Posts Tagged ‘electricity’

Decarbonising the electricity system is a piece of cake

February 4th, 2009

Interesting ideas were bounced off today in one of our lectures. Although we all know those ideas, we sometimes lose focus of where the problem really lies when we are looking at decarbonising the electricity system. NASA has put a man on the moon about 40 years ago and compared to that decarbonising the electricity system is a piece of cake. If we really want we can just build loads of renewables and it’s done. The problem is the cost.

I can hear you already, well of course the cost is a problem, we all know that. And yes we do, but we must remember that. You hear a lot of discussions on how difficult it is to decarbonise the system and you think if only we can find this new breakthrough technology. The technology of course is there, all our efforts are concentrated on making it cheap.

There is therefore much more work to be expended on financial and policy issues then technological issues. Spending on R&D might be a good idea but we must start taking action and start learning by doing. If you spend on R&D you do increase your chances of finding that cheap efficient technology but is you spend on demo projects, you get something at the end plus the actual output of the project.

Learning by doing has always been a cornerstone of human advancement. The cliche example of edison and his light bulb applies here. At the end of the day if governments really attached a high value to the enviornmental issue as they do to banks, we can just pay our way out of it. So in risk of repeating myself, focus on the cost and learn by doing.

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The state and development of the Chinese power sector

January 24th, 2009

I came across this description of the state and development of the Chinese power sector. It is written by Weimin Xi who kindly agreed for me to post it here. I am sure you will find it to be very interesting as I did.

Capacity in China, how many installed and how many to be installed?

Since I came here I have heard too much comment on the energy consumption of China. Hardly could you miss it in any lectures on general energy issues or in the general part of them. Although most lecturers are fairly objective in quoting figures (I especially appreciate Paul, who emphasized that the oil consumption increase can not simply be attributed to China and India in our course of International Oil and Gas Market), some of them made quite mistaken statements, and sometime the style of the expression is rather misleading. Also, there are some circumstances when the figure seems rather abnormal, while the lecturer fails to give further explanation. It is especially the case when it comes to power sector during the first decade of this century. For instance, China is building 2 coal-fired power stations a week, as demonstrated by Ed Miliband in some lecture. Ed is undoubtedly an interesting guy however, as a minister, it is not the right way to cheer people up like that.

So I will show some facts here.

1. How many generators were built in China

I have a table here, source mostly from CEC(Chinese Electricity Council), listing the total and annual incremental capacities and thermal capacities in China from 1997 to 2008 (unit: GW).

  1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008
Total 254 277 299 319 338 357 391 442 517 622 713 793
Annual 18 23 21 21 19 18 35 51 75 105 91 79
Thermal 192 210 233 238 253 266 290 329 391 484 554 601
Annual 14 17 14 14 16 13 24 40 62 93 70 47

It can be seen the annual increased capacity of China peaked in 2006, which was 105GW, including 93GW thermal power plants (the coal-fired station should be less, for there were quite a few gas-fired CCGTs). Last year, the annual increase of thermal power station has dropped to 47GW. And it’s almost certain this figure will continue dropping this year and on.

Let us verify what Ed Miliband said. It is really some tricky words from politician, instead of engineer. For 2 coal-fired power stations, you don’t know what the unit capacity is(2*6MW CHP, or 2*1000MW ultra supercritical coal fired station?), and you don’t know the time scale it is applying to(one month, one year, or a decade?). That means it is always right. We can easily infer the probability of 2 coal fired power stations commisioned in one week is high using whatever probability distribution, when there are in total 47GW commissioned. We all know he is just implicating that China is building too many coal-fired power plants, however, this kind of expression is really misleading. People who are not familiar with actual situation will naturally apply 2 of 2*600MW coal fired power plants every week for a year, which means 120GW installed per annum, almost 2 times of UK current total demand.

So, it is necessary to point out something on the unusual increase of capacity from 2005 and 2008, which have been abused by many lecturers in similar way of expression like ED.

It can be traced back to the end of last century, as the financial crisis swept Southeast Asia in 1998. Almost all countries influenced adjusted their demand forecast down to low level, some of which even made negative increase forecasts. China also made very conservative load forecast for 2005 and 2010. As the consequence, coal-fired power plants were rarely approved afterwards, considering the hydro projects(e.g. Three Gorges) and natural gas generators to be built. Take my province of Jiangsu as example, we had 4 gas projects and 1 pumped storage project approved since 1999 to 2003, without even one large coal-fired project(obviously, small CHPs still can be built).

