solar heat to electric

[nickle989]

I would have to completely disagree with only a 9% conversion ... that crap is for accademics caught in books and the four walled institutes .. no offence.  But lets just take 9% .. it is still a fraction of the cost to use solar heat conversion then it is to buy the PV panels from the thieves.

For the last few months I have been converting to solar heating.  It has taken some time as the off the shelf products do not transfer heat very well.  I live in central Canada.  On a -25 celcius day I have 234 celcius on the inside of the evacuated heat tube and 134 celcius on the heat exchanger exposed to the -25 degrees.  It takes under 2 minutes from a dead start exposure to reach over 100 degrees.Depending on the load that I put on I can raise or lower the heat exchanger.  A 1200 gallon water tank will be acting as a thermal mass.

I have University prof's come down and see and they can't believe what I am doing!  I will post some pics and videos much later as I need to finish my stirling engine.

I will be using a stirling engine to convert excess heat to electricity.  However it will be a sealed unit.  The sun has around 1300 plus watts per square meter.  In a sealed stirling unit one can use various gases that will get you a much higher rate of energy transfer.

Here is an older pic from an unrefined exchanger.

[jadaro2600]

The sun is good for heat - very good, and one of the primary uses of electricity in a home is the hot water heater.  Supplementing a good home with a solar heat exchanger can be effective at lowering the cost / or should I say / decreasing the net use of electricity.

A solar heat exchanger with a solar powered pump may be the first step in switching to solar.  As far as powering your air conditioner though - it's going to require some serious wattage.

[nickle989]

I would not say serious wattage ... an average central air uses around 4800 watts ... what is needed though is a good way to transfer the suns energy to electricity.

[Mark69]

@nickle,

I look forward to reading your posts on your home setup.  It would be great as well when you have it all running if you could make instructions on how we can duplicate your setup.  It is amazing you get such heat differences when starting at -25C!

Mark

[buzneg]

wow after reading some stuff I guess 10% is a reasonable number for solar thermal efficiency. The problem is light diffusion even on a clear day is 10%. Consentraitors can't make use of diffused light reflecting off the coulds where PV can. Also I read the heat collector diffuses IR 8%, and the black is 94% absorbive. When you add all this up, plus the few percent lost in the mirror it comes down to about 10%, but maybe 15%. Assuming the turbine is 50% efficient. Though, that being said solar thermal is still way cheaper then regular PV, and cheaper then wind, infact it's still near coal's build cost. The industry is saying Solar thermal is $3000 per kW capacity, but I would guess that they  averagly run at 10%-30% capacity??? Anyways with my figures it's still much cheaper then this, they use expensive mirrors or lenses, and it's still a new technology.

http://www.theoildrum.com/node/3791