Category Archives: SonSolar

A high reliable integrated control and management system


Fig. 1 — G. I.I. G.E. block diagram

ENEL has designed a multi-source energy control and management system to ensure the overall plant performance and reliability. In fact, the management of such kind of plants (located in remote areas where the presence of skilled personnel and the supply of spare parts are critical) has highlighted how the maintenance of the whole system can be very expensive and even requiring long trips by expert technicians. Ginostra Integrated Control and Management System (ICMS) has been designed taking into account these backgrounds.

To supply energy with high reliability and as well optimize the plant overall performance it is necessary to run the plant components using control and Fig. 2 — Ginostra ICMS

regulations methods specially designed.

The experience previously made in such tasks (hybrid prototype developed an run by ENEL) has highlighted that is extremely important that the control and regulation strategy of that kind of plants take into account the following factors:

Overall system reliability

— the system control is performed using a high end programmable logic controller (PLC) made by Siemens;

— no electromechanical actuators components have been used to switch the power conditioning units, they can be controlled directly by the PLC using both analog and digital low power signal;

— a remote plant monitoring/control via GSM modem is implemented in order to evaluate on line plant performance, take the control of the plant and quickly diagnostic the state of health of components;

— accurate main battery charge/discharge regulation will last long this expensive plant component.

— only high end industrial grade components have been selected and used

Plant performance

— accurate energy balance strategy avoid the production of surplus energy.

— minimize the usage of the backup generator (diesel generator set)

The Ginostra ICMS (see figure 2) manage the whole system according to the plant components status, mainly following two operation modes:

Normal operation

During this mode the PV generator supply energy to battery and to the user load (through the GIIGE’s DC/AC converters).

The control system manage the battery status by partially or totally disconnecting the PV generator when the battery voltage reaches an upper threshold, and, will start the back-up diesel generator set when the battery reaches a lower threshold.

When the diesel set is running the battery are charged through the GIIGE’s AC/DC converters, load demand energy is supply both by PV generator (if available) and diesel — set.

Battery charge is achieved by ICMS using the analog regulation control inputs of the embedded GIIGE AC/DC converter performing an accurate battery charge process using both current and voltage regulation. Particularly a constant current charge (at C10) is implemented to avoid main battery stress. The back-up generator set is finally turned off when the battery is fully charged.

In case of more than two power conditioning units (GIIGE) fault or when the battery goes below a protection threshold (even if the diesel back-up generator is on) the ICMS forces the plant into Emergency operation.

Emergency operation

During this mode, if the condition is caused by an excessive battery discharge condition (battery voltage goes below the protection threshold), the GIIGE’s embedded DC/AC converters will turn off, the PV generator will continue to supply energy (as much as can) to battery as well as the diesel generator back-up set. The load demand can be supplied only by the diesel generator set directly connected to the user load.

ICMS will restore the Normal operation condition only when the battery will reach a maximum charge voltage threshold.

If the condition is caused by the simultaneous fault of two of the three plant equipped power conditioning units (GIIGE) the load demand will be supplied only by the diesel generator set directly connected to the user load through the GIIGE’s embedded static — switch. In this unlikely condition ICMS will not restore to the Normal Operation.

This status is irreversible being necessary the presence of technicians who repair the GIIGE’s faults.

ICMS is made of two sub-systems: the plant and the industrial grade PC sub-system running the monitoring/control software.

The failure of the PC subsystem will not affect the normal operation of the plant.

Fig. 3 — ICMS user interface

PLC subsystem that within its firmware manage the

Fig. 4 — ICMS block diagram

ICMS includes a monitoring/control system based on a industrial grade personal computer that interact with the PLC collecting data and sending appropriate instructions.

This unit perform a user friendly graphic interface (GUI) touch screen based (see figure 3) able to give on-line information about the overall plant or single component. Through this unit it is possible to take the control (local or remote) of the overall plant: this is very helpful in some condition or when the presence of technicians is delayed for whatever reason.

