Having owned a small solar system for seven years now, I have a few things to say with a tribulation outlook. Whether to go solar in the trib is a tough decision, but an even harder one is whether to go solar before the trib. On the good side, you can start to pay for the solar system now by the money saved on the grid. And it's far better to enter the trib a little experienced on how to use the system best. The risk in buying early is obvious. Some people like to have a sense of security for future emergencies, not minding large expenditures in return for peace of mind, but if you would feel sore to have made large purchases for tribulation purposes, if the trib did not arrive in your lifetime, then you should be slower to make the leap.
Having a solar system isn't complete security, anyway, as the equipment can break down. I purchased Outback equipment, and had two major problems already, and two minor ones that are on the verge of major. The main mother board in the DC-AC converter unit has been replaced twice, even though I use minimal electricity while the unit is designed for much more. Outback uses its mother boards over and over. When they send me a "new one," they demand the old one back, and claim to refurbish it, but, obviously, there are resistors / capacitors and other items in the unit that are aged, and these units go out that way to other people, with certain break-down predicted at any time thereafter. Outback tells me that so long as the mother boards are in working condition, they go out that way. They give a five-year warranty on mother boards in a newly-bought inverter, but only 90 days in a refurbished unit. What's that tell you? This is an underhanded way for Outback to supply itself with extra money, but for us, it's a high risk.
My main mother board blew in less than two years from purchase of the inverter, and I spent the winters away from here at that time. In other words, the inverter was virtually new at the time. For trib purposes, we should have an extra mother board(s) in advance. In 2016, they are about $500 new, and half that refurbished.
I was "fortunate" when the electric company wanted about $12,000 to install power to my new property. It made it easier to go solar; I took the plunge (note I didn't say "leap" as in flight, but "plunge" as in the sense of drowning) at a cost of about $9,000 U.S. that included eight 130-watt solar panels and eight 530-amp batteries, which is considered a small solar system...but it's enough for me alone. I installed the system myself, but if you can't, it's yet another expense. If you're handy, you can use the manuals to install most of the system, then call an electrician in to make sure you've done it all correctly.
My 130-watt Kyocera panels (silicon) were more expensive in 2008 than in 2012. The threat of less-expensive, thin-film panels has pushed the cost of silicon panels way down. The webpage below tells (and shows in a chart) that, after testing, thin film out-performed, in the efficiency category (though the definition of "efficiency" is not well explained) the common / conventional types of panels. This contradicts what others are saying (perhaps rumors originating from silicon providers). The bottom line on efficiency is how much money it costs per watt of power absorbed from the sun. Silicon panels last 20 years or more, but we won't need them for that long. Should we buy used panels?
Inexpensive thin-film panels should prove to be important for us. The film doesn't last as many years, nor capture as much energy per area, but for trib purposes, who cares? The main goals are: 1) using little battery power, and, 2) getting batteries recharged as quickly as possible, and as fully as possible. However, until one has personal experience on a product, perhaps one shouldn't give thumbs-up so hastily. But we should look into thin film.
Batteries are still fairly expensive (mine were about $250US each in 2008). The good news is, we shouldn't need many batteries, and they last much more than four years, so long as they are not abused. The battery charger was $400, and the 3500-watt inverter $1,600, for a total of $4,000 not including panels and a gas-powered generator. After these expenditures, you'll be off to races...as the turtle.
Four panels and four batteries can run typical power tools for building shelters, but only for one or two workers on sunny days. If you're only doing repairs, this small system will be enough to run drills, circular saws, etc. Running a washing machine, no problem. Want music? No problem. The computer, no problem. The four panels will do it in most times of the year in most places without worry, and I've learned that I can even run a small (5.5 cubic foot) freezer and a small fridge together, in non-winter months of a northern latitude, using just four batteries and eight panels. All eight are not always needed, but in cloudy periods, the extra four can be the difference between frozen and thawed freezer foods. Besides, if you demand too much power from batteries when, in cloudy periods over consecutive days, they are in a low-charge condition, it can reduce the performance of the batteries permanently.
Your main tribulation concern might be the water pump. It takes very little power for your household needs if it's pumping horizontally, say from your rain barrels or nearby stream to a pressure tank in the house. Pumping vertical is another matter. The depth of water in a well determines how much wattage is needed to bring it up. Your pump's tag will inform you on the approximate amps/wattage used, and from that you can do the math to see how much power it draws per hour of operation, measured in so-called watt-hours. The worst part in pumping water is the power used in stuffing the pressurized tank with it. Pumping into an open tank takes far less power.
For example, I use a small pressurized tank of about 15 gallons because the pump (about 700 watts) runs about four minutes trying to get the pressure from about 20 psi to 40 psi. About two minutes of that is to get the last two or three gallons into the tank, a large waste of power. The pump could do nearly 10 gallons per minute if it were pumping into an open bucket or tank, though the volume depends on the diameter of pipe used. For example, through a garden hose, I get about four gallons per minute. I opted for a small tank because, the larger the tank, the more volume it needs to stuff into the tank once it reaches near-40 psi. The last five psi take a "long" time, and four batteries can't handle the pump running long when they are low. Battery power is measured in volts. As the pump runs, the battery voltage drops if there is no sun shining.
