Solar Panels?

[iamrich]

They have some pretty amazing stories on that page. I ran the calculator and it says I need 30kw of storage and 12kw of panels to service 30kw demand a day and be autonomous for 24 hours. I didn't see a place to adjust for location. I figure when I build my house the only issue will be storage. I am probably going to end up with 2 acres of panels feeding a 9v Duracell battery out of a smoke detector at the rate I am going, lol...

 

[AZRoadrunner]

I figure when I build my house the only issue will be storage. I am probably going to end up with 2 acres of panels feeding a 9v Duracell battery out of a smoke detector at the rate I am going, lol.

Storage is the achilles heel of renewables. It seems like every day there's a story somewhere about how the activists think we're going all-renewable in a matter of a few years. The cost of all that storage, the non-renewable energy required to manufacture it, and the environmental effects of the dumps being full of all those batteries as they age and need to be replaced -- is cringe-worthy. I believe it's California that is planning to go all-electric with vehicles. Pass the popcorn.

 

[unsubscribed]

@iamrich The Victron site knew that I was in Phx, and it set the solar graph appropriately. Since I didn't give it my location, I presume it's using my IP to figure it out. Now, if you're using Tor or some kind of obfuscator ...

As for storage ... yeah. There is one of those "Interview Puzzle Questions" that pertains to this. You drive up a hill for 1 mile at 30 mph. How fast do you have to go down the hill (1 mile) to average 60 mph?

As text books say, I'll let the reader figure it out.

The point is, it's very difficult to make up for lost time (say, in traffic). And it's very difficult to make up for a time when the sun isn't shining.

 

[iamrich]

Yep. It is also difficult to determine how much power you really need. If you are generating 10kw of solar per hour and using 10kw per hour in theory you don't need much of a battery, but when the generation drops off, does your demand also drop off? For instance if I am using 1kw per hour to run AC because the sun is beating on me, will I use the same if it is raining? In theory my AC load would be less so my demand is less. As long as I can generate enough power to not dip into my batteries I should be fine. Also a change in habits will seriously effect your demand. Say you vacuum, run the dishwasher, do laundry, run the AC, work on the lap top, etc. in the middle of the day when the power generation is greatest. In theory if you have a shit ton of panels providing more power than your batteries can handle, you are still ok because you have an outlet for it. The second your solar production drops off, you stop doing all that stuff and go into survival mode. Right now I never think about that. I pay $0.10 a kw no matter when I use power, so I use it when it is convenient for me. Power companies for years have been telling us to run all the heavy load stuff at night to even out demand, but with solar it is the exact opposite. Run everything in the middle of the day and shut down at night.

 

[unsubscribed]

For a few years now, we have been conditioned (by the power company) to avoid using power from 3 pm to 8 pm because of a Peak Charge. So in the summer, we set the programmable thermostats to pre-cool the house until 2:50 pm, and then let it drift to 82 after that. We don't do wash (clothes/dishwasher) during those hours. We try to avoid using the oven then.

One mistake can make a $100 difference in a monthly bill.

Anyway, I suppose with a good battery monitor, it would be somewhat easy to learn and adapt to the vagaries of solar. Especially after using up all your battery once or twice.

 

[AZRoadrunner]

@iamrich And the calculations aren't always reliable. For example, our rooftop, grid-tied solar was designed and installed by Sunrun. They "calculated" our energy needs by going through a year's worth of electric bills and then claimed to have added some extra padding. We ended up with 21 REC285TP2 panels (for a total of 5,985 watts) and the inverter is a Solis 5K-2G-US. The most I've ever seen the inverter roll up to is about 4800 watts on cloudless days at solar peak. The solar does save us a lot of money on our electric bill, but we don't bank a damn thing with Tucson Electric because Sunrun somehow undersized the system. AND, on top of it all, AFTER they installed the system we took measures to further and drastically reduce electric usage -- we replaced an electric oven with a gas one, installed a high-efficiency, multi-stage A/C system, and replaced every light fixture with LED. Figured we'd bank all kinds of power credits for use. Nope! Our system is undersized. It works fine as designed, but wasn't engineered with enough solar panels. Oh, and by the way, Sunrun is not a great company to deal with -- their customer service is almost non-existent. They take your money and run (pun intended).

 

[iamrich]

I had a similar experience I think with a local installer but I pulled the plug before any work was done. They planned to put 15 panels on my south facing roof (15x300w) for a bargain $30k. I didn't know anything about solar, other than I liked the idea of no electric bill. After trying to do the math on how long it would take me to break even not having to pay my yearly average $85 a month electric bill I decided I might not live that long and I was almost positive I wouldn't still have this house.... Now that I know more about solar, I figure that system probably would have generated about 20kw a day on a good day, so how that was going to cover my 30kw average usage, I don't know. The final straw was when the sales guy came back and said he could do it for $24k to break even.

 

[AZRoadrunner]

I had a similar experience I think with a local installer but I pulled the plug before any work was done.

