Author Topic: New Power Shed  (Read 3181 times)

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OperaHouse

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New Power Shed
« on: August 18, 2015, 08:35:25 AM »
Read very few of the posts, but most are into big dumb power.  Any time you use batteries, the cost per KWH used is about 12 cents. With that you can't win economically.  Add to that, most systems are over designed so they can operate without a bit of thought.   Most of the potential energy that can be harvested is wasted.  Making a system smart and scheduling loads will be the next generation of RE.

I live off grid in the summer for many months and use only a car battery out of a vehicle I don't bring with me.  It is used primarily for initial surge current of the fridge inverter.  Storage is not necessary to the massive extent most moronic solar systems are designed to.  Fridge runs real time off solar only during the day, I store cold for night.  Any excess power is converted to hot water at power point.  Currently I divert over 3KWH a day to heat water, more than enough for my uses.  It is possible to operate appliances real time without storing energy if done one at a time under processor control. I have next to nothing invested in all the electronics.

My neighbor commented during construction, "For a guy with no power you sure have a lot of power tools.

OperaHouse

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Re: New Power Shed
« Reply #1 on: August 18, 2015, 09:59:41 AM »
OOPS, copied wrong item.

The PV water heating system has been working better than expected and it was time to build a shelter
to house the two water tanks. This would insulate them better as cold weather sets in. I am also
thinking about moving all the electronics and batteries to this shed.  The location beside the
house is only suitable for a 4 X 6 foot enclosure.  I used up two windows and a sun roof I've had
hanging around for a while.  The sun roof had a date stamp of May 13, 2000.  Siding is fiber cement
Hardie Plank.  I love the look of this stuff and won't rot.  The sun roof gives lots of light, but
it won't overheat the shed due to tree cover.


DamonHD

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Re: New Power Shed
« Reply #2 on: August 18, 2015, 11:05:21 AM »
I agree, smart scheduling of as many loads as possible is the future.  Those who don't or won't, even on the grid in the UK, are predicted to pay 3x more than those of us who will help match load to energy availability.

(On the other hand, I may be rather guilty of overspecing my off-grid PV storage that runs my Internet server for earth.org.uk amongst other things, to nominally cover 3 months worst case.  Just today I have been fiddling with the settings (http://www.earth.org.uk/RPi201406/code/powermng.c) to more aggressively divert excess energy to my Internet modem to try and keep all of it off-grid more of the year.  And right now I am running my Mac directly off the secondary panel and battery.)

Rgds

Damon

Bruce S

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Re: New Power Shed
« Reply #3 on: August 18, 2015, 12:48:06 PM »
Though I am on the grid; I do have a small but very effective solar setup that continues to be used as a learning setup as well.
The issue that most have had to go with , mostly due to "what's out there" is over spec'd.
From what I can see from a DIY'er and a consumer, there just doesn't seem to be enough items on the market that wold allow the mainstream people to buy, install and save.
Even on forums such as this one, allot of items being built can be viewed as a one-off device, OR , there is a sharp learning curve people no longer "think" they have the time to commit to.

Your power shed posts will be if great interest to me 'cause I'm a tinkerer and will garner lessons from it that I can possibly use at my home.
The power scheduling is something I'm still playing with , even while on-grid to save my hard earned $$$.

Cheers
Bruce S
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OperaHouse

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Re: New Power Shed
« Reply #4 on: August 19, 2015, 07:30:32 AM »
Although I am 12V for storage, I am getting into using a raw 52 buss from the solar panels from a 36V string.  With that I can hang things off it at "power point".  The device with the lowest power point wins in the simplest example, just 100mv will do it and it can get more elaborate with communication.  Wife wants a dishwasher.  I could operate it in several minute slices turning everything else off or shutting down when there is a cloud. It doesn't really matter if it takes twice as long. 

There aren't the products out there for diversion or the understanding of how to use them effectively. It does take a lot of effort. I still waste power.  When the beer is cold,the milk doesn't stink  and there is hot water in the shower, it doesn't seem important.  I have a mish mash of 12V panels that just don't seem to contribute much.  Four of them are matches Sharp 80W that I will put in a 24V string.  That should be enough to run the fridge on good days.  That change should happen when I move the electronics.  It is now located in the basement stairway and the basement usually has a couple of inches of water in it, not good for the electronics.    I built this a couple years ago to have some place to sleep if the house caves in.

Ungrounded Lightning Rod

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Re: New Power Shed
« Reply #5 on: August 19, 2015, 10:56:20 PM »
Siding is fiber cement
Hardie Plank.  I love the look of this stuff and won't rot.
Yeah, great stuff.

We used the Hardie Plank with the cedar wood grain to reside our townhouse about a decade ago.  Looks fantastic.  With the paint on it you can't tell it's not wood - until it doesn't rot and the termites don't eat it after decades (or it doesn't burn down if there's ever a fire nearby).  B-)

MattM

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Re: New Power Shed
« Reply #6 on: August 20, 2015, 06:27:16 AM »
If people build hardiplank correctly with an air gap it does not get wet or dry rot conditions.  The problem is that so many poorly knowledgeable builders are out there using it wrong.

OperaHouse

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Re: New Power Shed
« Reply #7 on: August 27, 2015, 02:58:46 PM »
The tanks are now installed and we are getting plenty of hot water.  Picture is before fiberglass water heater blanket installed.  The shiny stuff on the walls is foil faced styrofoam.  The last three solar panels I got had  closed cell poly foam that was a half inch thick.  It cuts nicely and have used that for insulation between studs.  Other panels came with 5/16 foam and will try doubling that up in the walls. Black box above the tanks is the two heating element controller.  It will take a while to move the rest of the electronics

Bruce S

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Re: New Power Shed
« Reply #8 on: August 28, 2015, 07:00:34 AM »
That's a nice setup! It's also nice when the shipping company sends you free insulation  :).

