If we don´t interest in the energy future, we may see its collapse

We study English discussing actual technical problems

Compiled by Galina Vitkova

I have recently read a very interesting article about the future of energy sources (Renewable energy – our downfall? By Ralph Ellis). The author of the article, in the compliance with many other specialists, claims that conventional sources of energy (coal, gas, oil) will be exhausted in 30 years. Renewable sources of energy won´t be able replace the amount of electrical energy generated by power plants using conventional sources of energy. Here are some excerpts that summarise the main ideas of the article, with which I completely agree.

The governments, under pressure from environmentalists and greens, have agreed to press ahead with usage of renewable energy sources, including wind, tidal and wave power. Nevertheless, despite the vast sums of public money that will be allocated to these projects very little of open debate has been held on the subject. Nobody has even demonstrated the fundamental issue of whether any of these energy generation systems actually work. Any renewable energy resource is ‘free’. In the contrary the conversion from ‘free’ renewable energy to usable grid electricity is eminently expensive.

Our civilisation can´t exist without electricity. Six blackouts in 2003 through the whole world showed that. Especially impact of the blackout on 14^th August 2003 in the USA was terrible. Within one hour 256 power plants in American North-East fell out. The all North-East lived under emergency conditions, which caused great chaos. All transport (aircraft, trains, road traffic) came out of regular functioning. Water supplies, telecommunications were seriously damaged. Chaos looms, people die, production ceases, life is put on hold. And this was just a once-in-a-decade event. But if this occurs every week and lasts for a longer period, the situation becomes unmanageable.

According to recent EU Directives 40% of electricity should be powered from renewable resources by 2020. This energy will be likely mostly produced by winds turbines, which demands to install about 30 gigawatts (GW) of wind generating capacity. Now the UK has about 0.5 GW of wind capacity, but only 25% of it is delivered mainly due to wind fluctuations, i.e. in fact it demands to construct 120 GW of wind capacity. Supposing in average 2 MW rated capacity of a wind turbine, 60,000 wind turbines have to be installed over the next twelve years in the UK.

However, it is not everything. When wind does flow, no electricity is produced by all installed wind turbines. In Denmark their ‘wind carpet’, which is the largest array of wind turbines in Europe, generated less than 1% of installed power on 54 days during 2002. In fact, wind generation is so useless, that Denmark has never used any of its wind-generated electricity – because it is too variable. Denmark has merely exported its wind supplies to Norway and Sweden, where they have many hydro power stations to cope with fluctuations.

Assumption that renewable power can somehow be stored to cope with power outages doesn´t agree with reality. As for the UK the first energy storage facilities is considered the pumped water storage system, which in fact can´t save the situation:

1. Present pumped storage systems are fully utilised.
2. These storage systems provide with a very small percentage of the whole electricity for just a few hours.
3. Pumped storage systems can´t be built anywhere. In Britain, for example, only very few sites are available.

The same kind of arguments can be given for flywheel energy storage, compressed air storage, battery storage and hydrogen storage – for each and every one of these systems is very expensive, highly inefficient and limited in capacity. Besides hydrogen is not an energy source, it should be produced before its usage. Moreover, hydrogen powered vehicles and generators are only about 5% efficient. The hydrogen, is extremely flammable and potentially explosive. For ensuring recharge of hydrogen powered vehicles (and electric vehicles) the capacity of current power plants should be doubled or trebled.

That´s why for predictable future the nuclear technology (either fission or fusion) is the only practicable realizable energy source. Even if nuclear power has a bad sound especially due to Chernobyl only nuclear power plants can cover demands on electricity and keep the life level which people in the developed countries are used to having. New technological capabilities will ensure the safety and efficiency of nuclear power plants development and maintenance. Moreover, the nuclear power is non-polluting.

As for nuclear safety issues it is necessary to remind that ecological damages and number of people killed within oil and coal extraction industries over past decades are much bigger than in nuclear power plants incidents. But media devote much more attention to the incidents caused by nuclear power and so influence public opinion in this way.

Nonetheless, nuclear energy is not renewable. It means that it is only a temporary solution, a temporary stop-gap. But this stop-gap enables providing the world with 1000 years of energy. During this time more convenient source of energy could be found out.

A worm, a virus or a Trojan horse?

We study English discussing actual technical problems

By Pavel Macenauer

Many people often misuse these terms, which may in reality lead to great confusions while discussing this topic. Discrimination the differences between them might help you protect your computer.

What is a virus?

A virus is a malicious program usually hidden in an executable file. It is able to replicate and cause harm only as a consequence of a human action. For example, you´ve just received a suspicious email offering you to earn lots of money simply by filling out a form contained in an executable file. When you open this file, you basically run the virus. It has not only a harmful effect on you computer, but it also adds a copy of itself to every email you send.

What is a worm?

Worms are not very much different from viruses. Some people even consider them to be a subspecies of a virus. Worms take advantage of every piece of contact information in your computer and without any human action they replicate and then cause harm. Usually, they abuse contact information hidden in your email client or your instant messenger.

What is a Trojan horse?

At a first glance, Trojan horses appear as helpful software. Usually, they even mask as virus removal tools. In reality they are designed only to cause harm. The main difference between a horse and a virus or between a horse and a worm is that horses can’t replicate. They are mostly used for tunneling information or for enabling a third party to access your computer.

Many people often misuse these terms, which may in reality lead to great confusions while discussing this topic. Discrimination the differences between them might help you protect your computer.