Would like to do some solar hot water some day.
If you have a space for a HeatPumpWaterHeater? It will use fewer kWh than many if not most commercially installed solar DHW systems.
Would like to do some solar hot water some day.
How does a simple water pump use more KW than a compressor?If you have a space for a HeatPumpWaterHeater? It will use fewer kWh than many if not most commercially installed solar DHW systems.
If you have a space for a HeatPumpWaterHeater? It will use fewer kWh than many if not most commercially installed solar DHW systems.
My house has an electric when I moved in 6 years ago. It blew apart one day, I made the jump to a propane on demand it costs me $35.00 per month (or less). We take 2 showers, and 2 baths. We run the dishwasher every day along with the washing machine. When I installed the propane on demand my bill went down almost $70 per month. For me it was a no brainer and it has served me will for the last 5 years with out issue.
You were spending over $100 a month in electric JUST to heat hot water?!
How does a simple water pump use more KW than a compressor?
Most commercially installed residential solar DHW systems have a 'solar fraction' around 50-60%, the rest comes from a backup heater, usually a coil. A HPWH with a EF = 2.2, versus EF = 1 for a resistive backup (assume parasitic losses are supplied by the solar for 'free'), uses only 1/2.2 or 45% as much as a normal electric tank. IOW, it uses about the same amount of electricity as a typical commercial solar DHW system using coil backup with a 55% solar fraction, (and not costing the elec used by the pump). Oh yeah, and commercial solar costs 3x more than HPWH.
For some fraction numbers, look at: http://www.greenbuildingadvisor.com/blogs/dept/musings/solar-thermal-dead
Hi,
That solar fraction seems low to me.
Even my old system did better than 90%
http://www.builditsolar.com/Experimental/PEXColDHW/Performance.htm
I agree that commercially installed solar hot water is a lot more expensive than it should be, but prices vary a lot depending on where you are and who does the installing. We have a really good outfit in Bozeman that does commercial installs for $5000, which less the 30% federal and $1000 MT rebates is $2500.
Gary
Problem with a separate meter is its $15 a month JUST for the meter. Plus hot water for 2 people showers,washing dishes ect $5.00?Off-peak electric, two staged water heaters, 100 gal of storage, separate meter. Added 6+" fiberglass insulation to tanks, install U-shaped heat traps, and insulated all hot water piping. Cost for wife and me was $4-5.00 per month; estimate doubling of that now that daughter and 4-year old have joined the household as of the end of December.
Problem with a separate meter is its $15 a month JUST for the meter.
That must be a sub-meter with one main meter on a single line. Here in PA PP&L power was just granted a rate increase that included a jump in the Meter charge From $8 to $15 Almost double. If you have a seperate line for your garage thats another charge as well.This isn't quite true with out co-op electric company. We have 3 meters, one for general service, one for electric heat which can be interrupted, and one for off-peak dhw. My statement of $4-5/mo included charge for power, power cost adjustment, and distribution. I did not include one flat charge of $12.00, which is the same whether one meter or 3 meters, and it's called basic charge. There is no separate or additional charge for additional meters.