Nobrainer’s Think Tank

In Parts 1 & 2, I noted some egregious examples of people saying that increases in wind turbine output don’t reduce over all CO2 emissions. In both cases the authors cited work in support of their writing that on basic inspection proved to contradict what they were claiming. Where last I left off, I was writing how Richard S. Courtney was doing a horrid job of representing how the current grid operates.

Following some of what Courtney wrote are some choice excerpts from a lengthy document, Renewable Electricity and the Grid, the Challenge of Variability, that I ran across whist trying to find one of Courtney’s sources. The original source as well that as this document contradict Courtney.

Said Courtney:

Each thermal power station is designed to provide an output of electricity. It can only
provide very little more or very little less than this output

… only small variation to the output of each power station is possible.

But operating a power station at less than its optimum output severely reduces its efficiency so it has little reduction to its fuel consumption and emissions although it supplies less electricity.

Says this newer document (emphasis mine):

Output from steam plants can be reduced to about 50 per cent of design without much difficulty… The main effect is that by operating at reduced output, efficiency goes down slightly.

Actual CO2 savings are dependent upon what fossil fuel plant is displaced. These savings are reduced by efficiency losses in thermal plant affected by intermittency and additional use of reserve and response services. In practice, these losses are a small proportion of the energy provided. CO2 savings are, within a few percentage points, directly linked to the energy that renewable stations generate (Gross et al, 2006).

On the UK National Grid system there is approximately 1.5GW of ‘spinning reserve’ – typically, this takes the form of a large power station that is paid to produce at less than its full output. Such a station might have four generating sets each of 660MW, giving a total output of 2.64GW, but might only be operating at 2GW [with 500MW being generated per set] with the steam boiler full but the steam valve not fully open. On request from the National Grid control centre, this valve can open and deliver an extra 640MW in 20 to 30 seconds. This requires the boiler air fans and the coal feeders to increase output accordingly. The greater the total load on the system, and the
greater the expectation of large fluctuations (e.g. at the end of popular TV programmes), the larger the proportion of spinning reserve set by the NGT. It is worth noting that the cost of such spinning reserve is not high, as is often erroneously stated. The efficiency of a plant might change from, say, 37 to 36.5 per cent if the output of the set is dropped from 660MW to 500MW (i.e. 160MW spinning reserve). The fuel penalty involved (about 1.5 per cent) is tiny compared to the total amount of fuel passing through the power station.

In Part 4 I’ll show some data from one of my favorite plants that, like just about everything else, contradicts what Courtney wrote.

I’m not convinced that wind power is the greatest thing since sliced bread. I’m not too convinced that wind deserves the subsidies it receives. However, there are things being said against wind that are completely unfair. Since I both know better and have a blog, why not call some people out?

Out there in the aether that is the internet, is a person named Richard S. Courtney who argues against wind by completely misrepresenting how bulk power systems (i.e. the grid) currently operate. As early as 2006, he published a paper titled, “Wind Farms Provide Negligible Useful Electricity.” It’s quite a claim. In it there are two sections, numbers 8 & 9, in which he horribly mangles the current state of things. Fortunately the sections are short and easy to dissect.

Section 8 is Thermal Power Stations.

Conventional (i.e. thermal) power stations fission a material or burn a fuel to obtain heat that is used to boil water and superheat the resulting steam which is fed to the steam turbines (some power stations – e.g. combined cycle gas turbine: CCGT – also use gas turbines in combination with steam turbines). The turbines drive turbogenerators that make electricity.

The first paragraph, aside from leaving out simple-cycle gas turbines, is unobjectionable.

A thermal power station takes days to start producing electricity from a cold start.²⁰ Time is needed to boil the water, to superheat the steam, to warm all the components of the power station, and to spin the turbogenerators up to operating speed.

For steam plants, that’s approximately true. That’s not at all true for gas turbines or combined-cycle plants.

And if if it tells you anything else, the source listed for citation #20 is http://www.worley.com.au/v5/page.aspx?id=166, which no longer works.

Each thermal power station is designed to provide an output of electricity. It can only
provide very little more or very little less than this output (i.e. a power station has a “low
turndown ratio”).²¹

Citation #21 is Flynn P & Kumar A, ‘Site visit to Alholmens 240 MW power plant, Pietarsaari, Finland’ University of Alberta, September 2005. As the title suggests, the source is about a site visit to a lone power plant in Finland that happens to burn various non-traditional fuels such as wood waste. The source goes on to say, and I quote, “[a]t Alholmens it has a 35% turndown ratio (ratio of minimum sustainable operating level to design operating level).”

In other words, Courtney is extrapolating to every thermal plant from a single data point that actually says the opposite of what he’s claiming.

