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Instrumentation for the measurement of solar radiation—A survey of modern techniques and recent developments
Stanhill, G., "Solar Radiation
i n I s r a e l " , The Bulletin
of the Research Council of Israel, Vol. l l G , May
No.
l,
1962, 8 p., I l l u s .
The relationship between the a m o u n t of solar radiation measured at the e a r t h ' s surface 'rod the observed a m o u n t of cloud cover was i n v e s t i g a t e d using d a t a from three s t a t i o n s in Israel representing the main climatic regions. Mean m o n t h l y values of cloud cover observed at 45 s t a t i o n s in Israel were used to prepare maps showing the annual and m o n t h l ) ~ distrib u t i o n of solar radiation. D a t a on the year to year variance in the amounts to be expected are also p~resented. D r u m m o n d , A. J., T h e E p p l e y L a b o r a t o r y , I n c . N e w Port, Rhode Island, "Instrumentation for the Measu r e m e n t of S o l a r R a d i a t i o n A S u r v e y of M o d e r n Techniques and Recent Developments", United N a t i o n s C o n f e r e n c e o n N e w S o u r c e s of E n e r g y , R o m e , 1961, 13 p., I l l u s . A review is presented of the principal objectives of the m e a s u r e m e n t of the different components of solar radiation, particularly with regard to the applicability of the derived r a d i a t i o n d a t a in the several aspects of the utilization of solar energy. These radiation components of the t h e r m a l radiation balance at the ground are the direct solar contribution, the diffuse sky radiation, the reflected solar radiation and the longer wavelength t e m p e r a t u r e radiation which is exchanged within the terrestrial system. The major problems associated with the design of t h e r m a l radiation detectors for such purposes are discussed as are also the limiting factors, introduced by reasons of economy, which dictate i n s t r u m e n t a l performance.
XIV--C.eophysical and _~/[eteorological: Weather, Climate, Sundials, Telescopes, Magnetism, and Gravity S m i t h , H . J. a n d W . D . B o o t o n , " A S t u d y of S a c r a mento Peak Flares, IV Filament Disappearances, F l a r e S p r a y s , a n d L o o p l ) r o m i n e n c e s '', G e o p h y s i c s Research Directorate, Air Force Cambridge Research L a b o r a t o r i e s , Office of A e r o s p a c e R e s e a r c h , U S A F , B e d f o r d , M a s s . , O c t o b e r 1962, 60 p., I l l u s . Sacramento Peak flare fihns provide nearly complete, continuous observational d a t a for other forms of solar a c t i v i t y t h a n j u s t chromospheric flares. The character of the observations is optimum for flare detection and measurement, h u t for other phenomena the material is less satisfactory. The report t a b u l a t e s and gives det'dls of major occurrences in recent years of three types of events: ('~) sudden disappearances; (b) flare sprays; (c) coronal loops. Athay, R. Grant and G. E. Moreton, "Impulsive P h e n o m e n a of t h e S o l a r A t m o s p h e r e . I. S o m e O p t i c a l Events Associated with Flares Showing Explosive Phase." The Astrophysical Journal. 1 3 3 ( e ) : 9 3 5 945. M a y 1961. Illus. A new class of optical phenomen'~ of the solar atmosphere associated with flares is described. These phenomena are characterized hy higher velocities ( = 1500 km per sec) and shorter time sc'des t h a n has been indicated by previous ob-
84
servations. An explanation of some of tile observed p h e n o m e n a is offered in terms of corpuscular streams ejected from flares at the time of an "explosive p h a s e " occurring during the rise to maximum brightness.
