DSM-Saving energy for the future

2014年2月6日星期四

what is DSM?

Assessing Demand-Side Management Based on Game Theory for the future Smart Grid in China

By Lin Xiqiao

Energy demand side management is interesting in shifting the peak demand to reduce margin cost. Due to the technique innovation such as Smart Grid and its encapsulate smart functions , demand side management system will take advantages of the two-way digital communicate system. Therefore the behavior of the energy system will reform in the future.

Demand side management project interesting in the effect and payoff of shifting the load from peak demand to lower demand , it have been attracted attention since 1972 world energy crisis. Although supply side management like electrical biding market or tariff control on thermal turbine can have some impact in controlling the energy efficiency, it will be harder to continue in the future when renewable energy play a high proportion on the supply side due to its natural characteristic.
A DSM project could not only have the effect on shifting the peak load but also have some social impact.Due the the characteristic of electricity(electricity cannot be store) we can use such characteristic to get a better understanding of our economic by DSM. For example we can estimate the number of empty houses by calculating the number of low consumption electricity bill's house.In the future ,the appear of some applications like smart car will further enhance the requirement of electricity supply service.
Our project mainly focus on DSM project in China ,which announce its energy efficiency per GDP will increase 20% in the next 5 year. Further more as the biggest growing economic , China consume a lot of energy and create the horrible pollution. A DSM running for the future scenario could help the people better understanding the trend of electricity grow and shifting, have a better view for the future policy decision and reduce the pollution.

2014年1月12日星期日

How to save money by changing the electricity retailer? why they are different?

Many of the people have the experience of using the energy compare webside.By entering your postcode and some consuming details such as monthly consumption and payment methods, you will find out how much you could save by changing the energy retails.

But have you ever wondering that why shifting the energy retails will results in different prices? and why some of the company like E-on is always cheaper and some of the company like British gas is always expensive than others? More importantly the electricity they provide seems no different between each others.

The electricity industry in the UK is separated into four basic elements: generation; (high tension) transmission; (local) distribution; and supply. Transmission and distribution are both regulated in price. Therefore, the different of prices come from either end of the production process – generation and supply – with two strictly regulated in between – transmission and distribution.

Moreover, the EU carbon emission for different countries will results in the price competitive. The countries or the company which have higher emission allowance always could offer cheaper price to their costumers. Hence there are no wonder that the Germany(high developed in renewable energy) company E-On could always offer cheaper prices than British company.

2014年1月3日星期五

PLC(power line communication)- key element in the Smart Grid

By Lin Xiqiao

In recent years ,Smart Grid have become one of the hottest concepts in the electrical field ,it is widely consider Smart Grid will become the next power supply network. To meet the requirement of supply the energy reliable and flexible ,the smart grid network need to communicate between each components. There are many options for smart grid communication like Powerline communication (PLC), optical fiber communication and wireless communication. However PLC is widely considered the best choice for offering ‘last mile’ communication for smart grid due to the economic and convenience issues.

Smart grid is an expanded concept of energy system, inside this system, many components are involving like smart meters, sensors, control units etc. . .Besides hardware components, software like energy managing system is the key infrastructure making the Smart grid different with traditional energy supply network.

Powerline communication using the exist power transmission line as communication channel to transmit signal, it bring many advantages to Smart grid operator. However, because PLC communication channel is use the normal electrical transmission line which is cannot provide good channel environment ,unavoidable it has a noisy environment. On the one hands background noise, impulsive noise, narrowband interference and group delays up to several hundred microseconds will result in high frame error.On the other hand high attenuation rate of channel, which normally around 40dB/KM to 100dB/KM especially when signal go through an transformer it will suddenly reduce up to 30dB. Comparing by the good channel environments in the optical fiber which usually around 0.5dB/KM, Narrowband Powerline Communication, its viability for smart grid realization is being questioned.

PLC has a long history, it was experimented during the World War II, and witness a far development during the recent years .Traditional PLC use single carrier modulation such as FSK(frequency shift keying),PSK(phrase shift keying ),the output speed of single carrier communication usually too slow and with low reliability ,therefore cannot meet the requirement of Smart grid communication.

There are two leading OFDM based standard-G3 PLC and PRIME ,both of them attend to use EU A band to transmit signal modulating with DPSK .However due to the modulating domain is different(G3 PLC is t-DPSK and PRIME is f-DPSK),the design and result of those standard will very a lot . OFDM have been use in majority of wide band communication technology, because it can promote the efficiency in the frequency selective channel without channel estimate algorithm . Moreover PLC bandwidth allowance is also significant for standard design. Different bandwidth allowance will affect the performance of standard. For example, the European Standard CENELEC 50065-1 has divided the 3 kHz to 148.5 kHz low-frequency powerline spectrum into four different frequency bands, and PRIME is focus on CENELEC A band,which occupy the frequency range from 42 KHz to88 KHz while the “HomePlug Command and Control” which is design for America can operate up to 400KHz.Because the different range of frequency bandwidth allowance will have an effect on both physical protocols and data link protocols.