Tom M's posts

But this 120 volt device is ultimately drawing off a 12 volt battery. It is the power you can get from your battery, not the inverter that you should be dealing with. The inverter only changes the voltage and if you increase the voltage out by a factor of ten, you have to decrease the power coming from the battery by the same factor.....

So an overall output of 12000 Watts, over 10 hrs, would require at a recharging current of 1000 amps at 12 volts. You say you can deliver this 1000 amps in an average of 4 hrs. Then that would be a 250 amp service. I do not think that 14 to 16 gage wiring would handle this current. And if all you are providing is 20 amps max., then it would take 50 hrs at 12 volts to recharge your battery.
 And yes John B you are right, they are not taking into account that the 1200 Watts already incorporates the 10 amps of which they speak. If they pay attention to units, they would have 12000 Watt Amps, which doesn't make sense.

That's what makes it fuzzy....

Quick question, What gage wire do you use running from the unit to the charge controller or battery?

Well then, how long would it take to charge the battery. (Hrs, days, weeks.....). This seems to be the crux of what the thread is all about, how can your system can provide such power.
  Also if you understand batteries, then a 100 amp-hr battery will truly only provide 80 amp-hrs if properly discharged and maintained, in order for long life and for it to be continually recharged.

Good job Nathan, you can't argue with math if it is done correctly. This whole thread seemed to be based on fuzzy math and misunderstanding and misinterpreting results. It seems obvious just looking at the system that there is something wrong. A toy car won't give you highway performance. Also using a 24 hour period for your calculations to explain their numbers should make people think, since constant wind is questionable......  

Larry, maintaining a 160 to 170 degree temperature coming from a solar hot water panel is a stretch. Trying to heat up 500 gallons of water to these temperatures is a bigger stretch. You would need a large amount of panels and good sun all day to even come close. Most hot water systems operate on a differential. So anytime that the fluid in the panels is somewhat hotter than the water in the tank or radiant zone, the circulator turns on. This can happen at 40 F as well as 140 F so you may be circulating cool solar fluid if you are not careful.
 If you plan on installing a hot water system for domestic and heating, I would suggest that you either independently or series pipe the domestic and heating loops to get the maximum out of the solar loop. Unfortunately your radiant zones aren't the best. The one with cement is okay except for the tile surface. Tile is a resistive and reflective material though it still works okay. Carpeting is also an insulator as is the wood it is installed onto.

...Sounds like the panels are already grounded by resting on the ground....

Steve, sounds like you would need a small inverter. If you plan on keeping batteries charged using an AC charger then adding an inverter to convert from DC to AC should take care of your needs. Just be sure to size the inverter to cover your power needs. Eg. A 110 Volt appliance that draws 5 amps would require an inverter capable of putting out at least 5 x 110 = 550 to 600 Watts. You may also incorporate a fuse between the batteries and the inverter.

Andres, once again the amount of power it would take to pump water up over 150 meters would be better spent charging batteries for extra potential and reserve. If there was some way to feed the storage tank from the springs or rain then you may be in business. Or perhaps locate the generator below the pond and use it as the storage and supply. Only drawback is that you are now further away from your demand for electical runs. You could charge individual batteries and then haul them up to wherever they are needed.
  As far as output, you should be able to find charts on sites that sell hydro systems to determine required head/flow and power output. Most generators come with 1 to 4 nozzles. More nozzles needs more flow. More nozzles, more power.
  You can get power requirements for pumping water from the pump manufacture for whatever pump you choose to use. Shallow well submersible pumps are probably your best bet if you choose to go that route.
  I am not sure if you can operate the hydro automatically without using batteries. There are zone valves that can operater either NO / NC, so if batteries get low, the valve can open flow.......

Michael, an easy way to remove ice and water from panels is to use a hose with warm water. Hopefully you have enough pressure to reach your roof. This is another reason why ground mounting prevails in my book......

Jim, try going to your local plumbing supply or Home Depot type store. They may have a pump for you.....

Jerry, have you thought about using solar hot water instead.......

Andres, I have installed several hydro systems in the Andes of Peru. From what you have explained, it seems unwise to try and take the route of which you speak. The amount of power that you would expend pumping the water up into the tank may not compensate for the power gained from a storage tank of water to operate a hydro system. Hydro needs a large steady flow of water or water at high head to operate sufficiently.
  There are valves that can operate automatically if you choose to go this route.
  Where is the water you are pumping located? Is there a stream or channel or is it a well? Is there any way to locate the hydro near this water source? How long would the electrical runs be? Best to use batteries to store the power from the hydro if possible since different flows will produce changing electrical currents. Diversion loads may also be needed if power output continues after demand is satisfied......

....another consideration for consequences of charging and discharging is to rotate your batteries occasionally.....

