Photovoltaic panels

Since 1998, the California Energy Commission has been pushing a program to encourage homeowners to erect photovoltaic panels on their... 

The Sunmobile is charged solely with photovoltaic panels mounted as a roof canopy. It will travel at up to 30 mph with a range of up to 30 miles on a fully charged battery. A twist grip on the handlebars feeds information to a motor controller mounted under the chassis. 

Various combinations of applications, including different choices of photovoltaic panels and electrolysers were tested. The cumulative operating times logged for the various plant subsystems differed considerably according to the test programs run, ranging from 6000 h for the alkaline low-pressure electrolyser, to 2000 h for the membrane electrolyser, 5200 h for the catalytic heater, 3900 h for the PAFC fuel cell plant and 900 h for the LH2 filling station. 

The results of the Kythnos system economic analysis, presented in Table 5.2 are also of great interest for our study. According to the economic analysis, the main cost factor for such a hybrid system based on photovoltaic panels is the batteiy bank, followed by the diesel generating set and the PV array, since the lifetime of batteries is relatively limited (around 5 years), therefore the battery bank should be replaced several times during the project. Another important finding of the PV-diesel system economic analysis is high O M and fuel costs, which account for ca. 3616 /ycar. 

As for all case studies presented in this chapter, information on power component costs was drawn from RETScreen database (National Resources Canada, 1998). In more detail for photovoltaic panels a cost of 6750 /kW was used, resulting in a total acquisition cost of 67,500 . A capital cost of 450 /kW was used for the 35-kW diesel generator, which accounts in total for a cost of 15,750 . The total cost of the battery bank was considered equal to 17,600 . Finally, the total cost of the inverters installed in the system was 6700 . Lifetime, O M costs and power... 

A solar or photovoltaic panel is a solid-state power generation device which uses no fuel or water and produces no effluent. Electricity is produced when sunlight falls upon the devices or cells making up the panel. The sun s energy is absorbed and creates electrical charges, which are separated by the electric field in the device and flow externally as current. Commercially available photovoltaic panels convert between 5 and 15% of the sunlight to electricity. A square meter of photovoltaic panel will produce between 50 and 150 watts of power. A 1000-MW power generation facility would require an area of about 2 miles by 2 miles, which is comparable to the safety zone around a 1000-MW nuclear plant. 

A different approach is to reconsider the airship as a means of air travel. A first approach to this is considering an airship for high-altitude cruising (or as a stratospheric platform) powered by photovoltaic panels and using a reversible fuel cell system to store surplus solar power and use it when the sim is not visible. In this way, carrying possibly heavy batteries may be avoided. The envisaged relative shares of direct use of solar power, of elec-trolyser operation and of fuel cell power production are shown in Fig. 4.12. So far, testing of the equipment sketched in Fig. 4.12 has been performed on a 1-kW scale in the laboratory and in simulated airship conditions. 

This FloJet can be operated from a 12 volt battery which is charged by a photovoltaic panel, or some other source of DC (direct current) electricity. Since the pump is rated at 10 amps, the power supply must provide 12 volts with at least 10 amps. The operation of the pump is intermittent and only for very short periods of time. 

The gas output of the electrolyzer can be tested either with field tests or bench tests. Field and bench tests using a constant source of DC for the electrolyzer will give a fairly accurate picture of electrolyzer performance and efficiency. Field and bench tests that do not use a constant source of DC but rely on intermittent power supplies such as photovoltaic panels and wind turbines, etc., will give variable inputs depending on the intensity of the power source (for example, sunlight or wind), available. 

In a solar hydrogen system, the electrolyzer is the component which changes electrical energy from the photovoltaic panels into hydrogen gas. 

DC (direct current) electricity, which powers the electrolyzer, can come from a variety of renewable sources, such as wind generators, photovoltaic panels and small hydro and geothermal systems. Batteries are a common non-renewable source of DC current, as well as AC power supplies with rectifiers that change the AC to DC. 

The P41 consists of very few parts It is inexpensive to build, is suitably matched for renewable energy inputs from photovoltaic panels or wind generators, and it has a high volume of gas output for its size. 

In designing a power supply, consider the number of photovoltaic panels needed, as well as how many electrolyzers. Then, size the gas processing system and storage to provide the appropriate quantity and quality of gas for your fuel cells. 

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