ICMS is also able to evaluate plant components performance and diagnose incipient failure allowing the quick arrangement of the related maintenance.

This monitoring/control system allows also the connection to the plant from remote place using a standard GSM modem. The software design of ICMS has been performed using standard industrial platform: SIEMENS SCL for the PLC embedded firmware and Windows 2000 for the monitoring/control software. Both offer robustness and feasibility. Figure 4 show the ICMS block diagram.


The hybrid PV system realised in Ginostra, with the innovative solutions applied, constitutes therefore an optimal solution for the electrification of isolated communities, answering to the environmental safeguard requirements and to those of reliability and quality of the electrical service.

Cold Flow Analysis of Biomass Based Slurry in oil. Fired Furnace using CFD — Tool


1. Sr. Lecturer, MSRIT, MECH. DEPT., Bangalore-560054, yagprash@hotmail. com

2. Director, MSRSAS, Bangalore-560054, srspal@msrsas. org,


An existing oil fired furnace was modeled to obtain the maximum swirling of biomass based slurry fuel and air to achieve better combustion of the biomass fuel present in the slurry. For analysis a computational model of the furnace was constructed with a swirl burner placed at the bottom of the furnace using commercially available CFD preprocessing software (GAMBIT). The boundary conditions were set so as to allow biomass slurry and air with different swirl angles with respect to horizontal and vertical planes, with constant velocities of the mixtures. This research work studied the effect of different inlet angles of the fuel at constant velocity into the furnace for maximum combustion efficiency. Using Fluent code, the post process results shows the increase in residence time by 40 % with inlet angle of 45 deg with respect to the x and z-axis, 75 deg from positive y-axis and top partially opened, compared to the initial position of the swirl burner placed directly at 0deg.


The Biomass slurry fuel considered in this research work is a combination of coconut shell powder, light diesel oil, water and air. Since a long time lot of research work has been done to replace the fossil fuels by certain ecofriendly fuels, initially the diesel oil was tried to replace by coal-oil fuel combination so that they could save the oil at the same time control the pollution to certain extent, but there was lots of problem associated with the combustion of the coal oil slurry because of the presence of the ash, highly viscous and particles size [1]. However, by utilizing biomass with fossil fuels as external input fuels, we would get about 10-15 times more electric energy per unit fossil fuel, compared with a 100% fossil power system. All this past research motivated to the present work, which involves combustion of biomass slurry in oil fired furnaces, which can be use for either power generation, melting purposes or as a fuel in I. C.engine. Coal water slurries and coal-methanol studies were developed over the last 20 years as an alternative to liquid fuel mainly in industries and power generation furnaces [2-3]. Determination and improvement of combustion characteristics of coal-water slurries are as important as the preparation of the suitable slurry. Suspended single droplet combustion technique was the method used in the investigation of combustion characteristics of liquid fuel droplets. The
study includes the study of the droplet lifetime history, ignition delay, flame structure, center and surface temperature of the droplet and burning rate [4]. Later the problems involved in using the coal were overcome by using a novel technique by superfine grinding the coal and selective separation of the coal particles and other inorganic ingredients and finally combustion of the fine fraction coal in slurry droplets [5]. Based on the same principles in 1995 investigation on combustion of biomass-based fuel slurries were successfully done and the solid fuel particles were dispersed in a liquid medium and the resultant slurry fuel was burnt like a liquid fuel [6]. The biomass slurry considered were pulverized coconut shell powder, light diesel oil and water, the solid fuel was directly mixed with the liquid medium and was burnt in an oil-fired foundry furnace without adding any chemicals and no problems were encountered during the combustion process, since most of the study was concentrated on the combustion of the droplet of fuel burnt and its characteristics like droplet lifetime history, ignition delay, flame structure, center and surface temperature of the droplet and burning rate[7-10], now with the advent of the commercially available software like CFD with preprocessor(GAMBIT), postprocessor(FLUENT) and the solvent, the required properties for biomass slurry were developed and combined with the commercially available Fluent software to study the flow analysis of the fuel in the furnace and the problems that were encountered in the droplet study were easily overcome and a complete flow analysis of the fuel in the furnace was done. A pulverized biomass slurry combustion simulation involves modeling a continuous liquid phase flow fluid and its interaction with a discrete phase of biomass particles. The biomass particles traveling through the gas devolatalize and undergo char combustion, creating a source of fuel for reaction in the gas phase. Reaction can be modeled using either the species transport model or the non-premixed combustion model. The non-premixed combustion model uses a modeling approach that solves transport equations for one or two conserved scalars, the mixture fractions. Multiple chemical species, including radicals and intermediate species, may be included in the problem definition and their concentrations will be derived from the predicted mixture fraction distribution. Property data for the species are accessed through a chemical database and turbulence chemistry interaction is modeled using a beta or double beta probability density fraction (PDF). With relevant data as in annexure-1, the computational model and flow analysis was carried out.

