The economics of the satisfaction of needs
This paper is a proposal for the development of an econ­ omics that would be based on satisfaction of the unvarying and universal human needs and not of desires or wants, which are easily manipulable and change, not only from one society to another, but also from one individual to another and even for the same individual at different moments of his or her life. This economics would deal with the production, distribu tion, and use or consumption of all those entities goods, services, relations, self-expressions - that satisfy human needs. It is suggested that in order to achieve stability in social and economic growth, all needs should be simultaneously satisfied, not only the so-called basic needs - food, shelter, clothing, health care, and education. It is claimed that tech­ nological development is making this proposal possible, parti­ cularly because the satisfaction of most of the psychological and sociocultural needs relies mainly on gratuitous relations
a pathway to sustainability in urban sanitation: for developing Asian countries
............................................................................................................................... xii 1 Problematising urban sanitation in developing Asian countries .................................... 1 1.
Techno-economic analysis of solar thermal power plants using liquid sodium as heat transfer fluid
Abstract Solar thermal power plants with central receiver and thermal storage are expected to be one key technology in future electricity generation, because they are renewable and due to the thermal storage independent of the current solar radiation. State-of-the-art solar power plants often use molten nitrate salts as heat transfer fluid. The use of liquid sodium instead leads to lower electricity generation costs. Sodium has a high thermal conductivity and thus large heat transfer rates are possible. Hence, a smaller absorber surface is sufficient for the same thermal power. As a result, the sodium receiver achieves a higher efficiency at lower investment cost. Additionally, the aiming strategy, which reduces the peak heat flux on molten salt receivers isn’t necessary for sodium. Even at high heat flux densities, the absorber tubes will be cooled sufficiently due to the high heat transfer coefficients. Therefore, the sodium receiver in this analysis is designed for one single aim point, resulting in a heat flux density of q mean = 1.06 MW / m 2 and q peak = 2.99 MW / m 2 . The state-of-the-art system with molten salt considers q mean = 0.51 MW / m 2 and q peak = 1.0 MW / m 2 . The presented techno-economic analysis of two sodium based concepts compared to a reference system with molten salt results in up to 16% lower electricity generation costs.