Solar Water Heating using PV powered, air to water heat pump with minimal battery??

aglicknmex

Purpose of Post: Determine if concept is valid-- not to pick out or size components


Use of system: heat a COVERED swimming pool, YEAR-ROUND, with PV not solar thermal panels. Pool not indoors, but insulated cover

Location: Southwest New Mexico 340 days of sun


Components: Fujitsu WATERSTAGE air to water inverter style heat pump Use this link to see what the Waterstage product consists of.
http://www.hpac.net.nz/assets/pdfs/waterstagecatalog.pdf
http://www.fujitsu-general.com/global/products/atw/monobloc-compact/wpya100le.html#options

Minimal Battery- just enough to make the system work, not for storage. Prob 24 volts or 48 Maybe only 4- 12v Golf Cart sized batteries.

AC 240 v inverter approx 2400-3000 w ( just an estimate)

PV panels Wattage not known until more info and sizing work is done- just guessing 1200-1500 kwh

Charge controller -- perhaps Midnite

Theory: Surplus power during day goes to water heating. Battery will always be fully charged.

Has anyone have some real life experience in doing something similar??

I wish someone made the heat pump with direct inputs for PV panels. There is on like that available for air conditioning, but not for water heating to my knowledge.

Tnx for your ideas.

I would welcome any constructive comments and ideas!!!!!!

waynefromnscanada

Re: Solar Water Heating using PV powered, air to water heat pump with minimal battery??

Very inefficient, both in initial cost, and the relatively small amount of heating produced when compared to direct thermal solar collection.

NorthGuy

Re: Solar Water Heating using PV powered, air to water heat pump with minimal battery??

aglicknmex wrote: »

Theory: Surplus power during day goes to water heating. Battery will always be fully charged.

So, all the power goes to heating then. Batteries are there only because there's no direct heating controller on the market, right?

You need to calculate the amount of heat you need, then figure out how many panels would produce that on average. If this number doesn't scare you off then it's feasible.

Direct solar heating will be way cheaper/more efficient.

aglicknmex

Re: Solar Water Heating using PV powered, air to water heat pump with minimal battery??

Yes, the problem is a lack of pv direct appliances. We are just ahead of the curve in wanting them. Here is one on the market, but it not a company that I trust, after reading horror stories about their customer service. It is for AC not heating water, but the idea it right!! Pretty neat, check the link.

http://www.coolmygarage.com/shop/solar-powered-heat-pump/

My grundos solar pump runs direct from 475 w of pv or from a genset. uses 30-300 volts ac or dc!!!!!! I know its possible now!!!

Let me know if you guys run into any other new pv direct appliances. (thats what im calling them for lack of a better name)

NorthGuy

Re: Solar Water Heating using PV powered, air to water heat pump with minimal battery??

aglicknmex wrote: »

http://www.coolmygarage.com/shop/solar-powered-heat-pump/

Looks like an overpriced AC heat pump:

This unit is not an off grid system. Requires connection to 50hz or 60hz power, can operate with single phase 220v or 208v 3-phase power. Connects to ~30 VDC solar panels up to 700 watts maximum. Recommended configuration is two 230/235w panels, the efficiency of the unit is such that the third panel will really only come into play on cloudy, or extremely hot days.

aglicknmex

Re: Solar Water Heating using PV powered, air to water heat pump with minimal battery??

I just like the concept(I realize its not an off grid unit) .Makes sense to have it tied to another power source or it would be useless on a bad day. Its a good way to easily incorp. PV into a home that doesnt have a pv system.
Its not mature technology or anything i would buy..