Are microgrids a better answer for ensuring power resilience? The State of Connecticut in the US is running trials to find out.
Widespread power cuts are big news when they happen and they’re on the increase. In the US there were more than 3000 outages affecting 41m people in 2011, a significant increase from 2008 when it was 2100 outages affecting 25m people.
A State Governor in Connecticut, USA, decided enough was enough and asked a panel to come up with a solution. While they offered up all the usual answers, such as burying power cables, they also proffered “the “microgrid”.
Laptops are brilliant during a power cut. If you’ve got them in the business continuity team, you’ve probably had to remind other colleagues to let you know if there’s an outage as you might not be able to tell. Microgrids are a similar kind of concept – they isolate an area of power generation so that the area continues to work even if the rest of the grid fails.
The nature of the power grid as a grid structure is an inherent vulnerability to the utility infrastructre – and the impact of a big outage is significant. It’s not just homes and businesses that are affected: transport, traffic lights, water supplies… more or less everything is powered by mains these days.
The standard business solution to power protection is a combination of Uninterruptible Power Supply (UPS) units and generators.
[UPS systems are triggered by a power loss and - as their name suggests - ensures the powers supply to the protected items is not disrupted. But generally UPS run on batteries and often only last between 12 and 40 minutes. So those with real assets to protect often install a generator system that is activated to begin supplying power before the UPS runs out. Generators are often powered by diesel or gas, and can continue to supply power as long as they are fuelled. But they are relatively expensive to install and maintain and require a lot of technical expertise.]
So what’s a microgrid?
It’s basically a relatively small area of grid with its own power source. It’s usually linked to the main grid but can also work in isolation of it should the main grid lose power… seamlessly.
Microgrids also appeal to those who like ‘cleaner’ energy sources since their power sources are ofen more environmentally friendly than the larger grids. They’re also closer to the point of delivery: the electricity doesn’t have to travel so far so less is lost en route.
Since June 2012, Connecticut have had a microgrid pilot programme. The US Department Of Energy has also been granted $20m to develop the idea with the aim of having a number of microgrids in play by mid-2013.
The Connecticut trial will see the microgrids placed near critical facilities including emergency service stations, medical facilities and utility hubs. But there is also potential for them to be placed in commercial centres and shopping areas – including gas stations.
We’ll be watching Connecticut to see how the trials go…
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