You need to understand this if you're thinking of going solar, because you need to size your system according to the amount of power you'll need. A full battery pack in the dark, when using four batteries, sits at 25.2 volts. When the sun shines, the voltage rises to about 29 volts. So long as the sun is shining high in the sky, the water pump can run continuously, reducing the voltage to maybe 26 volts, and holding it there (the batteries will be fine under this load). The sun will hold the voltage there because the pump is feeding off of the sun rather than off of the batteries. But if three days of clouds move in, and the battery voltage drops to 24.4 volts in the dark, the water pump becomes a serious issue if the water demand, coupled with other demands, is great. Battery companies maintain that most battery damage (aging) occurs by bringing the standing voltage to less than 24.4. Batteries can be ruined in a year or less by doing so too often and too deeply. On the other hand, if the voltage is at 24.4 and the only thing running is a 50-watt laptop, one can use it all day long and see no change in the voltage.
A battery at about 24.0 is "dead." For trib purposes, have open water containers that can be refreshed in sunny periods, which allows you to shut the pump off during cloudy periods. You can survive the short periods without pressure at the taps. But the same battery problem exists with your freezer needs. If the voltage is below 24.4, you can't just shut the freezer off, for long, anyway, with no worries. Then again, foods are still edible if thawed and re-frozen. For critical times like this, solar users have a gas-powered generator as back-up to charge batteries. No problem, unless you can't get gasoline in the tribulation.
I'm reading online that a 1 HP deep-well pump uses 8 to 10 amps, or about 1000 - 1200 watts (multiply amps x 120 volts to find watts). However, I'm also reading that 1 HP is equivalent to 746 watts. I'm assuming that the loss of power due to conversion of electrical power to mechanical causes 746 watts to be in the neighborhood of 1000 - 1200. If you can use a 1/2 HP submersible to lift your shallow water, and it's using 600 watts, I'd say you're in pretty good shape, but the deeper your well water, the larger the pump need. Again, you can manage with a smaller pump if, instead of stuffing a water tank under pressure, you pump into an open tank. They say that a tank should be 45 feet above the taps for decent pressure, but my math tells me that 45 feet is equal to only 13 psi approx. From this, one can figure about .3 psi per foot of water height, meaning that a well pump 200 feet below tap level is under a water pressure of 60 psi, and on top of that, you've got to add whatever pressure you set your pressurized tank at.
One option is to set the pump to shut off at 30 psi instead of 40, saving an enormous amount of battery power. My pump gets the pressure to 30 quickly. It's only between 30 and 40 that the pumps takes a "long" time. If you're going to set the pump at 30 or less, put it where you can't hear it, because it's going to stop and start a lot more. And figure on enjoying showers a lot less. If you will be having a deep well, you should size your battery pack accordingly. The solar people can tell you what you'll need.
Having an open tank(s) is a very good idea for people on solar, even when the pump is more than strong enough to fill a pressure tank. You can have a shut-off valve at the tank so that, when it's shut, the pump fills the pressure tank instead. On sunny times, fill the pressure tank; in cloudy times, open the valve to the open tank. The pump won't shut off automatically when pumping into an open tank; you'll need to do it manually at the breaker (or put a switch between the breaker and the pump).
I have four batteries dedicated to DC circuits only, which runs the lights and the computer. The other four are run through the converter. This is the unit that feeds the house 120-volt power. I wired the lights with direct DC, even though it costs more for larger wiring, because the inverter uses 100 watts to power a 50-watt laptop, which I use at least eight hours on a daily average. In other words, this big inverter as a dismal 50-percent efficiency rate when providing small wattage. The efficiency rises quickly into the 90s above 200 watts at any given time. DC light bulbs cost more, but going DC for lighting is a wise choice for tribulation living. Don't trust the claimed hour rating of DC bulbs. Get extras.
My four batteries can handle a toaster (about 1000 watts) for several minutes consecutively without dropping battery voltage critically when the sun is high. But that's because my eight solar panels (rated for 1040 watts combined) can produce 800-900 watts even when the sun is not at its best angle to the panels. Although a toaster is not needed for the tribulation, this gives you an idea on how to size your panels. My laundry machine can take up to 800 watts, but 1040 watts of panels can handle that at midday on sunny days without demanding power from batteries, which makes batteries last longer i.e. provide better performance longer. You can get by doing laundry with only 500 watts of panel power, but you'll challenge the batteries more often. I would not chose less than 1000 watts of panel power, if I were you, if money's not an issue.
If you wish to water the garden for an hour or more, you can do it at midday so long as the panel power meets the pump requirement. If your pump uses 1200 watts, get about 1500 in panels. Provide a drain in the rain barrel(s), and refresh it on any sunny day with well water (though the longer the pump runs, the greater the chance of breakdown). Use rain barrels for bath water in cloudy periods. One can have a full "shower" with three gallons of water. If you expect a large trib family, rain barrels or their equivalent are a wise move.