In practice, it’s typical for fossil fuel fired steam plants to have a turndown ratio of 20 to 40%. Admittedly, however, gas turbines & nuclear power plants (at least those in the US) have a turndown ratio of about 100%. Combined-cycle plants fall somewhere in between.

Moving on to the next section.

Sec. 9 - Electricity demand matching²²
Electricity is wanted from a grid supply all the time but the demand for electricity varies from hour to hour, day to day, and month to month. The electricity grid has to match the supply of electricity to the demand for it at all times.

Going well so far..

This is difficult because thermal power stations cannot be switched on and off as demand varies, and only small variation to the output of each power station is possible.

That derailed quickly.

Gas turbines can be switched on and off as demand varies. Fossil fuel fired Steam turbines have can, and typically do, handle very large variations in output. The grid uses both technologies because they complement each other in this way. Courtney is taking the negatives from the separate technologies and applying them to all the thermal systems.

The problem of matching electricity supply to varying demand is overcome by operating
thermal power stations in three modes called
· ‘base load’,
· ‘generation’ and
· ‘spinning standby’ as backup capacity.
Some power stations operate all the time providing electricity to the grid, and they are said to provide the ‘base load’.

Other power stations also operate all the time but do not provide electricity all the time. They burn (or fission) their fuel to boil water and superheat the resulting steam which is fed to the steam turbines that are thus kept hot and spinning all the time. Of course, they emit all the emissions from use of their fuel all the time. But some of this time they dump heat from their cooling towers instead of generating electricity, and they are then said to be operating ‘spinning standby’.

One or more power stations can be switched from spinning standby to provide electricity to match an increase to demand for electricity. It is said to be operating ‘generation’ when it is providing electricity.

This is a relatively fair description. Although my experience says that it’s pretty rare for plants to be in ’spinning standby’ without also generating. Since steam plants can generate over a broad range, they can operate at 50% and still provide what is elsewhere referred to as ’spinning reserves.’ This basic premise carries over to show how his paragraph is similarly misinformed.

The wording about emissions also bothers me. Literally all he’s saying is that burned fuel releases emissions. However he seems to be implying that plants on spinning standby burn every bit as much fuel as those operating as base load.

Power stations are switched between spinning standby and generation as demand for electricity changes. Thus the grid operator manages the system to match supply with demand for electricity by switching power stations between ‘generation’ and ‘spinning standby’. And the small available variation in output from each power station is used to avoid large step changes in the supply when this switching is conducted. But operating a power station at less than its optimum output severely reduces its efficiency so it has little reduction to its fuel consumption and emissions although it supplies less electricity.²³

If you carefully consider the last sentence quoted above in the context of the rest of Courtney’s work, you’ll realize that he is actually contradicting himself. Think about it. Earlier he says, “only small variation to the output of each power station is possible.” But now he’s saying that being at less than “optimum output” reduces its efficiency “severely” resulting in “little reduction” to fuel use & emissions. If a small variation (10% would be my assumption) to output causes a severe (I’d guess a 50% change) efficiency loss, then fuel use & emissions can only increase. As I’ll show in a later post, output can achieve large variations with small efficiency changes leading to very large reductions in fuel consumption & emissions.

For all of these statements by Courtney in Sec. 9 about how things are run, and how that affects carbon emissions, there appears to be 2 sources. The citations page though shows that they are, in fact, the same source, a 2002 Platts article that I cannot access from Platts. However, a copy seems to exist here in Appendix I. The source agrees that the grid needs to be balanced between load and generation. That’s about all. It says nothing about carbon emissions nor fuel consumption. And it says this about backups:

Some of this spare capacity would be on ‘hot standby’, i.e. connected to the network and operating at part load to ensure a stability of connection as in the case of steam plant, or available for instant start-up and connection as is the case for hydro and gas-turbine plant.

Courtney provided 3 sources. Only 2 could I find, and both of them contradicted what he said. Sadly some people seem to trust Courtney.

Let me start by saying that I’m not the world’s biggest fan of wind energy. I doubt that I’ve been entirely fair to it in the past. I’m not convinced it’s really that great an investment. Although I certainly think it’s neat, and I even like seeing wind turbines on the horizon. However, some people are making critiques of wind that are pure rubbish. So why not spend some time taking out the trash?

I regularly see the argument that wind can’t reduce carbon output much if at all.

Here’s an example from the Canada’s National Press, which says, and I quote, “Der Spiegel reports that ‘Germany’s CO2 emissions haven’t been reduced by even a single gram’”. Umm, no. Says Der Spiegel:

Wind Turbines in Europe Do Nothing for Emissions-Reduction Goals

By Anselm Waldermann

Despite Europe’s boom in solar and wind energy, CO2 emissions haven’t been reduced by even a single gram.

