July 12, 2001
This web site discloses new solar technologies which should be freely exploited by international corporations for community scale energy systems. We believe that these technologies are in the public domain outside the USA.
Our objectives include the international commercialization of solar technologies which are less expensive than burning coal.
Significant capital and time have been expended on basic research leading to fundamental developments that may become mainstream features of future energy systems. Some of these developments involve hot water district heating systems with seasonal heat storage, solar dish concentrators, and advanced high-intensity photovoltaic cells. This web page is only an introduction. These technologies require additional management and engineering prior to deployment.
Whole cities have been made self-sufficient for heat and hot water via district heating and seasonal heat storage. District heating systems in Northern Europe, especially Sweden, supply community base and peak loads, day and night, summer and winter, without backup systems. Seasonal heat storage systems are made with small diameter plastic pipe loops punched 30 meters deep into the ground every two meters over an area less than an acre. The surface of the ground remains largely undisturbed and available for other applications. Hot water is collected in the summer and circulated through the pipes. The heat of the water is transferred through the pipe walls and stored deep in the ground. More than 80% of the heat collected in the summer is recovered in the winter and distributed to thousands of homes. Larger systems are more efficient. District heating and seasonal heat storage systems have lifetimes of at least 60 years. Scandinavian distribution systems of concentric plastic pipes separated by hard plastic foam are expected to last much longer than 120 years.
The most efficient solar collector is the dual-axis tracking hot water solar dish. This type collector uses approximately the same materials as other active solar collectors yet supplies more energy and is therefore more cost effective. Each square meter of dish aperture is worth about one barrel of burned oil per year in sunny climates and one-half barrel per year in average cloudy climates. Materials should cost less than $70 per square meter. Glass dishes have lifetimes of about 25 years and can be retrofitted or recycled for additional lifetime values. Our uniform matrix dish frame is assembled from identical copies of just three tube parts. Flat glass mirrors are flexed onto the frame forming near perfect parabolic curves for concentrating high-intensity uniform solar flux greater than 1000 suns. Post construction adjustments are not possible and quality assurance is not required.
The third main component is the power converter. Solar cells used in outer space to power satellites are the most efficient solar power generators available on Earth. These space cells are very rugged and reliable. Affixing high-intensity photovoltaic space cells in the flux of a 1000 sun solar dish concentrator produces 1000 times the power from the cells, thereby reducing the apparent cost of the high-performance space cells by a factor of 1000. This results in high-efficiency solar power at one-half the cost of coal power.
For example, a 10 square meter 1000 sun $700 solar dish would collect 7700 thermal watts of hot water with a 100 square centimeter (cm2) receiver at the focus, $0.09 per watt(t). Add 30% efficient space cells costing $10 per cm2, $1000 for 100 cm2, to produce 2400 watts of electricity. Total system cost is $1700 for 2400 watts electricity, $0.71 per watt(e), plus 3000 watts(t) of free hot water. Less expensive less efficient high-intensity photovoltaic cells are also available. Add 20% efficient space cells costing $3 per cm2, $300 for 100 cm2, to produce 1600 watts electricity, plus more hot water, for a system cost of $1000, $0.63 per watt(e). By way of comparison, a new coal power plant would cost $2.00 per watt(e) to build.
All of the materials are manufactured and can be assembled into large aggregate energy systems with existing labor and tooling. Time and capital requirements for 1000 megawatts of solar power would be similar to that required for a large conventional coal power plant. However, multi-billion dollar capital exposure is not required for a solar power plant. The risks can be managed in smaller increments.
Thank you for your time,
Doug Wood
fox@harbornet.com
The following links are documents describing subsystems under development, design programs, photos, CAD files, calculators, and comments.
1760 KB New Concepts for High-Intensity PV Modules for Use with Dish Concentrator Systems
5 KB Solar Dish Concentrator Materials
The following link is a good source for calculating the solar resource for a mix of fixed and tracking solar collectors. Solar Data
July 12, 2001