Spherical solar collectors, arranged for high temperature heat gathering, could supply the United States with its entire current energy consumption: The arrangement uses steam lines (or oil) to supply steam (600C plus) to turbines for day demand. Excess heat and electricity production can be sent to air fuel synthesis or compressed air storage (for night-time demand):
This type of facility is exceptionally effective from a land use perspective because the fixed mirror sets can be laid out in rows: Shadow-fall problems experienced in traditional arrays do not occur. The process is also very economic because the foundations are small, the mirrors are inexpensive flat plates which are simple to focus and the steel support structure is light (being a curve; almost a catenary).
Multi Unit Array example:
The Google Earth multi unit model (which can be downloaded below) shows a small part of one array bank configured to supply the USA or latitudes close to 30 degrees: To allow the model to be downloaded easily, the model has been reduced to three array lines, only simple boilers shown and curved support steelwork has been omitted.
This type of facility is exceptionally effective from a land use perspective because the fixed mirror sets can be laid out in rows: Shadow-fall problems experienced in traditional arrays do not occur. The process is also very economic because the foundations are small, the mirrors are inexpensive flat plates which are simple to focus and the steel support structure is light (being a curve; almost a catenary).
Multi Unit Array example:
The Google Earth multi unit model (which can be downloaded below) shows a small part of one array bank configured to supply the USA or latitudes close to 30 degrees: To allow the model to be downloaded easily, the model has been reduced to three array lines, only simple boilers shown and curved support steelwork has been omitted.
Image generated from Google Earth Model
Notes on downloading:
Note that this download is over 5 megabytes: Google Earth will load it and take you to empty desert. It may take up to 60 seconds to generate the array bank (which can then be 'walked through' using GE)
Single row multi unit line for Google Earth (smaller file size if above does not load)
Advantages:
- High land use efficiency;
- Low cost due to the fixed plate mirrors;
- Simple focus arrangement;
- Minimum moving parts;
- Low cost support structure;
- Minimum foundation requirements;
- Partially self-cleaning;
- Low maintenance.
Image generated from reduced GE model
Each
spherical dish segment (approx 30 metres diameter) is arranged with a receptor
pole rotating about a polar axis (pointed to the North Pole) and capable
of seasonal range movement of +/- 24 degrees relative to the polar axis
using cable stays. Arrangement shows a 'normal' spherical line receptor
for simplicity (similar to Auroville): This is not optimum for high temperature collection but allows the CAD file size to be kept small for indicative purposes.
Detail
A single unit, market up with text showing components, can be downloaded below:
Download single unit array for Google Earth here
Detail
A single unit, market up with text showing components, can be downloaded below:
Image generated from single unit model
Download single unit array for Google Earth here
Video 1: Theory
The mirror plates are fixed and do not have to be particularly good. Almost any polished metal will work:
Theory of the system (produced using CAD)
Video 2: A trial prototype reflector turning around the hinge
The video below shows a time-lapse as seen from behind the mirrors. This video shows the set-up arranged with a reflective surface rather than a collector.
Spherically arranged mirrors focusing light to a collector moving in a circle.
