Aerostat for electric power generation

Abstract

Solar power is one source of renewable energy that is well established but, in the UK, expensive per kilowatt due to low levels of insolation caused by cloud cover. To over- come the limitations of cloud cover, an aerostat for electrical power generation has been proposed in literature. The aerostat would float at an altitude of six kilometres, above the majority of cloud cover, and can receive around 3.3 times the annual insolation of a ground based system in the UK.

The aim of this work is to further demonstrate the feasibility of such an aerostat concept. This is achieved by considering three areas of study: the solar array shape, the control system and the thermal analysis. The analysis of the solar array compares two configurations, a spherical cap and a stepped array, in terms of size, mass, power production and sensitivity to pointing error. The results show that a spherical cap array has a lower sensitivity to pointing error and, with the support structure required for a stepped array, a lower mass despite its larger surface area.

The control system design takes a proposed system concept as its starting point and revises it. The system is sized and its Sun tracking and disturbance rejection performance is simulated. It is found that the system is capable of maintaining a pointing error of within 1.81◦ during tracking and of correcting disturbances.

The thermal analysis extends previous models to include the effects of a ballonet used for gas pressure regulation. The model is validated against experimental data and shows a good agreement (r ≥ 0.9). The model is then applied to the aerostat concept and shows that the gas pressure can be maintained within acceptable bounds and that the solar array does not become hot due to solar heating. Overall, the results of this study increase confidence in the feasibility of the aerostat concept.

More information

Identifiers

Catalogue record

Export record