Michael Qulek

I suppose this is a great opportunity to conduct an experiment yourself, and report back the results to us.  Why don't you try a variable distance planting and record your observations.  You could plant your pea plants at 1', 2', 4', and 8' spacing in different areas of your orchard, and measure the resulting nitrogen contents of the soil at periodic intervals.  A nitrogen percentage kit can be purchased at Home Depot.

Along with the effects of nitrogen concentration, you could also report on other effects, like the presence of wildlife, tree access to pruning, ect.

Keep in mind that nitrogen is NOT the only nutrient your trees need.  They also need Potassium, Phosphorus, and some other nutrients in smaller amounts.

I could suggest some alterations.  There are lots of DC water pumps that work on DC current at variable voltage, usually from 30V up to 300V.  With a solar pump controller, you could position a higher-voltage pump down the well, and then pump water out of the well, and up the hill to a relocated storage tank.  As you mentioned, high-voltage residential panels are dirt-cheap right now.  Here in the US, I'm getting 250W panels for <50USD.  With a higher voltage pump, you could position your storage tank ~30 meters above the well's location, pump during the day, and then feed the water to any nearby location by gravity any time of the day.  A one-way valve will keep the water from flowing back into the well.

For my own water system, I have two 20,000 liter tanks positioned about 50 meters above the well-head.  With the one-way valve positioned just downstream of my main water tap, I have pressurized water flowing 24/7.

Basically, the amount of force applied by a pulley(s) is multiplied by the number of times the pulling cable is added.  With a single pulley attached to the ceiling, and one length of the rope supporting the load, a pulling force of 50lbs results in a pulling force of 50lbs on the load.

If you add a second pulley wheel (one on the ceiling, and one at the load), you double the force.  50lbs of force on the rope yields 100lbs of force on the load.  But, the amount of rope you have to pull doubles.  So, in the first example, if you pull 1 foot of rope on the ceiling pulley, you lift the load 1 foot off the ground.  With the second example, you need to pull 2 feet on the rope to lift the load 1 foot.

With three pulleys, you increase the force 3 times, but have to pull the rope three times as far, and with four pulleys, it's 4X the force, but four times the length of rope pulled.

In each case there is conservation of energy,  With four pulleys, it's 4X the force, but you have to pull 4X as long.

Does that make sense?  You could use pulleys for any heavy load you can't pull on your own.  Maybe a engine out of a car, lifting bales of hay to the second floor of your barn, or using pulleys to tighten fencing wire? Lots of applications.

I don't even pay attention to it.  I purchase all my panels used on Craigslist, and my single most important criteria is watts/$.  BTW, don't shy away from used panels because they are used.  I've gotten better performance from used panels I got off Craigslist then the brand new panels I paid retail for.  Depending on your location, expect a good deal to be in the range of 3-5W/$.  Don't order your panels on the internet with shipping.  Cash and carry local purchases will be the best deals.

I do bring a voltmeter with me when purchasing to make sure one panel doesn't turn out to be a lemon.  Don't buy a panel that has a Voc more than 10% lower that what the sticker spec states.  So, if a panel sticker says the Voc is 37.5V, don't buy a panel putting out less than ~34Voc.

John C Daley wrote:Talking of fridges, I am off grid in Australia and had trouble with the fridge draining my small battery system.
I found the most efficient fridge made, Hisense, it was resonably priced for Australia $A1200 is about 315 L capacity and uses 25% of the power of other fridges.

What exactly is the size of your battery bank?  Is it being fully charged each and every day, even in June?

High-voltage residential panels are getting so cheap now that the single cheapest upgrade you can make to your system is more solar.  If my batteries are fully charged by 9-10am, my arrays are supplying 100% of my power needs for the rest of the daylight hours, with zero battery depletion.  That way I'm operating normally with a far less expensive standard AC frig/freezer.

Here in California, I used 3/4" plastic pipe designed for flamable gas.  I would suspect that would be far cheaper than 500 feet of copper.  I got it and all the proper fittings from Home Depot.  I do notice though that it takes quite a while for the stove's oven to warm up to 350F, and I think that 1" might have been a better choice.

