Ontario’s power glut means possible nuclear plant shutdowns

Surplus base-load generation (SBG) has become an issue lately.  It occurs when Ontario's "must run" electricity sources (predominantly nuclear and hydro but also wind and solar) exceed Ontario's minimum demand.  SBG typically occurs on weekends or late evenings when Ontario's tie-lines can't export the surplus.

The IESO has formed a committee (SE-91) to find solutions to the problem.  Their initial proposal was a band-aid approach to curtail wind production during periods of SBG.  The root cause of the problem, of course, is that Ontario's nuclear capacity has gradually grown even as the province's demand has flattened.  Fortunately, Paul Murphy, the CEO of the IESO, has the vision and courage to speak out against the nuclear lobby.

The original article is here.

The Ottawa Citizen

February 6, 2012

Ian MacLeod

OTTAWA — For at least eight hours Monday, Ontario is once again forecast to produce more electricity than it consumes, and the recurring glut has one top energy executive warning of temporary nuclear power plant shutdowns.

“We have largely been able to avoid nuclear shutdowns to deal with the (surplus) conditions but this may not be the case in the near future,” Paul Murphy, head of the Independent Electricity System Operator (IESO), recently told an industry gathering.

His comment is raising questions about Ontario’s plans to boost nuclear power as the province’s chief source of energy.

Nuclear-generated power supplies about 57 per cent of Ontario’s electricity. Based on the province’s assumption that demand will grow moderately over the long term, multi-billion-dollar projects are contemplated for new reactors and refurbishments of existing ones.

The problem is, unlike wind and some other forms of power production, nuclear reactors can’t easily be turned off when demand for electricity drops.

Returning them to full operating status can take two to four days and sometimes longer, making nuclear the least flexible portion of the supply mix at a time when demand is increasingly finicky.

And since electricity can’t be stored and must be used as soon as it is generated, the resulting “surplus baseload generation” in the system has to be exported to neighbouring provinces and states, usually at a bargain price, until the IESO can rebalance supply with demand.

In some cases, “negative pricing” is required. Ontario electricity producers shelled out $35 million in the first six months of last year alone to get neighbouring jurisdictions to take surplus power, up sharply from the same period in 2010, when negative pricing amounted to $4.2 million.

The supply surpluses have become increasingly common since 2005 and are expected to continue for at least a few more years, said Murphy.

Yet some surplus periods, which are forecast based on weather predictions and historic patterns, sometimes only last for a few hours.

“We need to find alternative ways to address (surpluses) to avoid using a multiday nuclear shutdown to address surplus conditions that could last for only a few short hours,” said Murphy.

“Given the potential of quick swings from surplus to shortage, those actions could have greater consequences in the future if the shutdown nuclear unit is not available by the time we need it again.”

Last June 8, for example, he said Ontario was exporting “everything we could to keep supply in line only to declare an energy emergency alert just 12 hours later. Demand climbed to the point where we were using every available megawatt in Ontario to meet that demand.”

Murphy’s remark about potentially and temporarily shutting down power reactors casts doubt on some fundamental assumptions of the province’s energy planning, says Mark Winfield, an associate professor in the faculty of environmental studies at York University.

“Given the province is theoretically committed to building a new nuclear plant and is considering refurbishment decisions on Bruce B (reactors), the implication is, one, you shouldn’t be adding supply on that scale and, two, if you’re going to add supply, it probably should be supply that you can turn off when you don’t need it,” says Winfield, who also co-chairs the school’s Sustainable Energy Imitative.

“It’s the IESO whose job it is to have their finger on the pulse of the system and also to be looking ahead (and it is) basically saying that potentially some pretty fundamental assumptions underlying planning for the system for the past decade need to revisited.”

Contributing factors to the excess supply include the global economic slump, consumer and industry conservation measures. and the Ontario economy’s transition away from manufacturing and resource-processing.

Seasonally, the situation typically worsens in spring and fall, when furnaces and air conditioners are turned off, and spring runoff forces hydro facilities to “spill” the water rather than store it for peak periods.

Additional factors will be the return to service of two refurbished reactors at the Bruce generation station near Kincardine and the increasing quantities of renewable energy coming on to the grid under Ontario’s Green Energy Act.

PJM and GM run trial charging from renewable energy

Here's a cross-post from Glen Estill's blog.  It describes yet another way that Ontario could manage electrical demand during times when we have an abundance of renewal energy.

