Is my power green?

June 6, 2012 5:29 PM

In 2009, 91.2% of Seattle's electricity was from hydroelectric sources, and in 2010, 87.9% was hydro. Is the hydro capacity maxed out, or will it scale up to meet additional demand and maintain that ratio? Here's what I'm getting at: If I were to use more electricity than now, will that incremental power effectively come from non-renewable sources rather than ~90% hydro?
posted by hodgebodge to science & nature (14 answers total)

There are not going to be more large dams built on the Columbia or its tributatries if that is what you are wondering. All the good sites are already dammed or protected and the current trend in dams is less, not more.

Whether the mix is Natural Gas/Coal or Wind/Solar in the future is up to the various regulatory bodies to decide.
posted by rockindata at 5:34 PM on June 6, 2012

So should I assume, then, that Nuclear/Coal/Wind/Others are scaling up to meet the needs of Seattle residents' new electric lawn mowers, etc.? Thus, the carbon footprint of, say, a new electric car would be much higher than it initially appears since none of its power would really come from hydro.
posted by hodgebodge at 5:46 PM on June 6, 2012

Yes in all likelihood the marginal power you demand will come from fossil fuels. Probably natural gas.
posted by JPD at 5:47 PM on June 6, 2012 [1 favorite]

Well un case of charging a car maybe not. Because you probably charge your car overnight when the dams might be producing more energy than normal baseload electricity demand. You should read the annual report of your local municipality.
posted by JPD at 5:50 PM on June 6, 2012

I'm only familiar with the Pacific NW power market as it affects CA's market, but, with that caveat:

1. Big hydro facilities simply aren't being built anymore, due to a combination of all the good sites being taken and concerns on the environmental effects (salmon and otherwise). There might be some small hydro facilities still being produced, but they aren't large enough to be a major factor.

2. Wind, and to a lesser extent, solar is stills growing segment of the market. So they're a possible contributer towards expanding the energy portfolio of WA as demand increases. However, there are real concerns regarding reliability of renewables - while hydro can be managed to be *fairly* steady, you're still ultimately relying on Mother Nature to supply you the power when you need it. Wind generates mostly at night. Solar takes awhile to ramp up during the day, and also is obviously less effective with cloud cover. Hydro is great (sometimes TOO great of a supplier) in the spring and early summer, but it always depends on the current snow pack, and how full the reservoirs are from the previous year's precip. Until our storage technology improves, we're going to require SOME fossil generation to manage the gaps. Given the nature of the Pacific NW's heavy hydro baseload, and my understanding of WA's emission regulations, the most likely case is natural gas combined cycles or combustion turbines.
posted by Gori Girl at 6:05 PM on June 6, 2012

So let me explain a little bit better. Yes most of power in Seattle is hydro, and during most nights 100% of the power is going to come from hydro, not only that by Seattle has more base capacity than it can use so about 20% of the utilities revenue comes from selling excess power to other users. So if you charging your car from 11PM to 6AM or so you aren't requiring Seattle to build a gas fired plant or buy a share of a wind farm. You might be forcing another utility to though - or probably an industrial user. But if its 6PM then Seattle is already using more electricity than the dams can provide - so if everyone decides they want to start doing something that requires more electricity at that time of the day then the Utility will have to procure the power someway - either by buying it or building a plant. Probably Natural Gas because you have to be able to get that many Mw on the grid at that exact moment in time, and most renewables just aren't reliable enough for something like that.
posted by JPD at 6:09 PM on June 6, 2012

Oh, and I have no idea if this is an option yet in WA, but it's becoming more popular down here in CA to offer customers a cost-adder to their electricity bill to "provide" them entirely with green energy only. Obviously, the particular electrons getting to your house would be from whatevers connected to the grid, but the company to procures extra renewable energy in line with your usage. If its not an option now, it could be in the near future.
posted by Gori Girl at 6:13 PM on June 6, 2012

So many variables to answer this question - it is hard to say anything simple. Daytime (peak) increased demand probably isn't coming from hydro. Off-peak (night) demand may well be (this time of year, power from some of the big dams on the Columbia can be free or even negatively priced at the wholesale level because there is more water than can be stored).

On the other side of the equation, we can free up a lot of current power usage by being more efficient with the power we do use. Conservation is a totally valid way to free up more power. While this sort of marginal exercise is sometimes useful, it also pays to remember that we make a whole lot of other choices that go into using the power we use now. It is far too easy to ignore the big picture about the energy we use.
posted by ssg at 6:52 PM on June 6, 2012 [1 favorite]

There are a few major dam decisions looming in our general geographic area.

First, BC Hydro's Site C, which is located in the North East corner of British Columbia. If all consultations and assessments go through without hangups, a major new dam will be built there within our lifetime.

Meanwhile, Seattle City Light's High Ross Dam question will be raised again in 2064. The deliberations leading up to that date will certainly begin sooner than we care to admit.

I agree with ssg: in the meantime, conservation is a very important way to free up more power. Let's not be wasteful where we can save.

However, with the proliferation of new electronic i-devices and the increased adoption of hybrid/electric cars, the demand for new sources of energy will only increase in the years to come. Conservation, wind, solar, coal, small-hydro and other sources of energy can only go so far.
posted by seawallrunner at 9:36 PM on June 6, 2012

Aside from the very rare new dams, there are plans to refurbishing many existing hydro facilities in the Pac NW with new generators. The impact being a smaller environmental footprint (smaller reservoir area) yet much higher total power output (at least twice or thrice). While this sounds almost like science fiction, bear in mind that many existing facilities were built in the 60s or 70s. By the time the upgrades happen, 50+ years of technological advancements will have occurred.
posted by wutangclan at 11:34 PM on June 6, 2012

Oh, and the reason why I haven't mentioned any specific projects is because my buddy who is a very senior (just below executive level) engineer with BC Hydro said that they can't go into specifics right now with a provincial election looming. Hopefully things will be pushed forward aggressively once a new, stable government is in place. Fingers crossed.
posted by wutangclan at 11:38 PM on June 6, 2012

the proliferation of new electronic i-devices

The growing popularity of these "i-devices" is a good thing from a power consumption standpoint. A big, bright tablet's charger might draw one or two watts; a whole household full of portable electronic devices might draw about the same amount of power as a single incandescent night-light. What's more, these devices tend to displace desktop computers, which draw something like 250 watts each, and TV sets, which draw in the neighborhood of 150 watts. On the whole, then, the proliferation of new portable electronic devices tends to reduce household power consumption.

increased adoption of hybrid/electric cars

This is more of a problem. Moving a car around takes an astonishing amount of energy. Fortunately most people who are currently looking into electric cars want to charge them overnight and drive them intermittently during the day, which fits well into the hydro & wind power profile.
posted by Mars Saxman at 10:49 AM on June 7, 2012

Thanks, everyone. Looks like these are the main points:

No, the hydro power won't scale up to meet the additional demand, at least in the near future. Hydro output might increase at some point in the (possibly distant) future.

The marginal power I would use would most likely come from natural gas, at least for the near future.

If I were to draw the power at night, it likely would be hydro. My use of that hydro power could mean that another utility would have to step up production from another source, though, since they won't get that otherwise excess hydro.

Remember that conservation is important.

There's a voluntary option to purchase electricity from renewable sources at a higher premium.

posted by hodgebodge at 9:18 PM on June 7, 2012

The only thing I would ad is that rather than paying a premium for "green" power spend that money instead on conservation

Green power doesn't really do what it says it's doing because it isn't something that can respond to load.
posted by JPD at 1:18 PM on June 8, 2012