Washing Clothes, No Charge Controller or Battery. Even Hot Water!

[efficientPV]

This is in my continuing attempts to live off grid with only a very minimal battery.
my case, a car battery. I purchased this LG washer because it had a variable frequency
motor drive which greatly reduces surge currents and overall consumption of power. I am
able to feed panel DC array voltage directly into a modified MSW inverter. The washer
doesn't care and probably prefers square waves as it only rectifies the AC.

The washer is located in the garage away from the house hot water. I got this tank from
a neighbor. It doesn't leak yet and was replaced because the cold water dip tube that sends
water to the bottom of the tank broke off. This fed cold water to the top of the tank instantly
cooling the hot water. I feed cold tap water into what was the drain valve. Tank is a little
bigger than I would like, but it was free.

The box at the top of the tank feeds excess panel power at power point into the tanks two 4500W
heaters which are in parallel for a combined resistance of 6.5 ohms. A good match for the 60V
array. This allows me to dump about 500W max. That is enough to get the water warm for better
washing.

Everything at the house works on a priority basis. Battery charging is primary, next comes refrigeration,
hot water tanks, dishwasher and last is clothes washer heater.

This is a 2,000W inverter which is way oversized I found in the attic. 60V comes from the house array and
these two Anderson Power Pole connectors select if the garage 60V array is placed in series or parallel.
I bought a QS-60 three phase motor reversing switch to do this. With center off this should have been easy.
In China they decided to save a small amount of plastic on the cam. This actually makes adjacent contats
to momentarily short as they are switches to off. Don't ever buy this switch for any reason.

I've been washing clothes for a week and it works great. Minor clouds don't make it shut down. If it does,
the washer remembers where it was last and you just have to press start. I'm generally out there working
anyway. Somehow I've been made laundry boy.

 

[HRTKD]

How many horsepower does the Banks Power sticker add to the water heater?

 

[efficientPV]

Wondered if anyone would notice that. It hides a nasty scratch.

 

[HRTKD]

My only constructive suggestion is that the system needs to be documented in place. My dad would put together something like this with far less polish out of leftover parts and zero documentation. The average layman would take one look at it and think, "Rube Goldberg". He did just that for a well pump for his house. I looked at it and had no idea it was for the well pump.

 

[Sunny Days]

Any more info about this?

 

[efficientPV]

The system has been running better than expected. Power is supplies by two separate arrays, two 30V 280W grid ties for 60V on the garage roof and another 60V array in the back. Both are placed in series for 120V DC. The rear is heavily shaded and has certain time windows when it produces enough power. That is just fed into an old MSW inverter (pre-micro) right to the high voltage capacitor. Inverter must have an on off switch. Power the control side with 12V 50ma and it works. The water heater is just for laundry and operates off the same 60V array. Two 4500W heating elements are in parallel. I've seen the temp as high as 127F and as low as 92 after washing two loads. Most times about 112F. he water heater control is custom and acts to keep array voltage at no more than 61V and acts as a shunt voltage regulator. It has the lowest priority. The house water heater has a higher priority and other loads even higher. So this is just normally wasted power diverted to water heating. You solar people don't even have a clue as to how much energy is wasted each day. I was just hoping to get the water up to 75-80F just to take the chill off for washing. This is way beyond my expectations.

 

[WYtreasure]

The system has been running better than expected. Power is supplies by two separate arrays, two 30V 280W grid ties for 60V on the garage roof and another 60V array in the back. Both are placed in series for 120V DC. The rear is heavily shaded and has certain time windows when it produces enough power. That is just fed into an old MSW inverter (pre-micro) right to the high voltage capacitor. Inverter must have an on off switch. Power the control side with 12V 50ma and it works. The water heater is just for laundry and operates off the same 60V array. Two 4500W heating elements are in parallel. I've seen the temp as high as 127F and as low as 92 after washing two loads. Most times about 112F. he water heater control is custom and acts to keep array voltage at no more than 61V and acts as a shunt voltage regulator. It has the lowest priority. The house water heater has a higher priority and other loads even higher. So this is just normally wasted power diverted to water heating. You solar people don't even have a clue as to how much energy is wasted each day. I was just hoping to get the water up to 75-80F just to take the chill off for washing. This is way beyond my expectations.

This is an awesome find for me.

Thanks

 

[Don B. Cilly]

You solar people don't even have a clue as to how much energy is wasted each day.