However, the power demand keeps increasing despite of the adversities of economy, and began to soar since around 2003 with a speed far exceeding what estimated. This is complex to explain, but the main drivers include the WTO entry of China in 2001, the huge investment on infrastructure, the heavy and chemistry industry dominated industrial structure, the competitive advantage of low energy and labor cost in China, and don’t forget the high borrowing of US. The power shortage from 2002 lasting until 2006 all over the country severely influced the industries and residentials. Government and investors hurried to build generators, however, power plant has considerably long lead time before operation. That is basically why most of the generators were commissioned from 2005 to 2008, as clearly seen in the figures. Unfortunately, these power plants are mostly thermal, where coal-fired dominated. The reason, as you can imagine, is that nuclear and hydro take too long construction time to meet the demand, while gas is very limited for generation. So, for the generators commissioned in 2005-2008, at least some of them should have been built before 2006 to avoid the power shortage. If we even out the incremental capacity during 2002(when power shortage appeared) and 2008, the annual increase of thermal units was 50GW. And one thing should be pointed out is in 2008, there had already been a very obvious signal of capacity surplus.

This also explains why the supercritical units orders of China skyrocketed after 2000. Compared with the continuous increase of US and Japan, there was actually an sudden abruption of large coal-fired power station construction for several years before 2002 in China.

After this summit of generators commissioning, actually since the end of 2006, the main theme of power sector in China has been tuned to closing down small low efficiency generators. Coal-fired power stations can only be built with precondition that proportional capacity of small generators be closed down first. New generators approval was strictly controlled. My province of Jiangsu, the third largest province in terms of economic scale in China, haven’t had even one big coal-fired generator begin to construct during Dec. 2005 and Oct. 2007, when a project of 2*600MW coal-fired projects begun construction after closing down 2*300MW old oil-fired units. Even now, there are few more coal-fired projects finally approved.

At the same time, more focuses are put on other clean generations. Wind power increased a lot during this period of time. In my province, there have already been more than 1000MW commissioned or in construction in less than 3 years. Following this years global credit crunch, the demand also dropped significantly. Although the coal-fired powe station capacity will still continue to increase, but the stunning figure of 2006 and 2007 would hardly appear again.

Above is roughly the depiction of what happened in Chinese power sector in those years. And it is also a mirror of the whole energy sector of China in that period.

2. How many generators will be built in China

This is something too complex to answer. Maybe someone can give us an answer using Mixed Integer Non-Linear Programming with millions of binary variables. Let’s use a simple model of elasticity, which is frequently used in long term power sector planning for verification. Simply set the elastic coefficiency(annual electricity demand growth ratio/annual GDP growth ratio) to be 0.6 in the long term. The officially expected GDP growth rate is 8%, then the demand growth rate should be 5.4%, plus a reserve margin would be roughly 6%. Based on current 780GW of capacity,  that is to say, to sustain the electric demand in CURRENT WAY(which is not possible to sustain), the annual net increase of capacity should be 47GW.

It’s obvious this number couldn’t last long. So, another simple and practical model can be used to estimate the ultimate capacity (maybe it can be called carrying capacity, according to Tuesday’s lecture), which is per capita method. Assuming China will ultimately have a per capita capacity of 1kW(a rather low level), the saturate capacity should be 1300GW, 500GW more than current level.

Even if we complete this task in 50 years, there would be 10GW built per year, which is a huge number for most countries. However, people should notice the fact below if he thinks the growth of China’s capacity too fast:

Firstly, even with 1kW per captia of capacity in China, it is still very low, compared with 3.6kW per capita of US(in 2006). China may never reach the level of US, but the current level of per capita capacity(much less than 1kW) is obviously too low still.

Secondly, as China is currently a net export country(in fact, a highly export-dependent country), significant portion of its energy consumption is actually exported. That means, this portion of energy will just be consumed, no matter where the factory is located. So it is not some isolated issue on China’s energy consumption, nor are any other countries.

