Tom M's posts

David, you say you added a rectifier to get AC out of your turbine. The C40 requires a DC input. This could be the problem. Also I believe that controller is used either as a charge controller OR a diversion controller, make sure you set it correctly......

Carrie,  wire two of the 12 volt panels in series to get 24 volts, then the two pair of panels in parallel. Batteries in series as well as you mention. Then set your controller for 24 volts...you should get 24 volts at around 12 amps out of the array

Donald, for test purposes and too keep the batteries charged without a panel, go for it. But be sure to use your charge controller off the 24 volt alternator to ensure proper voltage and to avoid over charging and rapid charging of the batteries. Check the current output of the alternator first before hooking it up to your charge controller and be careful that the current output is below the rating of the controller..

Sure, as long as you battery bank is set up for24 volts..just be aware of how much power you are draining in order to rechage them properly.

yes. those caps are small , so tuck the top under the shingle as best you can. doesn't hurt to seal around all edges of the copper cap either. I usually solder the cap directly to the pipe also.

Brian, use either a good roof sealant  or lapseal,  both come in regular tubes like caulking or use silicone if you have colored shingles. Caulk inside the hole before you insert your lag bolt and under the mount also.... apply to the piping around the hole and under the copper flashing also

Well Mike, it's hard to make a calculation with the limited information you gave. It take 1 BTU to raise a lb or water by one degree so first you have to determine the amount of water in your panel. Second you have to have the material properties of what your panel is made from. Third, you have to state how much absorber area is dedicated to each riser in the panel or the ratio of surface area to the tube area. Fourth,  the amount of insulation value from the glazing and the box.  Also include surrounding ambient temperature, fluid flow rate etc...

dave, are you sure you purged the heating zone to remove all the air in the lines?  The rattle of the impeller could be from air bubbles passing through...

Kevin, the only thing you didn't tell us is the amount of time the pump will be working. If you have a certain flow rate, and know the tank capacity before the pump turns on and the gpm of your pump , you should be able to figure out how much time your pump operates on a daily basis.  Here's a little something to get you started....

First:  120 v x 10.5 amp = 1260 watts

So minimum size inverter would be 1500 - 2000 watts

Since it is just pump, you could go with a cheaper modified sine wave inverter rather than a more expensive pure sine wave one.

If the pump runs 10 hrs a day then:
10.5 amp x 10 hrs =105 amp-hrs

A 120 watt 12 v (or 240 watt 24 v) panel gives you 10 amps and would have to have 10 hrs of sun to give you the 105 amp hrs you need which of course is  little unrealistic.  2 panels would cut the sun time in half.

Battery back up for three days would require 3, 100 + amp hr batteries.
 
To keep the batteries up to charge,  3 times the above panel selection would be needed.

Size a charge controller from the amount of amps coming from your panels.  Size wiring according to voltage and ampacity. (HIgher the voltage and smaller the current, the smaller, and cheaper the wire)

 Three 120 watt 12 volt panels producing 10 amps each would require a minimum of a 40 amp controller.

There are calculators here at AltE to help you with sizing components to your system , as well as employees, if you can't figure it out on your own.

 

Ed, I usually recommend a small pv panel and charge controller to charge a battery used in conjunction with a small inverter. Then you can use this setup year round to ensure that there is always power for your system.
 Step it up a little and you can have emergency power for other appliances and lights, as well as tv and radio for emergency information, should the power go out.
 If you have natural gas for heating and cooking, think about getting several small inverters or one larger one to operate these appliances since they use minimal power. Oil burners and electric stoves use more power but can be compensated for with a larger inverter.

 Just look around here at AltE for components or give them a call and  I am sure they can set you up with a system that is within your needs and budget.

Doug, which differential controller are you using? Does it provide for multiple sensor inputs? Even so, only one sensor will control the pump, the others will only give you temperature readings throughout the system.
 So when you say  you have the two  sensors in parallel, one at the top of the tank and one at the bottom, it makes me think that this is the problem, conflicting temperature (electrical) readings. Remember, current will divide when put through a parallel circuit depending upon the resistance of the load, in this case the sensor, and it is this current that the differential controller reads.

And when you say "Now, the bottom temperature overtakes the top temperature, and the circulating pump runs a lot longer than it should" , it definately sounds like the problem.

 Only one sensor will control the pump, so it's best to locate this sensor somewhere in the middle of the tank, or move it from the top to the bottom seasonally.

Tom, as an electrical engineer, it should be a no brainer. Just do a little research on systems and you should be able to figure things out. Most systems are plug and play and require very little electrical experience other than setting up a sufficient breaker box. The only thing that may be tough is sizing the system in order to get a properly sized inverter and enough battery backup and sufficient amount of panels to provide the daily power needed for use and battery charging.
 There are calculators here at AltE to help you do this.
  Keeping voltages at 24 Volts  will allow you to purchase off the shelf electrical components. Ground mounted panels will save you time and money on other necessary components for safe installation.
 Using DC lighting and other appliances will lower power demands.
  Installing multiple, independent systems (AC and DC) will provide redundancy and will allow you to grow your system as money allows or as power needs grow. It also allows you to purchase different brand components should original, compatible components not be available when needed or should portions of one system fail.
 Don't forget about solar hot water which can be used for domestic hot water and space heating. Also think passive gain and storage for heating and lighting.
  I am sure there are others who will help you here at the forums, or at AltE, to get you up and running. Good Luck.