The National Press fabricated a quote that is at odds with the article being reference. It’s clear from reading the actual article that they’re talking about European emissions not being reduced, not “Germany’s CO2 emissions.” In fact, the article makes the point that German CO2 emissions have declined because of its increased use of renewable energy. European emissions aren’t falling because Germany is selling it’s unused carbon credits to other nations who are then emitting carbon; such is life under a cap & trade system when the cap isn’t being lowered.

Allow me to follow up on my initial review of Thunderbird 3.

The new Thunderbird is growing on me. I’m getting used to the new position of buttons at about the same rate I adjust to the change in year. By April, or July if it’s a bad year, I should have it all figured out.

Since my last review, I installed Expression Search, which has made my email searching experience much more pleasant; in fact I like using this form of search far more than both the default Thunderbird and Google Desktop email searches. It appears that my quest for email search nirvana continues.

One bonus of the new Thunderbird is the ability to view email conversations. Sort of. From what I’ve observed, you can see all the participants and their initial remarks, but you can’t view the entire thing. Moreover, the format of the “conversation” in the reader pane is so devoid of contrast that I find it difficult, at least initially, to easily discern who is saying what to whom.

The most important improvement is the ability to open emails in tabs rather than in new windows. I like it for the same reason I liked the inclusion of tabs in the web browser. However, now that Thunderbird has tabs, I feel like there needs to be the option to incorporate Thunderbird directly into Firefox.

onsider this scenario I regularly encounter. In the morning, I awake to find dozens of new messages in my inbox. I triage them by opening the important or interesting ones in tabs. Once I make it through all the new messages, I attack the tabs. Frequently, the message in a tab is a Google News Alert, which, for the unfamiliar, includes possibly dozens of links of which there are a few worth clicking on.

As it happens now, those links open in new tabs in Firefox meaning I have to switch back and forth between the Firefox and Thunderbird windows. I would rather have those tabs open next to the email message I’m reading. There is a clunky extension for Thunderbird called ThunderBrowse, that accomplishes the task of opening web pages in Thunderbird. But it does not do so well. So rather than incorporating the browser into the email client, I think it needs to move in the other direction. It also needs to be more incorporated than the email/browser clients in SeaMonkey, where they’re basically separate programs where one can be used to open the other.

I would like to see the ability to create a dedicated Thunderbird tab, maybe that can be assigned a specific tab position, within Firefox. Then, email messages can be opened in tabs within FF and moved, sorted, maybe even bookmarked, in the same way that web pages are.

This really runs counter to the light, agile, browser concept. I accept that, which is why it should be an optional add on. But considering that 99.9% of the time I have Thunderbird and Firefox open anyway, I doubt there will be much of a change in system performance.

Thanks, Nanny State.

Microsoft was forced to introduce the browser “ballot box” following a ruling by the European Commission that Microsoft’s practice of pre-installing Internet Explorer on every new computer was anti-competitive…

“Millions of European consumers will benefit from this decision by having a free choice about which web browser they use,” said Neelie Kroes, the EU’s competition commissioner.

As opposed to opening your browser and freely downloading any of the plethora of free options?

This is what I’ve never understood about the governmental anti-competitive rulings against Microsoft & IE. Users have, I won’t say always, but for as long as I can remember, had the option to download & switch to any browser of their choice. It wasn’t as though Windows ever vetoed a browser and refused to use it.

In the past I’ve argued that even if we become “energy independent”, we’ll still import made things from foreign energy, meaning that we won’t truly be energy independent, that the only way to become “energy independent” is to remove all real meaning from the phrase. The other side of this is that alternatives may require that we become strongly dependent on other things found in other countries that may not like us. In other words, we’d be gaining independence by gaining dependence. Seems a bit silly, don’t you think?

It is silly. And it is real.

Some of the greenest technologies of the age, from electric cars to efficient light bulbs to very large wind turbines, are made possible by an unusual group of elements called rare earths. The world’s dependence on these substances is rising fast.

Just one problem: These elements come almost entirely from China, from some of the most environmentally damaging mines in the country, in an industry dominated by criminal gangs…

There are 17 rare-earth elements — some of which, despite the name, are not particularly rare — but two heavy rare earths, dysprosium and terbium, are in especially short supply, mainly because they have emerged as the miracle ingredients of green energy products. Tiny quantities of dysprosium can make magnets in electric motors lighter by 90 percent, while terbium can help cut the electricity usage of lights by 80 percent. Dysprosium prices have climbed nearly sevenfold since 2003, to $53 a pound. Terbium prices quadrupled from 2003 to 2008, peaking at $407 a pound, before slumping in the global economic crisis to $205 a pound.

China mines more than 99 percent of the world’s dysprosium and terbium.