5 p. / A description of the multiple hand tools commonly used to measure energy output of solar photovoltaic (PV) silicon-type modules. These tools include a digital multi-meter to measure voltage, a clamp-on ammeter to measure current, a pyranometer to measure solar irradience, an angle finder to measure module tilt angle, a non-contact thermometer to measure solar cell temperature, and a Solar Pathfinder to evaluate a potential site for shading issues.

A new instrument has been developed for making unimaged whole-disk observations of low-degree solar normal-mode oscillations. The apparatus, referred to as the sky monitor, does not track the solar disk, but instead measures the radiant flux scattered by the Earth's atmosphere at 1.6 and 0.5 μ. The expected diurnal flux variation was obtained from a detailed radiative transfer calculation. Data were acquired for 15.5 months during 1991-92. Seventy-two days of data were analyzed for evidence of solar p modes in the frequency range 1800-4776 μHz. Noise generated by the Earth's atmosphere was reduced by scaling the Fourier amplitude computed from the infrared signal and subtracting it from the Fourier amplitude computed from the visible signal. A superimposed frequency analysis was then performed which revealed ∼ 2 σ peaks within 0.3 μHz of symmetry-allowed locations, while no excess power was detected at the symmetry-forbidden frequencies. The probability of obtaining by chance the observed excess power density at symmetry-allowed frequencies and deficit of power density at symmetry-forbidden frequencies was computed to be 6.9 x 10⁻³. Correcting the frequencies for solar-cycle variations, the probability was reduced to 2.9 x 10⁻⁴. These results indicate that it is quite unlikely that the observed symmetry properties have occurred by chance, and support the hypothesis that solar normal-mode signals are manifested in the data. The amplitudes I'/Iₒ averaged over radial order n of the ℓ = 0 and ℓ = 2, m = 0 modes were found to be (7.54 ± 0.54) x 10⁻⁷ and (7.68 ± 0.56) x 10⁻⁷, respectively. These results are about a factor of two smaller than the amplitude of total irradiance oscillations measured from space. While the rotational splitting of the ℓ = 2 multiplet appears to be consistent with that reported by Hill (1985a), results for ℓ = 1 and ℓ = 3 are inconclusive.

Presented here is an analysis of some of the existing methods used for the determination of the series resistance of solar cells which is one of the key parameters in solar cell fabrication and technology together with the diode ideality factor and the reverse saturation current. These methods are based on the network analysis of the single-exponential lumped constant parameters model which has been accepted as being operationally sufficient to describe the current-voltage characteristics of the solar cell. The methods analyzed in this study are divided into two main groups. Methods using two I-V characteristics and methods using a single I-V output curve. For comparison purposes, all methods are applied first using data extracted from existing I-V curves and then using in-lab measurements of a commercial solar cell. It is demonstrated that the determination of the series resistance of solar cells using two I-V characteristics has several advantages over methods using a single I-V output curve. It becomes evident that methods which use a single I-V output curve are only accurate for cells operating under very high illumination conditions. At normal intensities, however, such methods result in erroneous R(s) values. This is due to the assumption of a constant diode ideality factor along the entire I-V output curve used in the derivation of these methods. It is shown that this assumption is inaccurate at normal intensity levels and can be appropriate only under very high illuminations. Three new methods are proposed in this study. One of the methods presents a new approach in determining the solar cell equation parameters. The new approach relies upon treating the diode ideality factor of the solar cell as a variable that is a function of both the terminal current and the light intensity level. The method uses two I-V output curves at different illumination levels in determining all solar cell parameters: The series resistance, the diode ideality factor and the reverse saturation current. Although somehow tedious, the new approach shows that, for accurate modeling of solar cells and prediction of illuminated characteristics at different light levels based on the single-exponential model, the diode ideality factor should be treated as a variable while the series resistance is held constant. Comparison between all methods is presented and a reasonable judgement and recommendations concerning the best method to be used are given.

