Travelling at a snail’s pace

January 26th, 2009 by admin 1 comment »

Cars are an amazing invention. They are mainly a combination of two inventions, the box and the wheel. Put a box on a set of wheels and voila you have a car. While it might not be practical to drive your car in a Flintstones style, with your legs popping out from under and pushing you through, sometimes it seems like that would be more efficient than what we did now. Your input will be biofuels and your carbon emissions is the CO2 in your breath.

Of course this arrangement will not allow you to go as fast as modern cars, but if you are in a city such as London, you might never need to.  A Transport for London report shows that the average traffic speed in the inner London area is between 11 and 12 miles per hour (17.5 – 19Km/hr). That is not particularly fast. We already know that internal combustion engines (car engines) are not terribly efficient, but they are even worse at low speeds.  Electric cars tend to have  flatter efficiency curve, that means they have the same efficiencies across the different speeds, and would thus serve quite well in a busy city situation.

What’s even more interesting about electric cars is that they have batteries, and a large number of cars will have a large number of batteries that can store a large amount of electricity. Now if we plug those in whenever we park them we have a large amount of electricity storage on hand to use in the grid. This means that in times of peak demand, instead of having a very expensive power plant start up just for that we can draw electricity from the parked cars. The car will make sure it does not give out a lot of electricity so that its owner can still go home. This should decrease the difference in demand on the grid between peak and minimum times, which means a lower planning margin, which means higher load factor, and which also means less money. (See comment on the Micro-CHP post).

Now why would I help the grid people with their problems and use up the lifetime of my battery? Because you would probably make some money out of it. You charge up at night, when electricity is cheap, and demand is low. Then you sell the electricity back during the day, when your car is parked and you are reading Dilbert cartoons at work.

Now aside from all the possible benefits of an electric car or electric vehicle (EV), here is a suggestion for Transport for London. The three lane system. One lane for public transport, one lane for electric vehicles and one lane for bicycles. Hmmm no normal cars there, exactly. This is the solution I came up with while day dreaming today, in the next post I will look for arguments why it could actually work.

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The state and development of the Chinese power sector

January 24th, 2009 by admin No comments »

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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An argument for nuclear power

January 21st, 2009 by admin No comments »

Nuclear power plants have caused much controversy over many years, and a lot of people can get very worked up when we talk about nuclear. But whether nuclear is a right or wrong decision is irrelevant. The fact is it happened. And now we are stuck with a lot of nuclear waste. The waste at the moment seems to be hanging around, just waiting for us to find a long-term solution for its disposal. So in effect we have already committed ourselves to find a way to dispose of nuclear waste, whether we build more nuclear or not.

New nuclear generation technologies apparently produce 10% of the waste that the older ones produced. This means that for every ton of waste we already have we just get another 100Kg. So it does not really change the dimensions of the problem. If you can find a long-term solution for 100% of the waste, you can find a long-term solution for 110%. And since we are committed anyway to solve the problem, and we have already borne the disadvantages of nuclear, we might as well make some use of the advantages.

Massive amounts of energy with low carbon footprint, sounds like a useful thing to have.

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Feed-in Tariff, fair?

January 19th, 2009 by admin No comments »

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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Electric cars are not inherently clean.

January 17th, 2009 by admin 5 comments »

I had a particularly long underground journey today. This meant that I read one of those free newspapers until I couldn’t find a word left to read, so I solved a Sudoku puzzle. Good thing I had my pen with me. There was a small news bit that said that the conservative party (UK) was taking advantage of how bad labour looks like with respect to the environment by promising to get people to switch to electric cars if they win the elections. My question is how is that supposed to help the environment?

When it comes to cars two words make them sound really clean, electric and hydrogen. In both cases it is not necessarily true. Electric cars are clean on the spot, because they have no direct emissions. The electricity in them however was not. To produce this electricity some power plant must have generated some pollution, unless of course it was a renewable. If it was a coal power plant then we are better off leaving cars to burn their fuel.

The same thing applies for hydrogen. How you produce your hydrogen is really the key factor in determining how clean it is. Is it solar hydrogen, nice! Is it hydrogen produced through electrolysis where the current was supplied by a coal power plant, not nice! Simple.

So the next time someone promises you an electric or hydrogen fuelled car, please ask them where they intend to generate those from.

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Micro-CHP (μCHP)

January 15th, 2009 by admin 4 comments »

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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Revisiting CHP

January 15th, 2009 by admin No comments »

In a previous post I have touched on why I don’t think CHP is the answer to all the UK’s problems. This time I want to expand a bit. I am not saying that CHP is bad, I am just saying that some people are overrating it. I will try and look at two things here, district heating CHP and microCHP (μCHP).

Let’s start with district heating. So in district heating there is a power plant in the middle of the community (figuratively) and its main role is to generate electricity. But when it generates electricity it also happens to generate heat and this heat is used to heat up the houses and water of the neighborhood. Now there must be some metering mode for the heat, otherwise it is subject to the tragedy of the commons and everyone will have their heating on maximum all the time. If it happens to be too hot they could just open a window, at least they are ventilating their houses.