A 130-watt panel provides about 130 watts when the sun's angle is straight on, when the sun's position is at its highest, and when the panels are new (they produce less with age). The further from the equator one's location, the less the panels can get maximum sun from a "high noon" position, albeit a position of one or two o'clock is nearly equivalent to high noon. Each 130-watt panel can only run two 60 watt bulbs, for example, at peak sun conditions. It's so precious little for a hundred dollars in panel expense it makes you want to cry.
In Canada, the sun on December 21 is significantly lower than 45 degrees. The amount of atmosphere that obstructs sunlight becomes significant between 60 and 45 degrees, but is critical at 30 degrees. Even in southern Canada, the sun reaches as low as the 30s. That's why Canadians will need a generator that will be sure to start at temperatures 10 below zero F. I purchased a new Yamaha model small enough that I can carry it into the house to warm up, if need be. In other words, if you get a monster compressor, and it's used and unreliable, that won't fit through your front door, you may have a problem in winter.
At the US-Canada border (not including the cloudy west coast), they say that solar panels achieve, on an average over a 24-hour period in the winter, the equivalent of one to two hours of sun directly overhead. Using a string of panels capable of providing 1040 watts max at high noon, you'll get 1040 watts for one or two hours (1040 watt-hours to 2080 watt-hours). Theoretically, on those days, you will be able to run a 1200-watt pump for an hour or more. But wait. At much of the time, the batteries will be low on sunny winter days so that the sun is needed to re-charge batteries, and you will feel as though you really have no power to spare on those days for yourself. You will become the electricity miser.
How much power do batteries wish to suck in, anyway? First of all, you need deep-cycle batteries, not car batteries. Deep-cycle batteries are made to be discharged up to 50 percent their capacity without suffering too much damage, and these can last ten years or more (the more they are discharged, the more they age), or over 1000 cycles of discharging from full to 50 percent. If the four batteries cost $1,000, it'll cost roughly one dollar per discharge to 50 percent. How much power do we get for one dollar? Well, I wish it were only one dollar, but we need to include the cost of the rest of the system too.
Solar batteries are rated in amp-hours, the number of amps the filled batteries can provide, when new, for one hour of usage. Mine are rated at 530 amp-hours, if one full discharge (between 100 and 0 percent) occurs slowly, over 100 hours of use. The shorter the period of full discharge, the less amp-hours we get. So, the Surrette battery company appears to promises that four batteries will provide the equivalent of 530 amps x 24 volts = 12,700 watt-hours over a slow-discharge rate i.e. lasting 100 hours. This is a trick, anyway, because there is no battery-aging factor involved with the procedure / test that provided the 530 figure. Besides, we can expect the companies to exaggerate battery capabilities because the rotten companies do it, forcing others to do the same.
We are left to guess at how much power we truly get through the life of the deteriorating batteries. I would guess that half the 12,700 figure is closer to the truth. Let's use 6,000 watts average, as this seems to reflect the reality of my experiences. We are to discharge only as low as 50 percent, meaning that, of the 6,000 watts per full discharge, I get 3,000 watts per cycle, on average, = 3,000 watts per dollar of battery (= 33 cents per KWH).
So, if the freezer uses 1,000 watts daily, is that 33 cents daily of battery usage. No.
You can readily see the benefit of having eight panels versus four. Long cloudy periods do some battery damage, when batteries tend not to climb in power, but rather drag on in the 50% area, day after day of usage. The only good news is that batteries can last you the entire tribulation period. The bad news may be: you might purchase a solar system some years before the tribulation, and then take the risk of using the batteries during the tribulation, not realizing how badly they have become deteriorated. Batteries receive less power with age. The battery charger stops charging the batteries when it thinks the batteries are full, and they are full when ruined, yet they are full only to what they can absorb in their deteriorated condition. The less the battery can absorb, the less you'll have per cycle. It's the same as saying that the battery shrinks in size. My battery charger isn't going to flash, "Time for new batteries now." If the batteries are being fully charged in a too-short period, something is wrong with the batteries.
Batteries become ruined when the plates become permanently covered in sulfate. Electrical power is stored in the plates so that if their surface area diminishes, that's why batteries shrink with age. The charger is programmed to stop charging when the voltage reaches a certain point, and it will reach that point sooner if there is only half the plate area to charge. The good parts of the plate will yet respond with voltage, but the sulfated parts of the plates will have less power. If only we could remove the plates and clean them.
As I understand it, sulphation is a normal process occurring during the discharge process, while the recharge process turns the sulfates back into normal acid material. Under certain conditions, the sulfates get too hard to be dislodged from the plates by the recharging energy. Battery companies have a fix for stubborn sulphation, by charging "hot" at 31 volts for as long as it takes to burn off the sulfate crust, but if this so-called "equalization" process isn't done often enough, the crust becomes permanent.
Charging at 31 volts produces a lot of hydrogen gas along with oxygen, very explosive. You don't want sparks inside the battery compartment at that time. Make sure all connections to battery terminals are tight. I don't have a perfectly tight gasket around the lid of my compartment, which allowed some fumes to get through during a charge of 31 volts. The fix was to install a small fan in the 2" tube that goes to the outside; there are 2" fans made for this purpose that run on low energy of about 10 watts; they can easily be programmed to run only when the sun is shining (they're not needed with cloud cover).
