Difference between revisions of "Grid Extension vs Off grid, Island / Isolated System"
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== Rules of thumb (ROT) == | == Rules of thumb (ROT) == | ||
− | ''<span>The suggested rules of thumb (ROT) for community selection are based on cost-effectiveness criteria.</span><span> The source of these rules is NORAD 2009, however they have been adapted based on experience during the implementation of Energising Development and discussions with the above mentioned experts. </span>'' | + | ''<span>The suggested rules of thumb (ROT) for community selection are based on cost-effectiveness criteria.</span><span> The source of these rules is NORAD 2009, however they have been adapted based on experience during the implementation of Energising Development and discussions with the above mentioned experts. </span>'' |
− | === <span> | + | === <span>ROT for grid extension</span> === |
− | <span>{'''WORK in PROGRESS'''}</span> | + | <span>{'''WORK in PROGRESS'''}</span> |
− | + | <br> | |
− | <div><span>A)<span> Estimate the total number of potential connections* (N) in a rural community</span></span></div><div> </div><div><span>B)<span> Find the average distance (D) from the rural community to the centralized grid</span></span></div><div><span>*Due to time span between planning and execution one may Take into consideration the Grid expansion within the</span></div><div><span> next 2-3 years., The topography is also crucial for this decision.</span></div><div> </div><div><span>C)<span> Calculate the number of connections (N) per distance = N/D</span></span></div><div> </div><div> </div><div><span>Case 1 =<span> N/D < 2 connections/km => Grid extension is not likely to be viable</span></span></div><div> </div><div><span>Case 2 =<span> N/D > 30 connections/km => Grid extension is likely to be a viable alternative (Compared to off-grid systems)</span></span></div><div> </div><div><span>Cases between N/D < 2 to N/D > 30, 28 Cases are undefined.</span></div><div> </div><div><span>As the Rule of Thumb has a very large Open, not defined, range it gives no solutions for many cases. But one can redefine it for its own proper country Regional situation. </span></div><div> </div><div><span>Sample Case calculation:</span></div><div> </div><div><span>Village 1) N = 500 HH / 11KM = 45,45 Conn/Km = Grid extension would be most viable</span></div><div> </div><div><span>Village 2) N = 1000 HH / 100 km = 10 Conn/ Km = ? ? ? ?</span></div><div><span>Here comparison factors as: e.g. Topography, Mountain Area , play a bigger role National Grid extension Plan etc. must be observed and researched more </span></div><div> </div><div> </div><div><span>* Normally households are the dominating customer group, but usually not all of them will connect. The existence of any high demand, industrial consumers must also be factored in.</span></div> | + | <div><span>A)<span> Estimate the total number of potential connections* (N) in a rural community</span></span></div><div> </div><div><span>B)<span> Find the average distance (D) from the rural community to the centralized grid</span></span></div><div><span>*Due to time span between planning and execution one may Take into consideration the Grid expansion within the</span></div><div><span> next 2-3 years., The topography is also crucial for this decision.</span></div><div> </div><div><span>C)<span> Calculate the number of connections (N) per distance = N/D</span></span></div><div> </div><div> </div><div><span>Case 1 =<span> N/D < 2 connections/km => Grid extension is not likely to be viable</span></span></div><div> </div><div><span>Case 2 =<span> N/D > 30 connections/km => Grid extension is likely to be a viable alternative (Compared to off-grid systems)</span></span></div><div> </div><div><span>Cases between N/D < 2 to N/D > 30, 28 Cases are undefined.</span></div><div> </div><div><span>As the Rule of Thumb has a very large Open, not defined, range it gives no solutions for many cases. But one can redefine it for its own proper country Regional situation. </span></div><div> </div><div><span>Sample Case calculation:</span></div><div> </div><div><span>Village 1) N = 500 HH / 11KM = 45,45 Conn/Km = Grid extension would be most viable</span></div><div> </div><div><span>Village 2) N = 1000 HH / 100 km = 10 Conn/ Km = ? ? ? ?</span></div><div><span>Here comparison factors as: e.g. Topography, Mountain Area , play a bigger role National Grid extension Plan etc. must be observed and researched more </span></div><div> </div><div> </div><div><span>* Normally households are the dominating customer group, but usually not all of them will connect. The existence of any high demand, industrial consumers must also be factored in.</span></div><div><span /></div> |
+ | == <span><div><span>ROT for single-phase vs three-phase configuration</span></div></span> == |
Revision as of 07:52, 20 August 2010
Main decision criteria
- Distance to the national / centralised grid (incl. capacity of grid)
- Demand
- Population density and number of households
- Long-term demand (in kwh and terms of energy services) and peak load (in kw)
- Number and (expected) demand (growth) of productive end uses / industrial users
- Levelized costs of energy production (to be consideres: long term marginal costs) in centralised grid and extension costs.
- Levelized costs of energy production in isolated system
- The selection of socially and environmentally appropriate technologies
- ...
Acknowledgement
Important considarations
Grid vs off-grid vs evolutionary approach
By the time the population has outgrown a particular service delivery level, incomes are likely to have risen and population densities increased, resulting in entirely different economic conditions under which other temporary solutions might now become feasible (such as added PV modules to the battery system at home, or mini grids connecting most village households). A grid-connected city person may find it difficult to imagine, but even the simplest first step up from kerosene lighting, a battery-based modern CFL or LED lamp, would immediately improve the quality of life for rural households. There are numerous options to improve living conditions without having grid electricity, and all have fairly low investment costs. Indeed, a range of individual alternatives should be promoted to improve the quality of rural life across the board and create wealth, to commensurate with households’ desire and ability to pay for such services. Although these services constitute a major step up from prevailing living conditions, several subsequent steps will still be required to reach comparable conditions in the future as in urban areas.
Development of criteria / rules of thumb
Basic definitions
Grid-connected (on-grid) power supply / provision is defined as electricity supply which is fed by centrally generated electricity, and uses a network of (high,) medium and low voltage distribution grid system that exceeds one village. Grid extension is therefore a network expansion from the national power transmission system to new areas and communities. Whereas decentralized power provision is understood as power generation in the village, such as solar home system or a mini-grid powered by a diesel generator / hydro power plant. Grid-connected (on-grid) electrification comprises the connection of entire villages through network extension (grid extension), so the construction of new transmission lines (transmission lines), as well as network densification measures. The latter are divided into two categories: (1) Grid densification by transformation, if villages which are located in close proximity to an existing transmission line will be connected, change of voltage level. (2) Densification within an existing low-voltage distribution grid, connection of additional households.
Decision tree
Cost-effectiveness criteria typically include distance to the existing grid, population size, affordability and productive potential. A consequence of using cost-effectiveness criteria is that they are likely to promote the connection of communities with less poor people. A cost-effectiveness approach can be justified due to its emphasis on financial sustainability.
One example of using cost-effectiveness criteria is how the Pakistan Rural Electrification Project selected communities. They selected communities with I/K ratios > 24, with I being the population size and K the distance to the grid.
Additional examples are:
Rural Electrification in Benin....{Julian Frede / Francois Carme, pls add here}
Rural Electrification in Madagaskar....{Sören David, pls add here}
Rules of thumb (ROT)
The suggested rules of thumb (ROT) for community selection are based on cost-effectiveness criteria. The source of these rules is NORAD 2009, however they have been adapted based on experience during the implementation of Energising Development and discussions with the above mentioned experts.
ROT for grid extension
{WORK in PROGRESS}