There are still to come more and more lectures in which China will be again and again mentioned as example to illustrate how world energy consumption growth, or the relationship between population and energy, or the comparison of energy density per unit of GDP. That’s nice. However, it will be better to know the reason of those unusual figures, in stead of staying at the level of knowing the figures, which only confuses people.

Finally, this article is not aimed at criticizing any people, even including Ed. Just to give some facts and views for sharing.

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Feed-in Tariff, fair?

January 19th, 2009

Feed-in tariffs (FiT) are one of multiple ways to push renewable energy technologies into commercial viability. The idea here is that if you install some sort of renewable electricity generator, someone will buy your excess production as you pump it into he grid. Not only are you guaranteed a buyer but you are also guaranteed a buying price. This works out brilliantly for would-be investors because they know exactly how much they can get from their investment. This isolates them from a lot of market risk and allows them to make their assessments confidently and spend their money happily. Of course if the buying price is too low they won’t invest in anything but at least they would be happy knowing that there is no opportunity missed there.

Now there are generally two types of electricity markets in the world (very broad generalisation there). A centrally planned one and a market based one. In a centrally planned electricity system, things are easy. The government is your buyer and it decides the price that it will pay you. Of course the buying price is normally at a premium so that you can make some money and help advance renewables. This premium, acting here effectively as a subsidy is out of tax payer’s money. In order to implement a FiT in an electricity market however the government has to force electricity suppliers to buy the premium electricity at a premium price. So the companies then have two choices, they can eat in their margins or they can pass the cost along to the consumers.

Now the question here, is a bit of an ideological one. In the centrally planned system, the government has decided that the tax payers should pay for it. They do not have a chance at saying no. They could of course not reelect the government, if this is in those rare countries where governments get elected. However there is bound to be more important issues in the election than the FiT and we can confidently say that re-election is not going to affect the path of the FiT policy or vice-versa. But then again if you have a centrally planned system, you tend to be in some sort of centrally planned government and you have already accepted the government making some decisions on  your behalf.

But in a market economy are FiT fair? Is it fair for the government to just impose something upon the companies? After all if people actually valued green energy then they would chose to pay for it. Why are we being forced into this. Not only that but once you put the company in a position of choosing between their margins and their prices, it is very fragile ground. Competitive forces are forcing them to try and absorb as much of the cost to hold on to their market share,  but if they cut their margins too thin they just might end up going out of business after incurring some losses. You have therefore forced the shareholders of those companies to subsidise a technology and effectively subsidise other people in the country.

There is also an issue of location. There is a saying that goes, equality in injustice is justice. But here is there an equality of injustice? Should one supplier happen to have more people on their network pumping green electricity in, doesn’t that put them at an unfair advantage as they have to pay more for their electricity? This would completely distort the market, and will have the companies trying to fight any renewables that will feed in into their networks. Hardly constructive, and definitely not helping competition.

So while it is important to find ways to make the renewable industry stand on its own two feet, we must watch out in how we implement that. And if we must be unjust, then we should try to be unjust across the board.

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Micro-CHP (μCHP)

January 15th, 2009

It’s μCHP’s turn. So the prime reason to use μCHP is not to generate electricity, but to generate heat. That’s right, it’s a boiler. But it’s a boiler that generates electricity, how cool! So what happens when it’s not cold, you turn the boiler off, and off goes the electricity as well. So you need a grid, and when you turn your boiler off, you are as efficient as the grid.

The fact that you are connected to the grid however is quite useful, because it means that if in course of generating enough heat for your house you generated too much electricity, it’s won’t go to waste. You just pump it into the grid and maybe make some money out of it.

So the efficiency here really comes from generating electricity as you generate heat and not the other way round, as in normal large CHPs. So μCHPs are useless in the summer (just like your boiler). Again the massive efficiency goes down the drain. It’s still better than those old central massive power plants though, so don’t get me wrong.

There are two problems I can think of right now about μCHP. First the poor people at the massive power plant. Not only are they being attacked for something that’s not their fault, (the fact that they have to dump 2/3 of the energy into the sea to give us 1/3, in reality the numbers are better, but still) but now they have to be ready to offset any electricity coming out of our μCHPs in case we feel like switching it off. Because they can’t control us, and we don’t have to even tell them when we are switching off our boilers, no one knows how much μCHP electricity there will be at any one time to count on. So they should always have backup capacity installed, and they have to be very responsive to our whims. Sounds very expensive and difficult.