Batteries receive electrons more easier the more they have been discharged, because there is less voltage in the batteries to "fight back" against the intruding charger's voltage. It may be that, to protect batteries, the charging system forces less power into the batteries the more they become filled, for I've noted that the gas generator pumps in more power when it starts to charge, and continuously less power with time.
I haven't been running my fridge and freezer for most of the night, and may be saving only 15 percent in electricity, but this is not what's important. My freezer operates on about 600 watt-hours daily (equivalent to 600 watts used for one hour), and perhaps 500 watts if shut off for 12 hours nightly. The important thing is that more than half of the 500 watts is acquired from the sun, leaving less than half for the batteries. The ideal situation is in summer, when there is sufficient sun for the fridge and freezer to 8 pm, and almost enough to run fully off the sun by 8 am. The first time that the units are turned on, in the morning, is when they run the longest to make up for being turned off all night. The freezer can wait even until 10 am. If no battery power is used to keep the freezer running, it costs 0 cents per kwh of battery use.
Testing with the watt meter (every solar-power monkey must have one), which keeps track of total wattage used on an on-going basis, this 5.5 cubic freezer, rated for 193 kwh annually, used up only 23 kwh hours over 46 days from July 1st to August 15, in a house not air-conditioned. That translates to 500 watts exactly per day, or 186 kwh annually...but it will do much better in all other months because they will all be cooler months, and besides, the freezer is placed in the cold garage as soon as bear season is over. It stays out there until April. It's working for me. The garage door to the house goes into the kitchen, and so the freezer is handy just outside the door. I barely turn it on all winter. The fridge manufacturer recommended not putting it outdoors in winter, but I've taken my chances over two years without apparent problem. Other fridges may be adversely affected, just a warning.
The freezer manual tells that its thermostat setting should be at about 0 F (-18C), but while that temperature will not be maintained by shutting the unit off for 12 hours nightly in a normal room, There is a bacteria said to grow in foods from temperatures of about 5-10 F, but if we sufficiently cook food, bacteria will be killed.
The freezer has 1.4 amps and 115 volts on its tag, amounting to 161 watts, and yet a watt meter ($25-40) shows that it starts up at 89 watts and eventually comes down to as much as 79 watts after running for a while. It appears that we can't trust those tags at all times.
With heat-exchanger tubes (often on the back of fridges) located in the cold, they will release heat more efficiently, requiring the fridge to operate less time. Plus, the colder the fluid, the better it will absorb heat from the freezer's interior. That was my thinking. The potential problem was that the chemical in the tubes may not liquefy, and may therefore spoil the heat-exchange process. I called Danby's tech department. He said without doubt that cold temperature does not adversely affect the operation of the heat-exchanger tubes. Just in case of any other problems, I didn't turn the freezer on until the outdoor temperature climbed above 25 F (-5 C). Below is a webpage with this general topic telling that cold temperatures may or may not kill a freezer's / fridge's compressor pump, but then the freezer can be turned off in the coldest periods (at the risk of forgetting to do so):
Both the webpage above and below say that extreme cold kills the freezer's insulation, making the unit require more power in warm months. Some say they have operated freezers in temperatures well below freezing without failures. Where do we find what is rumor verses what's true? Hopefully, your fridge company. Perhaps a good safeguard is to use your old freezer outdoors in winter only (bad insulation will then be less problematic), and to purchase a new one for indoors. If the pump goes in the outdoor one, it can still be used for some cooling purposes. If it holds water, use it as a tank...bonus with it's own lid to keep out the flies.
For trib purposes, the three main energy consumers are water pump, fridge and freezer. I'm not including the laundry machine because its usage can be chosen i.e. on sunny days. What we can do, if we think it's worthwhile, is to disconnect the heat-exchanger tubes from the back of the fridge. First of all, it's counter-productive when the tubes release heat right beside the fridge...which is why I'd also like to re-locate the tubes further away. I don't see why one couldn't locate the tubes outdoors, or in an unheated crawl space under the floor. I have both options. It would require a few feet of extra tubing to be soldered on, but the fridge repairman can either do it, or tell us how to. My new freezer, and many newer units, have the heat-exchanger build inside the walls of the unit so that the tubes cannot be accessed. In my opinion, this is a lousy way to release heat, in a trapped space as close as possible to the cold box.
I'm being perhaps too picky, but I'm keeping in mind that you may have this page saved in your computer during the trib, and may need to appeal to some things within it. You may not be able to get online at that time.
Eight 130-watt panels receiving three sun hours daily is a total of just (130 x 8 x 3 / 24 =) 130 watts per hour for 24 hours, i.e. 130 watts constant on average all year long. You can easily add up your annual watt requirements for one fridge and freezer. Then add your well-pump estimates. Check your local area for the average number of sun hours. Four of my batteries, needing about 3,000 watts to re-charge fully, need about three solar hours i.e. can be done in one sunny day at most times of the year in most locations.
