In terms of fuel quantities, the general equation for the green energy fraction (GREF) of a solar power plant system is, by definition,

GREF = (gr baseline — gr input)/ gr baseline

GREF = 1 — (gr input)/(gr baseline)

gr input — — total fuel consumption in the hybrid system

in grams per 1kWhe net electrical plant-output (gr/kWhe)

gr baseline — — 160 gr/kWhe, the specific fuel consumption of the chosen reference system (baseline standard), (for visualization, a CC using fuel of around 9000 kcal/kg)

For simplicity, both the hybrid system and the reference power system here use the same fuel. It should be realized that the grams-ratio expressions signify the inverse efficiencies ratio. The use of grams emphasizes the requirement that any fuel used in the plant should be counted and included in the equation.

The concept of fuel avoidance requires to compare the fuel-blended, renewable hybrid system to a baseline standard, which is a real, competing, efficient, non-renewable system, set as reference. On circumstances where CC systems cannot be considered as a useful alternative fuel fired electricity generator, thence the 60% baseline becomes impractical. Then, another a locally competing, fuel-fired, efficient system is to be selected for reference standard. Thus, the 40% Rankine-cycle system may serve as a secondary standard against which solar systems will have to compete. In such a case, because by definition the green energy is a functionally reference-dependent parameter, the resulting value for the green energy fraction will be different.

Transformation of a green energy fraction from one reference standard to another can be performed by

GREF1/GREFF2 = (B2/B1) (B1-gr)/ (B2-gr))

Where,

B1 — — baseline 1- — in gr/kWhe, (reference standard 1)

B2 — — baseline 2- — in gr/kWhe, (reference standard 2)

gr — — the total fuel consumption in grams by the hybrid system, per 1kWhe net

plant electricity output

This equation converts a GREF 1 of baseline 1 to GREF 2 of baseline 2. It is significant for enabling comparison between technologies and systems.

II.1- The first steps: the metallic lens

Father Himalaya, from his early days, saw solar energy as means to provide energy not just for the production of hot water or steam, but as a direct means to provide energy for industrial processes, in particular to those associated with materials production or processing, if high enough temperatures could be achieved. Among other objectives, he wanted to produce nitrogen based agricultural fertilizers by extracting the nitrogen directly from the air! He could never achieve that with his devices, as we can today well understand, but he managed to achieve perhaps the highest controlled temperatures of the day, about 3800°C, in the solar furnace of his pyheliophoro, a truly remarkable achievement.

If not before, at least in Paris, at the end of the turn of century, he became quite likely familiar with the works of A. Mouchot [2], Louis de Royaumont [3], Charles Metelier [4]. Also, mainly from his corresponcence and from documents found among his belongings, it is fair to assume that he must have had some degree of familiarity with the works of John Ericson [1,8] W. Adams [1,8], Calver [1,8,5], Aubrey Eneas [1,6,7,8], among others.

He was critical of the devices produced by Mouchot-Piffre, and soon understood that he needed to modify them in order to obtain higher temperatures and also in order to break the mechanical coupling between the solar furnace ( placed in the "focal zone") from the structure supporting the mirrors. If possible he also wanted a stationary solar furnace, while only the optics would do the necessary tracking of the sun’s apparent motion in the sky.

In Fig1.(a) the device developed by Mouchot-Piffre is shown, a paraboloid like shaped structure with reflecting inner walls, and a furnace place along its optical axis.

(a) (b)

Fig.1.- (a) Solar device of Mouchot-Piffre (b) parabolic trough of Ericson

Truncated cone like shaped mirrors (Eneas Fig.1. (c)[6,7], Pasadena, California, 1901) and large flat ones (Calver, [5]Tucson, 1901) were among some of the solar optics of the day. John Ericson [1,8] proposed a parabolic shaped mirror in 1880 (Fig. 1(b)), but Himalaya’s ideas went in rather different directions.

References [5,6,7] are explicit instances of Portuguese magazines dedicating space, in those days, to those and other inventions and F. Himalaya likely read them. It was not possible to consult the referred magazines and therefore their level of technical detail is not known to the author. However these were publications for a general audience and little should be expected beyond some photos or drawings and a reference to the purpose of the inventions. .

