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March 31, 2003
I must apologize to everybody who waited patiently for a column last week and got nothing for their efforts. Paradoxically, there was so much going on and so much to write about that I simply did not get around to sitting down to write. As it is, I have about three different topics from the last week alone that I could write about, but I'm now fending off my second cold this season and have very little energy. Sitting down to write a 1200 word article seems like way too much effort right now.
However, instead of stranding you twice in as many weeks without anything to read, I've polished up something I've had on the burners for a while. Perhaps next week I'll be feeling up to sharing the adventures of the past two weeks with you. In the meantime, please enjoy;
Electricity: Smoothing The Peak
Is Ernie Eves a compassionate consumer-minded politician, or is he a meddling waste of tax dollars? I'm sure we'll hear arguments for both sides in the upcoming Ontario provincial election that everyone assumes will be called this spring. One thing is for sure - the Ontario Conservative government (we'll give Harris some credit where due as well) has really done a number on Ontario's power generation system. Between canceling the privatization of power generation and transmission and freezing the rate until 2006, there isn't much else Eves can do to mess with the system. Oops, better not say that - he may take it as a challenge. Is it too late to send him back to the Founders? Anyways...
Regardless, the meddlesome tactics of the current Ontario Progressive Conservatives do not factor into our topic for this week. While the topic is electricity, we will not be talking about rates, rate freezes, rebates, energy policy, or any of that namby-pamby frou-frou intangible stuff. Instead, I want to discuss the technical side of how our power is generated and stored. More specifically, I want to discuss the total lack of storage capacity in the power grid.
Way back in the 1970's and 80's conservation was the buzzword when it came to electricity. Turn out lights, don't use so much. Friends, colleagues, and family members have all commented to me at one point or another the complete absence of this word in today's talk about energy. While it is implied when we are urged to change out our incandescent lightbulbs for compact fluorescent units, it's not stated outright. Instead, the big push seems to be load shifting instead. Why? My pet theory is that with so much capacity already online, the powers that be in power generation don't necessarily want a huge reduction in demand, as it will make paying for the existing capacity that much harder. What they'd rather see is a more efficient use of the capacity we have, instead of having to build even more. Fair enough, I suppose. The other possibility is that demand growth is far outstripping what impact conservation could have, although that seems like a rather nebulous self-referential knee-jerk argument to me.
The problem with power generation capacity is that the demand for power isn't constant throughout the day. At night, with only streetlights, refrigerators, alarm clocks, and a couple of night lights using power, demand is very low, far below the capacity of the system. During the day, however, with industry running at full tilt, demand spikes. In summertime with air conditioners eating up electricity like it's nobody's business, this demand spike can be even worse. The only thing the power generators can do is have enough capacity on hand to cover all demand, irrespective of how much the demand will dip later that evening. Having idle capacity is expensive, however. It produces nothing, generates no revenue, and thereby does not pay for itself, like all good investments should.
So, we the consumers are being asked to Do Our Part and help shift the load - smooth out the midday demand spike. To do this, we can do laundry in the evening instead of during the day, for example. Use as much electricity as you need to at night, but minimize your use during daylight hours. I can understand why we're being asked to do this - a smoothed demand curve would cause a lot less brownout warnings and grey hairs during summer months. Unfortunately, it really doesn't get to the root cause of the problem inherent with the system.
The system is designed to produce power. Pretty straightforward, right? Well, the problem is that there is no capacity for storage. If there were, power generation costs could plummet, as could power prices. Instead of building extra capacity to have enough for those high humidex, air quality advisory days with air conditioners running constantly, they would simply be able to recognize a forecasted high humidex, hot day and keep generating and storing power overnight the previous night, and use it up during the day's peak. With some even simple software, power generation could be kept at a near steady state over the course of many days and even weeks. Running a system at a nearly steady state is a lot more efficient than throttling it up and down, like they do currently. The question then remains, why hasn't the industry developed storage capacity? There is one possible answer I can think of, and it's purely technological.
