Reliability and sustainability analyses of frugal solar photovoltaic micro-grid systems in emerging markets

Massive over-consumption of natural resources has resulted in severe environmental and climate problems, which in turn threaten life supporting ecosystems. Moreover, despite some nations driving this over-consumption, millions of people in other parts of the world, still suffer from energy poverty: 2.7 billion people live without access to clean cooking facilities, and one billion without access to electricity mainly in the sub-Saharan Africa and the developing regions of Asia. The main motivation of this dissertation is to better understand the relevance of frugal energy innovations in providing affordable energy services to impoverished people in emerging economies in a sustainable manner. The dissertation contains a novel five-criteria method for the identification of frugal energy innovations, which underlines local appropriateness, affordability, sustainability and technical durability. A frugal technology, a solar micro-grid system with locally manufactured pre-paid energy meters was investigated in rural Northern India through a set of field measurement trials. The micro-grids included an advanced pricing method that could potentially decrease system cost, which is of the utmost importance in low-income communities. However, the dynamic pricing function was not found beneficial in the field trial, because the impoverished customers minimized their power consumption, so demand response benefits could not be demonstrated. Therefore it is recommended to design technology and business models with an essential user-centered approach without overlooking the potential necessity of educating end-users in areas where people may have not had access to power grid services before. Moreover, the frugal electronic component quality requires attention. A particular focus in this dissertation is on the reliability of solar micro-grid systems. In the field trial, power was measured to be available for the households 87% of the time. The number of days without blackouts was 200 out of 356 days measured. The reasons for a lack of reliability were related to a lack of solar energy in the winter season, component failures, and unexpected user activities such as power theft. This study also presents a new reliability assessment method for renewable off-grid power systems, based on an interview study with solar micro-grid operators in India. The method is descriptive, which has an advantage of better highlighting localized problems, such as long maintenance outages in remote regions or a lack of sufficient protective measures of some critical system units. The use of the framework may encourage reliability thinking and assist in designing more reliable power systems.