Efficient use of solar chargers with the help of ambient light sensors on smartphones

This paper discusses the possibilities to measure the amount of light with the help of portable devices such as mobile phones and tablets. Focus is directed to the accuracy of the ambient light sensor on smartphones in order to obtain the illuminance indoors and the solar radiation level outdoors. In general, information on the ambient conditions is vital to improve the performance of solar chargers. For example, if users are able to allocate beneficial locations to deploy solar chargers inside buildings, up to 100 times more energy can be gathered during the same periodic time. Similarly, under outdoor environmental conditions, solar modules can be aligned better towards the sun to increase the possible amount of output power. We analyse the accuracy of ambient light sensors which are available in today's low-cost and upper-class smartphones. Additionally, we present calibration strategies for ambient light sensors in order to minimise the error between conventional measurement equipment and mobile phones

Off-Grid mobile phone charging systems for rural energy needs

For several decades, rural electrification has remained a formidable challenge, particularly in Nigeria. Financial constraints, difficult rural terrain, inefficient policy, and a lack of industrial community development have all contributed to the grid expansion problem in these areas. These areas are energy-deficient, and their energy demands to keep up with cutting-edge communication technology are constantly rising. As a result, rural areas are confronted with the issue of charging. Consequently, many rural residents are forced to rely on diesel/petrol generators or travel long distances and pay a premium to have their mobile phones charged. Thus, this paper proposes an off-grid solar-powered charging system as an alternative, sustainable solution to meet rural mobile phone energy demand. The methodology employed six-tier architectural features, with the economic comparison metric based on net present value and payback period. Furthermore, the proposed model's performance analysis revealed that the charging rate is dependent on the phone battery type and charger type. Furthermore, the off-grid mobile charging system has a higher net present value ($20,658US) and a shorter payback period of 2.5 years than the alternative investment of a gasolne generator