Go Back   DIY Chatroom Home Improvement Forum > Home Improvement > Green Home Improvement

CLICK HERE AND JOIN OUR COMMUNITY TODAY...IT'S FREE!

Reply
 
Thread Tools Search this Thread Display Modes
Old 10-04-2012, 06:14 PM   #1
Newbie
 
Join Date: May 2012
Posts: 9
Share |
Lightbulb

PV Solar electricity tied directly to a DC Water Heater


There are DC heater elements available for use in electric water heaters. Therefore, can PV Solar panel output (DC) be directly wired to a DC Water Heater of the matching voltage (assuming a thermal controller is installed to prevent over heating). Any ideas or brain storming?

Thanks,
Joe

JStofik is offline   Reply With Quote
Old 10-04-2012, 08:41 PM   #2
Member
 
Missouri Bound's Avatar
 
Join Date: Apr 2011
Location: Almost Arkansas
Posts: 2,764
Default

PV Solar electricity tied directly to a DC Water Heater


Why not? What heats the water when it's cloudy?

__________________
Do you want it your way or the right way?
Missouri Bound is offline   Reply With Quote
Old 10-05-2012, 09:15 AM   #3
Newbie
 
Join Date: May 2012
Posts: 9
Default

PV Solar electricity tied directly to a DC Water Heater


On cloudy days, the existing gas hot water heater will supply hot water. It will be plumbed so the DC electric is a feed tank to the existing gas water heater.
JStofik is offline   Reply With Quote
Old 10-05-2012, 09:24 AM   #4
Member
 
Missouri Bound's Avatar
 
Join Date: Apr 2011
Location: Almost Arkansas
Posts: 2,764
Default

PV Solar electricity tied directly to a DC Water Heater


Got it!
__________________
Do you want it your way or the right way?
Missouri Bound is offline   Reply With Quote
Old 11-09-2012, 09:50 PM   #5
Member
 
Join Date: May 2011
Location: Massachusetts, USA
Posts: 325
Default

PV Solar electricity tied directly to a DC Water Heater


You can do this, but energy-wise it is a waste of panel area. You would get more heat into the water using indirect solar thermal instead of PV.

You generally only get about 10% of your incident solar into the form of electricity in PV. Solar thermal is far more efficient if your goal is to make hot water.
Thunder Chicken is offline   Reply With Quote
Old 08-23-2013, 05:16 PM   #6
Newbie
 
Join Date: Aug 2013
Location: Northern Wisconsin
Posts: 19
Default

PV Solar electricity tied directly to a DC Water Heater


There are some situations where a PV to thermal might be considered...the collectors are lighter and easier to anchor. Wire is easier to run than pipe, especially if you have a long and complicated pipe run. PV system doesn't need freeze protection. There should be some efficiency gain without an inverter, and no batteries or grid tie is needed.
But you are right, Thunder Chicken...last I checked, it took 5X's the money and 7X's the collector area for PV's to match thermal solar.
Solarboy is offline   Reply With Quote
Old 08-24-2013, 11:35 AM   #7
Member
 
Oso954's Avatar
 
Join Date: Jun 2012
Location: Northern Calif.
Posts: 1,405
Default

PV Solar electricity tied directly to a DC Water Heater


Quote:
There should be some efficiency gain without an inverter, and no batteries or grid tie is needed.
Wiring PV directly to a heating element is not efficient. In fact, it may not work at all. The resistance of the heater will drive up the panel voltage. When you hit open circuit voltage, there will be no current flow.

You will need at minimum some type of heater controller, or a solar charge controller and a battery.
Oso954 is offline   Reply With Quote
The Following User Says Thank You to Oso954 For This Useful Post:
Solarboy (08-24-2013)
Old 08-24-2013, 03:32 PM   #8
An old Tradesmen
 
Join Date: Oct 2008
Location: PA
Posts: 24,490
Default

PV Solar electricity tied directly to a DC Water Heater


Quote:
Originally Posted by Oso954 View Post
Wiring PV directly to a heating element is not efficient. In fact, it may not work at all. The resistance of the heater will drive up the panel voltage. When you hit open circuit voltage, there will be no current flow.

You will need at minimum some type of heater controller, or a solar charge controller and a battery.
So 1 ohm of resistance is too much?
__________________
When posting in certain forums, knowing your location will help others give better feedback/advice/solutions to your questions.
beenthere is online now   Reply With Quote
Old 08-24-2013, 08:37 PM   #9
Newbie
 
Join Date: Aug 2013
Location: Northern Wisconsin
Posts: 19
Default

PV Solar electricity tied directly to a DC Water Heater


While PV is not my field (thermal solar is my thing) my gut instinct says that PV panels producing DC, into DC heating elements...without an inverter should be more efficient overall. I don't know "what it would take", but the fewer conversions the better, as a general rule. A charge controller and battery? Ok....so the PV's charge the battery and the battery runs the heater?
Solarboy is offline   Reply With Quote
Old 08-27-2013, 10:59 PM   #10
Member
 
Join Date: May 2008
Posts: 116
Default

PV Solar electricity tied directly to a DC Water Heater


any links?

ehoez is offline   Reply With Quote
Reply

Tags
hot water from a pv


Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Best practices for Water Heater install? simanco Plumbing 4 08-22-2012 11:36 PM
Tankless hot water heater during winter when water shut off jdabs Plumbing 3 07-10-2012 12:50 AM
No hot water at any faucet, water heater working fine rivercliff Plumbing 5 10-27-2011 09:47 AM
Poor Hot Water Pressure After HW Heater Flush linuxrunner Plumbing 4 04-07-2011 07:24 PM
Oil fired furnace and hot water heater question steveinpa Plumbing 3 08-10-2010 08:42 AM




Top of Page | View New Posts

Copyright © 2003-2014 Escalate Media. All Rights Reserved.