Glen Estill's wind-blog
January 29, 2012

PJM – the regional transmission operator for Pennsylvania, New Jersey and Maryland has an interesting trial underway with charging of the Chevy Volt, the plug in hybrid from General Motors.

The system operator will monitor the output from the region’s renewable energy sources, and when surplus is available, will send a signal to General Motors. General Motors will then relay the signal on to the Chevy Volts connected to the system via their On Star system, and tell those vehicles to beginning charging their batteries. It shows forward thinking both by PJM and GM.

I like the fact that it is using existing technology – the On Star system, that is standard with the Volt. This makes such a system insanely cheap to implement.

Of course if the system operator can send signals for when renewable energy is available, they could act on almost any parameter, such as when power is in surplus from any source, or when power is cheapest. The renewable energy aspect of this is mainly for public relations – system operators need more tools to allow them to manage both times of surplus and shortage of power, and this is a powerful and very low cost tool.

PJM is showing great foresight in looking into this now. There are still some unknowns about electric cars. How many will there be? How much power can the average one take? How many cars are plugged in when the signal is sent? Gathering information now will help them greatly as the number of electric cars proliferates. They will also learn how to quickly implement systems, and standardize software interfaces to accommodate new electric car makes and models.

The Ontario IESO has talked about an emerging problem of surplus baseload generation (SBG). This is when generation in the province exceeds demand (including exports). As we bring on more inflexible refurbished nuclear plants, that can’t be shut down easily, the problem is likely to get worse. Of course, if you can shift demand to times of SBG, you could solve the problem. Using electric cars is just one solution, but one that will become more important as the electric car fleet increases in size.

The Chevy Volt stores 16 kWh fully charged. If an average Volt requires 10 kWh to be topped up at the end of the day, then 100,000 Volts would require 1 million kWh, or 1000 MW of generation for an hour. This is equal to 70% of Ontario’s wind fleet, or equal to the output of 2 of the Pickering units. This is not a trivial amount. And 100,000 Chevy Volts is only a little over 1% of the vehicle fleet in Ontario, and less than half the current fleet of hybrid vehicles. In addition to the Volt, there is the Nissan Leaf, which stores 24 kWh, and another 10 plug in electric vehicles coming to the market in the next year or two. 1% may be conservative.

The bottom line is electric cars offer interesting potential to buffer times of surplus power on a system. If this is added to using dams to store water when surplus generation exists, either in Ontario or neighbouring hydraulic based Quebec and Manitoba, or switching on hot water heaters, and other innovative load shifting techniques, the problem of SBG can be addressed. It would be good if the IESO would begin their own trials with GM.

Minnesota Wind To Be Stored By Manitoba Hydro

This is another terrific cross-post from Glen Estill

Wind-blog.com

January 31, 2012

Glen Estill

An interesting story crossed my screen this morning. Minnesota is going to buy electricity from Manitoba’s hydroelectric system. Part of the agreement allows them to send energy from Minnesota wind north to Manitoba, to allow Manitoba to store that energy behind their power dams.

Minnesota is one of the leading States in supplying their power from wind. Minnesota has over 2700 MW of wind capacity, much of it located on the Buffalo Ridge in the south west corner of the state. They have almost double the installed capacity of Ontario, and their total consumption is a little over 40% of Ontario’s. So they get a lot more of their power from wind than we do – more than 4 times as a percentage of supply. They have been doing it longer, so they have more experience integrating it with other power sources. And that is why this agreement is significant. They realize that one of the least cost ways of storing is to use existing hydro dams.

The agreement calls for the purchase of 250 MW of electricity from water power for 15 years, beginning in 2020. And it allows Minnesota to export power when they have surplus from their wind facilities.

Ontario also borders Manitoba. But Manitoba is a long way from Ontario’s big load centers. It is costly to use Manitoba to store our wind energy during times of surplus, at least if new transmission needs to be built. Ontario has only small connections to Manitoba today. Ontario can use its own hydro resources to store a lot of wind today, but in times of surplus, it would make the most sense for Ontario to use the existing storage available in Quebec. They have multi year storage capability. Even better, the Province of Quebec is a winter peaking jurisdiction, exactly when the wind is strongest. Quebec could use Ontario’s wind when their water flows are lowest, saving energy behind their dams, to sell back to us when Ontario’s summer peaks occur. This would use existing power dams, and existing transmission – we have over 2000 MW of connection to Quebec already. This is enough to transmit all of Ontario’s wind production, should it all be in surplus at any point.

It is time for the government or the IESO to begin the discussion.