Well its forty below and we don't give a #@%### , if you are from Western Canada you will know the song.

But amazing as it seems the sun has lots of potential energy same just not alot of hours of sunshine..

For you engineering types

Project Objectives

This project set out to determine if the panels could produce heat in cold climates and if so, how much? The project also attempted to develop a heating system for a building that could be totally solar powered and be independent of grid power.

The technical uncertainties were as follows:

• Will the panel produce any net heat in a climate where the temperature can drop to -40º C
• Which operating fluid is most suitable to use in sub-zero temperatures
• Will the panel act in a negative fashion to refrigerate on clear nights
• Can a system be devised that would not require any connection to a power grid

Background work completed

The operating fluid must be able to tolerate sub-zero temperatures without freezing. Windshield washer fluid, RV antifreeze and ethylene glycol are possible candidates. However since RV antifreeze and windshield washer fluids contain ethanol which presents a fire hazard, ethylene glycol was chosen in spite of its relatively high cost.

The system was set up with the panel facing due south and tilted at an angle of 45 degrees. See figure 2.

Note the snow and ice on the above picture. At the time of this photo, the outdoor temperature was -15º C and the fluid supply temperature was 40º C.

The fluid was pumped indoors to the fan coil unit. See Figure 3.

Fig.3

Technical Problems Resolved

The research showed that these panels will work in northern climates. The system was operated over a one month period in February and March when temperatures were at times lower than -20º C. Figure 4 shows typical results from March 21, 2007.

A number of conclusions can be reached from this research:

• The panel will produce heat in cold climates
• The heat output is fairly independent of the solar angle during the day
• The heat output is fairly independent of ambient temperature
• Using a 12 volt automotive battery and solar panel this system can operate in remote areas where no power is available.
• While the fluid in the panel can cool below ambient temperature at night due to radiation into outer space, it does not pose a problem since the cold high density fluid simply stays in the tubes until re-heated after sunrise.
• The panel captures at least 80% of the total solar energy

Figure 4- Solar heat as a function of time.