Hey Ben, as Amy said, most pasteurization of water borne bacteria is a time -temperature relationship. Messing with temperature settings would be more of a safety concern to  me, unless you drink a lot of hot tap water.
  I really don't like having the electric back up in a solar tank since they tend to compete with each other. Normal setting for most any tank is 120-130 deg. so by time it gets to a faucet it is down to 110. Shower valves are to be set at this temperature too, so irregardless of incoming hot water temp. you can't burn yourself in the shower. 
   The thing with electric backup, if you use hot water at night, then the electric kicks in. Then in the morning, when sun is available, and depending where your sensor is located on the tank, the solar will stay off until it gets up to well over the already hot, tank water temperature. This adds lots of energy real quick and can raise the top of the tank temperature well over safety levels, This is great to keep the electricity off but you may notice your relief valve on the tank start to drip. 
    If your sensor is located near the bottom of the tank, and is set for a high limit of 160, then the solar will keep heating and possible bring top of tank temperatures near boiling. 
  If you are getting plenty of sun and use minimal hot water, I would just shut the electric off all together and locate the sensor properly on the tank and use your hot water wisely
. If you know you need hot water and it is cloudy, it is easy enough to turn on the electricity a few minutes before you need it.
  If pathogens are that much of a concern,  a UV light type device may be your answer.

or you could consider an off the shelf submersible sump pump in conjunction with a pv panel, controller, battery and small inverter...

Alley, just a few suggestions to get you thinking in the right direction:

loft on each end- plan on installing a grate in each floor of the lofts to promote air circulation and heat from being trapped

a wood stove - plan on it being centrally located to promote even heat flow and circulation. Think passive gain and storage.

refrigerator and freezer- plan on using through the wall application to use during winter times for free cooling and freezing. Think ice box.

ceiling fan - plan on having roof vent  or cupola, to remove hot summer air. Roof overhangs for summertime shading.

3 lights - plan on DC lighting to reduce power consumption

washer and dryer - think clothesline, inside and out for drying

electric, hand or wind powered pump - Think DC pump or motor in conjunction with elevated storage tank for pressure

Check out load calculators here at AltE or other solar sites to determine electrical loads and storage needed for the applances you plan to use.

shannon, first, where is the cabing located? eg. cold region,  warm region, woods , state, etc.

What type of exposure do you have? eg. good sun all day, large unobstructed area that gets sun "x" hours of sun a day.

How large is the cabin?

What future appliances are you planning on? Lighting needs?

 Is there potable water? Well with pump? Need for hot water?

Is there electricity there now? Is the cabin wired at all?

Do you need heating? Is there propane or natural gas?

Just a few questions to get a better idea of the situation and your needs in order to determine what would work best and what is necessary in order for you to make purchases today that may help you save money tomorrow.

Tom, there is really no typical load data for individual systems. Every situation is different. As mentioned, the best way to determine loads is to look at the current and past utility bills.
 If you are looking for example spreadsheets, you can find them here at Alte. They have a load calculator where you can punch in some numbers.
  Basically, you look at an appliance's power consumtion, figure the Watts then multiply that times the amount of time of usage. For off grid, multiply that by 2 or 3 to determine the amount of storage you will need for times when daylight is minimal.
  Then use that figure to find some kind of balance between the number of panels and time of availabe daylight each day. 
 There are also other sites that offer these types of load calculators, links of which you can find here or at other solar sites like Home Power Magazine and such.....

Sean, you can also add a coil of tubing around the same height as the drainback tank on the outlet side to increase system water volume......

Tom, first look at your utility bills to get an idea of how much power is being used then design a system around that. You may find that you will not be able to cover the total amount of power used without spending a whole lot of money.
 I would suggest building your system over time. Start small and dedicate  a little power to each unit so each unit, and common places, has some backup and everyday power for emergency use and reduction of power usage. Then, as you save money, add a secondary system and keep going from there.
 Using several system setups also adds redundancy in case of failure.

James, I know you don't have an extra panel, my suggestion was to remove one panel from the other, working array, (the array with no shading), and use that panel to replace the bad panel on the other array to ensure that there are no other problems with the shaded array. 
 I also took a quick look at the sunnyboy literature. It shows that the input wattage is over a range so I am not sure if it has to meet the maximum in order to produce.

  I would swap out one panel from the working array, if easily done,  for test purposes, just to make sure the rest of the underperforming array is okay.
   Is there any way to adjust the input voltage minimum on the inverter?
  Even with one missing panel, voltages can vary, and the array may still produce with the bad panel removed. (If one array gets more sun than the other, make that the 8 panel array) Then you can monitor the array until you find a new panel. 

