Local Power Generation and Small-Scale Grids

Getting the power back on is often one of the first objectives in a disaster. Many communication systems are dependent on it, and in general, quickly restoring order during chaos over a large area tends to require it. At a minimum, having access to energy infrastructure makes things substantially easier.

One idea that has been explored in the area of energy is local power generation and the use of small-scale electrical grids.

What is this and how does it potentially help us control disaster risk?

Traditionally, people in large cities are used to large power grids. To better understand how local generation and small grids, it can be easier to understand traditional large grids to compare and see how they are different.

For many people, in order for their computer screen to turn on: 

1. Generation: A power generation plant like a nuclear power plant, hydroelectric dam, coal plant, etc. generates electricity.

2. Transportation: The electricity is transported at high voltage over power lines.

3. Distribution: The electricity is run through power transformers when closer to end-use so that it can be utilized by low-voltage appliances.

For context, here are some different volt levels at different stages of this:

Long distance power distribution: ~69,000 to 765,000 volts.

Local power distribution ~750 to 34,500 volts.

A 120-volt washing machine appliance: 120 volts.

Distribution is necessary because sending something at too high a voltage into a low voltage appliance creates a situation where energy cannot be utilized. The extra energy will have to go somewhere. In the hypothetical situation where a power line is ‘plugged’ directly into an appliance, it would almost certainly catch fire and/or explode violently.

With local generation, the power generation happens either at a small-scale generation facility that supplies a small community directly, or potentially is done at numerous locations. One idea effectively turns every person’s house or residence into a power generation source.

The idea here is that instead of having one or a few massive power plants feeding a grid, there is a focus on a massive number of small power sourcing feeding a grid.

There are a few benefits to this approach:

1. Distributed risk: The risk from an individual facility ‘going down’ or being disrupted is reduced. Losing a single generator feeding into a grid is less of an impact than losing a power plant.

2. Greater expertise in the public: If there are more people involved in the power generation process then the average competency of people in this area will be higher. This would likely result in the average person being more effective at assisting to re-establish power during a disaster.

3. Redundancy: These two types of systems are not necessarily exclusive to each other. It is possible to design a system where these forms of power generation act as a backup or redundancy for each other.

If there is an issue with the power plant or the grid transmission network, an individual can power their home from their personal generator. If there is an issue with someone’s personal generator, they can use power from the grid.

But why is this any different from just having a backup generator?

This idea goes further, a backup generator does not feed back into the grid. A local generation system could be designed such that any given small-scale location could both draw power from the grid or feed power to the grid.

Consider the potential impact during heat waves. During a heat wave there is increased load on power systems, the risk of power outages increases due to demand.

With local grid generation, an individual that produces more power locally than they require could feed the excess power back into the grid to be used somewhere else. This means that the maximum power or surge capacity the total system can generate increases.

Increasing this maximum means increasing the maximum stress the system can receive before it breaks.

There are several different proposed ways to implement such a system, but for now the goal was to give people an overview of the idea.

If there is sufficient interest in further detail on this topic, let us know and we can explore more specifics around it.

Vezina is the CEO of Prepared Canada Corp. and is the author of Continuity 101. He can be reached at info@prepared.ca.