Typescript (photocopy). / Digitized by Kansas Correctional Industries

Solar powered cars may never be practical. Nevertheless, in the 1996 World Solar Challenge the Honda Dream carried two people 3000km across Australia at an average speed of 90km/h, powered only by sunlight. You clearly don?t need a 2500kg machine powered by polluting fuels to get you to work and back each day. The Australian Aurora 101 solar powered car requires less than 2000W of power to travel at 100km/h. To achieve such high performance the car has high aerodynamic efficiency, motor efficiency greater than 98%, low rolling resistance tyres, and weighs less than 280kg with the driver in it. The energy used to propel the car is generated by high-efficiency photovoltaic cells Another key to achieving high performance is efficient energy management. The car has a small battery that can store enough energy to drive the car about 250km at 100km/h. Energy stored in the battery can be used when extra power is required for climbing hills or for driving under clouds. More importantly, energy stored while the car is not racing can be used to increase the average speed of the car. How should the battery be used? The motivation for this problem was to develop an energy management strategy for the Aurora solar racing team to use in the World Solar Challenge, a triennial race across Australia from Darwin to Adelaide. The real problem? with weather prediction, detailed models of the car and numerous race constraints?is intractable. But by studying several simplified problems it is possible to discover simple rules for an efficient energy management strategy. The simplest problem is to find a strategy that minimises the energy required to drive a car with a perfectly efficient battery and a constant drive efficiency. The optimal strategy is to drive at a constant speed. This is just the beginning of the solar car problem, however. More general problems, with more general models for the battery, drive system and solar power, can be formulated as optimal control problems, where the control is (usually) the flow of power from or to the battery. By forming a Hamiltonian function we can use Pontryagin?s Maximum Principle to derive necessary conditions for an optimal strategy. We then use these conditions to construct an optimal strategy. The strategies for the various simplified problems are similar: ? On a level road, with solar power a known function of time, and with a perfectly efficient drive system and battery, the optimal strategy has three driving modes: maximum power, speed holding, and maximum regenerative braking. ? If the perfectly efficient battery is replaced by a battery with constant energy efficiency then the single holding speed is replaced by two critical speeds. The lower speed is held when solar power is low, and the upper speed is held when solar power is high. The battery discharges at the lower speed and charges at the higher speed. The difference between the upper and lower critical speeds is about 10km/h. There are precise conditions for switching from one mode to another, but small switching errors do not have a significant effect on the journey. ? If we now change from a level road to an undulating road, the optimal strategy still has two critical speeds. With hills, however, the conditions for switching between driving modes are more complex. Steep gradients must be anticipated. For steep inclines the control should be switched to power before the incline so that speed increases before the incline and drops while the car is on the incline. Similarly, for steep declines the speed of the car should be allowed to drop before the decline and increase on the decline. ? With more realistic battery models the optimal control is continuous rather than discrete. The optimal strategy is found by following an optimal trajectory in the phase space of the state and adjoint equations. This optimal trajectory is very close to a critical point of the phase space for most of the journey. Speed increases slightly with solar power. As before, the optimal speed lies within a narrow range for most of the journey. ? Power losses in the drive system affect the initial power phase, the final regenerative braking phase, and the speed profile over hills. The optimal speed still lies within a narrow range for most of the journey. ? With spatial variations in solar power it is possible to vary the speed of the car in such a way that the extra energy collected more than compensates for the extra energy used. Speed should be increased under clouds, and decreased in bright sunlight. The benefits of ?sun-chasing? are small, however. ? Solar power is not known in advance. By modelling solar power as a Markov process we can use dynamic programming to determine the target distance for each remaining day of the race. Alternatively, we can calculate the probability of completing the race at any given speed. These principles of efficient control have been used successfully since 1993 to develop practical strategy calculations for the Aurora solar racing team, winner of the 1999 World Solar Challenge. / Thesis (PhD)--University of South Australia, 2000

Solar heating systems are a proven technology which can significantly reduce the amount of fossil fuel needed to meet the heating reuqirements of homes. The southern part of Australia represents the region which requires considerable heating and experiences significant levels of sunshine during the winter period. However existing solar heating systems are not a viable technology due to practical, aesthetic and cost factors. A novel concept for a solar heating system has therefore been proposed which attempts to address these factors.

Thesis (M.S.)--University of Toledo, 2009. / Typescript. "Submitted as partial fulfillment of the requirements for The Master of Science degree in Chemistry." "A thesis entitled"--at head of title. Bibliography: leaves 75-77.

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