snow can take the PVs off line for quite a while in the wintertime), we seem to be reliably covering our annual electricity needs with them. We do take advantage of "net metering" (i.e., any energy we produce in excess of our needs flows back to the grid) and, for us, it's netted out favorably. We had this house built (and the first array installed) long ago enough to have a pretty favorable deal with the utility company in that regard. I am not sure current regulations in our fiercely libertarian US state ("Live Free or Die" is the state motto!) are as generous as they were ca. 2011.
I could see adding battery storage and/or a pure-play electric vehicle at some point, but both of those are expensive "solutions".

 

[Osvaldo de Garay]

The big majority of humans ignore how difficult is to generate a single watt of his own. Once those guys learn it, just there they will start to be more austere using it and valorate what it costs.

 

[mhardy6647]

Well, OK, I guess technically the sun and the PV panels are doin' the "generating", not humans per se.
That said, I generate plenty of energy, fueled by things like pasta, pesto and grilled meats, but I'm not a terribly efficient Carnot heat engine myself, and I expend most of that energy typing drivel on internet forums nowadays...

 

[Imakeller]

I just got a fairly extensive solar system installed at my home. It’s comprised of dual 18kW Sol-Ark inverters, 2 x 19.2kW Homegrid by Lithion battery stacks, Tigo DC optimizers on all panels, and 200amp load panels with an outside quick disconnect. 60 Axitec black solar panels are on the S-E-W roof surfaces (nothing on the front, N facing side of the house). Also put in a 24kW natural gas Generac generator as backup for my backup. I spec’d pretty aggressively to get my utility company bill to ZERO.

 

[Osvaldo de Garay]

I'm in doubth with Li ion batteries. I watched several videos reporting they catching fire or exploding. The primitive lead-acid ones, OTOH, are more confidable and cheaper. There are several home in fires here known to be started by motorcycles, bikes, phones, computers, cars, buses, USB speakers, containing Li ion batts. The only one under my ceiling is the A06 in which I type this lines.

OK that they are dangerous because of their internal components (sulphuric acid and plumb/lead) but while they stay sure inside its package, no risk is evident, at less for me.

 

[Osvaldo de Garay]

... fueled by things like pasta, pesto and grilled meats, but I'm not a terribly efficient Carnot heat engine myself, and I expend most of that energy typing drivel on internet forums nowadays...

Are you Italian? I was born argentine, but I have my EU passaporto ready for the moment I can migrate elsewhere. I really hate this place.

 

[mhardy6647]

Are you Italian? I was born argentine, but I have my EU passaporto ready for the moment I can migrate elsewhere. I really hate this place.

US American.

 

[JeffS7444]

Nice, if unconventional! This is the first time I've seen PV arrays oriented like that. Wires seem very thin for 12 VDC, but if lengths are short and current draw is minimal, I suppose that could work.

 

[voodooless]

I'm in doubth with Li ion batteries. I watched several videos reporting they catching fire or exploding. The primitive lead-acid ones, OTOH, are more confidable and cheaper. There are several home in fires here known to be started by motorcycles, bikes, phones, computers, cars, buses, USB speakers, containing Li ion batts

Most home batteries are now LiFePo4. They are a lot safer than most of the other lithium-ion batteries.

Also, they consume like 2 to 4x less volume VS lead acid, so you can pack a lot more in the same space.

You really have 27x10W? That’s like less than a single modern conventionally sized panel.

 

[Osvaldo de Garay]

Yes, 27 units. Fixed, not sun tracking. I'm unable to build a better mounting mechanism, I din't know to use electric arc welder, nor I know about mechanics, so I did I could: a light aluminum structure, with as little resistance to wind as possible. Also, my home is >6mts by side, or about 40m². So it is few what can I do over I did. OP cables are 1mm² for each 3 cells but they join togheter in a plastic box to a 6mm² which is 3m long only. The regulators are just under the roof place where SC are, so the cable lenght is at minimum. At maximum illumination, total current is just under 12~13 amper over a fully charged battery, so cables seem to be sufficient. Certainly, when I started build it, cell went with 2 screw teminals, unwired. So, to avoud from mix technogies, I removed the special wires that the lasts of them carried attached them. I am single and live alone, so no women, no children nor pets under risk.

