Clean power for off-grid locations

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Comprehensive look at the global mini-grids market and key industry trends

Thanks to our friends at the Alliance for Rural Electrification for pointing us toward an exceptional report on the state of the global mini-grids market in 2020. Compiled by Sustainable Energy for All in collaboration with BloombergNEF and the Mini-Grids Partnership, the report aims to raise awareness about mini-grids, promote investment in the mini-grid sector, and serve as a benchmark to measure progress. It provides updates on the global mini-grids market and highlights key trends in the industry. Among its findings:


Today the mini-grid market is nascent, despite being the least-cost option for electricity access in many areas. While 5,544 installed mini-grids currently exist in Sub-Saharan Africa, Asia, small island nations, and Latin America, there are still 111 million households that could be served by mini-grids in these regions by 2030.

According to the report, the total estimated number of people who lack access to electricity globally fell from 1.4 billion in 2010 to about 900 million by 2018. Grid extension as well as deployment of off-grid solar kits contributed to this remarkable progress, particularly in Asia. However, in Sub-Saharan Africa, the number of people without access is stuck around 600 million – two thirds of the total. Given continued population growth, the International Energy Agency (IEA) projects that about 620 million people will be without access by 2030.

However, the areas that main grids can reach economically are slowly being exhausted and the incremental costs of adding new rural customers via this route are becoming prohibitive. At the same time, many state-owned utilities are debt ridden, making it difficult for governments and utilities to take a least-cost approach.

The good news is that solar hybrid mini-grids that integrate PV and other DERs can now complement and compete with main grid extensions in terms of the cost of electricity and the speed of deployment. As a result, these technologies now comprise the fastest growing segment of the global mini-grids market. This is because mini-grid technology is often the most suitable option for many low- and medium-density areas and can address a larger number of low-income families more economically than the alternative options.


A surprising finding from the report was that levelized costs of electricity (LCOEs) ranged from USD 0.49–0.68/kWh for solar hybrid mini-grids operating in isolated areas and serving both households and productive use customers in six case-studied countries. The variance was mainly due to differing prices for diesel, equipment, installation, and financing. The overall high level of these prices, however, is due largely to high transport-related costs for diesel, plus continued dependence on diesel for power much of the time. The latter, in turn, is because rural, agriculture-based communities do not always use electricity during the day, when PV is online.

247Solar Plants™, when combined with PV or wind plus batteries, can create economically optimal off-grid solutions for continuous clean electricity, entirely without diesel gensets, that offer fuel savings of up to 90%.






Innovative heat exchanger eliminates need for combustion

247Solar, along with microturbine supplier Capstone Turbine Corporation, has successfully tested a revolutionary commercial turbine that can generate electricity using hot air at atmospheric pressure, without combustion.

This significant breakthrough is made possible by an ultra-high temperature heat exchanger with technology that has its origins at the Massachusetts Institute of Technology (MIT). The 247Solar Heat Exchanger™ uses a proprietary nickel-chromium-aluminum-iron alloy engineered for sustained operation at very high temperatures.

This turbine is the heart of the first operational 247Solar Plant™, being built in California. The Plant includes a system that concentrates sunlight to heat ambient-pressure air to 970℃ (1800℉), a high-enough temperature to drive the turbine to produce electricity without burning fuel.

The Plant also includes the 247Solar Thermal Storage System™, which stores sunlight as heat instead of electricity, at a fraction of the cost of batteries. The stored heat powers the turbine up to 20 hours at night and on cloudy days, reducing fuel consumption up to 90% — far more than PV and batteries.

To guarantee electricity 24/7, even when there is no solar-heated air available, the turbine includes an optional combustor. The combustor is external to the turbine and can be engineered to burn most liquid and gaseous fuels, including alternative fuels like hydrogen and biogas.

Engineering development partners include Brayton Energy (Hampton, NH), specialists in high efficiency turbomachinery and gas turbine design, and URSA Energy Solutions (Laguna Niguel, CA). Contact us to learn more.