XVIII--Energy Storage Goldstein, Martin, "Some Physical Chemical Aspects of H e a t S t o r a g e " , U n i t e d N a t i o n a l C o n f e r e n c e o n N e w S o u r c e s of E n e r g y , R o m e , 1961, 17 p. No pure s u b s t a n c e among those considered for storing heat by melting has a storage capacity in excess of 100 Kcal per liter. There appear to be m a n y such whose capacities lie between 75 to 100 Kcal per liter. The heats of transitions of hydrates also lie in this range. A few solid-solid transitions out of a very large nulnher examined h,~d storage capacities comparahle to heats of fusion: the highest found was 75 Kcal per liter (KHF.., at 196 degrees C). Heats of solution of salts forming highly non-ideal solutions did not, on the basis of a calculation on only one salt, but t h a t a very promising one, show much enlmncement of storage cap'~city over systems using sensible heat. Some concentrated, highly nonideal aqueous solutions considered gave storage capacities as high as 200 Kcal per liter and the decomposition of solid h y d r a t e s g~ve capacities up to 500 Kcal per liter. A d i s a d v a n t a g e however is t h a t the storage system requires two chambers instead of a simple insulated t a n k , and the performance of the system is influenced by changes in a m b i e n t t e m p e r a t u r e . In addition to f u r t h e r t h e r m o d y n a m i c d a t a required to evaluate more precisely the storage capacities, d a t a is needed on the kinetics of the chemical or physic'd processes occurring to ascertain if the r'~te at which they will store or deliver t h e i r energy is comparable to the rate required by practical considerations. Equally i m p o r t a n t are the economic and engineering considerations t h a t were either passed over so lightly in this paper, or ignored entirely. B a c o n , F. T . , N a t i o n a l D e v e l o p m e n t Corporation, United Kingdom, "Energy Storage Based on Eleetrolysers and Hydrogen/Oxygen Fuel Cells", United N a t i o n s C o n f e r e n e e o n N e w S o u r ( ' e s of E n e r g y , R o m e , M a y 6, 1961, 12 p. It is suggested in the paper t h a t the utility of this method of energy storage will be largely determined by the overall capital cost, and also to a secondary extent by the energy efficiency achieved. Up till the present time, it has not been possible to combine the functions of electrolyser and current generating cell in one apparatus, so separate units must be allowed for. For nfinimuin costs it would seem essential to ctloose the new type of medium pressure electrolyser now being made in G e r m a n y ; this operates at a pressure of about 30 atmospheres (440 psi), and a voltage per cell of about 1.72 to 1.76 at a reasonable current density. A n u m b e r of different methods of gas storage are suggested, and these are outlined in the Tat)le. As regards the types of fuel cell which could be used, it is t e n t a t i v e l y concluded t h a t either the atmospheric pressure type, working up to 70 degrees C could be used, a good example being the Union Carbide cell; or a l t e r n a t i v e l y the medium pressure type with which the a u t h o r has been associated. As regards capital cost, assuming an A.C. network, and a fuel cell of 100 kw. output, a rough estilnate indicates this migtlt a m o u n t to £116 per kw, exclusive of such items as transport, buildings and erection; this assulnes the use of a medium pressure electrolyser, gas ciunpressi)rs and medium pressure fuel cell of the strum power as the electrolyser. It is difficult to visualize a commercial unit with 'm o u t p u t less t h a n 'd)()ut 10 kw, and the capital cost per kw might he excessive even for "~ unit of this size; capital cos|s would certainly fall with "m increase in size.
Solar Energy
i n I s r a e l " , The Bulletin
of the Research Council of Israel, Vol. l l G , May
No.
l,
1962, 8 p., I l l u s .
The relationship between the a m o u n t of solar radiation measured at the e a r t h ' s surface 'rod the observed a m o u n t of cloud cover was i n v e s t i g a t e d using d a t a from three s t a t i o n s in Israel representing the main climatic regions. Mean m o n t h l y values of cloud cover observed at 45 s t a t i o n s in Israel were used to prepare maps showing the annual and m o n t h l ) ~ distrib u t i o n of solar radiation. D a t a on the year to year variance in the amounts to be expected are also p~resented. D r u m m o n d , A. J., T h e E p p l e y L a b o r a t o r y , I n c . N e w Port, Rhode Island, "Instrumentation for the Measu r e m e n t of S o l a r R a d i a t i o n A S u r v e y of M o d e r n Techniques and Recent Developments", United N a t i o n s C o n f e r e n c e o n N e w S o u r c e s of E n e r g y , R o m e , 1961, 13 p., I l l u s . A review is presented of the principal objectives of the m e a s u r e m e n t of the different components of solar radiation, particularly with regard to the applicability of the derived r a d i a t i o n d a t a in the several aspects of the utilization of solar energy. These radiation components of the t h e r m a l radiation balance at the ground are the direct solar contribution, the diffuse sky radiation, the reflected solar radiation and the longer wavelength t e m p e r a t u r e radiation which is exchanged within the terrestrial system. The major problems associated with the design of t h e r m a l radiation detectors for such purposes are discussed as are also the limiting factors, introduced by reasons of economy, which dictate i n s t r u m e n t a l performance.
