Custom Search

Saturday, May 30, 2009

Electricity Price

Windy changes in Spain

In May 2007, the Spanish government published a long-awaited decree that regulates renewable energy generation payments. Two issues have focused particular attention: the amount of, and caps to, renewable energy subsidies; the alleged retroactivity of the proposed regulation.

Renewable energy sources, and particularly wind energy, enjoy subsidies that can complement electricity market price (“Traditional hydro” is not considered to be renewable for these purposes). These subsidies represent a significant part of the energy cost in Spain, as shown in the figure below, based on data from CNE, the Spanish National Energy Commission.

Energy generation costs, and renewable energy sources (mostly wind) and combined heat plant subsidies are shown in red and salmon, respectively. Permanent costs (orange) mainly include subsidies to the Spanish archipelagos (Canary and Balearic islands) as well as payments because of past years’ deficits. Final electricity price is regulated by the government. In 2006 average final electricity price was 77.644 €/MW-h, slightly lower than average cost, 78.220 €/MW-h. For 2007, the forecasted figures are 88.810 €/MW-h and 101.244 €/MW-h. The deficit is forecasted to be 12.439 €/MW-h that makes a sizeable pink rectangle. Main reason is, on the one hand, greater fuel prices that have lead to increased production costs; and, on the other hand, the government reluctance to significantly raise final electricity price.

The previously mentioned figures are quite relevant for wind energy remuneration under the former regime: that of Royal Decree 436/2004 issued in March 12th, 2004. Wind generators could choose between being paid a regulated tariff or the wholesale market price plus a subsidy. The figures were given as percentages of a reference final electricity price, namely 90% of it in the case of regulated tariff, or 50% in the case of subsidy. The final reference price is similar to the average final electricity price, and wholesale price is closely related to production cost. The percentages above were established when electricity wholesale price was about 36 €/MW-h. As fuel prices have escalated, so electricity market price has done (from 28.74 €/MW-h in 2004 to 55.75 €/MW-h in 2006).

Wind generators have mostly chosen to be remunerated according the “market price plus subsidy” option. For instance, if we assume a reference price in 2004 equal to average final price (77,644 €/MW-h) and that wind generators sell at average 2004 market price (55.750 €/MW-h), they would be remunerated at 0.5*77.644 + 55.750 = 94.572 €/MW-h. Actual remuneration has been possibly lower, because reference price is not exactly average final price and periods of high wind generation are correlated with lower than usual electricity market prices. The new decree (Royal Decree 661/2007 issued in May 25th, 2007), as the former one, establishes that wind generators may choose between a fixed payment or the market price plus a subsidy. A key difference is that any wind generator that decides to go for the “market price plus subsidy” will have its income bounded.

Specifically, a cap and floor of the income have been established at 84.944 and 71.275 €/MW-h respectively. Note that the floor is quite close to the regulated tariff and, perhaps more significantly, that the width between floor and cap is relatively narrow. Besides, facilities operating prior to 2008 have the right to perpetually receive the more generous tariff of the previous decree, or the previous decree subsidies until 2012.

Another novelty is the provision of special subsidies for wind generators re-powering. The subsidies are capped to 7 €/MW-h, being granted by the government on a case-by-case basis. Only facilities operating prior to 2002 are eligible.

The above economic regime is intended to incentive wind power penetration. Therefore, new wind facilities will no longer be eligible once the national objectives are met. Specifically, the decree set this objective at 20,155 MW of installed capacity (presently, installed capacity is about 11,000 MW). The government initial draft significantly differs from the final decree. Generators argued that proposed changes in the regulation regarding existing plants were not only inconvenient, but possibly illegal under Spanish law. CNE was legally obliged to report on the proposed draft. As explained above, the final decree is somewhat closer to the position of generators and wind-generators makers that the initial proposal.

The remuneration based on market price plus subsidy has been justified on the basis of providing economic signals to efficiently operate wind generators. However, this scheme also remunerates wind investment according to market prices, whilst government objectives on renewable penetration are actually independent of whatever the market behaviour may be. The new decree provisions regarding caps and floors, and a maximum wind capacity to be subsidised possibly aim to balance these concerns. In the Spanish case, the combined value of these justifications seems to hover around 30 €/MW-h (the difference between a desired wind price of about 80 €/MW-h that regulation suggests, and an expected long-term electricity price of around 50 €/MW-h).