To the interested reader the author recommends the first section of a modern book [8] containing an interesting introductory chapter on the history of solar energy. This book makes an explicit mention of Father Himalaya and his crown solar achievement — the Pyrheliophoro — at the St. Louis Fair of 1904.

He soon understood that the very high concentration factor he needed required two axis type tracking. With materials processing in mind, he needed solutions that would not have, in his own words, "the furnace between the reflector and the sun”. He thus first thought of lenses to do the job, since these could send the concentrated light down and out, towards the target. However the required dielectric (glass!) lenses were not a practical idea in those days and his first remarkable attempt can be seen in Fig.2 and 3. It is a metallic Fresnel lens type, done with flat-strip — mirrors, ring shaped, the whole ingeniously tracking the sun in elevation and compensating for the earth’s rotation, by moving together on circular rails.

Fig2.- Figures from Patent [10]

Fig.3(a)- the device and Himalaya standing in front of it, in Paris

His experiments were carried out in the French Pyrenees, (Castel d’Ultrera) not far from Odeillo and Font-Romeu (of later day fame, for very similar solar reasons!)

The results he obtained were not as good as he expected, but it seems that he was able to achieve temperatures in excess of 1500°C (melting iron), a remarkable achievement, given the choice he had of materials for the mirrors, and a good measure of the mechanical precision with which he was able to produce his device. It should be noted that the solar furnace itself was object of careful developments, to be able to contain the materials he was melting/processing with it. His temperature measurements were crucially dependent on what he was able to melt.

In fact the furnace itself was the object of patents, perhaps the most important of which being Patent [9].

Fig.4 is taken from that patent, showing a radiative type furnace, where the side walls c, c’ were to be heated with the burning of fuel and the heat radiated into the triangular shaped cavity was to be concentrated (focussed) down onto the hot cavity F, by a paraboloid shaped upper wall d. This furnace was later very easily (and much better) adapted to the solar focussing optics to be described next, with solar radiation coming trough an aperture placed in d and the side walls c, c’ now serving as a second stage concentrator.

In the process of these developments he invented also a radiometer — to measure solar radiation intensity using his metallic lens concept.

Many specialists share our opinion that in the near future a change of paradigma will occur in the solar cell production. It means that instead of elemental semiconductors, compound semiconductors will be used as solar cell materials [3]. The indirect energy band transition of silicon is not really suitable for optoelectronic devices. The reasons for using it in the fabrication of solar cells are: it has a stable technology and the relaively low price. The amorphous silicon is a more suitable material, because there is no longdistance orderlines of atoms, so the fine energy structures are undefined. The technology of amorphous silicon is made with chemical vapour deposition or sputtering. Its band gap is strongly technology dependent. High efficiency solar cells can be produced from direct band structure materials e. g. from galliumarsenide. For the selection of suitable semiconductor materials their electronic band structure has to be known. It is also important to know the absorption coefficients of these semiconductor materials. The most efficient solar cells are made from galliumarsenide, their efficiency is over forty percent. In the case of latter materials instead of the pn-junction one can use the built-in electronic field generated by different layers (so-called heterostructures) which are grown above each other, by metal-semiconductor interface (so-called Schottky junction) or by electrolyte junction. These materials are e. g. cadmiuntellurid, cooper-indium-diselenide and the above mentioned amorpous silicon or silicon- germanium. Because of the high absorption coefficience of the above materials thinner absorption layer can be used, too. These structures can be produced with different thin layer technics. Some of these materials have bad transport properties, therefore on these materials there are grown wide band gap, transparent and well conducting materials. They are e. g. zincoxid, tindioxid. These so-called windows materials serve not only as a transparent electrode but as antireflection coating and heat mirror, energy efficient window, as well. The window layers can be produced by thin layer technics, too.

A great deal needs to be done to overcome the main problems in the development of renewable energy sector. The national RES strategy places specific obligations on the Government, while specifying tasks for the Ministers of several sectors.

The government strategy is to be evaluated every three years and recommendations concerning necessary changes and solutions will be proposed. A detailed inventory of renewable energy installations in Poland will be carried out and the results published in Statistics Yearly. A database of available renewable technologies should be created.

