[Oldtimer]

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If we didn't have to convert sunlight  into electricity, to in turn charge a battery then convert that into AC, and then run an electric heater - we could enjoy a conversion efficiency increase.

The suns shines in the winter, but the BTU output is so low. If the sunlight that came through a window could shine on a small plate that would warm chemically and radiate heat we could save Billions of dollars on home heating this year.

 The standard Solar heating system isn't quite the same as what I'm thinking.

Andy

[buckminsterfullerene]

hey andy, you are thinking about a solar water heater, they do have them, and i have made one, works excellent in places light south florida, where on average you have sunlight sunlight that can be converted great into heat energy something like 7 hours a day (read it on a worksheet my teacher handed me).  And it is true they could save a lot of money, specially taking into consideration that the water heater takes on average about 40% of the energy use in your home (or something like that).  

If we didn't have to convert sunlight  into electricity, to in turn charge a battery then convert that into AC, and then run an electric heater - we could enjoy a conversion efficiency increase.

you really do not need such a complicated method, when you talk about a solar water heater, you have to take into consideration that you would only be getting heat for your water only when the sun is out, which means that if you have a solar panel, you would not need to have a batter in order to meet they heat requirement of a solar collector collecting heat, you would only need the solar panel to send the electric current to an inverter and have the energy that you want to run an electric heater.  batteries are place with solar panels in order to have an overnight system but they are not really required to operate a solar panel.

[buckminsterfullerene]

soemthing i forgot to add, you do want a solar collector to heat the water, because it would not only be soo efficient, but some systems produce so much energy that they can turn a turbine and generate electricity at the same time.  there are 3 main systems that will heat water and turn a turbine,   atleast 1 of the systems you can add to your home the third one its a bit more expensive and meets the requirement for entire towns.  the systems are explained below:

1. Parabolic trough: they operate by focusing the sunlight from the sun on a relatively small area, the tube would hold something like perhaps some kind of oil that will heat up faster and would be connected to a storage tank which would heat the water.. Heats up to 315_oC
2.  parabolic dish system:  this system uses a parabolic dish, think about it as the dish of your satellite network, only larger, the way that this works is that the slope through out the dish means that no matter where you shot a laser for example, the laser would get reflected and there is a point (epicenter) where it will always pass through.  at this point the heat from the sun gets concentrated from 100-2000 times. however, this system would have low storage capacity and high maintanance cost, as well as cost quite a bit.
3. central receiver system:  there are currently if i am not mistaken 2 such systems in the US, one in Draggett, California (called Solar One) and one in Albuqurque, New Mexico.  this system uses thousands of reflective mirrors called heliostats and heats a center tower about 200 feet high to 570^oC, generates about 10 megawatts, it has a storage tank and could generate electricity through out the day.

the system that you are looking for is the solar water heater, pictured below
generally you put the collector on your roof have a storage tank, if possible next to the collectors or you could add a pump that will send the warm water to the storage tank and the cold water to the solar collector.  This system is a bit expensive though, but its the one that is used to heat the water in a house.