The Upper Austrian solar campaign

The Upper Austrian solar campaign aims above all to increase the number of large scale solar installations. Target groups of this campaign are especially companies, mulit-family buildings and public authorities. In order to trigger the market development for large-scale solar thermal installations, a number of activities are carried out:

Awareness raising

A number of information and awareness raising activities are carried out including publications and events. One main part of the information activities is the promotion of large scale solar thermal installations. In order to overcome the barrier of lack of know­how, a planning manual ("solar guide") was developed and training courses for the planning and installation of large solar thermal systems were organised.

Additionally targeted folders for different sectors of commerce and industry were produced, which summarise the opportunities and possibilities for implementing solar energy installations.

Energy advice service

Energy advice given at the moment when investment decisions are made is an important tool for the promotion of energy efficiency and renewable energy sources. O. O. Energiesparverband offers therefore a broad energy advice service programme offering energy advice for households, companies & public bodies.

For companies and industry the service has been extended recently, offering 2 days energy advice for businesses, 75% of the costs are covered by the regional government. Since the start of the energy advice programme for companies, more than 370 advice session have been held, 22 of them focusing about large scale solar thermal installations only.

In order to promote renewable energy applications in companies, together with energy experts, energy strategies for four industry sectors (metal, wood, hotels, real estate) were developed. Based on these guidelines, individual energy advice sessions for the companies were held, leading to concrete renewable energy installations.

Training activities

A number of training programmes are carried out. The most important one is the training of energy advisers. The training course comprises a basic (50 lectures) and a advanced
training course (120 lectures). So far more than 400 people have passed these courses. A special training course for planning and installing large scale solar thermal installations was designed and is now regularly hold.

Recently also 2 new educational programmes for more jobs in the field of energy efficiency and renewable energy sources were started:

• a new university course at the Fachhochschule Wels from which "Sustainable Energy Engineers" will graduate" and

• a vocational training, called "Okoenergie-Installateure", training installers especially in solar and biomass.

Financial Support

A new solar impetus is expected in Upper Austria from the increase of subsidy (e. g. 2,100 € for a 10 m2 standard flat plate solar system). Additionally, the enlargement of existing installations is supported.

Especially attractive is also the financial support for renewable energy installations in companies, which covers up to 44 % of the investment costs for solar thermal installations.

Promoting the solar energy industry

Another main part of the promotion programme is the support for industry and companies. In order to support business development, the "Okoenergie-Cluster" (OEC), a network of green energy businesses was established.

Presently 134 companies are partner of the network, employing 2,100 people and achieving a turn-over of around 270 M€. The network is managed by O. O. Energiesparverband.

The aim of the Okoenergie-Cluster network is to foster co-operation between the partners by common training & information, research and export activities. Among the very successful activities within the network was also a co-operation project for triggering large scale solar thermal installations.

R&D & international co-operation

A regional R&D programme ("ETP" — energy technology programme) supports R&D projects in the fields of energy efficiency and renewable energy sources. So far 79 R&D projects and 153 thesis papers have been supported including several innovations in the solar thermal sector.

