Showing papers in "Solar Energy in 1984"

TL;DR: In this article, a spectral model for cloudless days that uses simple mathematical expressions and tabulated look-up tables to generate direct-normal and diffuse horizontal irradiance is presented.

TL;DR: In this paper, a new algorithm has been developed for calculating the thermal radiant temperature of the sky based on a simple empirical and theoretical model of clouds, together with a correlation between clear sky emissivity and the surface dewpoint temperature.

TL;DR: Using a maximum-likelihood quadratic fit, the authors showed that monthly averages and its standard deviation σ s S can be used to estimate the monthly average of H H 0, the ratio of total horizontal radiation to that outside the atmosphere.

TL;DR: In this article, the authors presented additional data and the corresponding improved formula for the sky emissivity and presented measured data from three U.S. cities in the form of a correlation of sky emissonivity versus surface dewpoint temperature.

TL;DR: In this article, the authors present thermodynamic and physical property data equations for the NH 3 −LiNO 3 and NH 3 -NaSCNSCN absorption refrigeration systems.

TL;DR: In this article, an accurate 200 W/m2 threshold pyreheliometer instrument for measuring the duration of bright sunshine has been used to derive daily and monthly regressions for direct, diffuse, and global solar radiation component vs sunshine duration.

TL;DR: In this article, the authors compare statistically correlations for estimating the monthly average daily global/diffuse radiation incident on a horizontal surface and to recommend one in each catagory that best fits measured data from a number of locations chosen and is the simplest to use.

TL;DR: In this paper, two chlorinated hydrocarbons (trichloroethylene and chloroform) in dilute aqueous solution (50 ppm) were catalytically degraded to HCl and CO2 in the presence of solar-illuminated undoped n-type titanium dioxide (anatase) (band gap = 3.0 eV ≈ 350 nm).

TL;DR: In this paper, an inexpensive pyrradiometer, made for that purpose, is described, and an analysis of five years of observations with the Carpentras pyrrradiometers (National Meteorology) lead to a formulation for Tc which points out the influence of the boundary layer.

TL;DR: In this paper, the authors used the Laplacian smoothing splines with generalized cross validation to estimate the mean values of total daily solar radiation at any point on the continent with a root mean square predictive error of no more than 1.

TL;DR: In this paper, the authors developed a sufficiently good fit for the measured I-V curve of a PV module and array using only three easily measurable parameters: the open-circuit voltage (Voc), the short-Circuit current (Isc), and the maximum power (Pm).

TL;DR: In this paper, a simplified method for the optimal sizing of a photovoltaic system is presented for Italian meteorological data, but the methodology can be applied to any geographical area.

TL;DR: In this article, a direct expansion solar assisted heat pump, in which a bare flat plate collector also acts as the evaporator for the refrigerant, Freon-12, is designed and operated.

TL;DR: In this paper, a direct coupling between a photovoltaic (PV) solar panel and a water pumping system driven by a permanent magnet dc motor is analyzed theoretically based on the simulated performance of a pumping system which consists of a Jacuzzi general purpose pump and a DC motor with selected characteristics.

TL;DR: The optical properties of metal coated glass substrates have been investigated in this paper, where the front and backside reflectance and the transmittance between 0.35 and 15 μ m were measured.

TL;DR: In this article, the authors describe a new model and a new generator of hourly wind speeds which were obtained using the Box-Jenkins method, and all the steps leading to the determination of an autoregressive model are described.

TL;DR: In this paper, a method is presented for predicting the long-term average performance of photovoltaic systems having storage batteries and subject to any diurnal load profile, where the monthly average fraction of the load met by the system is estimated from array parameters and monthly-average meteorological data.

TL;DR: In this article, a multiband model, taking into consideration the effect of fine particle suspension in a continuous fluid on radiation and absorption characteristics, was formulated to analyze the unsteady one-dimensional heat transfer in a horizontal FPSS layer heated by thermal radiation.

TL;DR: In this article, the authors consider the thermal flywheel effect in adobe buildings and design a non-homogeneous wall to optimize this effect and show that the room temperature is kept approximately constant.

TL;DR: In this paper, ground heat losses from solar ponds are modelled numerically for various perimeter insulation strategies and several solar pond sizes, and the numerical results are used to derive coefficients for a semi-empirical equation describing ground heat loss as a function of pond area, pond perimeter and insulation strategy.

TL;DR: In this paper, the authors compared the performance of a domestic hot water system employing evacuated tubular collectors with two others employing flat plate collectors over a period of one year and found that the efficiency of the evacuated system was about 1.8 times that of a non-selective flat plate system and about 3.3 times higher than a high quality selective flat plate collector.

TL;DR: In this article, a dip-coating process using an ethanol-based colloidal silical sol is described for the deposition of antireflection coatings onto collector cover plates.

TL;DR: In this paper, the authors describe a reliable and low-cost sun tracker that is built with a two axis universal mount and controlled by a classical electronic system, which can be used for photometric measurement as well as for small or medium photovoltaic plants using flat collectors or concentrated sun light systems.

TL;DR: In this article, the spectral and angular sky emissivities are estimated from a knowledge of the total sky emissonivities, using an empirical "sky emissivity" equation, and the results are of particular relevance to the performance of radiative cooling systems designed to make use of spectral or angular selectivity.

TL;DR: In this article, a CaCl2·6H2O composition with a slight excess of water was found very stable on repeated phase change (over 1000 cycles) in a heat cycle test (35 ∼ 18°C), using vertical glass tubes of 950 mm height.

TL;DR: Based on existing evidence of mesoscale variability in solar radiation at the earth's surface the conclusion is reached that significant variability does occur at this spatial scale but that full evaluation is hampered by the lack of long term observations.

TL;DR: Sun position sensing is successfully performed using phototransistors mounted in a simple structure using a small panel of solar cells with a rechargeable battery as a back-up and night time supply.

TL;DR: In this article, the authors investigated the decreasing heat storage capacity of CH/sub 3/CO/sub 2/Na during thermal cycling, and performed calorimetric measurements on three kinds of samples.

TL;DR: In this paper, atmospheric water vapour content or specific humidity was used along with sunshine duration to obtain a relation to estimate the global irradiation G using data for stations near sea level only of north and central India.