Mini Grids and Micro Grids: Lessons from Decades of Global Development
Rural Mini Grid Power Supply
Mini grids and micro grids are not interchangeable terms. They refer to electrical supply systems differentiated in size and application. They both however are designed to operate independent of the main grid, islanding, occasionally or throughout their lifetime.
There are three scales of electrical supply or distribution systems. The main grid or the national grid, mini grids, and micro grids.
Mini grids, sometimes known as ‘skinny grids’, are scaled down versions of the main grid. They serve communities the main grid hasn’t extended to, either due to a location’s remoteness or political turmoil harming development. They can serve up to 100 households with locally generated power from a variety of sources according to the region’s means to generate power. Mini grids are found today in sub–Saharan Africa and South and East Asia. And previously in Cambodia, Sri Lanka, and Indonesia
There are three scales of electrical supply or distribution systems. The main grid or the national grid, mini grids, and micro grids.
Mini grids, sometimes known as ‘skinny grids’, are scaled down versions of the main grid. They serve communities the main grid hasn’t extended to, either due to a location’s remoteness or political turmoil harming development. They can serve up to 100 households with locally generated power from a variety of sources according to the region’s means to generate power. Mini grids are found today in sub–Saharan Africa and South and East Asia. And previously in Cambodia, Sri Lanka, and Indonesia
Hospital Back-Up Generators
Micro grids are smaller, highly localised systems serving single facilities. They are used to ensure a ‘five nines’ (99.999%) standard of reliability essential for hospitals and other critical infrastructure. Micro grids often lie dormant until backup is required during main grid failures or to mitigate stress by subsidising energy dependence during high demand. Diesel generators serve quick response needs best.
Unlike mini grids, micro grids have been designed to function alongside a facility’s connection to the main grid. Mini grids have often been used as temporary energy system until absorbed by main grid.
Unlike mini grids, micro grids have been designed to function alongside a facility’s connection to the main grid. Mini grids have often been used as temporary energy system until absorbed by main grid.
Three Generations of Grids
Mini grids have rolled out in three ‘generations’. The first generation was the electrification of the industrial world between the late nineteenth and twentieth century. What began as localised electricity networks expanded to form the first national grids.
The second generation took place between the 1980s and 2000s as developments in electrically assess-deficit nations and regions. A study by ESMAP, Energy Sector Management Assistance Program, took case studies of former second-generation mini grids in Cambodia, Sri Lanka, and Indonesia to understand the adaptations and end games of mini grids when the main grid arrives.
These findings can be used to enhance and prolong the performance of the current generation of mini grids and potentially revive older grids.
The second generation took place between the 1980s and 2000s as developments in electrically assess-deficit nations and regions. A study by ESMAP, Energy Sector Management Assistance Program, took case studies of former second-generation mini grids in Cambodia, Sri Lanka, and Indonesia to understand the adaptations and end games of mini grids when the main grid arrives.
These findings can be used to enhance and prolong the performance of the current generation of mini grids and potentially revive older grids.
Mini Grid Outcomes from Second Generation Development
The study found six outcomes for mini grids upon the arrival of the main grid:
(1) converting into small power producers (SPPs),
(2) converting into small power distributers (SPDs),
(3) a combination of both,
(4) continuing to operate side by side with the main grid,
(5) integration into the main grid, and
(6) being abandoned.
These outcomes were dependent on the size of the mini grids and their compatibility with the main grid. In Sri Lanka the average mini grid served only 27 people (micro grids in scale but mini grids in application). Converting the grids to meet renewed energy standards was not economical. Only 3 grids remained viable, sustained by selling power back to the grid.
250 isolated grids converted into SPDs serving 1 million people in Cambodia’s when the main grid arrived in the 1990’s. Grid operators distributed power wholesale from the main grid to the mini grid.
Indonesia’s mini grids had more varied outcomes on account of their more varied size and costs. Where converting to the main grid was cheaper than remaining on the preexisting mini grids, grids were either abandoned or integrated into the main grid. Mini grids continued to operate either fully side-by-side or convert to SPDs or SPPs where switching to the main grids was more costly.
Many mini grids today are in essence still second generation. Conceived as temporary energy solutions until the main grid arrives, leading to post-main grid uncertainty.
(1) converting into small power producers (SPPs),
(2) converting into small power distributers (SPDs),
(3) a combination of both,
(4) continuing to operate side by side with the main grid,
(5) integration into the main grid, and
(6) being abandoned.