Additionally an R&D centre (ASiC — Austrian Solar Innovation Centre) was established to support the local solar companies in their research activities, a solar R&D laboratory is under planning.

International projects are another tool to increase exchange of know-how and experience in the field of solar thermal. O. O. Energiesparverband has already implemented about 60 European co-operation projects, a recent one for example focuses about solar thermal cooling.

Third Party Financing

In order to support innovative financing mechanisms, such as third party financing (TPF), a regional TPF programme is managed by O. O. Energiesparverband. The successful programme has so far supported 45 municipalities with the implementation of energy efficiency projects. Throughout the whole process, the programme provides detailed information, advice and guidance to local authorities and companies interested in TPF.

The programme was extended to cover both municipalities and companies, as well as investments in energy efficiency and in the construction or retrofitting of installations. It is expected that the new programme will give a strong boost to retrofitting large buildings and installations, and that it will trigger new (large) RES installations.

Overview of Solar Energy Developments in Georgia

Bidzina Kekelia, 52 Paliashvili Street, Apt. 10, Tbilisi, 0179, Georgia

George Ramishvili, Nino Shanidze, PA Government Services — Georgia (PA Consulting

Group), 44 Leselidze Street, Tbilisi, 0105, Georgia

This paper provides an overview of current state and future development prospects for solar energy technologies in Georgia. It gives a brief description of climatic and geographical location advantages/drawbacks of the country and provides the authors’ views on possibilities for various solar energy applications in the given area. It also gives an overview of currently used technologies and companies present on the Georgian market.


Generally, in Georgia, renewable energy applications other than hydropower (which accounts for approximately 80-90% of Georgia’s current electricity generation) are not well developed and their contribution to energy generation of the country is negligible. Having abundant (mostly untapped) hydropower and solar energy resources, Georgia seemingly should not have a problem satisfying its electrical energy needs. But in reality this is not so. The causes are a variety of internal and external political and economic factors, as well as financial and institutional crisis Georgia is facing after break up of Soviet Union.

PV Cooperation Projects with Oil and Electrical Utility Companies in Brazil

With private companies and utilities, LABSOLAR has also been carrying out research and demonstration projects aiming at investigating scientific aspects, and at the same time disseminating the use of PV in Brazil. One of such partners is the national oil company PETROBRAS (www. petrobras. com. br), with whom LABSOLAR is in the process of installing what will be the largest grid-connected PV system in Brazil, a 44.4kWp system using six thin-film PV model types from different manufacturers [7], as shown in Figure 11, and two petrol stations with 10kWp of BIPV modules each. Also shown in Figure 11 is the recently dedicated oil pumping project, where PV is being used for the first time in the country to deliver power to an oil pumping system in the northeast, where PETROBRAS explores a great number of small and scattered oil wells, and where PV might be the least cost option.

Eff. loss Set A

Colorado-USA ■ Arizona-USA Florianopolis-BR


Eff. loss Set B

Eff. loss Set C

Eff. loss Set D

Figure 10: Comparison of degradation behaviour for the three identical groups of four different a — Si multi-junction PV module manufacturers (Sets A to D), after one year of simultaneous outdoor exposure in Colorado (leftmost bars for each set), Arizona and Florianopolis (rightmost bars for each set). The site with the highest minimum operating temperature (Florianopolis) experienced the lowest degree of efficiency loss (lowest degradation rate). Measurements carried out at the NREL @ STC.

Figure 11: Examples of PV projects carried out by LABSOLAR in cooperation with private companies. Left top and bottom shows the PETROBRAS building and a schematic of the 44.4kWp roof mounted thin-film installation; top right shows the PV oil pumping project with PETROBRAS, and bottom right shows one of the BIPVprojects with CELESC.

