Will,
I too have been experimenting and trying to get all my energy from renewables. First was to have a structure that needed a minimum of energy. I have a simple structure with 12" thick walls filled with fiberglass insulation.
I use no power for heating or A/C.As long as there is light outside it is enough to serve my needs inside ... the roof has clear sections insulated with bubble wrap.
But my experience with solar panels show them to be an abject failure.
- Cost is high. My 165W high voltage panel cost over 0
- My 165W panel has never delivered more than 90W
- The panel can only supply current about 5 hrs per day
- The panel only supply useful power on sunny days
- The panel loses lots of efficiency on hot days
- Any shadow on the panel is the same as complete panel in shade
- Can lose 30% or more if panel is not perpendicular to sun's rays
- Charge controller must be very efficient or more is lost
- For anything practical a huge number of panels and batteries is necessary
The solution I have arrived at is hybrid. I use my one panel to charge batteries when I'm away. When away, my refrigerator is my only load (about 120W with 30% duty cycle). My battery bank is 10 70AH car batteries. All together they cost about as much as my 1 PV panel. I don't use deep discharge because they are much more expensive and I haven't seen an inverter that works below 10V. Most shut down at 11.5V.
My real power source is a 3hp diesel engine driving a car alternator capable of delivering 40A. I run it on waste vegatable oil (WVO) at low RPM (~1,000). I route it through the same high voltage (up to 53VDC) charge controller that I use with the PV panel. It does a splendid job of keeping the batteries charged and only runs 4 to 5 hours per day. It uses hopper cooling so I get my hot water from it as well.
The batteries have enough charge to get me through the night with no other power source. I use small fluorescent lights and all that is usually running is my refrigerator. I use less than 50AH over night and the diesel recovers that in the morning in less than 2 hours.
My average daily consumption is about 1.2KWH.
Regards,
Todd Marshall Plantersville, TX
Will wrote: