11 November 2011

Just How Smart are Smart Grids?

The smart grid will supposedly give the electricity industry the information it needs to be more efficient. But what is it and how does it work?

A lot has happened during the past 50 years: adding machines have given way to computers, the jet engine has put every country in the world no more than 24 hours away from any other, and the wired phone – with a choice of no more than three colours – has given way to the smart phone, sporting a whole cornucopia of features.

The structure of the electricity industry, however, has remained substantially unaltered. Indeed, it would be largely familiar to the pioneering inventors of electric power, Thomas Edison and Nikola Tesla. Even the first nuclear power stations have only been decommissioned in recent years.

But that world is about to be shaken up by the concept of the ‘smart grid’ – even impoverished Romania has its own ‘smart grid development plan’.

Traditionally, electricity companies have had to anticipate demand and make sure that it is met – if they do not, the subsequent brownouts will certainly hit the headlines.

But with smart grids, the idea is that electricity companies will be given accurate minute-by-minute feedback on demand from smart metres so that they know the precise level of aggregate demand from their customers at any one time. As demand rises, point-by-point, the companies will be able to react accordingly.

This is important with a growing number of wind and solar farms inconsistently generating power, depending on the weather at any one time.

At the same time, the proliferation of micro-generation – as a result of feed-in tariffs to encourage householders to fit wind-power generators and solar panels – has started to make the generation end of the power equation much more complex. With power companies obligated to take surplus micro-generated power at set rates, they do not want to be seeking to meet an increase in demand by increasing their own output if micro-generated power can bridge the gap instead.

In other words, electricity generation has become a complicated balancing act, which requires some form of automated, second-by-second tallying of supply and demand to ensure that a minimal amount of power is wasted.

But the current structure of the electricity grid is monolithic. It is based on the concept of the big power station pumping out electricity to homes and businesses within a particular region. The bosses at the power company, therefore, must anticipate demand – perhaps turning on an auxiliary gas-fired station to satisfy demand at half time in the World Cup semi-final (when everyone goes into their kitchen and switches on their electric kettle for a nice cup of tea).

Key breakthroughs

One of the key breakthroughs was made around 15 years ago when UK regional electricity utility company Norweb (later to become United Utilities) announced the development of its Digital Powerline technology for carrying Internet protocol (IP) communications over ordinary power lines at one megabits per second.

That was pretty fast for the time, but as a means of transmitting and receiving data was quickly eclipsed by ADSL and fibre. Besides, Norweb quickly decided that it wasn’t really in the Internet service provider business and sold its technology to a third-party for an undisclosed sum.

Yet the ability to transmit and receive standard IP communications over power lines remains the bedrock of smart grid technology. This enabled computing and networking communications companies, such as IBM, Cisco Systems and others, to move in and build systems to support the smart grid.

The ‘old’ grid was also capable of communications, but only very limited, point-to-point communication between specific devices. The smart grid, though, will positively chatter with communications.

What that means, however, is an electricity network full of routers and switches – ones without moving parts, or fans, or hard drives. They need to be able to work outside, in all weathers, from -40 degrees centigrade to 60 degrees centigrade. That is why networking hardware vendors are so interested in the smart grid: such devices will not be cheap.

Cisco’s CGR 2010 router and CGS 2050 switches were designed to be housed in neighborhood power substations. They can tie into video surveillance systems and, like other Cisco products, have intelligent routing so that they can redirect traffic in the event of outages on the IP network. Cisco expects power companies to put one or two of these routers and switches into every substation.

In addition, each endpoint – household, office or factory – will need smart metres. These are already being rolled out in some place. These have the ability to relay usage information both to the electricity utility, as well as the end user. For households, they offer the opportunity to see second-by-second usage of power and, hence, to determine what devices are costing them money.

By giving end-users the means to monitor their own power consumption, governments hope that this alone will help people and businesses to reduce their own power consumption without any coercion.

At the same time, usage information needs to be fed back to the power company to enable them to gauge consumption and, hence, the power they need to be feeding into the grid.

The hope is that this information will be married up with the output from generating capacity being fed into the grid from multiple sources to enable big savings to be made by generators. The more finely that they can hone output, the less energy they will ultimately consume and the lower end-users’ bills will be.

Well, one can dream, anyway.

Copyright © 2011 Resources Magazine

Technology, Thought leadership