MomsintheGarden and I are taking 10,000 IUs of Vitamin D3 daily. I suspect we will do this indefinitely since Vitamin D is so critical for immune function. She recently got tested and even though we had been doing this for months she was right on the low end of O.K. I ordered a home test kit the other day, but I haven't received it, yet.

Homeschoolers: Start your engines!

That may very well be so, but this exercise is all about scoping the problem. (I'm still on the "Could it be done?" question.) Most people I know (IRL and online) know next to nothing about energy and even less about renewable energy. I suppose that is why I hear such widely-disparate opinions regarding a transition to renewable energy such as "It's impossible!" or "It will be cheap and easy!". IMO, both of those positions are flat wrong and are based on nothing other than ignorance. This board is about education. My goal in this thread is to educate others who may not have access to the information I have at my fingertips. I also hope to learn about things that I have not researched fully. If I can get some in the "It's impossible!" crowd to realize that it is quite possible (at least in some well-suited places like Texas and at some perhaps-high cost) and some in the "It will be cheap and easy!" crowd to see that nothing about eliminating fossil fuels is cheap or easy, I will feel like I have achieved my goals. If no one wants to step out of their comfort zones, so be it. But I believe that most posters on this board are willing to learn about other viewpoints than the one they currently hold. If they weren't, they'd be long gone!

A massive study recently published by a hospital in Barcelona, Spain, in which they gave half of the patients massive doses of Vitamin D4 upon admission, on day 3, day 5, etc. showed a much lower rate of both ITU (same as ICU?) admission AND a much lower death rate in the Vitamin D group versus the control. I'll post a link if I can find it. Here is a link to a YouTube video with all of the details.

