Hello Tommy and welcome to Writefix

Thanks for your essay. Using the online tools at http://www.read-able.com/check.php (see “Useful LInks” at the top of this page), we find it is 310 words, which is good, and has an average of 17.8 words a sentence, which is too long.

Essentially, although your essay reads well and has very few mistakes, there are two problems with it:

1. the sentences are too long, without a mix of long and short
2. you don't have enough ideas

You should try writing some short sentences. A mix of short and long sentences is good, and short sentences are very effective as the beginning of paragraphs (as topic sentences) or at the end, as summaries.

Here are some short sentences you could use

• A better solution is alternative energy (5 words).
• Public transport also creates pollution.
• Solar power is becoming more popular.

Unnecessary Words

Another way to write shorter sentences is to remove unnecessary words.

You wrote:

Firstly, fuel can be used not only for running vehicles but also for operating machines in manufacturing industry. Therefore, increasing petrol price may have an influence on the use of such machines. For example, some machines may need to be replaced by those which consume less petrol in order to reduce the operating cost. This might reduce the productivity at work because normally machine with lower level of fuel consumption will work at lower efficiency. 75 words, 18 average per sentence

Here's a possible rewrite: 

First, fuel is used not just in vehicles but also in industry. Higher fuel prices would mean more expensive products and services. To save money, manufacturers might be forced to use different energy sources or change production processes. (37 words,  12.3 average words per sentence)

Paragraph Two

Secondly, the use of alternative energy might be a better solution for reducing the pollution. For instance, solar energy has been used quite popularly  for running vehicles such as cars or motorbikes recently. This source of energy is not only cost effective [really? where?] but also environmentally friendly. Therefore, low income people will have more opportunities to purchase their own vehicles with reasonable price without worrying about pollution. (68 words, 17 per sentence)

One idea is not enough. There should be THREE ideas in this paragraph:

Alternative energy is one way to reduce pollution. Solar-powered cars and motorbikes are becoming more efficient. As costs drop, they may become affordable and provide clean transport for billions in sunny countries.  (32 words, 10.6 average)

Paragraph Three

You wrote:

Supporters of increasing fuel cost may argue that this strategy can make a good contribution to reduce the level of carbon dioxide emission. They point out that by discouraging people to use cars or motorbikes to travel, the level of carbon dioxide in the atmosphere will decrease considerably. This argument may be true to some extents. However, the less private vehicles running on the street, the more public transport vehicles need to be manufactured to accommodate more passengers. While limiting private vehicles may help to reduce the level of carbon dioxide, the need of extra public transport vehicles will contribute to raise this level again. (105 words, 21 words per sentence)

  I'm going to add an idea AND still reduce it. Remember there should be THREE ideas, however:

Supporters of higher fuel prices argue that less private transport will result in lower carbon emissions and pollution. This may be true, but public transport also creates pollution, along with the environmental impact of construction. In many cases, public transport simply moves the problem away from the city.  The electricity for a train system, for example, has to be generated somewhere. (61 words, 15.2 average).

Conclusion

Your conclusion is fine, but even with your skill at writing, you were not able to make it stronger! Why? Because there weren't enough ideas in Paragraphs 2 and 3! You wrote: 

All in all, it is obvious that increasing fuel price is not the best option to tackle the environmental issues. Alternative ways such as using solar energy can be considered to provide better outcome. (34 words, 17 average per sentence)

This conclusion could have more meat, especially in the last sentence. The problem is that you don’t have enough ideas in Paragraph 3 to add to the example of solar energy in the conclusion!

Overall, Tommy, you have very few mistakes and the essay is well written. You are definitely able to write good sentences, and I hope you can help some of the other people in this forum.

Have More Ideas

You really need to have a few more ideas in the two body paragraphs. At present, you have essentially only two ideas where you should have SIX! 

The essay looks great, but essentially, this is what it has:

• Higher fuel prices – not just for vehicles, but industry
• Solar power -  solar cars will be cheap one day

You shouldn’t start to write until you have at least SIX ideas. Ten is better, because you can throw some away and keep the best ones. Some ideas need to be developed more, rather than simply repeated or rephrased. See the official IELTS descriptors for Task 2 writing here  and look under Task Response. You don't want to end up with Band 5 ("presents a few limited ideas"). 

Hoping to see some really solid essays here soon which have both good ideas AND your good writing! Please help some others  - perhaps have a look at MoeMoe's essays.

Thanks again.