It might be a good idea to spend the available money on an extra set of batteries, laid aside and not used until needed (they'll leak energy just sitting around, and will need to be charged from time to time). What happens if others ask to come live with you? That's when they might bring extra appliances, for which you can use the extra batteries. But if the number of panels are insufficient to get all batteries acceptably charged, it becomes a risk. If money is not a problem, then, obviously, get extra panels. As I understand it, thin film can be applied to any substrate; plywood, for example. You can buy the thin film and leave it uninstalled until needed. For trib purposes, thin-film seems the best way to go.
Your system will only be able to provide, in AC power, what its inverter can provide. The higher the provision, the higher the inverter cost. My Outback inverter can provide up to 3500 watts at any time. While I never use that much, it's helpful for motor start up. Some start-up surges can come near to 3500 watts. If the inverter can't handle the surge, it's trip its breaker, meaning you won't be able to use those motors. Therefore, unfortunately, we are all forced to purchase larger inverters than we need for day-to-day energy needs.
You can use the DC power straight from the batteries as easily as hooking two wires to two battery terminals and to your end use. If your four batteries are wired like mine in a 24-volt system, you can yet get 12 volts from them by connecting one wire to the positive terminal of one battery, and to the negative terminal of the battery directly beside it. If the latter wire is connected to the next battery (three in all between the two wires), you'll get 18 volts. While that voltage is not needed for most things, my laptop works on 19.3, and should work on the 18 too (I use a DC-to-DC converter ($150) to convert the 24 volts to 19.3).
However, if for example you use two of the batteries to get 12 volts, you will drain those two more than the other two, and this is not good if it's done regularly. But you can alternate from one pair to the other so that all four batteries are used equally. A set of batteries has the problem of some of its cells becoming more sulfated than the others. If you use only two of the four batteries, that's what you'll get. A spoiled cell spoils the performance of all the good cells. This is what "equalization" speaks to, the burning of sulfates so that all cells are brought back to equality.
The lower the voltage, the larger the wire needs to be in order to not lose voltage while moving down the wire. This is why I chose a 24-volt system versus 12. For long runs in the house, I was required to use 10 gauge wire for 24 volts (smaller, 14 gauge is sufficient for normal AC power). If your house is wired with 14 gauge, you'll lose some voltage trying to run 12 volts through them to significant distances. It won't matter much if the distance between batteries and the end-use is a few feet, but the longer the wire, the more volts you'll lose. If your 12-volt light bulb is only getting 9 volts, how will that affect the brightness of the bulb? It's something to inquire about. If you use your car's CD player (12 volts) in the house, how will it operate on only 9 volts? Here is a wire-sizing chart if interested: http://www.powerupco.com/technical/24VWireSizing.pdf
With solar, one needs to become a power miser. To save more energy in a tribulation situation, and to have better security in the meantime, it would be a good idea to wire the fridge and freezer straight from the batteries. I have a small fridge (57" x 24 ") drawing 130-135 watts from the inverter, but the inverter's poor efficiency at this demand level means that the fridge is taking over 200 watts from the batteries (when it's the only electrical thing on at the time). If the inverter is by-passed for both the fridge and freezer, not only would the inverter last longer before failing, but the batteries will last longer too. For me to run the appliances direct from the 24-volt batteries, I would need a single, small device made to convert 24 volts to normal AC power. Reliable ones aren't cheap under $100. But for a trib situation, spending $4-600 for such a device might prove priceless because it's like having a spare one in the meantime for low-watt usages.
The problem is that the converter device (has it's own built-in breaker) needs to handle the momentary surge from the fridge / freezer motor, otherwise one could purchase a converter for far less. I've just called someone to inquire, and he says they don't usually make low-wattage converters to handle a large surge. I can't see why not. The page below shows a 24-volt converter to a maximum 700 watts AC for $278 US (Apr 2016). One installs such a device at the beginning of the wire (to the fridge and freezer) so that there will be no need to run 24-volt power through the home's wiring. Just tack on (to the wall) an electrical junction box (cheap) between the batteries and the household breakers. This website has many different converters for all your expected needs:
My fridge is bigger than it looks because it has no freezer box. Although it's only 24 inches wide, it's fridge space is about the equivalent of a typical (with freezer box) 30-inch unit. Opening the fridge door just once (when it's not running) significantly reduces the time to its next start-up. That's because cold air is heavier, which pours out the bottom half of the fridge door while being replaced in the top half by the warm air in the kitchen. On the other hand, the freezer has the door on top so that all the cold air tends to stay inside when opened. If you're to have a large number of occupants in the house, the energy needed for the fridge will increase significantly. Figure this into your math for sizing your solar system.
I don't need the generator all spring and summer long. The message here is that you shouldn't necessary think that you'll be using a generator at all times. In my area, the months of October through to the end of December are heavily clouded, compounded by the sun lower in the sky at that time. Yet, I use the generator less than ten times over an hour on average, a total of two to three gallons of gasoline. But that's because I've adapted to not using the fridge all winter, with the freezer outdoors. It's very doable for trib survival, especially if we'll be eating dried foods and largely out of cans. I use a camping cooler box as my fridge all winter (but that's because I've been home all day). Whenever I need to get to the "fridge," out I go into the cold garage, several times daily. I need to assure that the box comes into the house to warm up so that things don't freeze within it. I've learned to be okay with this.