XIV--C.eophysical and _~/[eteorological: Weather, Climate, Sundials, Telescopes, Magnetism, and Gravity S m i t h , H . J. a n d W . D . B o o t o n , " A S t u d y of S a c r a mento Peak Flares, IV Filament Disappearances, F l a r e S p r a y s , a n d L o o p l ) r o m i n e n c e s '', G e o p h y s i c s Research Directorate, Air Force Cambridge Research L a b o r a t o r i e s , Office of A e r o s p a c e R e s e a r c h , U S A F , B e d f o r d , M a s s . , O c t o b e r 1962, 60 p., I l l u s . Sacramento Peak flare fihns provide nearly complete, continuous observational d a t a for other forms of solar a c t i v i t y t h a n j u s t chromospheric flares. The character of the observations is optimum for flare detection and measurement, h u t for other phenomena the material is less satisfactory. The report t a b u l a t e s and gives det'dls of major occurrences in recent years of three types of events: ('~) sudden disappearances; (b) flare sprays; (c) coronal loops. Athay, R. Grant and G. E. Moreton, "Impulsive P h e n o m e n a of t h e S o l a r A t m o s p h e r e . I. S o m e O p t i c a l Events Associated with Flares Showing Explosive Phase." The Astrophysical Journal. 1 3 3 ( e ) : 9 3 5 945. M a y 1961. Illus. A new class of optical phenomen'~ of the solar atmosphere associated with flares is described. These phenomena are characterized hy higher velocities ( = 1500 km per sec) and shorter time sc'des t h a n has been indicated by previous ob-
84
servations. An explanation of some of tile observed p h e n o m e n a is offered in terms of corpuscular streams ejected from flares at the time of an "explosive p h a s e " occurring during the rise to maximum brightness.
XVIII--Energy Storage Goldstein, Martin, "Some Physical Chemical Aspects of H e a t S t o r a g e " , U n i t e d N a t i o n a l C o n f e r e n c e o n N e w S o u r c e s of E n e r g y , R o m e , 1961, 17 p. No pure s u b s t a n c e among those considered for storing heat by melting has a storage capacity in excess of 100 Kcal per liter. There appear to be m a n y such whose capacities lie between 75 to 100 Kcal per liter. The heats of transitions of hydrates also lie in this range. A few solid-solid transitions out of a very large nulnher examined h,~d storage capacities comparahle to heats of fusion: the highest found was 75 Kcal per liter (KHF.., at 196 degrees C). Heats of solution of salts forming highly non-ideal solutions did not, on the basis of a calculation on only one salt, but t h a t a very promising one, show much enlmncement of storage cap'~city over systems using sensible heat. Some concentrated, highly nonideal aqueous solutions considered gave storage capacities as high as 200 Kcal per liter and the decomposition of solid h y d r a t e s g~ve capacities up to 500 Kcal per liter. A d i s a d v a n t a g e however is t h a t the storage system requires two chambers instead of a simple insulated t a n k , and the performance of the system is influenced by changes in a m b i e n t t e m p e r a t u r e . In addition to f u r t h e r t h e r m o d y n a m i c d a t a required to evaluate more precisely the storage capacities, d a t a is needed on the kinetics of the chemical or physic'd processes occurring to ascertain if the r'~te at which they will store or deliver t h e i r energy is comparable to the rate required by practical considerations. Equally i m p o r t a n t are the economic and engineering considerations t h a t were either passed over so lightly in this paper, or ignored entirely. B a c o n , F. T . , N a t i o n a l D e v e l o p m e n t Corporation, United Kingdom, "Energy Storage Based on Eleetrolysers and Hydrogen/Oxygen Fuel Cells", United N a t i o n s C o n f e r e n e e o n N e w S o u r ( ' e s of E n e r g y , R o m e , M a y 6, 1961, 12 p. It is suggested in the paper t h a t the utility of this method of energy storage will be largely determined by the overall capital cost, and also to a secondary extent by the energy efficiency achieved. Up till the present time, it has not been possible to combine the functions of electrolyser and current generating cell in one apparatus, so separate units must be allowed for. For nfinimuin costs it would seem essential to ctloose the new type of medium pressure electrolyser now being made in G e r m a n y ; this operates at a pressure of about 30 atmospheres (440 psi), and a voltage per cell of about 1.72 to 1.76 at a reasonable current density. A n u m b e r of different methods of gas storage are suggested, and these are outlined in the Tat)le. As regards the types of fuel cell which could be used, it is t e n t a t i v e l y concluded t h a t either the atmospheric pressure type, working up to 70 degrees C could be used, a good example being the Union Carbide cell; or a l t e r n a t i v e l y the medium pressure type with which the a u t h o r has been associated. As regards capital cost, assuming an A.C. network, and a fuel cell of 100 kw. output, a rough estilnate indicates this migtlt a m o u n t to £116 per kw, exclusive of such items as transport, buildings and erection; this assulnes the use of a medium pressure electrolyser, gas ciunpressi)rs and medium pressure fuel cell of the strum power as the electrolyser. It is difficult to visualize a commercial unit with 'm o u t p u t less t h a n 'd)()ut 10 kw, and the capital cost per kw might he excessive even for "~ unit of this size; capital cos|s would certainly fall with "m increase in size.
Solar Energy