Anand S. Joshi

Solar Hydrogen Production

The common methods of hydrogen production impose many concerns regarding the decline in fossil fuel resources, CO2 emission, and ecological impacts. Subsequently, all the downstream industries that consume hydrogen involve the aforementioned drawbacks and risks. Therefore, H2 production technologies with almost zero greenhouse gas emissions are the ideal candidates to address the hydrogen supply issue. In one approach, biomass gasification can be utilized to release hydrogen and carbon monoxide. Considering the CO2 adsorption characteristics during the photosynthesis process, this method is basically carbon neutral. Alternatively, water electrolysis using renewable power sources such as geothermal, wind, and solar cells can be utilized.

Hydrogen Production Methods

As hydrogen appears to be a potential solution for a carbon-free society, its production plays a critical role in showing how well it fulfills the criteria of being environmentally benign and sustainable. Of course, hydrogen can be produced from a number of sources, such as water, hydrocarbon fuels, biomass, hydrogen sulfide, boron hydrides, and chemical elements with hydrogen. Because hydrogen is not available anywhere as a separate element, it needs to be separated from the aforementioned sources, for which energy is necessary to do this disassociation. The forms of energy that can drive a hydrogen production process can be classified in four categories: thermal, electrical, photonic, and biochemical energy. These kinds of energy can be obtained from primary energy (fossil, nuclear, and renewable) or from recovered energy through various paths. The literature is quite large and covers many options.

Role of Renewable Energy in Sustainable Development

The conversion of energy is directly related to the pollution in terms of greenhouse gas emission caused by the power plants. The major greenhouse gases like carbon dioxide and carbon monoxide are causing global warming to the environment and hence there is a need to find out alternatives to produce energy in an environmentally benign way. The photovoltaic technology, amongst the others, is one that can be a novel alternative to this problem.

Solar exergy maps for photovoltaic/thermal systems

In this paper, the thermal and electrical exergies and the exergy destructions are calculated for a photovoltaic thermal (PV/T) system based on solar exergy rates for some Indian climates namely Bangalore, Jodhpur, Mumbai, New Delhi and Srinagar for a year and for different US climates namely Chicago, Las Vegas, Miami, New York, Portland, San Antonio, San Francisco, Tucson and Tulsa for January, April, June and October. Maps for exergy destruction and thermal exergy of solar radiations are also developed. It is observed that the average thermal exergy is highest in Bangalore from January (146.1 W) to April (241.5 W) and September (237.6 W) to December (233.3 W) and it is highest in Srinagar from May (177.5 W) to August (126 W) for Indian climates, and for USA, the thermal exergy in Las Vegas (226.4–233 W) and Tucson (238–218.2 W) are higher in April and June. The energy efficiency is also calculated and compared with the experimental exergy efficiency for New Delhi.

Thermodynamic Performance of a Photovoltaic System

In this paper, an attempt is made to investigate the thermodynamic characteristics of a photovoltaic (PV) system based on exergy. A new efficiency is developed that is useful in studying the PV performance and possible improvements. Exergy analysis is applied to a PV system and its components, in order to evaluate the effect of various parameters e.g., voltage, current, area of the PV panel, fill factor and ambient temperature on exergy efficiency. Effect of solar radiation on power conversion efficiency is also evaluated.Copyright

Solar Energy Aspects

To utilize solar energy, the solar irradiance of the place where it is being used should be known, including the type of day and the number of sunshine hours or daylength. The days of a year can be divided into four types, namely, clear day (blue sky), hazy day, partially hazy and cloudy day, and completely cloudy day, based on the ratio of daily diffuse to daily global radiation and the number of sunshine hours (Singh and Tiwari [32]). Their criteria are given in Table 3.1.

Environmental Impact and Sustainability Assessment

The world’s energy demand is ever increasing, and to fulfill that demand we often look for engineering solutions, that is, conversion of energy from one form to another. We convert one form of energy to another convenient form to use the energy better. This statement can better be understood by the following example: we convert chemical energy of fossil fuels to heat (thermal energy) first, and then the thermal energy is converted to electrical energy for our convenience to use it in our homes, offices, industries, hospitals, schools, etc. Such energy conversion activities come under engineering activities. Engineering activities are often associated with some environmental problems/issues, mainly the injection of greenhouse gas into the environment. Environmental damage caused by the greenhouse effect further causes global warming, which is responsible for climate change. Therefore, it is important to know how adversely engineering activities are affecting our environment. Environmental impact assessment is simply an indicator of these concerns.