EcoRenovator - View Single Post - Dump the plumbing and use PV to heat water?

Xringer · 03-20-10, 09:30 AM

Yeah, that's Fanney & Dougherty, the guys who did most of the research for the USG.

Here's a list of their papers. BFRL: Solar Photovoltaic Hot Water System

Besides getting PVWH field testing started, their big idea was Power Point Tracking.
They even took out a patent on it.

My current PVWH project idea does not use Power Point Tracking,
but does use Sun Tracking, with an old TVRO dish mount.
http://ecorenovator.org/forum/projec...r-project.html

The plan is, to track the sun, so the panels harvest the peak power
available and then feed that power into a fixed load.
The fixed load would be pre-matched to the panels..

For now, I think keeping it simple is the best choice. However, in the
coming months, I will be looking at Fanney & Dougherty's ideas about
automatic load matching. If it can be done without undue complexity, I'll do it.

For a hot-water assist heater, I'm thinking of 2 thin-film 54v panels in series.
Kaneka Thin Film Solar Panel 110w
For about 108 volts at 220 watts (750 BTUh), which might not be enough to notice..

But, I plan to pre-test the 220 watt idea, by plugging in a 250 watt heater
(using AC power).
http://ecorenovator.org/forum/applia...ad-heater.html

If 250 watts doesn't help reduce oil consumption, then I will have to think
about using a larger fixed PV array..

I have been tracking daily oil use by logging the AC power use of the oil burner and hope to install the heater pad this week.
http://ecorenovator.org/forum/projec....html#post6105

Once the 250 Watt heater is installed, and spring is here (home heating off)
I can log oil usage data that only reflects domestic hot water usage.
Maybe one week on and one week off will tell me if 250 watts makes a difference.
If I see it's working ok, early on, I'll switch to 5 hours a day (11am to 4pm)
and see how that works.

This spring, I plan to install more insulation and a new (fully functional) water mixer on the boiler. The old mixer is pretty useless and wastes a lot of energy.

Honeywell-Sparco AM100C-US-1 - Honeywell-Sparco - 1/2" Sweat Union Mixing Valve
The new mixer goes down to 80 degrees F, which might be okay in the summer time..

03-20-10, 09:30 AM	#10
Xringer Lex Parsimoniae Join Date: Feb 2009 Location: Woburn, MA Posts: 4,918 Thanks: 114 Thanked 250 Times in 230 Posts	Yeah, that's Fanney & Dougherty, the guys who did most of the research for the USG. Here's a list of their papers. BFRL: Solar Photovoltaic Hot Water System Besides getting PVWH field testing started, their big idea was Power Point Tracking. They even took out a patent on it. My current PVWH project idea does not use Power Point Tracking, but does use Sun Tracking, with an old TVRO dish mount. http://ecorenovator.org/forum/projec...r-project.html The plan is, to track the sun, so the panels harvest the peak power available and then feed that power into a fixed load. The fixed load would be pre-matched to the panels.. For now, I think keeping it simple is the best choice. However, in the coming months, I will be looking at Fanney & Dougherty's ideas about automatic load matching. If it can be done without undue complexity, I'll do it. For a hot-water assist heater, I'm thinking of 2 thin-film 54v panels in series. Kaneka Thin Film Solar Panel 110w For about 108 volts at 220 watts (750 BTUh), which might not be enough to notice.. But, I plan to pre-test the 220 watt idea, by plugging in a 250 watt heater (using AC power). http://ecorenovator.org/forum/applia...ad-heater.html If 250 watts doesn't help reduce oil consumption, then I will have to think about using a larger fixed PV array.. I have been tracking daily oil use by logging the AC power use of the oil burner and hope to install the heater pad this week. http://ecorenovator.org/forum/projec....html#post6105 Once the 250 Watt heater is installed, and spring is here (home heating off) I can log oil usage data that only reflects domestic hot water usage. Maybe one week on and one week off will tell me if 250 watts makes a difference. If I see it's working ok, early on, I'll switch to 5 hours a day (11am to 4pm) and see how that works. This spring, I plan to install more insulation and a new (fully functional) water mixer on the boiler. The old mixer is pretty useless and wastes a lot of energy. Honeywell-Sparco AM100C-US-1 - Honeywell-Sparco - 1/2" Sweat Union Mixing Valve The new mixer goes down to 80 degrees F, which might be okay in the summer time..