Expanded Polystyrene (EPS) concrete forms: In the mid 1970s I debugged boiler problems in a factory that made the Styrofoam "logs" that were ~4 ft wide by about a foot thick and 16 ft long that weighed about 65 pounds. Easy to set on end to cure before hot-wire cutting into panels, planks, or blocks etc.
http://www.benchmarkfoam.com/benchmark/poly/default.asp http://www.benchmarkfoam.com/benchmark/products/cforming.asp Bubble- Wrap runs about $0.07 per square foot in rolls up to 4 feet wide by 250 feet long. http://www.packagingprice.com/forms/product_listing.cfm?CategoryID=10108&CFID=421578&CFTOKEN=76025033 Fred A solar-thermal collector using a heat engine for power generation offers many advantages over photovoltaic collectors. They can be built "from the ground up" by the "do-it-yourselfer" using precast concrete storage tanks (such as precast septic tanks) for water-heat storage allowing use of "heat depleted" water for comfort heating and act as a support for the solar collector. Styrofoam (polystyrene) blocks or boards can be used for insulation, and forms for monolithic pour concrete, where the Styrofoam forms can be dissolved out of a poured tank using acetone or gasoline etc. Dirt can be used for added support against wind, and protection of the foam insulation. Bubble-Wrap used for "thermopane" over blackened metal roofing sheets can achieve temperatures of 140 F (600 Rankine) or more. Low power water-circulating pumps and PVC plumbing allows long lasting system reliability. Even with a 2% overall power generation efficiency the cost per Kilowatt-hour is attractive even with ready-mix concrete costing $100.00 per cubic yard. delivered. Fred
