In India, we are familiar with the centralized grid - A system where electricity is produced in large-scale (hydro electric plants, coal, nuclear, wind, etc) and then is transported to the areas of consumption using large T&D (Transmission & Distribution) infrastructure.
There is another type of grid - It's called Microgrid.
In a Microgrid, electricity is produced at the location where it needs to be consumed (or nearby) and it is distributed among all the consumers under its wings (usually over a few KM). Microgrid is usually a self-sustaining model that can work with/without interface to the central grid, and hence it may be preferred in rural (or even urban) areas.
Don't we get economies of scale with centralized grid? Yes we do, but creation and maintaining a large T&D network is more expensive than what we think, and power losses while transmitting power over long-distances is very huge. Besides, why would we want to have a single point of failure, especially with something that is as important as electricity? We all know that the entire northern grid (in India) was down last year and millions of people were cut-off from electricity.
Have a look at some limitations of centralized grid:
- Less reliable - Single point of failure.
- Almost all forms of large-scale power generation methods are associated with some form of environmental issues/pollution.
- It is very expensive to establish T&D infrastructure to all the localities, and in many cases, it is simply not possible.
- There are huge T&D losses that result in loss of power (and money) since we are transmitting power over long distances.
- Demand keeps increasing, but it is difficult/time-consuming/capital intensive to construct new power plants to keep up with the demand.
Now have a look at some advantages of distributed generation & Microgrids:
- Economies from mass-production (for microgrid) - like power production through solar panels installed on many houses, combined., Vs. economies from of scale (for centralized grid).
- Lower investment, faster execution, lower financial risk.
- Less complex, easier to maintain, engineering flexibility.
- Low T&D losses (as microgrids are established closer to consumers).
- Higher reliability and capability for accurate forecasting/production.
- Can be connected to centralized grid for back-up/operation. But this is not necessary - microgrids can operate independently, if required.
- Microgrids better support integration of small-scale renewable energy technologies (like solar power, wind energy, biomass, biogas, etc.) into the grid.
- Generally microgrids cover smaller regions like 30 - 50 KM and have a capacity of 5 - 10 MW.
- Microgrids support smart meters and other high-tech equipment for accurate mechanism and control. Easier predictive analysis, forecasting and control possible.
Of course, microgrids also have their problems - they are more expensive to establish, economical energy storage is a challenge, maintenance might be complex, new technology - will take some time for maturation, not many pilot projects to test their effectiveness, etc.
Greenpeace has commenced a pilot solar-powered project in Bihar for rural electrification based on Smart Microgrid technology. This experiment involves establishing 100 KW of solar panels to power 350 houses and this set-up is expected to become operational over the next year. If successful, this model might quickly catch up with many more rural/remote locations where it is currently expensive/impossible to establish powerline connections from the central grid. More details here.
Let's hope state governments and central governments will consider testing and establishing microgrids. It's important that we start experimenting now, because microgrid might as well become the future of electricity production/distribution.