This is not a big deal if there are a few units installed here and there, but it could be an issue if you have them everywhere.

Second problem, how much money do you give the people for their electricity. Give me too much money and I will have my heating on all the time. Hey you’re the one who’s paying me to heat my house. In summer, I’ll just open all the windows. The cash is worth it. Pay me too little and I won’t care. Why would I pay more for a fancy boiler and then donate my electricity to you. No thank you, I think I will stick with the old system.

So frankly, if you have the right policy in place you will find that indeed μCHPs are useful. But of course they are no where near as useful as some (Greenpeace) want us to believe. No they won’t save the world, but they’ll help bring us one step closer.

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How much carbon do you emit through Facebook?

January 4th, 2009

3% of the electricity produced by the US goes into its computers. We tend to think of computers as a low energy consumption devices, and they are. But without much notice they have crept into every aspect of our life. And now the computers in the US use 3% of its electricity. I wonder how much kettles use.

And some of those computers are housed in massive data centres such as those that are running Facebook. As Facebook adds 600,000 new users every day and as their monthly electricity bill passes $1,000,000 (see here), a lot of carbon is being emitted. We don’t really see it but every time we click on a Facebook link, some computer starts processing and some hard disk starts turning (if it wasn’t already) and some network card starts sending, all contributing to the electricity usage and thus the carbon emissions. But how much is all of this really.

My suggestion to Facebook, which any reasonable person in Facebook would strongly reject, is to put a small counter somewhere on the screen that measures your contribution to Facebook’s carbon emissions. Let’s find out how much carbon we emitted just by browsing through our friend’s photos because we are bored at work.

A quick calculation to show how much electricity each user is responsible for consuming (1m dollars / 140m users) will give you about 8.5 cents worth of electricity per year. Of course you have to add your own computer’s electrcitiy usage too. It doesn’t sound like much but every litte bit adds up.

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DESERTEC – A concept for the future

December 28th, 2008

Desertec (http://www.desertec.org/) is a very interesting and simple concept. It can play a large part in the future of energy and can provide a solution for today’s problems.

The idea is simple, take the Middle East, North Africa and Europe. Put renewable power plants in all of them, each depending on what resource they have, and connect them all together with high voltage DC transmission lines.

The Middle East and north Africa have a lot of desert, and deserts have a lot of sun, and the sun has a lot of energy. Now let’s put many of those solar thermal power plants (Wikipedia) in the dessert and we are generating a lot of electricity out of the desert. Land that’s barely used and I doubt anyone would be missing it. The land area available is also massive and taking Egypt as an example, we can find 300 Watts per square metre coming out of the sky, and there is rarely a cloud to be seen.

So what about Europe? The western coast of Europe has substantial wind power. A country like the UK is the windiest in Europe. Spain also has substantial solar capabilities. There are some geothermal sources scattered across Europe as well.

So now we have the deserts with their solar power, the western european coast with wind and geothermal scattered all over. Connect all those together and you have a super grid of renewables. So what’s the point of connecting them all together and sending the electricity over thousands of kilometers?

Well, renewables are intermittent, the sun is not always as powerful and the wind is not always as strong. So if we connect all those renewables there is a chance that when the wind is not as strong as we want it to be in Europe, the sun will be a bit more powerful in the Middle East. And the more sources we connect the better chance we have of meeting our collective needs for electricity.

Another reason is that while most of the electricity is expected to be generated in the deserts, most of the consumption will not be there. Europe, being far more developed than North Africa, means that they will require more electricity. However North Africa would have an abundance of electricity that it will be willing to sell to Europe.

So now this seems to be working well for everyone on many different levels. The whole world will emitt less pollutants as we use more renewables. Europe will then be on its way to achieve the targets it has set itself as well as the kyoto targets it needs to acheieve in emissions. North Africa and the Middle East will be making money out of the deserts and will have clean electricity to fuel their development. Energy securty will be highly improved as we add more sources and connect them all together. Europe will be importing its electricity from many more sources than today and shouldn’t be as worried about political instability.

So overall, it seems like a good idea. What do you think?

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