Tasks to implement the strategy include not only organisational activities within the Government, but legal actions such as executive regulations, assistance provided to the local and regional authorities in the preparation of energy plans, simplification of licensing procedures for electricity generation from RES etc.

As instruments enhancing economic viability of RES in the initial phase of the implementation of investments, specific funds are allocated from national and foreign institutions. Financial support for beneficiares and investors in the form of grants or preferential loans is available, though with some difficulty. National institutions such as: National Fund for Environmental Protection and Water Economy (NFOSiGW), Regional Funds for Environmental Protection (WFOS), Bank of Environmental Protection (BOS), EcoFund Foundation (EKOFUNDUSZ), Thermo-modernisation Foundation, Foundation for Support Programs for Agriculture (FaPa) and Techniques and Technology Agency (ATT) are engaged in allocation funds to RES purposes. In the framework of international co­operation EU pre-accession funds (ISPA, SAPARD) and PHARE have been launched. Participation of Polish partners in research and demonstration projects of European Union (FP5, FP6, ALTENER II, SYNERGY) is a support and good possibility to implement new techniques and technologies. Bilateral funds and others could be of assistance to Polish investors. These instruments should be resorted to until renewable energy sector is fully competitive on the market.

It must be emphasised that the development of the green sector would be of great benefit to the environment and to the regional and local communities in creating new jobs. And above all, diversification and decentralisation of the Polish Energy sector would contribute to security of energy supply.

Georg Bopp, Sebastian Golz, Felix Holz, Werner Roth, Gisela Vogt
Fraunhofer Institute for Solar Energy Systems ISE, Heidenhofstr.2, 79110 Freiburg, Germany
Tel +49 (0)761/4588-5228; Fax: +49(0)761/4588-9283; sebastian. goelz@ise. fraunhofer. de

Introduction

Education, training and awareness raising is recognised to be a main task for the development of markets and technologies. One reason for the failure of many projects and programs of rural electrification attributes to the lack of knowledge, training and competence of participating people at all levels. (International Energy Agency IEA, 2003).

All these alerting experiences advise that different accompanying measures have to be considered in line with designing and implementing solar power systems. Both in grid coupled and off-grid markets cultural, social, economical, organisational, and financial aspects have to be incorporated (Will & Vogt, 2003). Various competencies and skills are required to plan, implement, commission, and promote solar power systems. Therefore the substantial objective of this article is to illustrate the spectrum of relevant training topics, to report from current state of knowledge in two exemplary markets and to describe the profit of customised training programs.

1. Training and further education for comprehensive market support

At all levels of off-grid and rural electrification projects an extensive demand for training can be identified (Vogt, Will, & Sauer, 2003). Investors, politicians, planners, installers, suppliers, users, and service personnel frame the target groups of different training programs. During the last years, the Fraunhofer Institute for Solar Energy Systems ISE has conducted various projects (SUNRISE, SOPRA-RE; SOLTRAIN) to design and to accomplish training concepts for these target groups. Starting from these experiences Fraunhofer ISE offers a broad assortment of programs for further education. The various job training, designed and applied by an interdisciplinary team, cover the following target groups and topics as listed in chart 1:

The University of Applied Sciences Nordhausen pursues a fundamental system — oriented education in the domain of development, planning and operation of renewable energy systems. In addition to solid engineering basics the energy — and process-related principles of solar thermal, photovoltaic or wind energy systems and their integration into existing — and here in particular electrical — supply systems takes the centre of the training. Special attentions will be put to renewable energies in the vehicle technology — keyword fuel cell — and to bio energy systems.

Graduates of this study program are to acquire expertise of renewable energy systems. This means for the example of a wind power plant knowledge of the fluid mechanics at the rotor, of the shaft bearing, of the conversion of mechanical into

electrical energy and of the feed of the electric energy into the public power supply system. In order to open the graduates a broad spectrum of vocational possibilities, the training also involves classical power engineering and additional subjects. Latter are for example information and diagnostic systems, management in the energy industry, energy law or the use of recycling materials for power generation.

SHAPE * MERGEFORMAT