The Perfect Winter Solar Day (February 8, 2021) Let's start here, since this is what many people imagine solar production looks like. In dry places that don't get much rain or snow, it DOES often look like this. What was the weather like on February 8, 2021? February 8 was a beautiful, cloudless day. It was also cold in the morning. When the solar inverters started up in the morning, the outside temperature was 16° F. I think the midday temperature was around 45° F. (BTW, I KNOW the temperature at first daylight because the solar inverters measure their internal temperature, Unfortunately, that temperature is not as meaningful in the middle of the day because there is self-heating which changes the temperature after that initial wake-up temperature.) Brief description of the graph: The X-axis is time. It goes from midnight to midnight and the day shown here is February 8, 2021. The Y-axis is power in Watts (abbreviated "W"). The blue curve is the production of the solar array and the orange curve is the consumption of my house. What is going on with production? Note that the shape of the solar production resembles a cosine function if you put zero angle at noon. But it's not quite right, is it? The peak happens at 1:00 PM, not noon, and the curve is kind of skewed toward the afternoon. So, why is the production curve shaped like this? After all, the sun is just as bright in the morning as it is at noon as it is in the afternoon. My solar array does NOT track the sun, so on a cloudless day the shape all has to do with the compass angle, the elevation angle of the array, and the path of the Sun through the sky. It also can be affected by shadows which are created by things like other parts of the roof, trees, or possibly snow sitting on the panels. We'll talk about clouds in a later post. Think of holding a single solar panel in your hands. If you hold it directly facing the sun, it will receive the most sunlight and can produce the most power. (In this position, the Sun is said to be in the "boresight" of the solar panel, even though it is not a gun.) If you hold it edge-on to the sun, it will produce very little power because no direct sunlight will hit the solar panel (although there will be reflected light hitting it). The peak at 1:00PM is easy to explain: My roof points about 14° west of South. Since 15° is 1/24 of 360°, 15° is equivalent to one hour. So my solar array is pointed so that its production peaks at a little before 1:00 PM. What about the skew in shape? Well, that is partly due to the 14° angle shift mentioned above. Think about this: I cannot point my solar panels due North and get a peak in production at midnight, can I? How about if I point them due West? Would production peak at 6:00 PM? In the summertime, it would! But not on February 8: the Sun has already gone down by then. How about directly Southwest, would it peak at 3:00 PM? Yes! But that production curve would rise slowly from sunrise until 3:00 PM and then it would come down rapidly after 3:00 PM. It wouldn't look much like a cosine. So some of the skewing is due to pointing angle. But wait, there's more! Some of the shape of the morning production rise is due to shadows from another section of roof which gradually clears by 10:00 AM or so. Finally, there was a little bit of snow on a few of the panels on February 8 that did not all melt until just before noon. Now, the less obvious part: I said that this solar array had a DC rating over 13 kW and an AC rating of 12.6 kW, so why is the peak production shown in the image on this fully-sunny day only 11.233 kW? Is it because it was cold? No, actually, photovoltaic panels produce MORE electricity when they are cold than when they are hot. The answer is that, even though it was cold that day, the sun NEVER went through the boresight of my array on February 8, 2021. That tends to only ever happen in late March or early April and also sometime in the Fall (I'm not sure when in the Fall). What is going on with consumption? In the middle of the night, our load dropped down to about 500W. That's mainly some computers, etc., that are on all the time. I need to work on that! But it got cold early that morning, so just before 3:00 AM the heat pump came on. At 4:00 AM the thermostat starts trying to ramp up the temperature from 58° F toward 64° F, but it was doomed. First of all, the heat pump is only rated to be able to efficiently move heat down to an air temperature of around 18° F. Secondly, I had not cleaned the filter in the air handler for a couple of months before that day (I have since!). The result is that the resistive heaters in the air handlers came on at around 6:00 AM and the heating system drew over 8 kW for HOURS until about 10:00 AM! After the Sun came up in the sky, sunlight streams through our South-facing windows and the heat pump ramped down and then eventually turned off for the rest of the evening. How much energy was produced? The amount of energy produced is the integral of the blue curve, which simply means it is the area under the blue curve. The attached image does not give you the value, but I can see it elsewhere: 73.147 kWh. How much energy was consumed? The energy consumed is calculated by taking the area under the orange curve: 75.526 kWh. Bottom Line and Takeaways: As you can see, even on a nearly-perfect solar day, we still had to BUY about 2.4 kWh of electricity from the electric company (worth about a quarter). Why did this happen? In an all-electric house, temperature is the main driver of the electrical load. Below about 20° F, my heat pump reverts to resistive heating, so it is not nearly as efficient as it is at warmer temperatures. Could we have saved energy? Absolutely! After I saw this data, I cleaned the air filter in the air handler the next day. We could also turn off more electronics to further save electricity. But, by far, most of the energy consumption that day was for heating. 75 kWh is certainly a lot of electricity, but the worst day we have ever seen in this house was twice that: 150 kWh. Uggh!! A Note About Storage: February 8, 2021, is fairly instructive about daily storage requirements since it was a day when energy produced nearly matched energy consumed. Let's imagine that all days were just like this one (that is NOT true here, but it is a much more reasonable assumption for Texas in wintertime). How much battery capacity would be needed each night to shift the daytime production into the nighttime. That number is given by the area between the blue curve and the orange curve during the daytime while the solar array is producing. In other words, that is electricity which is available to be stored in batteries because it is not being used at the time of production. I don't have the tools to calculate that number accurately, but I can estimate it from the image below. Since we know that the area under the blue curve is roughly 75 kWh, I will estimate that the amount available for storage is around half of that, so let's say 38 kWh. I will point out here that if we put 38 kWh into a modern Li-ion battery, we will only get about 90% of that back, or about 34 kWh will be recovered. So our original 2.4 kWh shortfall has now grown to about 6.4 kWh once we use actual batteries for storage rather than just the infinite, perfectly-efficient battery known as the power grid. Finally, a modern, maintenance-free, 40 kWh Li-ion battery with a 10-year guaranty about US$52,000.00.

The driveway is clear, but the road is packed snow and ice. I doubt the plows will be able to get that off today. It's 29F now, but we should be above freezing for about 5 hours. I suspect the driving conditions will be a LOT worse on the drive home than on the way to work today.