A kind word often goes unsaid BUT never goes unheard

OperaHouse

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Re: New Power Shed
« Reply #9 on: September 10, 2015, 02:15:23 PM »
Sadly, there is a fatal injury to report. In what UL would call a finger access point
a tree frog decided to sleep in the hot water controller between the 52V bus and the
aluminum case.  The initial move of all the electronics is finished.  It will take a
while to clean up the wiring.

From right to left is the 12V power point controller, this will be changed to 24V soon.
Next is the 36V power point controller.  This 52V bus is nice to work with because because
most common FETs are 60V variety and many wall warts at this voltage to some degree.  A
common 5V cell phone charger works well with a TP4056 board to charge Li cells.  I bought
a pack of ten of those.  At 36 cents who cares if they are clones of clones.  In the top
corner are two Morningstar SL-10. Came into a bunch of these and sold most of them.  Still
nice to use with the assorted odd 12V panels and have a backup if the UNO is off line.  The
box below that turns everything on in the morning.  This system only works during daylight
hours.  Meter below that gives battery voltage and charging current. 

Lower panel contains the 2000W inverter that is only used for the fridge.  All fans were
removed and it is spaced off with the back panel removed for natural air circulation and
eliminate fan current that was close to a half amp.  At only 150 watts it runs cool.  There
is another small inverter in the house to run small kitchen appliances.  Also on that panel
is pump control and a relay that connects a second battery.  This insures the fridge battery
is always at full charge first thing in the morning.  All charging will go to that battery
first.  The second battery supplies the house at night and is only charges after the fridge
battery has a full charge.

The panel to the right is the UNO controller that runs everything.  In the lower left hand
corner is a temperature display for the primary water tank.  This changes a bit on the uno
to indicate the first tank is up to temperature.  At $3.60 shipped on ebay I love these
things.  I get a display and the ability to change settings without using a lot of pins on
the uno.  I have no displays in the house, just a blinking LED for the status and how much
time before the fridge can run again or how much time is left.  Not a believer in big data.
I can always access the UNO if I need more.  Last, the black box the the right is the hot
water controller.  No smarts inside, just the high current drivers that insure the panels
are always operating at power point. The display gives total WH, instant power, peak amps
and peak watts. I have seen up to 3.5KWH diverted to water heating a day.  This is excess
power potential that most people waste.  It has been fabulous this year.  Wife has hot water
for dishes even in the morning.  The transition from charging to heating is seamless and
power can be diverted to either or both tanks.

It is nice to have a place now to do development work.  The entrance to the basement that
held most of the electronics was dark and damp.  The stairway had only three steps left,
one of which was cracked. Doing any work was risking a fall.  If anything was dropped it
likely went into water. In UNO controller board was in the kitchen and the laptop would
sit on the chest freezer.  Any time I would edit software the wife would want to get
into the fridge.

This is not a conventional system.  It relies on using solar energy real time and not
storing it. The battery is primarily for starting surge currenis from my other vehicle
that I do not bring to camp.  The second battery is for the boat. The size of the solar
array is sufficient to run the fridge on even a cloudy rainy day. The fridge is a chest
freezer that "stores cold" for night in a large mass of liquid drinks.  The system works.
The only caution is not to load the fridge later in the day with a large mass of room
temperature items.  The system will always be changing as I experiment with new ideas.

OperaHouse

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Re: New Power Shed
« Reply #10 on: November 14, 2015, 09:12:18 AM »
We left the camp for the season about a month ago and the hot water system has performed
beyond expectations.  Even days before leaving I was still able to get nearly 3500WH of
tank heating in fall conditions and on pretty bad days over a thousand.  A few days
before leaving my wife said she had to move two solar panels and I could put them back
in the room we use for storage. A whole season and I had forgotten to put them out!
There is still work to be done insulating as I lose about 10C at night and A faster
way of draining the tanks is needed when I close up.  I had planned on an air tank to
blow out the pipes.  It still takes till three in the afternoon to close up the house.
This success heating water demonstrates just how much power is wasted in many systems.

An oak tabletop was added on top of the water heaters that provides a place for the
laptop when altering software and protect the insulation.   While it looked like a lot,
the foam packing from solar panels soon ran out as I used it for building insulation.
The door has historical significance.  Made of wainscoting, it used to be on my old
garage that was replaced eight years ago.  That garage was made in the early 30's from
wood scavenged from an amusement park located across the street.  The construction quality
of the door is at a higher level than the garage construction.  This leads me to believe
the door was used on one of the concession stands. It gives the shed a perfect look. As
these old garages have been torn down, painted areas have shown words like bath house and
confectionery.  I managed to save enough wainscoting to make a 3 foot border around the
inside of the garage.

Harold in CR

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Re: New Power Shed
« Reply #11 on: November 14, 2015, 06:05:21 PM »

 Nice write-up.  I have no idea what the things are you listed, but, I do have a solar water heater and need to build a tank. Electric tanks here are scarce and usually mashed up as soon as they quit working.  ::)

 I have 3 solar panels to build. I have 16 4.15 33Ahr battery cells and another part of a Chevy Volt lithium battery, so I can have about any voltage amperage I want to put together.

 Fridge is 10 years old and a cheapy, so, one day I need to replace it.

 I have 3-4 sets of blades for wind turbines, as soon as I get time to build-modify generators for them.

 We use roughly 330Kwh/month, but, pay nearly $80.00/month.

 I will be sure to use the info you posted to guide me to a more efficient power system, so I can laugh at the power Co. when they come to figure out why My bill is nearly 0000  ;D