With the state utility CELESC (www. celesc. com. br), and with the neighbour state utility CEMIG (www. cemig. com. br), LABSOLAR has also cooperation agreements that involve education and training on PV, as well as scientific and demonstration projects. One example is shown in Figure 11 (bottom right). In this project three identical 1.4kWp BIPV systems were recently installed together with CELESC at different climatic conditions around the state, to study the behaviour of these installations, in which a certain degree of architectural vs. output performance compromise was reached. With these two utilities, LABSOLAR is carrying out a study on the Effective Load Carrying Capacity (ELCC) of PV, aiming at identifying, especially in urban areas and strained distribution networks with loads that “follow the sun”, the sites where grid-connected PV would lead to the highest benefits in terms of grid reliability, grid support, distribution system avoided costs, and other benefits that installing PV generators strategically in the urban environment might have, on top of the photogenerated energy itself. This study will lead to one M. Sc. and one Ph. D. thesis currently under way and partially sponsored by these utilities.


A sample of the most relevant projects carried out by LABSOLAR has been presented. All these projects include both a scientific and a PV dissemination component, and undergraduate, as well as postgraduate, students are always involved. With these continuing efforts LABSOLAR aims at promoting photovoltaics in Brazil.


The author acknowledges with thanks the support of the Alexander von Humboldt-Stiftung (AvH), Agencia Nacional de Energia Eletrica (ANEEL), Centrais Eletricas de Santa Catarina (CELESC), Companhia Energetica de Minas Gerais (CEMIG), Conselho Nacional de Desenvolvimento Cientlfico e Tecnologico (CNPq), the Brazilian Ministry of Mines and Energy (MME), the National Renewable Energy Laboratory (NREL) and Petroleo Brasileiro (PETROBRAS) for the research grants which allowed LABSOLAR to carry out most of the projects described in this paper.


Early history of vertical p-n-junctions and advantages of vertical structures

The first silicon solar cell was made entirely by accident in early 1940 by Russell Ohl [1,2]. When he used a flashlight for illuminating a piece of silicon he was studying, the voltmeter, which was connected across, showed a surprisingly large reading. The samples of cells, cut from recrystallized material, allowed to investigate both types of p — n junction geometry: with the junction, which was perpendicular and parallel to the illuminated surface. It is interesting to see (Fig.1 [1,2]) that the first solar cells were made with vertical p-n-junctions.

The first practical solar cell was developed in 1954 after considerable theoretical and experimental work. This solar cell was made from monocrystalline silicon and had the planar junction. It was the forerunner of today’s solar cell.

Later vertical p-n junctions were analysed, current-voltage characteristic with the assumption of infinite velocity of recombination and without build-in field was calculated
and conclusion that SC with vertical p-n junctions (SCVJ) are not suitable for conversion of solar energy was made.

At the same time the main problem: to decrease series resistance for conversion of concentrated light, is much easier to solve for vertical design.

SCVJ have a number of advantages in comparison to conventional SC:

1. low series resistance leads to the absence of mutual contradictions between sheet resistance of emitter, spectral sensitivity, surface of electrical contact grid and so on;

2. high tolerance to damage radiation (it is easier to optimize the radiation resistance in space solar cells);

3. lower equilibrium temperature (no need of metallization on the front and back surfaces, that is why SCVJ are transparent to IR behind the main absorption band);

4. in comparison to planar double-sided (bifacial) SC, SCVJ have ideal symmetrical frontal and back sensitive surfaces, that allows to use a both side illumination;

5. can be used as component part of tandem SC (because they are transparent behind the main absorption band;

6. high output voltage (series connection of cells) and small current under the same power lead to more efficient battery (because of decreasing losses, which are arising at the high current cells).

Assessment of technical and economical potential of. biomass exploitation in Sicily — A GIS based. methodology

Marco Beccali, Maurizio Cellura, Vincenzo D’Alberti. DREAM Dipartimento di Ricerche
Energetiche ed Ambientali Universita di Palermo;

Viale delle Scienze, edif.9-90128 PALERMO ITALY
Tel.+39+091236141; Fax. +39+091484425; marco. beccali@dream. unipa. it
Pietro Columba; DESAF Dipartimento di Economia dei Sistemi Agro-Forestali. Universita

di Palermo.