Ram pumps work, by utilizing the mass of the moving water, to temperarily raise the pressure to the point where water can be pumped uphill.  But, the efficiency is only a few percent, meaning only a few percent of water flowing downhill is actually pumped back uphill.  Basically, a very LARGE volume of water falling downhill can push a very small amount of water back uphill.  A closed loop system would run for a little while until the water in the upper tank is drained, and then it will simply grind to a halt.

Your implication is that it would be an engine that could somehow be applied to producing useful work.  You simply can't get something for nothing. The laws of physics is not on your side.

In making solar power, one important concept to understand is what's called a "peak sunhour" (sh), which is basically the amount of "FULL" sun you get per day.  You multiply your solar panel size by the sunhours to get the total amount of power you can make in a day.  For London, at 51 degrees North, I think you'll get approximately 1.5-2.0 sh per day in December, and 4.0 sh in June, in full sun.  On cloudy/rainy days however, the sh is likely to drop down to ~0.5sh.

These numbers become centrally important with a whole-home solar system, where you're counting on the system to make ALL your power.  I'm working with neighbors down the hill from me right now because they can't understand the idea that there are less sunhours in December, and they have to deal with completed dead batteries right now.

A second factor to consider is that the rating of your solar panel is measured in a controlled temperature chamber with artificial sunlight scaled at exactly 1000W/square meter.  Your real-world solar output is almost always somewhat lower, because of dust in the air, less than optimal angle to the sun, and how hot the panel is.  So, for real-world output, I usually recommend 85% of what name-plate production is.  That means that your 10W panel is likely at best to make only ~8.5-9.0W.  On a cloudy day, maybe just 1W.

When you want to power anything with an electric motor, you also have to contend with something called "starting surge", or "inrush current".  For something like a free-spinning window fan, the starting surge might only be 1.1X the running power, but for motors starting under load, the starting surge might be 3-4X the running power, for maybe 500-1000 miliseconds.  I'd consider a blender an appliance that would have a significant starting surge.  With too small an inverter, and too small a battery, that starting surge might drive the inverter into low-voltage shutdown.

What that means in the real-world is that people are always overestimating how much power they can make, and underestimate how much power they are consuming.  With what you are describing, I'd recommend you'll more likely be served with a 200W panel, charging a 100Ah battery.  Because an inverter is also a power drain on your system, look into powering all your needs with DC-only appliances that can bypass needing to make AC power.

R Scott wrote:There is higher efficiency when the inverter can convert directly from solar instead of charging the batteries and then pulling the power out for the inverter. Choose the string that gets direct light when you use the most power

I don't think this statement is correct.  As far as my understanding goes, ALL solar power passes through the controller into the batteries, and then All power comes out of the batteries to fuel the inverter.

What you might be thinking about is system potential, instead of battery voltage?  When sitting idle at night time, with no power coming in, the system potential is the voltage of the battery.  In daylight however, the system potential is the battery voltage, plus the charging voltage.  So, for example, a fully charged 24V battery bank at 8pm might be 25.4V, but the system potential would be ~28-29V towards the end of the absorption phase during the day.

The system potential becomes very important when you're trying to run a very big load, such as a 240V well-pump.  A BIG load like the well-pump could cause so much voltage drop that the inverter shuts off from a low-voltage warning.  While charging, the higher system potential prevents inverter shutdown because the battery has to first drop from a higher potential, and because power is coming into the batteries, the voltage sag will not be as great.

What's the brand/model of your All in One inverter?  With some brands, they make more than one model of either inverter or a stand alone MPPT charger.  Some brands are designed so that they can communicate with each other via a serial connection, and if your brand supports that, it might be able to slave a second controller to the AiO?  Some controllers, such as my Midnite 200, have this function, and controllers can be placed in parallel, but without knowing your brand/model, that's just guessing.

The second option, already suggested, is to just wire in a second MPPT controller in parallel, with the bulk/absorb/float setting identical to those of the AiO.  That is likely to be good enough.