These outcomes were dependent on the size of the mini grids and their compatibility with the main grid. In Sri Lanka the average mini grid served only 27 people (micro grids in scale but mini grids in application). Converting the grids to meet renewed energy standards was not economical. Only 3 grids remained viable, sustained by selling power back to the grid.
250 isolated grids converted into SPDs serving 1 million people in Cambodia’s when the main grid arrived in the 1990’s. Grid operators distributed power wholesale from the main grid to the mini grid.
Indonesia’s mini grids had more varied outcomes on account of their more varied size and costs. Where converting to the main grid was cheaper than remaining on the preexisting mini grids, grids were either abandoned or integrated into the main grid. Mini grids continued to operate either fully side-by-side or convert to SPDs or SPPs where switching to the main grids was more costly.
Many mini grids today are in essence still second generation. Conceived as temporary energy solutions until the main grid arrives, leading to post-main grid uncertainty.
Third Generation Grids: A Permanent Solution
Third generation grids are no longer just temporary developments. By drawing on a range of green energy sources and integrating smart technologies, mini grids have become economically adaptable and technologically robust with and without the main grid.
Mini grids can be deployed faster than the main grid can extend, expanding business developments beyond the reach of national infrastructure. Though costing between £400,000 and £800,000 upfront, a mini grid can pay itself back even after the main grid arrives. Attracting anchor clients and energy payback schemes either to the grid or through selling ‘carbon certificates’ earned from producing green energy are primary economic advantages.
Plummeting PV prices and an increasing supply of second-hand lithium batteries have lowered start-up costs dramatically. Where PV is at a disadvantage, green energy sources combine to generate power year-round. Scottland’s ski resort grids benefit from PV and hydropower in particular.
Mini grids can be deployed faster than the main grid can extend, expanding business developments beyond the reach of national infrastructure. Though costing between £400,000 and £800,000 upfront, a mini grid can pay itself back even after the main grid arrives. Attracting anchor clients and energy payback schemes either to the grid or through selling ‘carbon certificates’ earned from producing green energy are primary economic advantages.
Plummeting PV prices and an increasing supply of second-hand lithium batteries have lowered start-up costs dramatically. Where PV is at a disadvantage, green energy sources combine to generate power year-round. Scottland’s ski resort grids benefit from PV and hydropower in particular.
Policy and Regulatory Landscape
Mini grid developments rely on clear energy sector forecasting. Unforeseen steps compatibility requirements was a major barrier to survival in Sri Lanka where conversion costs sunk small grids.
In the UK small scale energy producers must be certified by the Microgeneration Certification Scheme (MCS). The MCS largely applies to PV and BIPV (built in photovoltaic) regulating safety standards and structural assessments.
Separate licences for electricity distribution, generation, interconnection, and supply are laid out in the Energy Act 1989. Denominated regulatory conditions provide mini grid operators ample guidance to safely and legally interconnect with the national grid.
Updated features in the Energy Act 2023 seeks to streamline decentralised grid connection by unjamming the planning process from stalled ‘zombie projects’ and prioritising green energy suppliers to the national grid across the local level.
In the UK small scale energy producers must be certified by the Microgeneration Certification Scheme (MCS). The MCS largely applies to PV and BIPV (built in photovoltaic) regulating safety standards and structural assessments.
Separate licences for electricity distribution, generation, interconnection, and supply are laid out in the Energy Act 1989. Denominated regulatory conditions provide mini grid operators ample guidance to safely and legally interconnect with the national grid.
Updated features in the Energy Act 2023 seeks to streamline decentralised grid connection by unjamming the planning process from stalled ‘zombie projects’ and prioritising green energy suppliers to the national grid across the local level.
The Importance of Energy Storage
Energy storage solutions are a major component for mini and micro grids and green energy at large. Independent energy storage guards against the pitfalls of the UK’s just-in-time energy model critiqued by Professor Dieter Helm following a loss of power at Heathrow in March “it’s a miracle these things don’t happen more often.”
Green energy production is let down by our capacity to store it presenting split paths in the pursuit of net zero and energy resilience.
Businesses are built on the predation of reliable energy sources but we are learning this is not a given. Mini and micro grids, supported by energy storage, ensures resilience and an adaptability beyond what the main provides.
Green energy production is let down by our capacity to store it presenting split paths in the pursuit of net zero and energy resilience.
Businesses are built on the predation of reliable energy sources but we are learning this is not a given. Mini and micro grids, supported by energy storage, ensures resilience and an adaptability beyond what the main provides.