Here is a screen capture from Google maps where you see the cells, unfortunatelly the star shadow them partially. And the panel specifications.

 

[DVinylfan]

I plan a 6 panel (pole mounted, tilt and swivel able) system for our modest off-grid home. A water heater, fridge, a freezer, a small oven, an outdoor grill, not much else except a few LED lights, charging phone, tablet, speaker.
How many batteries do we need? Is four enough? And with a charge controller that is spec'd for a few more panels/ batteries would be great.
Anyone know of a kit like this available in Europe?

 

[voodooless]

I plan a 6 panel (pole mounted, tilt and swivel able) system for our modest off-grid home. A water heater, fridge, a freezer, a small oven, an outdoor grill, not much else except a few LED lights, charging phone, tablet, speaker.

Oven and Grill and Water heater are the main power eaters. If 6 panels are enough will depend highly on the frequency of use, as well as your actual location. Finland vs Sicily will make a massive difference

How many batteries do we need? Is four enough?

That question doesn't make sense. Batteries come in all kinds of capacities. For true off-grid usage, once again, you'll need to factor in the above points at the very least: needed capacities can vary wildly depending on location and intended use.

And with a charge controller that is spec'd for a few more panels/ batteries would be great.
Anyone know of a kit like this available in Europe?

There is really a lot out there for a lot of reputable brands, both European and some pretty good Chinese stuff.

 

[Osvaldo de Garay]

I agree. Generate hot from electricity is expensive always. Regarding batteries, it depends in electrochemistry, size, quality, charge/discharge duty ratio, cell composition, orientation, day/night ratio, habitat, kind of use.... Too many more.

I strongly dislike to power 220V devices from 12V plus inverters. Last company I job I repaired several of them, with iron transformer ditectly to 50Hz and PWM giving quasi or sine waves. All them have an internal objectionably high intrinsic power consumption, still more with some foolery like pretty screens, blue ray or wifi connections, remote controllers and the like. All that shit drain current from your battery.
And power stages are always sand based, thus, delicate.

 

[DVinylfan]

Oven and Grill and Water heater are the main power eaters. If 6 panels are enough will depend highly on the frequency of use, as well as your actual location. Finland vs Sicily will make a massive difference

That question doesn't make sense. Batteries come in all kinds of capacities. For true off-grid usage, once again, you'll need to factor in the above points at the very least: needed capacities can vary wildly depending on location and intended use.

There is really a lot out there for a lot of reputable brands, both European and some pretty good Chinese stuff.

Great! I'm moving the project forwards

 

[Philbo King]

I'm in doubth with Li ion batteries. I watched several videos reporting they catching fire or exploding. The primitive lead-acid ones, OTOH, are more confidable and cheaper. There are several home in fires here known to be started by motorcycles, bikes, phones, computers, cars, buses, USB speakers, containing Li ion batts. The only one under my ceiling is the A06 in which I type this lines.

OK that they are dangerous because of their internal components (sulphuric acid and plumb/lead) but while they stay sure inside its package, no risk is evident, at less for me.

Well lead-acid do release hydrogen gas when being charged. If housed in a leaky structure and owned by a nonsmoker that might be ok. Maybe.

 

[Osvaldo de Garay]

Yes, they release hydrogen and oxygen, but when overloaded (boiling). Ir you were true, no car can be usable because it works hot and with sparks. Also, actual batteries recombine H² and O² in the caps, I sincerely ignore how.

 

[mhardy6647]

I agree. Generate hot from electricity is expensive always.

It's better than generating cold -- that darned thermodynamics thing gets you, every time!

 

[Osvaldo de Garay]

Mmmmm. I disagree. A regular fridge/refrigerator needs 160/180W. An induction heater, more than a killowatt.

My apologies by the off topic.