I purchased an "inverter" generator (Yamaha EF2400IS) that saves gas when it's putting out less power, whereas typical generators (less money) tend to use roughly the same amount of gas regardless of how much power they push. This means that gas is saved when charging in the later stages of any one battery-recharge session. Moreover, this Yamaha generator can be converted to run on propane, which I could do for tribulation endurance because propane has a long shelf life. The question is, how much money will be needed to purchase a propane tank(s).
They say that gasoline lasts for about a year before going bad, and that's only if treated with a conditioner. In my first year of owning a generator ($1,000), I didn't treat the gasoline (in the generator tank) over summer, and it started to run improperly. It's never been right since, and would probably have suffered more damage, to the point of inoperable, had I repeated the same neglect a couple of more times. The old gasoline has a negative effect at the carburator, meaning: be sure not to let aging gasoline sit in the carburator. Same as with your chain saw, run the generator until it runs out of gas if you know it will be on the same tank of gas for three months or more. It's not enough just to remove the gas from the tank; you need to get it out of the carb.
The winters, when the snow covers the panels way up on the roof, is when the generator might be most used. I created an opening through the roof in the middle of the eight panels. There is a place to stand on as soon as I get on the roof. For a wiper / scraper, I have a one-foot 2x4 nailed to the end of an eight-foot 2x4, and because there are four panels on either side of my standing spot, they amount to eight feet long on either side. The 2x4 scraper is long enough to wipe / scrape the snow off the panels. That's what I do, as many as a dozen times per winter. And that's why I don't use much gas for the generator. If you don't provide a way to wipe your panels clear of snow, it would be unwise.
How about having many small barbecue tanks for generator use exclusively, as well as your own large tank for other uses? For safety reasons, barbecue tanks can only be used for so many years, and people dispose of the barbecue type even though they would likely go on working fine (without leakage) for many more years. How does one get several of them? Ask the hazardous-waste disposal site? Maybe Home Depot has a few aging tanks with little time left on them. The tanks are all dated.
What if someone living on your property needs gas for a stove but he/she is situated hundreds of feet or more from your large propane tank? That's why it's good to know how to fill small tanks yourself. The website below tells how, and claims: "It's perfectly legal to refill them for personal use, however."
You might like to go solar as soon as you see the anti-Christ in the first half of the trib. I think that's a good plan. If you start three years before the skincode arrives, you'll be experienced in solar power for when you need to be, and your batteries should easily live until the end of the 1260 days. There are short-life and long-life batteries; the longer they live, the more they cost. If you buy seven years ahead of the rapture, buy for a 10 or 12 year duration so that you can abuse them a little without their dying before the seven years are up.
The life of my batteries are rated in the ballpark of 1,000-1,200 cycles when depleted to half capacity. If I do one cycle per week to 50% depletion, I'm to get about 1,000 weeks, or some 20 years. Therefore, one who aims for a lifespan of seven years in 1,000-cycle batteries (of my type) should have a wattage requirement of about two such cycles per week. But when figuring out this math for your situation, don't mistaken battery draw with appliance draw, for the appliance will draw partly from the sun, and partly from the battery (when the sun isn't shining sufficient to cover the full load). If I haven't got this correct, I'll be a monkey's uncle.
This may be a tricky area. I haven't verified whether batteries are being depleted of their metal plates when appliances are running during sunshine. I'm thinking / hoping that, while power is being fed to the batteries from the sun, power simultaneously drawn from the battery terminal does not eat up battery plates. My understanding is that batteries die a slow death, even aside from sulphation, because their plates / terminals are thinned by the charge / discharge process. One Outback techie told me that the power is "skimmed off the top of batteries," her phrase, when household power is drawn during sunshine. I'm thinking / guessing that plates are not reduced if power is skimmed off the top. The way the system is rigged, household power is not taken directly from the panels or charger. In order for the system to take household power, it needs to take them from the battery terminal.
Through a wire from the panels, the charger takes sun energy as electrons, and feeds them to the battery terminal, from which they work themselves into the plates. I've yet to ask whether plates / terminals reduce due to charging verses discharging, but it's a chemical reaction during one of the two. In either charging or discharging of the plates, the electrons flow through the acid between terminals and the plates. In the discharge part of the cycle, the AC inverter takes the power from the battery terminal (it sucks electrons out of the plates in the meantime, to re-fill the terminal). I assume that, as solar electrons are fed to the terminal by the charger, the inverter takes them "directly" from the charger i.e. from the terminal before they go into the plates. If this is correct, no batter damage occurs when household power is taken during sunshine (unless the power requirement is greater than the solar feed).
Power tools do not use the same wattage at all times. For example, my 20-amp saw does not always use 20 amps (= about 2400 watts); it might use a few hundred watts when running freely on no material; 1,000 watts when cutting plywood; and 1,500 watts when cutting 2 x 4s (I've never measured, but you get the point). If in the trib your inverter's breaker shuts off while cutting, try cutting slower. If starting the saw shuts the breaker off half the times, don't shut the saw off between cuts.