A Geographical Information System (GIS) supported methodology has been defined and adopted in order to assess the real technical and economical potential of biomass for energy production in Sicily contest. This methodology is based on a data referred to a (GIS) collecting data about cover land use, transport facilities, urban cartography, regional territorial planning, terrain digital model, lithology, climatic types, civil and industry users. By means of that GIS was possible to highlight the potential areas where gather the residues coming from pruning of olives, vineyards and other agricultures crops and to assess the tons of biomass available for energy purpose. The economic availability has been assessed assuming a price of the biomass comparing it with other fuels and the evaluation carried out shows the strong competitiveness of firewood in comparison with the traditional fossil fuels when the collection system is implemented in efficient way. At the same time the study has shown a good competitiveness of the finished biomasses (pellets), and good potentiality for a long term development of this market. According to these, as important result of the study is to show the opportunities stemming from the harmonisation of Energy Policy with the Waste Management System.


In the last decade there has been a renewed interest toward the use of Agro-Forest Biomass (A. F.B.) for energy production both at political and users level.

Therefore, research efforts have been directed to the study of possibility and consequences of using A. F.B. for energy production.

The purpose of this study is to describe a methodology able to assess the real technical and economical potential of biomass in Sicily.

The main sector where it is possible the introduction of such resources, is represented by the residential one, in particular for domestic heating systems.

The analysis were oriented also, to the possibility of biomasses exploitation potentially used as fuel in power plants for electricity generation or in central heating plants. While the fuel required in small direct combustion systems can be of various typology, quality and dimension (wood chip, pellets, olive husk), for power application fuels with rather homogeneous physical and chemical characteristics are required. So as a matter of fact, biomasses have to be conditioned through various processes such as chipping, slash chopping or cutting, and, if necessary cleaned from extraneous matter (soil, iron material, etc.) and dried.

In addition fuel which is homogeneous in size and typology represents an
enormous advantage for handling operations, storage in silos and fuelling
operations of the systems. Anyway these needs can easily be met by introducing

intermediate processing operations, such as chipping and desiccation, to be carried out before the storage at the combustion plant. The introduction of these further operations determines an increase in the operating costs with consequent higher risk for the investment.

Consequently the study proceeded to analyse the typologies of fuel obtainable from the different productive sectors, considering both characteristics of the raw matter and the presence of competing markets (conventional fuel) that could invalidate the availability of certain green resources.


The main sectors that can provide biomass for energy users are:

□ Forest harvesting;

□ Short Rotation forestry;

□ Agricultural sector;

□ Food and wood industries

□ Zootechnic sector;

Each sector will provide different typologies of biomasses with different physical and chemical characteristics.

Simply on the basis of the evaluation of physical characteristics, woody and cellulosic products of the above mentioned, activity can be classified in three broad categories of raw matter:

□ directly usable

□ usable after been subjected to a homogenisation process

□ usable after been subjected to a homogenisation process and used in plants provided with an exhaust air treatment system.

Analysing the wood-cellulosic biomasses obtainable from the agricultural sector, it can noticed, (see figure 1), that the products are mainly represented by residues coming from the activities of annual and periodical maintenance of agricultural tree crops. These are constituted mainly by branchwood coming from pruning operations, which are not marketable and are occasionally used to heat houses within the farm.

The raw matter obtained from agricultural tree crops should be processed (chipped or lopped) when the material is loaded, for example with an industrial bio-triturator.

These kinds of products have characteristic similar to Short Rotation Forest crops. Such forest crops are yet in an experimental phase, but potentially they might be able to take the place of many of the present marginal agricultural crops, improving the development perspectives in various agricultural areas. Forest harvesting has a relevant utilization in same areas of the Region.

