How efficient are solar hot water systems?

Question

I live in Northwest Pennsylvania, and I would like to know how much these systems cost, how efficient they are, how much space I'll need on my roof and how long it will take to pay back the initial cost of the system.

Answer 1

In your area I don't think I'd rely on a solar system as my only source of hot water.

You could use it as a tempering or preheating system.

50-60 percent of the energy is used to raise the water from entry temperature to room temperature.

The other 40-50 percent is used to raise the temperature to the standard.

By mixing your solar heated water to preheat the water you can should be able to save 40-50 percent

Answer 2

if u lived in america it would be much better n

Answer 3

since you live up north, you'll need a 4 panel solar thermal system with at least 108 gallon tank.  Not only will you be taking care of your domestic hot water, but you should put a hot water heat coil (looks like a radiator) in your duct to preheat your air.  the equipment and labor will cost the installer roughly $6,000, a max of $7,000.  thats with the heat coil.  now, whatever they tack on to that is up to them.  but that is their cost.  A domestic system (3 panels because of you being up north, 2 panel if in south) it would run the installer about $5,000 installed including labor.  again that is the 'before' profit estimate.  make sure you facing south and clear of shade.  ask for a mixing valve unless you already have one.  usually you state and federal tax credits can enable you to cut the cost by about 50%.  so if you paid a total of $11,000, you would get about $5,000 back in taxes.  of course states vary in tax benefits.  payback with hot water coil would be about 8 to 10 years, domestic only about 13, depending on how much you use it.  the panels i install are 4 feet by 7 feet.  you can get some that are 4 feet by 10 feet, pending the make.  these system are 95% efficient compared to a max of 16 to 18% for pv.  hope this helps, dont let the installer charge you an arm and a leg.  my estimate for the cost for the install is close to dead on, of course they have to make a profit.  the job should be completed in no more than 4 days.

**hey mike, solar thermal is used in residential for the soul purpose of pre heating your current hot water heater.

Answer 4

Solar water heating systems work almost anywhere in the country, and are usually eligible for state rebates that mean that they pay for themselves within 10 years - even less with incentives.  (Unlike photovoltaic systems, which rarely pay for themselves in less than 30 years and often take more than 50 years to pay back.)  Solar water heating systems are the most cost effective solar system that you can install on your home.

I would contact a local solar installer and get a quote on a system for your home.  That way, you'll have some real solid information about your specific area, your particular home, and your family's hot water needs.  The North American Board of Certified Energy Practioners has a listing of installers that have passed a test on installing solar systems.  From their web site, you should be able to find a local installer that can help you choose a system.  By using the NABCEP web site, you'll be sure that you are dealing with someone knowledgable about solar systems.

Good luck!

Answer 5

I live in Calif where solar systems are becoming more and more popular.  Many cities give reduce rates to permit seekers for the installation and the electric company gives rebates.  Yet the conventional wisdom is that if you go solar - at least right now - your motivation should be guided more towards going 'green', than expectation of benefiting financially in the near term.  Probably not for several years, if you still live in the same house.  That's the same theory given to hybrid cars.

Answer 6

In Pa. it will probably never pay back the investment, but it would be good for the environment (I think?).

If you lived somewhere like Phoenix, it may pay back within 10 years.

Our power costs are still so low, and our new appliances so efficient, it is very difficult to justify any Solar systems on economics. These systems were very popular in Phoenix some years ago when the government gave huge rebates, but as soon as the rebates ended, all the companies selling them dried up.

Answer 7

I have looked into lots of solar electricity stuff. What I have found is that hot water is actually the most efficient way to use solar electricity. I'm not sure how much you would need just for the hot water system, but to power a house (in ohio, pennsylvania, anywhere pretty much sunless) you would need approximately 230sq feet of panel. this would cost $30-$50k, and would pay back in 20 years (without inflation)