The sales people say that we can't combine a new battery pack with an aging one without some damage / diminishment to the new pack. Just so you know to inquire about this (the Surrette battery company allows the addition of new batteries when the others are not more than a year old). I don't yet know how extensive the adversity is when adding new packs to aging ones, but in my case, I decided to keep the two sets of four batteries separate from one another. I suppose that one could age the new pack for a while until both packs can be linked together.
Using two separate battery packs requires a transfer switch (mine's "home-made" using an inexpensive DC switch available at auto-parts stores). Inside the switch box, the wire from the charger can be directed (transferred) from it's normal operation in feeding the original four batteries to the second set of batteries. Simple enough. Only one set of batteries can be charged at a time...unless an extra charger is installed, in which case one needs to split the full number of solar panels into two separate circuits, one set per charger. To assure that the two chargers are not charging the same batteries simultaneously (I fear damage if that were the case), the first switch must be at the position needed to avoid that situation, before the second charger is fed with power from the other switch. I rarely use the second charger, but then I live alone. With a full household, that second charger would prove invaluable.
The other option is to keep it simple: all panels through one charger charging all batteries. My fear, however, is that parts of winters won't get all eight batteries charged sufficient to keep sulphation at bay. The way I have it rigged up now, I let four batteries sit idle all winter, and charge only four using all eight panels. It works, of course, but only because the fridge is shut down all winter while running the freezer sparingly. I can't tell you, therefore, whether my situation would be healthy when running both appliances indoors all winter. I doubt it very much that doing so, with a full house of occupants needing showers too, would keep batteries healthy whether four or eight are used. But showers in winter and in a trib situation (no workplace to report to) can be minimized.
And speaking of not workplace to report to, you might like to have your solar panels on/near the ground rather than on the roof. When not holding regular jobs, we will not be inconvenienced to turn the panels by hand toward the sun in the morning, then turn the panels toward the sun at noon, then turn them toward the sun in mid afternoon. If you have your panels suspended on a pole in the ground, and you have arranged a method of spinning the pole, you have that option to maximize power when you need it. People who hold jobs daily might purchase an automatic solar tracker, but then it's said that including just one or two more panels gives as much additional power as a solar tracker.
Gasoline may be out of the question for long-term trib use, as it supposedly has a short shelf life. Propane is the way to go, but propane generators cost a small fortune, so you may do what I did, buy a gasoline generator that can be modified to propane:
"Our do-it-yourself change over kits allow you to run your Honda gasoline generator on propane, natural gas, or all three. Your engine will last longer, start better in cold weather and even start next year when you go to use it in an emergency...
...If you have propane available you probably know you can store propane for years. It does not gum up, go bad, or pollute the air like gasoline does. Use the little bar-b-q grill type cylinders as shown above or up to the 1000 gallon ASME tanks."
The following webpage is not a Yamaha dealer, but promises to provide me with a tri-fuel carburetor kit, allowing my machine to run on gasoline, propane or natural gas at the turn of a switch:
"...You could run the generator from the [small propane] cylinder while camping and then, when you come home, you can connect the same generator right into a natural gas line or just fill the generators gasoline tank and run. That's right. It's as simple as turning one fuel off and the other fuel on."
Here's the tri-kit and how it works.
You run the risk of damaging sensitive equipment when running them off of a generator. My Chinese model ruined two computers, but Yamaha claims that its inverter-generator won't harm computers.
It's not easy to find an article with a chart showing the reduction in solar energy on solar panels depending on the angle of the sun in relation to the panels. But here's one at the article below.
I came across this: "...a panel that is one square meter and turn it 45 degrees away from the sun the effective surface is Area divided by 1.41." My understanding here is that the sun shining at a 45-degree angle is not half the energy as one might assume, but 1 / 1.41 = 71%, which is pretty good. The chart above shows a 30 percent loss at a 45-degree angle.
The chart at the page below tells that a tilt angle 30 degrees away from the optimum angle reduces power by 11-12 percent, while a tilt angle of 60 degrees away from optimum reduced annual energy by 44 percent. If your panels are on the ground, or easily accessible higher up, you can arrange to change their angle to the sky with the changing seasons. I lose a lot of power in summer when the sun crosses directly overhead, for my panels are at more than 50 degrees off the horizontal.
I didn't know the following, or at least I hadn't read anything so drastic on tree shading of panels, until my fourth year of owning a solar system:
If even a small section of a photovoltaic panel is shaded - for example by the branch of a tree - there is a very significant drop in power output from the panel. This is because a PV solar panel is made up of a string of individual solar cells connected in series with one another. The current output from the whole panel is limited to that passing through the weakest link cell. If one cell (out of for example 36 in a panel) is completely shaded, the power output from the panel will fall to zero. If one cell is 50% shaded, then the power output from the whole panel will fall by 50% - a very significant drop for such a small area of shading.
...Bypass diodes can be connected between panels in a system, and also between groups of cells in a panel so that the only power loss is from the shaded portion.
