PV Solar Radiant Heating

System

I am a newbee to PV solar, and recently read an article on a family man in SoCa that remodeled and used PV solar for radiant heating his house. I am assuming he is net metering, then sized his PV system to replace as much electrical demand as he can use. Does anyone have any knowledge or coments regarding on radiant heating and the best way to go when using net metering PV solar.
Thanks

BB.

Re: PV Solar Radiant Heating

I have another thread here that talks about Solar Hot Water heating (I am interested in adding it to my Grid Tied Solar PV connected home)... I mostly wanted to use it for domestic hot water, but many folks also use it for space heating too...

In general, Solar Hot Water collectors are more efficient (1/2 to 1/4 of the panel space for the same amount of "heat") and, should be, much less costly to install. However, maintenance costs and laborb appear to be much greater for solar hot water collector system vs Solar PV...

One hybrid alternative to look at is a Solar Hot Air system. It is simply a collector that you use a small fan to force air through and into your house. If you have the space to install the panels and run the air ducts, this type of system would seem to win hands down for low costs and maintenance.

You do have the issue with solar hot air of no storage medium... However, as always, you should first spend your bucks on conservation, then on solar... I live just south of San Francisco, and, if I button my home up, I see, at most, a 10F drop from evening to morning--so adding the heat storage (hot water, rocks, etc.) did not make sense for me. (in our 65 year old home I put in wall/ceiling/floor insulation, double pane windows, venting skylights, CPF lights, Energy Star appliances, and just keep on the family to not waste energy). With my net metered solar (using electric space heaters for a couple of rooms) and new a new efficient gas furnace, I spent $45-$65 bucks per month for gas (including gas hot water/drier/stove for 4 people and ~$5-$6 per month for electricity (this last winter).

Regarding net metering--it differs by state/utility... For me, I choose the PG&E E7 Time Of Use Net Metering plan. During the summer the peak rate starts around $0.29 / kWh (Mon-Fri/Noon to 6pm) and $0.09 / kWhr for off peak (normal E1 rate is ~$0.11 / kWh). With a solar system, it basically gives me 3x the amount of energy generated in the afternoons, for use during the rest of the week. There are some squirrelly issues with "base line" charges that I have heard about with PG&E--but it has not bit me yet (my system is only 7 months old) (the issue being that PG&E uses up your "baseline" credit while generating electricity--thereby jumping you into a higher billing tier for the off-peak charges... So far, I have not seen this explained by PG&E on their tariff sheets yet).

I choose to put a much solar as would fit (and I wanted to pay for) in the hope that I can get a small electric car in the near future and power it with my home panels (and/or a small air conditioner for our few weeks of hot weather every year).

Here, net metering charges you, roughly $6/month minimum charge and puts the rest of your bill into the "bank". You can choose to pay any outstanding balance (if you buy more power than you sell) every month--or you can wait until the end of the 1 year contract and settle up (pay the outstanding balance in one lump sum, or, if you have credits, they are reset to zero for the next one year contract). If you get the Time of Use meter, there is a $277 one time fee to buy/install the meter.

Also, make sure that you right down the meter readings when they change you meter out--it seems that PG&E has difficulty with your first Net Metering Bill (I went from $20-30 per month to $300 for a few weeks of power--my new solar installation was "live" before PG&E did the accounting changes... So, they saw the meter numbers went backwards and, probably, a computer program assumed that the reader miss-read a digit and simply added 1,000 kWh to my reading--while my wife as asking "How much was Solar PV's supposed to save us...????")... PG&E eventually (after several months) fixed the bill without too much grief.

Any questions? It is confusing and, somewhat difficult to cover everything in one general post.

-Bill

System2

Re: PV Solar Radiant Heating

Bill , Thanks for all the history, comment and suggestions.
I will continue to do more research on this radiant system. From what I am told you put it on a timer, heat up the floors for an hour or so in the AM depending on how cold it is outsid/inside then turn it off till you need it again in or at night for a few hours to take the chill off.

Regarding Electric Cars, this is my next area to investigation. My wife wants to buy a Hybrid and I am trying to explain to her she need to change her driving experience from the thrill of excelerating between stop lights, to the thrill of driving quietly on home grown electricity for short commute to the store and work. If you hear of any good electric car's keep me posted.
Regards, Anselmo