James, is this panel 24 volts? If so, and the rest of the system is designed for 24 volts, then removing the bad panel will have no effect on the voltage of the array.  When  same voltage panels are connected together  in parallel, through a combiner or junction box, the current is added,

(eg. 9 -170 W - 24 volt panels combined together, all + and -  leads combined, the total amperager would be around
170W/24V x 9 panels =60+/- amps)

 so removing a single panel will only cause the current to be reduced from that part of the array by 170 W/ 24 V =7 amps.

If you are feeding 9 X 24 or 220 volts into your inverter, then yes you MAY have to replace the single panel

James, you should be able to disconnect the one panel that has damage in order to verify that all the othe panels are in good working order.  The logical first step would be to simply remove the wires from the one panel in the junction or combiner box and then check the status. Having one bad panel in the string may reduce the power of the entire string.  Removing the panel, if it is in parallel with all the others, will only show a small reduction in amps out from the array.

Your welcome Gregory, just remember the pump will not run continously, especially if you use a differential controller, which you should. Other wise, if you just use a pv panel to run the pump, you may be losing heat. A differential controller ensures that the pump only runs when the panels are hotter than the water in the tank. With just a pv running the pump it will circulate whenever there is enough power from the pv panel irregardless of temperature differences, drawing heat from the tank and losing it through the panels. Just think of a sunny winter morning, the hot water panels may be cold but the pump turns on based on the sun hitting the pv panel.

Gregory, you don't have to get that big of a panel or controller. You only need to maintain the battery based upon  your pumps power draw.  Just figure the amount of watts needed per day, amps x voltage and how long the pump will run, maybe 2-6 hrs at best, based on the rating of the pump you choose, and then buy a panel that will replace this power based upon the amount of sun you get each day.
 check out the Morningstar sunsaver series controllers here at alte...they're cheap., 30-50 bucks..Only need one that will handle the PV panel amperage output.....
    ..choose a 12 volt panel, not a 24 volt as you suggest,  20 -whatever watts, (20 Watts..around 1.5 amps...60 watts...5 amps)
   small inverter available here or your local auto store, 100 bucks or less (GoPower as you have suggested) and deep cycle battery (like you also suggest) and you should be all set.
  You can also charge the battery with a regular battery charger should the sun hours not be sufficient.
  Or skip the whole setup all together and just use you regular house power for the pump, the amount of power draw is really minimal if paying for electricity is not that big of a concern. 

Gregory, I usually recommend using a battery, small inverter and controller in conjunction with a PV panel to power a pump. That way there enough power is always available rather than intermittant power from direct sunlight alone...eg. a few clouds go by and the pump stops even though the panels are hot. Then you can use a converntional off the shelf pump suitable to overcome the head needed. TACO and Grundfos both make high head models.  It also gives you a small backup system for other uses when power goes out.

Yeah Mike it can get pretty expensive. Dealing with a customer now with the same situation. She has the setup you want only in 24 volts. A little cheaper that way especially when it comes to breakers and such.
 You could also consider using 12 volt batteries and a basic battery charger that you can get at any automotive store to maintain the batteries' charge til you need them. Then you can wire them up in any configuration you want.
 The well pump is an issue as far as power goes but you could purchase several smaller inverters for dedicated power neccessities.
 PV panels can be used also as you know and can maintain their charge for year round use.
 The generator can be used also to charge the batteries. '
 So lots of options and lots of cost options also. Good luck.

John, that controller is capable of using a 12 or 24 volt input to charge a 12 volt battery, so I guess either way could work, series or parallel. Might as well stick to series since you only have two of the panels to reduce losses and reduce wire size. A little expensive though with all the bells and whistles. Check some controllers here at Alte for price comparison.

John, if you are charging a 12 volt battery setup, I would think you would want to use a 12 volt supply from  your panels. So parallel should be the way to go. Your controller has more to do with the battery than the panels so it too should be set, if it has a setting, to 12 volts.
 The power gained is in Watts so it really doesn't matter if you change voltage or amps, it will still come out the same, W = V x A, so if you increase amps, voltage will drop and vice versa, but the watts will be the same.
 What charge controller do you have?

Steve, if you are already rigged up to connect to a hose, you can try drilling different size holes into a hose cap to get the size nozzle you need for best operation. Using several nozzles, piped off the 2-1/2 pipe, may give you more power. then, if you put a pressure gage near the turbine, you can figure the head, and a 5 gallon bucket and a watch can give you the flow rate so you can compare your machine's output with one of those fancy store bought ones.
  And don't throw away that 1-1/2 black tubing yet, 200 ft of that gives you around 18 gallons of solar hot water that can get up to 120+ degrees. Just lay the coil out flat somewhere  in concentric circles, (you may need a friend for this too) and then cold water in ...hot water out...good for outside showers.....