I'm not sure whether the writer is fully accurate, but the obvious question: do your solar panels have bypass diodes? The writer didn't mention that it's so-called "hard shading" that has such adverse effects:
Shading obstructions are considered "hard' when objects are in direct contact with the glass...Bird droppings, broken tree branches and wayward frisbees are examples of hard shading...Partial hard shading of one cell in a photovoltaic panel can create a power drop as much as 50%...
...Most manufacturers use bypass diodes...
Should we or shouldn't we wire the batteries to a ground rod / plate? One electrical place I called, though not selling solar, said that batteries don't need to be connected to the earth, and yet I can't avoid grounding them to the earth because the panel box (to which the battery cables are connected) needs to be grounded to the earth for the other equipment that it services. I've wondered whether some battery energy leaks to the earth as a result. Here's what one man writes who sounds like he knows what he's talking about:
You don't need to ground batteries. In fact, if you are using an inverter, you better NOT ground your batteries...
...What can happen, is sneak paths develop, and you can trip Ground Fault Protectors - ( AC & DC ) or blow some of the internal protection fuses in inverters.
I don't understand that, but thought I'd pass that along.
My thinking is that lightning is more attracted to the metal frames of solar panels when the frames are more positively charged (the ground is positive), which is why I temporarily disconnect the ground wire (from earth to the panel frames) at the electrical panel when lightning storms approach. In other words, I don't want solar panels acting as lightning rods, and don't want a lightning strike near my ground plate to enter any part of my solar system through the ground wire, wherefore I just disconnect the ground wire (with the turn of a screw) as soon as it enters the house (at the electrical panel). This is an important precaution you can take in the trib, if you think it's wise for your system. If your ground rod/plate is near a buried part of solid rock, lightning, if it strikes the wet solid rock jutting above ground level, could enter the ground wire.
I've read those who opinionate that the panels need to be grounded to earth in case of lightning, but my ground wire from the frames of panels (does not contact the cells in the panels) is just 10-gauge, not thick enough to transfer the power from a direct lightning strike. Therefore, while the panels may act as a lightning rod, they won't work as a lightning rod should. The ground wire of panels is to protect one who touches the frames while power somehow slips to the frame. On-line comment: "Grounding the panels is a safety feature to prevent electrical shock in case the wiring touches the frame." Still, others insist that the secondary use of the ground wire is for lightning, and that six-gauge wire (larger than 10-gauge) should be used.
Some say that lightning rods can be installed higher up on the roof than the solar panels, but even that makes me nervous, as a fork in the lighting can hit a panel once the entire lightning beam has been attracted to the lightning rod. I'm thinking that if the panels are not grounded at all, the panels will simply hide, invisible from lightning. In all my life, lightning has struck the house I was in only once, but you have probably not had even one strike in all your life. Why have a lightning rod to attract lightning? Plus, the size of ground wires recommended for lightning rods in homes is very thick = very expensive:
I do not have a copy of NFPA 780-2004 which explains lightning protection procedures. Hope somebody can answer a few questions. I am connecting a lightning ground rod to a cross ontop of a church. The print specifies that the lightning ground wire be run INSIDE the building through emt and that the emt should be spaced 6ft from any other wiring or metal structure. It also says that the ground wire be #1AWG [= size of wire]. Now first of all, I didn't think lightning protection was allowed to be run indoors. Nor does it even sound like a good idea. And the #1AWG seems a bit undersized. Anybody have any input on this? "
I don't use any part of my solar system during lightning storms (I.e. I shut off all power to household items). I shut all breakers down too.
Electricity runs from negative to positive...except in the case of batteries, because when they first assigned positive and negative charges in the pioneer days of batteries, they got it backward. The scientific establishment kept it backward to this day for convenience...meaning that the positive terminal of a battery is really the electrically-charged, or negative, terminal.
If you're like many who loath to purchase arrestors / suppressors (some say they are unnecessary / useless), you may find yourself trusting in circuit breakers and fuses for trib insurance. When lightning arrestors are being discussed by solar-power people, the primary danger may be from electric-grid wires in the area (because many people on solar are also on the electric grid), but in the trib we can disconnect from the grid. Having two circuit breakers / fuses in any electrical line may act as an effective "lightning arrestor" (so long as you shut the breakers off in a storm). If the lightning power jumps the first breaker's gap, then hopefully, there won't be enough to jump the second breaker's gap.
Here's an article on battery charging.
Here's a site for checking out generators and other solar-power ideas:
As you can see on a sun-hour map below, the best places for solar power are in the western United States, west of and including Texas, while extreme-western Canada rates amongst the worst. Extreme-western Canada is not very cold in winter (for refrigeration purposes), and has high humidity (it rains nearly every day in some places, and I mean six days a week for nearly the entire winter) that can spoil the garden harvest quickly if not refrigerated. You might decide wisely not to have a trib retreat in that area, but then there are ways to off-set these problems.
http://sunelec.com/index.php?main_page=page_2 There's a global sun-hour map at http://lreese911.tripod.com/sitebuildercontent/sitebuilderfiles/solorpower.pdf