Too Good To Be True Project

DanS26 · December 2012

Last November I installed an 8.6 Kw system which has produced over 12,000 kWh so far this year. My big problem is that my local utility forced me to use a net billing system. As most of you know, a net billing system allows you to sell excess solar produced energy at wholesale rates and then buy it back at night at retail rates. Bummer!!! So I am constantly on the lookout for ways to use my excess daytime solar power.

Well, I have found a way to use some of that excess. I installed an in-house heat pump system that supplements my hot water heater. It is basically a dedicated heat pump that attaches to my water heater. The unit sits right next to or on top of the water heater. I also installed a timer which only allows the heat pump to operate during daylight hours, thus using that excess daytime power.

Here's why I call it my "Too Good To Be True Project":
1. It uses excess daytime power which I produce for under $.04 kwh but replaces power that I would have to purchase for $.09 kwh.
2. It is also a 1 ton rated air conditioner, which I connected to the cold air return of my home cooling system.
3. It dehumidifies my basement air, which reduces dampness and makes my basement dry.
4. It qualifies for the 30% tax credit from the IRS.
5. It qualifies for a $300 rebate from my local utility.
6. My out of pocket cost after tax credits and utility rebate is $300, thus my payback is under 2 years.

I have been operating the system for over 8 months now and have been very pleased with the results. Just thought I would share with the rest of the solar community.

BB. · December 2012

Re: Too Good To Be True Project

Sounds like a successful project.

-Bill

waynefromnscanada · December 2012

Re: Too Good To Be True Project

Self contained all in one unit heat pump water heaters are only just beginning to appear in these parts. So far I've been seeing $1500. price tags.

solarvic · December 2012

Re: Too Good To Be True Project

Dan What is the brand of your system? I would like to read up on it. I have the GE GEOSPRING WATER HEATER which does most of the tasks you mentioned. It takes heat out of the air and dispells cold air and dehumidifies the air. But it doesn,t have provisons for ducting into ductwork. I have it installed into utility room which is off kitchen so helps to cool kitchen in hot weather. I have one of my gt inverters beside waterheater and any heat from inverter is directed to waterheater. Never thought about the waterheater timer as I leave it on all the time this time of year. In the summer when I need the cooling I turn off the waterheater at night and back on late morning or when I am going to do laundry ect. :Dsolarvic:D

DanS26 · December 2012

Re: Too Good To Be True Project

It's a Nyle Geyser-RO system. See here:

http://www.nyle.com/water-heating/geyser-r/

I installed it myself, just need to be a little handy with plumbing techniques. As you can see from the product pics, there is a round grating that is removed and you can install standard 8" duct work. I used off the shelf Intermatic timers which are rated for the proper amperage for my application. My water heater is a "power shot" type LP gas heater, which allows me to shut it down automatically when the Nyle systems turns on by using a two stage timer (see the Intermatic product line).

I shut both systems down at night, not so much for electrical or gas savings, but just to keep the house quiet at night since both systems make mechanical noise. Noise is barely perceptible in both systems, but I like to sleep in a quiet house. Early in the morning the gas system turns on, then when the sun comes up and hits the panels the Nyle is turned on. I do not run both systems at the same time since I think the gas burner might interfere with the thermostat on the Nyle system. If you have an electric water heater, then I don't think a conflict would occur. In the evening, just before the sun goes down the Nyle is shut off and I run the gas until about 10pm.

There are conflicting opinions about putting a timer on a water heater at night. Like I said I use a timer for noise reasons as opposed to energy use at night.

DanS26 · December 2012

Re: Too Good To Be True Project

Just thought I'd post a few pics of the project. Before you ask, there are two sets of timers, one for summer and one for winter. I do not plan to run the Nyle during the dead of winter since it is a one ton rated AC unit which would mean I'd be running an AC system and a heating system at the same time.

inetdog · December 2012

Re: Too Good To Be True Project

DanS26 wrote: »

Just thought I'd post a few pics of the project.

Nice pictures, thanks!

One thing makes me very curious: It looks like both the inlet and outlet pipes from the Nyle connect near the bottom of the water heater tank. Is this some sort of concentric or parallel tube system which feeds a cooling loop inside the tank using only the one standard drain hole in the tank, or is something about the tank special too?

DanS26 · December 2012

Re: Too Good To Be True Project

inetdog wrote: »

One thing makes me very curious: It looks like both the inlet and outlet pipes from the Nyle connect near the bottom of the water heater tank. Is this some sort of concentric or parallel tube system which feeds a cooling loop inside the tank using only the one standard drain hole in the tank, or is something about the tank special too?

Good observation. It's a concentric tube which uses only one hole in the tank, which in turn is connected to the standard drain connection in a standard water heater tank. The hot water return is the innermost tube that extends 8 to 10 inches into the tank bottom. The outer tube extracts cooler water from near the tank wall. So as the heated water is inserted into the middle of the tank and then rises, then cooler water by convection moves down the tank wall to be extracted to the Nyle in a continuous loop. Very ingenious.

Just to give you an idea of how well this works, in the pic my tank is a 40 gal tank. The Nyle can raise the temp 1 deg in about 30 to 45 seconds. An engineer will come along and calc the btu output, but to me it heats the water fast. The Nyle thermostat is adjustable so that you can control water temp, etc.

Too Good To Be True Project

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