Off-grid solar photovoltaic systems for rural electrification and emissions mitigation in India Philip Sandwell 1,2 , Ngai Lam Alvin Chan 1,2 , Samuel Foster 1 , Divyam Nagpal, Christopher J M Emmott 1,2 , Chiara Candelise 3, 4 , Simon J Buckle 2 , Ned Ekins-Daukes 1,2 , Ajay Gambhir 2 and Jenny Nelson 1,2 1. Department of Physics, Imperial College London, Blackett Laboratory, Prince Consort Road, London SW7 2AZ 2. Grantham Institute – Climate Change and the Environment, Imperial College London, London SW7 2AZ 3. Centre for Energy Policy and Technology, Imperial College London, London SW7 2AZ 4. IEFE, Bocconi University, Via Roengten 1, 20136 Milan Over one billion people lack access to electricity and many of them in rural areas far from existing infrastructure. Off-grid systems can provide an alternative to extending the grid network and using renewable energy, for example solar photovoltaics (PV) and battery storage, can mitigate greenhouse gas emissions from electricity that would otherwise come from fossil fuel sources. This paper presents a model capable of comparing several mature and emerging PV technologies for rural electrification with diesel generation and grid extension for locations in India in terms of both the levelised cost and lifecycle emissions intensity of electricity. The levelised cost of used electricity, ranging from $0.46-1.20/kWh, and greenhouse gas emissions are highly dependent on the PV technology chosen, with battery storage contributing significantly to both metrics. The conditions under which PV and storage becomes more favourable than grid extension are calculated and hybrid systems of PV, storage and diesel generation are evaluated. Analysis of expected price evolutions suggest that the most cost-effective hybrid systems will be dominated by PV generation around 2018. 1. Introduction Developing countries with ambitions both to expand access to electric power and to meet national and international carbon emissions targets need to consider the emissions implications of alternative development pathways[1]. Such countries may also benefit from the opportunity to adopt more innovative energy technologies than developed nations, whose energy economy may already be ‘locked in’ to conventional, and typically high carbon, power sources. Diesel generators are a common source of off-grid electricity as they provide low- cost power[2] but with a high carbon intensity[3]. Connection to an electricity grid is often aspired to, allowing flexibility in the power mix and avoiding the need for energy storage, but requires expensive and energy-intensive infrastructure, is slow to reach remote areas and suffers poor reliability in such regions[4, 5]. Renewable sources offer the lowest carbon intensity of generated power but suffer from varying availability and high initial costs, with intermittency in supply leading to the need for storage. Solar photovoltaics (PV) is the most universally available of the renewables but normally engenders the highest price of electricity. The historically high costs of