CLOVER: A modelling framework for sustainable community-scale energy systems

Sustainable Development Goal 7 aims to provide sustainable, affordable, reliable and modern energy access to all by 2030 (United Nations, 2015). In order for this goal to be achieved, sustainable energy interventions in developing countries must be supported with design tools which can evaluate the technical performance of energy systems as well as their economic and climate impacts. CLOVER (Continuous Lifetime Optimisation of Variable Electricity Resources) is a software tool for simulating and optimising community-scale energy systems, typically minigrids, to support energy access in developing countries (Winchester et al., 2022). CLOVER can be used to model electricity demand and supply at an hourly resolution, for example allowing users to investigate how an electricity system might perform at a given location. CLOVER can also identify an optimally-sized energy system to meet the needs of the community under specified constraints. For example, a user could define an optimum system as one which provides a desired level of reliability at the lowest cost of electricity. CLOVER can provide an insight into the technical performance, costs, and climate change impact of a system, and allow the user to evaluate many different scenarios to decide on the best way to provide sustainable, affordable and reliable electricity to a community. CLOVER can be used on both personal computers and high-performance computing facilities. Its design separates its general framework (code, contained in a source src directory) from user inputs (data, contained in a directory entitled locations) which are specific to their investigations. The user inputs these data via a combination of .csv and .yaml files. CLOVER’s straightforward command-line interface provides simple operation for both experienced Python users and those with little prior exposure to coding. An installable package, clover-energy, is available for users to download without needing to become familiar with GitHub’s interface. Information about CLOVER and how to use it is available on the CLOVER wiki pages

Integrated simulation and optimisation of hybrid photovoltaic-thermal (PV-T) and photovoltaic systems for decentralised rural hot water provision and electrification

Demands for electricity and hot water continue to rise worldwide, with many people in low-income countries, especially in rural areas, lacking access to these basic services. Decentralised minigrids, capable of powering small off-grid communities, are increasingly used in low-income countries as a means of providing power to the 13% of people globally without access to electricity. Hybrid solar photovoltaic-thermal (PV-T) collectors combine both photovoltaic (PV) cell and solar-thermal absorbers and, therefore, output both electricity and heat from a single collector with efficiency benefits over standalone PV panels and solar-thermal collectors. Despite this, no models have yet been developed capable of assessing the performance of PV-T collectors generalisable across a range of off-grid settings. We present an integrated model for simulating and optimising combined systems comprising PV panels and PV-T collectors, accurate to within +/- 5% rms error, connected to wider electrical and hot water systems, and employ this to evaluate their potential to meet both electrical and hot-water demands of rural communities. We provide a tool for simulating the lifetime output from combined PV and PV-T systems, assessing their economic and environmental impact, and for optimising the systems to meet the needs of specific communities. We carry out simulations for a case study of a combined PV and PV-T system in Uttar Pradesh, India, and find that the system is able to meet 59.3% and 33.5% of hot water demand for upper and lower bounds for installed capacity. We carry out optimisations for static high demand and growing low-demand scenarios and find that that 35 kWpel and 5 hot-water tanks and 75 kWpel and 15 hot-water tanks are needed to meet these demand scenarios respectively

Techno-economic assessment of biomass gasification-based mini-grids for productive energy applications: The case of rural India

As the costs of solar PV continuously decrease and pollution legislation imposes less burning of agricultural residues, decentralized renewable energy is increasingly affordable for providing electricity to one billion people lacking access to a power grid. This paper presents a techno-economic feasibility case study of biomass gasification in off-grid and grid-connected mini-grids for community-scale energy application in rural Uttar Pradesh, India. Energy demand data was collected through surveys in a village with irrigation and agro-processing loads and off-grid households and used to construct a seasonal load profile based on statistical methods. This was used to simulate single-source and hybrid mini-grids based on solar PV, biomass gasification and diesel generation using HOMER Pro. Hybrid PV-biomass or PV-diesel systems were found to offer the highest reliability for off-grid power at the lowest cost. Single-source PV was cheaper than biomass gasification, though the cost of electricity is highly sensitive to biomass supply and gasifier maintenance. Both renewable options were around half the cost of diesel generation. The findings held across grid-connected systems with weak, moderate and strong reliability of grid supply. This suggests that biomass gasification-based mini-grids are not cost-competitive with PV unless the two generation sources are combined in a hybrid system, though they require operational testing prior to implementation