Check out my other articles on Power Generator
Source: EnergyPolicyBlog.com

Sunday, May 24, 2009

House Wiring

Home Wiring Basics

Home wiring is not something to fool around with. It is literally a life and death matter. In order to ensure your home wiring is done correctly, there are a few basics that you need to be aware of.

No Power = No Trouble

The key to safe basic house wiring is always keeping in mind that electricity packs a big, and deadly, punch. Even the most trained professional takes their life in their hands if they don't follow basic safety procedure. The best preventative measure you can take, whether you're installing basic electrical wiring, or just examining the wiring you do have, is to always make sure the power is turned off from the get go. Whether you're re-wiring your entire home or just replacing a faulty outlet, be sure to take a trip to the control panel and cut the power to the area you're working on.

Know Your Electrical Code

With electrical work there is never an excuse not to follow rules and regulations. As mentioned before, electricity can be a dangerous animal if it isn't treated properly. Your locality's codes and regulations regarding residential wiring have been put in place for a reason: to protect you, the homeowner. Anytime you are working with basic house wiring, study up on standard procedures so you don't put your family or yourself in jeopardy. And if you're undertaking a major home wiring project, get familiar with your local inspector.

Components of Basic Electrical Wiring


Besides safety considerations and regulations, the other thing you want to familiarize yourself with is the make up of your home wiring. It boils down to three basic components:
  • Service Entry. This refers to the point in your home where your electrical service goes from the main grid into your home. Besides that, make sure your service entry is properly installed so no water can penetrate the access point.
  • Panel Board. Your panel board is your control center when it comes to electrical wiring. Whether you're installing a dishwasher or running wiring to a new addition, this is the place you visit to ensure electricity is cut off when you start your work, and where you install new breakers if you're undergoing a major remodel.
  • Branch Circuits. This refers to the isolated areas of areas of your home where your panel board directs electrical currents. It's the reason you can cut power to your kitchen while leaving the rest of the house operational.
Electrical work is one of the exceptions. Unless you're experienced in home wiring, you don't want to do this job yourself. The safety risks are just too great. Add to that the need to meet local rules and regulations, and it's a good idea to hire someone who is experienced in basic house wiring to tackle this job for you.

Saturday, May 23, 2009

Electromagnetics

Engineering Electromagnetics

Engineering Electromagnetics is a new text aimed primarily at undergraduate teaching although it could easily serve as a reference text for those interested in the area. Electromagnetics is a notoriously unpopular topic with many engineering undergraduates. This text however provides a very comprehensive theoretical treatment of electromagnetics whilst attempting to treat the subject as a primary topic itself rather than playing a subordinate role to other courses. This is achieved by including a large and varied number of experiments and practical engineering applications, something sadly lacking in many other texts.

The book contains a rigorous treatment of all the main theoretical aspects of electromagnetics. Chapters 1 and 2 are devoted solely to vector algebra and calculus. Chapters 3 and 4 introduce electric fields and potential whilst Chapters 5 and 6 extend this into the analytical and numerical solution of electric field problems. Numerical solution techniques (finite difference and finite element) are a particular topic that is often omitted from many undergraduate textbooks. Chapter 7 concentrates on the treatment of steady current flow. Static magnetic fields and magnetic materials are introduced to the reader in Chapters 8-10. Chapter 11 is devoted to the development of Maxwell's equations whilst Chapters 12 and 13 continue the development into electromagnetic waves, propagation, reflection and transmission. The remaining six chapters focus on transmission lines including transients, waveguides and antennas. Each chapter contains many illustrations and examples, concluding with sections containing experiments with explanations, and applications and problems.

This is without doubt an impressive and comprehensive text. However it is a book that would be a useful addition to any library collection and one that I personally have found to be extremely useful in the development of undergraduate courses in electromagnetics.

Check out my other articles on Power Generator
Source: FindArticles.com