Actually some of us do. Some of us also heat water without electricity.
And what the reason might be to have no battery at all between panels and inverter, is really beyond comprehension. Using a small, inefficient car starter one, it's like having a big capacitor. Except cheaper and more efficient.

Talking about comprehension, and your avatar... ;·)

 

[WYtreasure]

Actually some of us do. Some of us also heat water without electricity.
And what the reason might be to have no battery at all between panels and inverter, is really beyond comprehension. Using a small, inefficient car starter one, it's like having a big capacitor. Except cheaper and more efficient.

Funny picture.

I'm confused, as usual. Are you saying "good and good could be better", or something else?

 

[Don B. Cilly]

No, I'm just saying, why not have any battery at all.
Is it proof of concept? Is it an exercise in futility? Just wondering. Honestly.
-

 

[WYtreasure]

No, I'm just saying, why not have any battery at all.
Is it proof of concept? Is it an exercise in futility? Just wondering. Honestly.
-

Yep, I get it, but for some reason I get stuck on "Why Not?" in both directions.
I know it makes me look goofy sometimes, but I couldn't care less.

 

[WYtreasure]

So @efficientPV
I asked about water heater element in the thread "PV without grid or Batteries", fully expecting to see where you had some special dc voltage heating element. Are the heating elements getting AC or DC power?

I have no idea what I am looking at behind the Banks Power sticker.
To me it looks like wires, cooling fins, D cell batteries, a voltmeter and 3 "I dunnos".

AND you do have one of those fancy electronic washing machines. I expected to see one like mine with mechanical dials.
Does that washing machine get DC voltage or is there a magic box (or inverter) attached to it as well?

 

[Bud Martin]

I am curious about the water heater electronics.
I see 5 lytics caps, one module with large heatsink, another smaller module, and a potentiometer. What are they for?

 

[efficientPV]

Yep, I get it, but for some reason I get stuck on "Why Not?" in both directions.
I know it makes me look goofy sometimes, but I couldn't care less.

View attachment 87211

The house has a car battery to provide starting current for the fridge. That was measured at 120A at startup. The house basics will even run with days of rain. Chest fridge is a cheap option but I'd like to go to something else. Fridge only starts when battery is over 13.8V and will stop at 12.8 volts. I will always need a battery because i need to power a couple things to keep me alive at night.

 

[efficientPV]

I am curious about the water heater electronics.
I see 5 lytics caps, one module with large heatsink, another smaller module, and a potentiometer. What are they for?

The water heater is a basic PWM shunt regulator that prevents the PV array from going over power point voltage. Total array is 2S6P. Because of extreme shading the array can seldom produce more than 600W. This is the diversion concept, when array goes over power point the charge controller is not using all the power available. That board is a modified 300W 12V inverter board. These used to sell for $7 shipped. Now you don't know what version they will ship you and they now use 50V FET which is to low to be used by most systems. The capacitors store panel energy during off times and they keep the panel voltage and current fairly constant. This has now been replaced with this board which works up to 200V

This shows the diversion on scattered cloud day for just a half hour around noon. Note the array drops to about 44V at the end when the refrigerator turns on. The washer is a fancy LG which is powered by and old 2,000W MSW inverter. I just wired array voltage into the high voltage caps. The 12v to high voltage does not work. I only power control electronics with 12V.

 

[efficientPV]

I just got a video of a camp in Minesota using smart diversion. The video was private, but this is a screen shot. He has 650W of panels, charge controller and a 12V lithium battery. He wanted to heat water and provide some cabin heat from PV to supplement his propane heater which he leaves on to prevent freezing pipes, he is gone most of the time. The green board is the diversion control which operates from panels without batteries. This connects to a 6 gallon water tank that had the standard thermostat with upper thermostat which switches to a 1500W 120V space heater when the tank is up to temperature. The space heater has an external temp sensor which turns on a 12V fan when the space heater gets hot. Notice the wall 3 way wall switch. In the up position the diversion control feeds the heater which can switch to the space heater when up to temperature. Down position powers only the heater.


The nice thing about this is the battery is always left fully charged. Any heating device can be daisy chained because the control has arc interrupt and any AC rated switch can be used. This is using his existing solar system and no extra panels were added. And now he has hot water when he gets there because of smart diversion. Adding a little extra heat to the cabin saves him some propane. The meter is reading 565W diverted to heating from his 650W array. This is a little low because currently it is a 1500W 125V element and it should be a 2000W element to get full power. Note the voltage is 81.2 @6.96A, power point would be around 77V at this temperature.