Dave, every generator has it's upper limits regardless of the factors you mention. The main factors in a micro hydro system are the head pressure and volume flow. You have to have one or the other. Both in turn make the generator spin faster and produce more juice. But usually there is a regulator, just as in your car, to maintain a certain voltage to keep the other system components from frying out....

Daniel, to make things even easier and cheaper, if possible, why not mount panels on the ground, if you have the space, then there is no worries about new roofing or damages thereto....

Sharon, first start with what you would like to operate with your solar system. This will help you determine what size system you need and thus what to buy. Best to start small and grow your system over time. I would think starting with some low voltage lighting would be the first step. This would reduce your electric bills and give you emergency lighting should you lose power. Solar hot water for bathroom use and to preheat kitchen water should also be considered. SHW can also be used for some residual heating come winter time.

Stanford, is there any way you can route the water closer to your final destination? Plastic plumbing pipes may be cheaper than large copper wiring. If you can gain some extra head pressure at the same time, you may make out in the long run...

Jerry, maybe you can mount them on some sort of cart with wheels to make the move easier...

Aine, perhaps you can line the oven with glass or metal over the plastic. Aluminum foil may even work...

Russell, perhaps since this system is in remote location, with users that are not totally sure how to operate the system, my best guess is that they have used the batteries at night to a point that one or more batteries may have been discharged to a point that it can no longer gain or hold a charge and that may be preventing the others from charging. Have them check each battery individually to see if it is still good then remove whichever battery is bad if that is the case....

If you think of space as a fluid, mass moving very fast, then think of Bernoulli's equation. If a fluid moves fast between two objects, then there is a lower pressure there  causing the two objects to come together, making it look like an attractive force that some call gravity.

James, here are some quick answers to your questionsl;

1. The controller usually limits the temperature of the storage. Instructions for the controller should show you how to adjust this setting. There may also be a mixing valve coming from the tank itself to adjust the hot water temp. leaving the tank.

2. There should be some indicator lights on the controller to tell you whent he system is on.

3. You can get the electric wired for "off peak" so the tank turns off at night. Best to use the hot water when it is available and leave time to make more.

4. That specific tank does not have a heat exchanger, so there can not be any antifreeze in the solar loop.
Is there a separate tank to which the pump is attached that holds water. If so, then perhaps you have a drainback system.

I am curious as to why you have an optimizer. Do you have any solar electric panels as well?

If you need service you can give me a call.

Tom
Solar Innovations
Lowell, Ma
978-394-3555

..don't forget about the earth itself...it floats...try looking at some fluid dynamics forums or cosmology or physics sites or forums

Martin, if you only plan on installing one panel, why does it have to be on the roof. A good location, anywhere but the roof, in a sunny spot, and as close to the battery as possible, would seem the sensible thing to do. Mounted on a small pole that penetrates the ground would solve your delemma.

Murry, have you checked each panel separately to ensure that each panel is giving out the correct power? If there is one bad panel or cell, it can effect the whole system. Also check for loose connections that may be hindering performance.

Ray, I would start by doing some basic calculations. If the parabolic dish supposedly heats 500 gallons a day, then that would be  a flow rate of one gallon a minute over an eight hour period.
 What volume of water does the sun focus on in collector itself? What temperature is the incoming water? What is the area of the dish? How many BTU/HR*Ft^2 do you gain in your area? What are the conductive properties of the collector and tubing? What are the heat losses? Then, through calculation, what is the resulting temperature of the water after it passes through the dish with this flow rate and incoming radiation? And then, how long will it take for a volume of water to be raised by a certain temperature?
  The main factor that makes flat plates more effective is the overall area and material properties of the collectors themselves. Good insulation also prevents energy losses. The heating fluid also stays in the collector longer to absorb more heat during flow.
  A BTU is a BTU whether it is concentrated from an area or absorbed over the same flat area. So careful calculations would help you determine how you would have to regulate your systems in order to get the same results from both. Unfortunately you may find that you would have to decrease flow rate significantly with a dish collector and you may not get that large volume of water heated to 160 unless you have many dishes. 

Funny James, I worked at Solviva many times as a plumber, out in WT on MV, and yes she had a composting toilet, in her main house, along with a normal bathroom, and in a little stone house out back in the woods. Her name is Anna E. and she's the one responsible for all the expensive mixed salad greens you see in restaurants and markets in the Boston area. She grew them all in her greenhouse/barn and her main house. And she was into some, even then, wacky solar stuff.
 Anyway there are modern composting toilet available, some companies have been around for years. One company is in Concord, MA. Most of the models use peat and an electric coil or dryer to remove moisture. Simple to install. Just need to vent properly. 

Karen is the low spot where the water collects any higher than the deepest part of your pond? If so, you may be able to just use a syphon.