Girding for Expanding Alberta’s Electricity Grid

Electricity is something we take for granted.  Flick a switch, or push a button, and on go the lights, the computer, the television and the dishwasher - with the refrigerator and furnace fan steadily humming in the background.  But in recent years, Alberta's network of transmission lines has grown sufficiently old and crowded that this endless, uninterrupted supply of electricity may no longer be guaranteed.

Twenty years of rapid economic growth have prompted Alberta's power consumption to more than double, from 33 million megawatt hours in 1987 to 69 million in 2007.  In the past two years, that growth surge has been punctuated by the setting of several records, in both winter and summer, for peak electricity consumption.

But over the past two decades, only one significant transmission line (between Edmonton and Fort McMurray) has been added to the province's electric grid.  As one power supplier points out, this means Alberta's reserve electricity margin - essentially the ability to handle unexpected outages - has tumbled from a healthy 23 per cent in 2003 to a razor-thin seven per cent in 2008.  While Alberta regularly buys and sells electricity with B.C., the province's grid is one of the least interconnected in Canada, with limited capacity to import or export electricity when needed.  As a result of all these things, some industry players believe, the transmission system has been stretched close to the breaking point.

"The risk of a catastrophic failure, of, say, rolling brownouts throughout the province, has never been greater because of the lack of new transmission capacity," says Epcor Senior Vice President Jim Oosterbaan, noting an 80-minute brownout two years ago could easily have been much worse.  "We can get by with the status quo for a while, but it's unexpected outages from a plant shutdown, a lightning strike or an ice storm that are the immediate concern.  There's a real need to upgrade and strengthen the whole transmission grid in the province."

What role can renewable energy and, specifically, micro-generation projects, play in resolving this looming electricity shortfall?  There are two aspects to this issue: addressing congested transmission and helping meet the growing demand for electricity.  On the first point, some distributed generation proponents argue that having a number of small, autonomous electricity generators will provide a diversity of electricity sources, adjacent to loads, that could help reduce the overall demand for power and thus lessen the strain on transmission and distribution lines.

Overcrowded transmission lines are bad news for reasons beyond potential brownouts.  The more electricity that is squeezed onto these lines, the hotter they get, resulting in energy losses often exceeding five or even 10 per cent.

"The transmission system is now wasting enough electricity to power half the city of Red Deer.  To make up for those losses, you have to generate more electricity, which means additional greenhouse gases and pollution," says Martin Merritt, Alberta's Market Surveillance Administrator, charged with ensuring the province's electricity market functions competitively.

A third problem with a constrained transmission system, says Merritt, is it restricts access to the grid by new sources of generation and diminishes consumers' ability to get electricity from the lowest-cost generator anywhere on the grid.  He likens it to being forced, by congested roads, to shop for groceries at nearby but expensive convenience stores instead of going across town to cheaper big-box stores.

In its new energy strategy, the Alberta government promises to lead the development of a plan for a comprehensive upgrade to the province's transmission system.  This includes building transmission lines to new sources of renewable, low-emission electricity such as hydroelectric power in Alberta's north, solar and wind in the south and biomass in the northwest.  A robust transmission system, the strategy argues, would also support new, low-emission consumer products such as plug-in electric cars.

There are, however, competing visions of how this transmission bottleneck should be overcome along Alberta's major power corridor.  One includes building a proposed $600-million, 500-kilovolt line connecting the electrical-generating heartland near Edmonton with Calgary-area customers and allowing more electricity to be exported to B.C.   The hearing process into the controversial location of this line has now been extended until the end of 2009.  "This delay is very disconcerting, and it only increases the risk of catastrophic failure," says Epcor's Oosterbaan. "We need to move promptly."

Meanwhile, Calgary-based Enmax Corporation contends that even constructing this high-voltage line would not resolve the problem of insufficient transmission capacity, at the end of this line, to bring that electricity into Calgary.  Enmax is calling for a comprehensive review of all options, including generation located close to major loads, to find the best economic and environmental solution.  It is moving ahead with a $1-billion-plus plan to build two gas-fired electrical generators, in and near Calgary, with a total capacity of 1,200 megawatts, along with a smaller transmission line to deliver that power to the city by about 2015.

"The provincial grid upgrades contemplated over the next while total about $10 billion, while the total generation we need over the same time will cost about $5 billion," says Enmax CEO Gary Holden. "It's a really odd situation where we need to spend twice as much capital to hook up the energy we need.  We are adamant that we must look at alternatives to just building wire, which is paid for by customers, not the generators."

At the same time, the Alberta Electric System Operator (AESO) - which is responsible for overseeing the planning and operation of Alberta's electric grid - forecasts Alberta's electricity supply needs to increase by 5,000 megawatts (or 42 per cent) by 2017 and by 11,700 megawatts by 2027 to supply Alberta's growing market.  Some of that demand will be met by Enmax's proposed gas-fired plants and by Epcor's and TransAlta's planned $1.6-billion, 450-megawatt unit west of Edmonton, complementing a similar-sized coal-fired unit that began operating in 2005.  The AESO estimates the equivalent of 11 more such units will be required by 2017.

What role might renewable energies such as wind farms and distributed generation projects play in supplying this demand?  Southern Alberta wind farms, which currently have the capacity to produce 497 megawatts of electricity, could be a significant future contributor. A surprising 11,000 megawatts in new wind power projects have been proposed, though there's neither the transmission capacity or backup to accommodate this much wind in the foreseeable future. An approved new transmission line to southwest Alberta, for example, will only add some 500 megawatts of capacity when completed in 2010.

It's also hard to predict how much electricity will be supplied by Alberta's fledgling distributed generation sector.  One sizable project is ATCO's and TransCanada Corp.'s planned 1,200 megawatt run-of-river hydro development on the Slave River in northeast Alberta.

Most distributed generation projects are, by their nature, much, much smaller, typically producing about as much total electricity as that consumed by the individual households they're connected to.  But such dispersed tiny "power plants" could eventually add up to a considerable amount of produced electricity, thanks in part to a couple of new developments.  For one thing, new provincial regulations, which go into effect January 1, 2009, make it much easier for micro-generation installations such as solar photovoltaic systems and residential wind turbines to be approved and to be connected to the grid, allowing homeowners to sell their surplus electricity.  At the same time, Enmax is proposing to install and rent these renewable energy systems to homeowners and thus make it much easier for them to generate their own electricity.

A major obstacle to the widespread growth of all these renewable electricity systems is their intermittent nature.  In other words, they don't produce power when the sun isn't shining or the wind isn't blowing, and their surplus can't easily be stored when they are producing lots of electricity.  That means you need considerable amounts of reliable standby power, usually produced by fossil fuels such as coal or natural gas.

"I think distributed technologies have a terrific role to play in Alberta's future electricity supply, especially from an environmental perspective, but renewables alone are not the answer," says Merritt.  "Society is not going to find the solutions to the problems we face if there is a willful ignorance of the challenges that intermittent technologies present and the fact that they need to use the grid as a big battery."

Still, an expanded transmission network, better interconnections with other jurisdictions and a diversity of new generation sources will make it easier for renewable energies to become an important part of Alberta's future electricity mix.  "We've become a lot better at integrating more wind while maintaining a reliable grid," says Warren Frost, AESO's vice president of operations and reliability.  "In a nutshell, it's a matter of being able to forecast winds and being able to adjust your resources and procedures to ramp up and down other, flexible resources to balance supply and demand."