Let's have a look at some solar production and consumption data for an all-electric home to see what things look like in wintertime. This data is from my home, which is in VA rather than TX, but we can use it to help understand what is needed to try to completely away from grid-based power and become self-sufficient. For reference, the house was built in around 1993, so it is not the most efficient construction available. The solar array has a DC power rating of 13 kW and an AC power rating of 12.6 kW. Those ratings are a bit confusing to many people, so I will try to simplify it. First, I will point out that kW stands for kilowatts, which is a measure of the FLOW of electricity, also known as power. (It does NOT tell us how much ENERGY will be produced. That is measured in kWh or kilowatt-hours, which is much more difficult to determine.) The AC rating is the absolute maximum amount of power that the system could ever produce at any moment in time. The DC rating of the panel is an indication of how big the solar array is. For instance, if I wanted to compare two solar arrays on two nearby houses that were pointed in the same direction, I would use the DC ratings to make the comparison. The AC rating simply needs to be high enough to avoid limiting the production of the array too much. Generally and AC rating that is at least 85% of the DC rating is sufficient to do that. Now, let's start by looking at what happens on both "good" and "bad" solar days and how things look during a "bad" month, like this one.

We had just a dusting of snow overnight. The rest of the driveway is being cleared and MomsintheGarden and DD28 will be off to work within the next hour or so. I guess it is time for me to get out there and rake the snow off the solar array.

Whoa!! Archimedes' got nuthin' on that first bird. Please keep them over there!!

I suppose you're gonna bring all of those over here to join their friends, the starlings, are you? Before you do, please tell me: what's wrong with them?

Seriously, what language are you ladies speaking??

Quill, you are in the WRONG THREAD. Squirrel-on-bird-feeder stories belong in the United Kingdom thread! Get it right! 🙃

Do you have chickens? MomsintheGarden invented a device which catches the Japanese beetles and feeds them to the chickens. Saves chicken feed and no more nasty bags of beetles to empty!

No, you didn't scare me away! I was off to EAT supper which DS21 made. It was an AMAZING stir fry. Yes, thanks to everyone for the great cat stories! Please keep them coming! Now that we know what your cats do in the kitchen, we need to know what they do in the bathroom. Indigo Blue and I have already shared...

We didn't get any additional precipitation after about 11:30 AM. But the temperature also did not get above 27F all day. We don't know if anyone will be leaving here tomorrow for work, or not. Is seems unlikely (which is pretty odd after only getting 3.5 inches).

She is! I didn't mean to be insulting. It was the photograph I was commenting on. Please accept my apology!

It is interesting that you bring this up now. I just ran across this video showing that Elon Musk really does believe in using his own products. It shows that they have a medium-sized Tesla solar array and some Tesla storage batteries at their Boca Chica, TX, Starship launch site and this installation helped keep the lights on during this whole debacle. That's one thing I like about him: If he makes a product, he uses it. They've been testing the Tesla Semi truck by carrying batteries from their Gigafactory in Utah to the assembly plant in Fremont, CA. The route is a difficult one through the Rocky Mountains with significant climbs and drops. They've been pretty tight-lipped about the performance of their Tesla Semi prototypes on this tough journey, so it will be interesting to see if they really to use them for the actual logistics for their own products. Good on them if they do!

She's cute, but she has demon eyes!

Obama?! Our cat is orange. I call him "Orange cat bad".

O.K. We can top that. A few years ago we got a bidet for the toilet in our master bedroom. (Search if you want to learn all about that!) Our other cat (the one who NEVER gets on the counter) often sleeps on our bed. If he is there when one of us uses the bidet, he immediately jumps off the bed and comes in for "petties"! He KNOWS that he will have our undivided attention for TWO WHOLE MINUTES to pet him continually. And, yes, when we get up he puts his paws on the toilet and looks to see what is going on in there every.single.time.

How in the world did you get that picture?! I've seen that many times, but I cannot imagine the cat letting me get that close while he is doing something so verboten.

After I read the first sentence of your post I was already preparing my reply to counter such nonsense. Thanks for completing the story! Your cat is clearly more devious than many!

I did. Where were you? Snow removal: Wovel: 3 Electric snowblower: 0

Actually, our cat gets on the table for the express purpose of drinking from our water glasses. Clearly OUR water is preferable to THEIR water. That is why when I get a drink I now get a saucer, not for under the drink, but as a lid to keep the cat out.

As a testament to how much better the wovel is than a shovel (and we have one of the nice snow shovels with the bent handle), my two sons who have been sent out to clear the driveway have BOTH opted to use the one-armed wovel rather than shovel the driveway. Our driveway is about 5000 square feet (paved) and I think they have cleared about 3000 square feet. It is certainly taking longer than normal with the broken wovel.