water heater

[hughconley3]

I was wondering if I had a 3800 watt 240 volt hot water heater how many solar panels would I need to power it? I'd have an on off switch and only use it about 3 hours a day. So how many amps and volts on a solar panel would I need to power it for an hour. Also how do I calculate how many amps a 12 volt solar battery will hold?

[Sunking]

How many thousand of dollars are you willing to spend? It will take at least high 4 decimal places $$$$, more than likely low 5 $$$$$ unless you live on the Left Southern coast of LA or south of there . Need to know more?

[Mike90250]

I would look at a solar hot water heater, not electric .

Collecting solar heat is about 40% efficient, solar electric is about 15%.

Look at http://solarroofs.com/ for some good DIY sizer and info.

[Stomp]

I know you didn't ask this, but these guys look cool. I hope they're successful and the technology plays out! Hot water & electricity generation in the same unit (from what I can tell)

http://www.pvtsolar.com/

[russ]

I don't like a website that is pretty but has no facts or details on it.

The most informative statement provided on the entire site is, 'PVT Solar cannot guarantee performance results'.

The hot water and electrical generation assumptions they make are not supported by anything but salesman talk.

The graphics page shown is pretty. Until they become more informative I would not bother with them. They do know all the buzz words and catch phrases. They throw in the DOE and the names of it's programs and software - you can also get that stuff off the DOE site.

Russ

[Mike90250]

I know you didn't ask this, but these guys look cool. I hope they're successful and the technology plays out! Hot water & electricity generation in the same unit (from what I can tell)

http://www.pvtsolar.com/

vapor ware

[hughconley3]

I saw a water heater that was around 3800 watts, 16 amps, 240 volts. So wouldn't it take a lot less watts to power, like a solar panel that was 24 volts, 15 amps, it would only have to be around 160 watts if I don't use it at night anyway so I'd need no extra.

[russ]

How many liters (gallons) hot water would you plan on using? What is the water temperature before heating and the desired hot water temperature. Those numbers are the basis of all calculations.

To estimate the consumption the DOE web site has a format http://www.energysavers.gov/your_hom.../mytopic=12990

If you provide a quantity I will try to assist you.

Russ

[raydias]

Heliatos solar water heater

I came across this product that looks promising.

http://www.heliatos.com/

Ray

[russ]

The problem with Heliatos is that they are very small units 24'' square more or less (600mm square. They seem to be certified by 'Tony, Two Guys and a Truck'. They would not qualify for any rebates certainly.

If a panel is not listed by the Solar Rating and Certification Corporation http://www.solar-rating.org/

A good source of information is 1) http://www2.fsec.ucf.edu/en/industry...nual/index.htm

Russ

[Perry]

Also how do I calculate how many amps a 12 volt solar battery will hold?

you need to find out the AMP-HOURS of the battery.

For example, a 100 AMP-HOUR Battery will power a 1 AMP load for 100 hours or a 10 amp load for 10 hours. However, you should not discharge your battery more than 50% or your battery life will be shortened, so divide those numbers by two.

[Mike90250]

....Also how do I calculate how many amps a 12 volt solar battery will hold?

No calculation needed, it's printed on the battery. Batteries are sold by volts and amp hours.