We went forward with grid-tied solar because this is our retirement home and we're going nowhere except in a pine box (or an urn on someone's fireplace mantle). I'm in my 60s, and paying for the system while I'm still working is a good investment for the years when I may choose not to work (or can't work for some reason) -- which is why we went for the 20-year "lease prepay" option. Sunrun owns and maintains the equipment, but we don't have any monthly bill from them, nor are we subject to any Sunrun lease payment increases. It works for us -- but is certainly not for everyone. Our system produces about 35 - 40 kWH per (sunny) day.

 

[Dr Mark]

Power outages are rare here in the Tucson area -- for now. However, I work in the power industry and behind the scenes it's overall nothing short of a volcano waiting to erupt. My consulting work takes me to power utilities all across the country and into generation plants, substations, and control centers. There are influential people and organizations in our country who seemingly have no clue what it actually takes to generate reliable, affordable electric power. They don't understand the physics or the logistics involved and they think the electric grid can run off of pink unicorn farts. As a result we, as a country, are walking on a tightrope with no more safety net and evil leprechauns are shaking the wire, trying to make us fall. I wouldn't classify myself as a "prepper"; rather, more of a realist. I'm all for "green" energy, by the way -- but the way the activists and politicians are trying to implement it is positively insane and will lead to rolling blackouts -- or worse. And on top of all that are the growing cyber security threats (that's my direct line of work) that our power utilities are having an enormous amount of difficulty keeping up with. It's a bad scene that's only masked by the fact that the lights are still on.

I have wanted a solar backup for a couple years so when I watch Will's videos, I decided to buy an all-in-one, battery, and panels. I have read many instances like your post. I feel more secure now that I do not rely solely on the grid for my power. I could get by with what my solar panels provide. It would not be comfortable but I would make it work. I may upgrade my system at some point (1.5k to 3k). California is a good example of the consequences that come with an under funded, neglected electrical grid. Solar is great but you cannot neglect the infrastructure needed for electrical power. Here in Florida, we seem to be maintaining it but I am not sure it is.

 

[AZRoadrunner]

Solar is great but you cannot neglect the infrastructure needed for electrical power. Here in Florida, we seem to be maintaining it but I am not sure it is.

We don't have an emergency at this moment, but our power grid (which is actually several interconnected grids) is, indeed, fragile. Many people don't realize that in a real blackout situation where generators have gone offline it's not possible to simply fire them back up and hit the switch. AC electricity has to be carefully and precisely synchronized out onto the transmission lines or generators and transformers can literally blow up. It takes a lot of coordination and timing, and -- in cases where a generator is completely down -- that's usually referred to as a "black start" situation, where it takes a generator to start a generator. In the days gone by when we had plenty of excess generation capacity this wasn't so much of a problem -- a problem generator could be dropped off of the grid and there were others to take up the slack. At the rate our generation is being dismantled by crazy people -- all bets are off now.

 

[unsubscribed]

I sometimes wonder (and perhaps rationalize my expenses in buying LiFePo4 batteries) if batteries will be used for barter in the future? Almost as heavy as gold, but more useful.

Buy 'em while they're 'cheap'?

 

[Dr Mark]

I sometimes wonder (and perhaps rationalize my expenses in buying LiFePo4 batteries) if batteries will be used for barter in the future? Almost as heavy as gold, but more useful.

Buy 'em while they're 'cheap'?

Or buy them (batteries and panels) while they are still available. I started buying some bitcoin so if it seems necessary at some point I am ready to buy as much as I like or can buy.

 

[Dr Mark]

Makes perfect sense to me. I am not spending an unreasonable amount yet, but I am prepared if things start to get more extreme. I am not under the impression that "it cannot happen here" or "not in America". Whether its gas, food, electricity, money they all can become scarce.

 

[fred333]

So here's what I'm currently doing. (Pun intended.) I am powering a mother-in-law sweet with my solar station. With one light on continuously, and this desktop computer, I draw about 170 Watts 24/7. It will be a bit more when I hook up the small refrigerator too.

As long as you're not a [computer] power-user or serious game-player, that is, your computing requirements run more along the lines of sending/receiving email, web-browsing, watching cat (or solar) videos on youtube, image editing, document creation, et al, you can save a good bit o' juice by replacing the desktop computer with a 4-8GB Raspberry Pi 4, which generally sucks < 4-ish watts. And if you live in a sunny locale, get a gaggle o' solar-rechargeable 12W LED lights that charge outside during the day and light your inside at night. Add a coupla O2COOL Smart fans and you're made-in-the-shade, figuratively speaking. Works for me..

 

[unsubscribed]

Actually, I could shut the desktop down and save a lot more energy. For now this is a learning experience. (I just read Amazon reviews about my Ali meter. Waiting for it to fail.)

 

[snoobler]

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[snoobler]

This thread has been hijacked and gone way off-topic.