Mapping Status and Conservation of Global At-Risk Marine Biodiversity

To conserve marine biodiversity, we must first understand the spatial distribution and status of at‐risk biodiversity. We combined range maps and conservation status for 5,291 marine species to map the global distribution of extinction risk of marine biodiversity. We find that for 83% of the ocean, \u3e25% of assessed species are considered threatened, and 15% of the ocean shows \u3e50% of assessed species threatened when weighting for range‐limited species. By comparing mean extinction risk of marine biodiversity to no‐take marine reserve placement, we identify regions where reserves preferentially afford proactive protection (i.e., preserving low‐risk areas) or reactive protection (i.e., mitigating high‐risk areas), indicating opportunities and needs for effective future protection at national and regional scales. In addition, elevated risk to high seas biodiversity highlights the need for credible protection and minimization of threatening activities in international waters

A PESTLE analysis of solar home systems in refugee camps in Rwanda

There is a paucity of data on energy access in refugee camps and limited analysis regarding the viability of modern energy technologies such as solar home systems in these contexts. This paper addresses these by presenting an overview of the household and small enterprise electricity access situation in Kigeme, Nyabiheke and Gihembe camps in Rwanda and through the application of a Political, Economic, Social, Technological, Legal and Environmental (PESTLE) analysis to assess the barriers influencing solar home system provision. Most households and small enterprises currently have limited or no access to electricity and there is significant unmet demand for energy services such as mobile phone charging, lighting, and entertainment in the camps. The analysis suggests that solar home systems can meet these energy needs and identifies important factors in ensuring projects are successful. Projects should be informed by the needs and priorities of end-users and should be aligned with national policies, such as achieving Tier 2 energy access, to garner political support. Where possible, local market systems should be nurtured to normalise paying for energy products and to avoid free distribution. This can support private sector engagement and result in longer system lifetimes through improved maintenance. Energy literacy programmes can also improve awareness of solar home systems and their benefits compared to traditional sources of energy. These findings can inform practitioners on the supporting policy/financial frameworks, design requirements and implementation measures needed to maximise the benefits of future solar home system projects and help achieve electrification targets

Leaving no aspect of sustainability behind: A framework for designing sustainable energy interventions applied to refugee camps

The issues of forced displacement and energy for sustainable development are convergent: an estimated 90% of displaced people globally have no access to electricity, while 85% of refugees are hosted in developing countries. However, few tools to plan and design sustainable energy access interventions have been transposed to displacement settings. This paper presents a novel framework for the holistic planning of energy projects which considers both sustainability aspects and the specificities of displacement settings. The framework is the result of a review of literature which aimed to define a “sustainable energy intervention” in displacement contexts and an assessment of relevant planning tools against this definition. The framework includes the use of an energy delivery model toolkit, an inclusive design approach, an assessment of the desired impacts, energy system modelling, business model design, and an assessment of economic viability. We apply the framework in the design of a solar mini grid of Holl Holl refugee camp in Djibouti, in which a sustainable intervention and business model are proposed that could be compatible with the local conditions. We highlight issues that arise from the humanitarian sector status quo and propose that this framework could help to enhance sustainable energy practices in the humanitarian and development sectors

The role of mini-grids for electricity access and climate change mitigation in India

Sustainable Development Goal 7 aims to achieve access to sustainable, affordable, reliable, and modern energy for all. Access to electricity is critical for development and economic growth and can support productive livelihoods and power critical community services such as for healthcare and education. Solar mini-grids can offer the most cost-effective option for rural and remote communities not yet connected to the grid and can deliver reliable, high-quality power which is able to serve multiple uses and meet growing demand over time

Off-grid solar photovoltaic systems for rural electrification and emissions mitigation in India

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

Maximising the benefits of renewable energy infrastructure in displacement settings: optimising the operation of a solar-hybrid mini-grid for institutional and business users in Mahama Refugee Camp, Rwanda

Humanitarian organisations typically rely on expensive, polluting diesel generators to provide power for services in refugee camps, whilst camp residents often have no access to electricity. Integrating solar and battery storage capacity into existing diesel-based systems can provide significant cost and emissions savings and offer an opportunity to provide power to displaced communities. By analysing monitored demand data and using computational energy system modelling, we assess the savings made possible by the integration of solar (18.4 kWp) and battery (78 kWh) capacity into the existing diesel-powered mini-grid in Mahama Refugee Camp, Rwanda. We find that the renewables infrastructure reduces fuel expenditure by $41,500 and emissions by 44 tCO2eq (both 74$4100 and 12.4 tCO2eq, using 33% of battery lifetime versus 15% under the original strategy. This reduces the cost of electricity by 33% versus diesel generation alone, whilst more aggressive cycling strategies could prove economical if moderate battery price decreases are realised. Extending the system to businesses in the camp marketplace can completely offset the system fuel costs if the mini-grid company charges customers the same tariff as the one it uses in the host community, but not the national grid tariff. Humanitarian organisations and the private sector should explore opportunities to integrate renewables into existing diesel-based infrastructure, and optimise its performance once installed, to reduce costs and emissions and provide meaningful livelihood opportunities to displaced communities