Quite simply, it's the same reason you don't see electric vehicles on the road today - storage mediums for electricity have progressed in the past few decades, but not very quickly. The current methods of energy storage include batteries, flywheels, and capacitors, along with some other less-proven technologies. Batteries are heavy, expensive, and depending on what kind of battery you're talking about, they can give off hydrogen gas (which requires venting lest an explosion occur) and require periodic watering, or possibly contain hazardous or toxic materials. Flywheels are also heavy, require electric generators/motors to both store and release energy, and if you don't want to lose an excessive amount of energy to friction, you'll need low-friction bearings (like magnetic levitation bearings), and possibly even an airtight evacuated enclosure. Not exactly your WalMart variety off-the-shelf part. Capacitors, while less problematic than batteries, are not very good at storing energy. The capacitors with the largest capacities that I am aware of hold only 2800 joules of energy each. Put into perspective, that's enough energy to warm a mug of tea up from room temperature - hardly an astonishing amount as compared to batteries.
There are other technologies, none of which I've ever heard put into practice. The most ambitious I've read about, about a decade back, was to install huge loops of superconducting material underground, where it would be easier to keep the material down below the temperature that allows supercondution. Thus far the highest temperature superconductor I've ever read about operates at a temperature of 175° Kelvin - approximately -125° Celsius. Rather chilly.
There are likely technological solutions out there that would work, but would not have the efficiency desirable in such a system. For instance, I could use electricity to melt a material, say metal, and store the molten mass in an insulated crucible of some form. To extract the energy, one could pipe water (or other liquid) through a heat exchanger submerged in the molten mass and turn the water into steam, which could then turn a steam turbine attached to a generator. It would work, but at what efficiency? The system as described is fraught with inefficiencies simply due to the number of different stages that the energy has to pass through. It would be an interesting investigation, however, to determine what minimum efficiency that would be required to be effectively the same energy cost as today's no-storage system. The issue I could see arising is the issue of generating excessive greenhouse gases (or nuclear waste, or outright pollution) in generating energy that is just going to be wasted.
One method of storing energy overnight has already been proposed by the electric vehicle industry. To use a typical electric vehicle, one would drive it to work in the morning, home at night, and recharge it at home overnight to have a full charge in the morning to start the process all over again. That alone will help smooth the demand curve, as electric vehicles will be recharging overnight instead of during the day, and they'll be storing a fair amount energy doing so. However, it has been proposed that so-called grid hybrids could take this idea one step farther.
The idea is that the grid hybrid would have an energy storage capacity well beyond what is required to drive to and from home on any given day. The vehicle would start out in the morning fully charged, and be driven to work, at which point the majority of its charge is still available. During the day, the vehicle is left plugged in, and will actually discharge back into the grid during peak hours. At the end of the day enough charge is still left to comfortably get home. Once back in your driveway the vehicle is again plugged in to charge overnight and start the cycle over. The best part about grid hybrids is that the technology exists right now to do it - the only problem being that electric vehicles are not exactly abundant. When (not if) that does happen, most likely in California before anywhere else in North America, grid hybrids could theoretically make money simply by purchasing and storing cheap nighttime power and reselling it back to the grid at peak energy prices. Wouldn't that be cool? A car that doesn't pollute, eases the energy burden, and actually pays for itself. Sign me up!
Perhaps there are other non-technological ways of smoothing the energy demand cycle. Maybe we could start to promote alternate work hours for all sorts of different industries. Production facilities can run 3 shifts 24 hours a day, why no other industries? Although most service-oriented businesses have times when they definitely need to be open, there's no reason some office jobs or indoor skilled work needs to be done during the day. The more industry shifts to afternoon or night shifts, the smoother the energy demand curve becomes. Of course, asking someone to work midnights at the office instead of regular business hours would probably be met with a combination of anger, bewilderment, and outright refusal, whereas asking someone to do their laundry before they go to bed instead of during the day is more likely to be at least given a second thought.
Personally, I favour the grid-hybrid electric vehicle approach. They can be implemented immediately without any changes to our power grid, and will have the ancillary benefits of zero pollution, no gas consumption, reduced noise pollution, and seeing a lot of really vehicles on our roads. Unfortunately, getting people out of their SUVs and into electric vehicles would be a much bigger battle than asking them to buy a compact fluorescent lightbulb or doing their laundry at night. I suppose I'll just have to wait for $1.50/L gasoline and $0.20/kWh electricity.
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