Solar Concentrator
See http://heliosync.tumblr.com/ for more frequent updates.
A project to generate some non-trivial amount of electricity via solar energy in 3 parts.
- A solar concentrating "dish" to collect roughly 100 square feet of reflect light into 1 square or smaller area reaching temperatures of approximately 1,000F
- A working fluid and turbine to convert heat energy into rotary motion. Optionally this may include/necessitate some kind of heat storage to moderate peaks/valleys in sun fall and potentially provide night electricity.
- A generator to convert rotary motion into AC electricity. The goal would be to generate at a minimum 8 1KW hours per day.
- Implement the project in a way that it is economically sensible. In metro phoenix the real adjusted per KWH hour cost is $0.15 . Which mean this project on a budget of $500.00 would pay for itself in 1 year or $1000.00 in two years. Costs exclude labor.
- Implement the project in a way that is reproducible with the production of easy to follow online steps for other groups to implement with.
Project Tasks
- Confirm location with tentative heatsync member who has land near gangplank or find alternative location. Need 10H'x15L'x10W' space at a minimum. Must be able to poor concrete footing. Project is intended to be in operation for 3 months at a minimum.
- Create scale model of concentrator frame. Pictures of a complete frame that may be a good starting point are http://imgur.com/sWEAW.jpg and http://imgur.com/GxCOh.jpg. Define math to establish correct fastened offsets to construct square parabola from matrix frame.
- If final model is to use 10' 1/2" EMT conduit determine lengths needed. From picture estimate 46, which is cost of $1.70 * 46 = $80 with tax.
- Source low iron mirrored glass, we will need 10 1'x10' lengths.
- Build mounting/housing and drive gear/pulley for generator rotor and stator. Parts are being donated, approximate retail value $50.
- Determine input power/torque/speed needs for generator. Existing generator stator and rotor are 1KW. Potential upgrade would be http://www.harborfreight.com/10000-watts-max-7200-watts-rated-belt-driven-generator-head-45416.html which would more than pay for itself if sufficient power/torque. is available.
- Determine turbine design, configuration, linkage. Determine math to identify heat/efficiency requirements for 1KW generation. Determine if heat storage is feasible/possible. Determine working fluid, steam seems probable.
Local Solar Data
Solar Cell Data gathered over a 9 day period in Dec 2010 by Jasper Nance
Here is the data which I double checked with a good Candian friend who has lots of experience with solar applications.
We got 9 days worth of data (even got temperature data, it dipped to -0.8 degrees at one point. Brrr)
Wsun = Vsun.*Isun; %watts Psun = Wsun / 0.00387096; Pideal = Psun / .04; plot(Time, Pideal);
max(Pideal) = 645.9 Watts per square meter. This will be clipped slightly as the current did rail.
Paul gives us a sanity check (which is even closer when you realize that we railed a tiny bit on the current)
I just dug out said Handbook. Interpolating Table 3.2 on page 3-16 says that at a 56 degree zenith angle the solar irradiance is 697 W/m^2. Yeah, I'd say you nailed it. ( the raw data from that table I mention is from D.M. Gates, "Spectra Distribution of Solar Radiation at the Earth's Surface," Science V.151, pp523-529, published in 1966. )
Glass Supplier Search
Wright Brothers Glassworks - 623-780-4000 - has no suppliers that can offer below 1/8th thickness with low-iron glass
chandler glass - (480) 899-1656 - can only offer 1/8th and above, and not at 10 foot length
AZ glass - (602) 923-0079 - no answer, generic 'voicemail box full' message
The Glass Works - (602) 253-7683 - Answering machine
Southern glass works - emailed, awaiting response.
I can't find any local or online suppliers that offer low-iron/starphire mirrored glass at 3/32nd or below. If anyone else wants to try to find a supplier, this may be our main bottleneck.
We should also check the deflection of a 1/8th thickness glass to see if it might work instead.