Ok so we put a meter on the heat exchangers in every house. Now people are paying for both heat and electricity. Come the summer and no one wants the heating on, so everyone turns their heating off. So all the CHP heat has to find somewhere to go. This might actually end up costing the power plant owner some money for a cold utility to take the heat away. Lets hope the neighbourhood is near a river or a sea so they can just pump that water through. Yes there is still demand for hot water, but this is nowhere near as much as required for heating space and water.

OK, I can hear you saying Trigen. Put an absorption refrigerator there and cool the place. This way we haven’t wasted the heat. Now I am quite certain that the efficiency of the refrigeration process is lower than the heating process, so all those claiming 95% efficiency can stop it. It’s better than completely wasting it, but then if we weren’t going to use it in the first place are we wasting it or not?

British people rarely need air conditioning during their two-week summers. There is a substantial time when the weather is somewhat mild, according to British standards, and heating and cooling are not greatly required. What happens then? If they use the heating or cooling when they don’t really want to then it’s wasteful, and if they don’t use it it’s also wasteful. It all depends on the way you look at it.

This would probably be a typical scenario where people become complacent with their energy use because they feel like they have already been more efficient. Buy the energy saver light bulb and keep it on all the time kind of thing. This completely defies the point.

Next post μCHP…

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Public transport, good for you and the enviornment

January 12th, 2009 by admin No comments »

We all know that public transport is good for the environment. Many people on the same bus or train means less carbon per person. There are many reasons for why traveling with strangers is better than traveling alone or with a friend or two, but I won’t get into them. However I am going to encourage you to use public transport using a new method, wikipedia statistics.

The table below shows how many people die using different types of transport. There are many different ways of measuring it, and we will be looking at three types here, deaths per billion journeys, deaths per billion hours, and deaths per billion kilometers. You are free to chose the statistic which best serves your needs, in my case I will use all. Just take a look at the top three spots. When comparing by hours it’s all public transport (yes I am considering air public transport, I don’t think private jet is included in this statistic) except for the third spot for the journeys, it’s a van. But come on, we all know that a van journey can be to the supermarket, not a very long one.

Travel Safety Statistics (wikipedia)

So the bottom line is if you use public transport, you might die less. I am only afraid of one thing, that I might be encouraging you to replace your car with a bus. That is definitely not good for our air.

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Is the recession good for renewables?

January 11th, 2009 by admin 3 comments »

The Bank of England has made a recent cut in its interest levels to reach 1.5%. This is the lowest level it has ever set since it was founded in 1694. One way to think of the interest rate is that it tells you about the cost of capital. If you borrow capital today you would be expected to pay a rate proportional to the interest rate (depending on how you do your borrowing). The idea is to make capital cheap so people would borrow and start spending, and in the process getting the wheels of the economy to turn again.

Renewable energy projects are very capital intensive. You pay a lot of money upfront and then you sit back and reap the rewards as your plant generates electricity with minimum maintenance costs. So if the interest rates are low, and thus the debt service is cheap, wouldn’t this be a good time to start building some renewables?

The average bank is not really passing through the savings and thus it will be difficult for John Smith to remortgage his house (and that is especially difficult now with how the housing market is acting) and take the money and put up some wind turbines. But what happens if you have a major project to finance? Surely there must be a way to access large capital cheaply. With the world today calling for reduction in the carbon footprint, and with some politicians looking at the green industry to overturn the recession, would it be wise for the government to start some program through which the large project developers could take out loads of cash, and start building something? Or maybe even encourage some firms to take out lump sum cash amounts cheaply and then finance microrenewables at a small profit (in percentage terms).

The bottom line is, cash is cheap, renewables need cash, so someone should start building some renewables.

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Wait! Don’t paint that plane.

January 6th, 2009 by admin 10 comments »

We’ve all seen planes (if you haven’t click here) and some of us flew on them. You stand at the gate looking in admiration at the beautiful machine. Fascinated by the curves on its body and the shear size of its engines, or maybe that’s only me. But I am sure that most of us have noticed that airplanes tend to be nicely painted with the airline colours. It makes it look good, acts as marketing material and adds to the flight experience.

But there is also a technical reason why airlines paint planes, and that’s to protect the body from corrosion. As the paint fades away though, planes get repainted. And then repainted and then repainted. And after some time, believe it or not, all this paint has added weight on the plane. A Boeing 747 for example when fully painted adds 250Kg of paint (see here). So paint it only twice and you have half a ton extra on the plane. If you remove 500Kg off a 747 you can reduce carbon emissions by 0.2% OK it’s not much, but it doesn’t take much effort not to paint a plane.

Or does it? In order to protect the plane against corrosion once the paint is gone, we must polish it. If we polish our 747 and put some airline logos on it we end up with only 25 Kg of paint on it, so quite a good saving.

Now think about those airlines which charge you a lot of money for that extra kilogram you have in your bag. Every extra kilogram burns some extra fuel and that costs a lot of money. And since the major cost for airlines is fuel, it pays to take 250Kg off your plane. So if I was a CEO of an airline, you would hear me shouting “Wait! Don’t paint that plane.”

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