Regarding by-products of wood and food industries they are usually used directly in the industry same process and zootechnic sector in Sicily is little relevant. For there reasons, in these two last sectors, the investigation has not been focused in this study.

Figure 1: The agricultural sector for biomass production.

The methodology adopted, in order to asses the quantity and the distribution of these potential recourses, is based on the creation of a Geographical Information System. The GIS was implemented by acquirement of a database containing information about: Corine land cover land use map, Regional cartography, administrative boundaries, populated areas, road network, Terrain digital model, lithological map, climatic types, Industry and civil census.

By mean essentially of the land cover map was possible to highlight the potential areas where gather the residues coming from pruning of olives, vineyards and other crops as well as for forest harvesting and potential SRF areas. Assuming a coefficient of productivity, inserted in the GIS, in term of biomass for hectares has been possible to assess the tons of biomass available for energy purpose. This was the first theoretical, assessment of the available resources.

Wood residues from agricultural tree crops

According to the crop system present in Sicily, we considered the following crops:

□ Vineyards pruning

□ Olive trees pruning

□ Fruit trees pruning

□ Poplar trees pruning

□ Citrus crop pruning

In order to assess the quantity of the fuel coming from these crops there was necessary to highlight by means of the Corine Land Cover map the area where the biomass is produced. Assuming a coefficient of productivity of 2 t/ha for the vineyards and fruit trees and one of 1,8 t/ha for olive and citrus crops was possible to calculate the quantity of the theoretical potential. From the assessment were excluded all the areas with a slope major than 70% and with arid climate.

These biomasses, which generally were burnt near the plots may be removed and reduced into chips for energy purposes. For this purpose in the region are present 144.125 ha of vineyards and 167.727 ha of olive crop. These represent the main economic sectors from which it is possible to obtain wood residues available for energy uses. The potential, that could be gathered in Sicily from this sector had been assessed into over 1.000.000 of ton each year.

Cost minimum for a European/Transeuropean electricity. supply entirely with renewable energies

• Dipl.-Phys. Gregor Czisch (ISET)

• Abstract

Diminishing natural resources and global climate change are threatening the peaceful course of human development. A fundamental prerequisite for alleviating these dangers is to convert our energy system to renewable generation technologies that neither consume exhaustible resources nor degrade environmental quality despite continuous operation. Therefore also the questions have to be answered how the future electricity system should be structured, which techniques should be used and, of course, how costly the shift to a renewable electricity might be. This also raises the question how far we can get with the existing technologies and what costs are to be expected if one applies them at their today’s costs, as a worst case assumption. It is apparent, however, only taking into account currently available technologies at their actual costs would constitute a worst-case cost assumption, since future developments will unquestionably improve economic performance. But on the other hand it is a conservative approach not overstressing the phantasy with optimistic cost assumptions and therefore it is resulting in a sound basis for further considerations. These questions have constituted the focus of a study to determine the optimum cost of an electricity supply realized for Europe and near-proximity Asian and African regions, an area with 1.1 billion inhabitants and an electricity consumption of about 4000 TWh. The approach includes the option of supplying electrical energy to national economies not only or mainly from domestic resources but likewise in cooperation with neighbouring countries and distant regions using transmission systems to interconnect all participants within a wide-supply area containing huge renewable energy resources. The freedom for international cooperation between the nations opens up for synergetic benefits. Many of the nations within the area of consideration are emerging nations bounding on Europe with renewable potentials far in excess of national demand. Due to this circumstance, the possibilities of wide-area interconnection promise unprecedented economic and technical benefits for all participating nations. The investigations have confirmed that a totally renewable electricity supply is well within the range of current technology, delivering the electricity at costs only slightly above the current cost of electricity even if future equipment cost reductions are neglected.

These findings have resulted from a computational optimisation process determining the system configuration as well as the temporal dispatch (on a annual three-hourly basis) of all power plants and other components, thus establishing a minimum-cost system on a very detailed basis. The resulting optimal configuration is a system dominated by wind power that incorporates generation at good wind sites throughout the entire supply area. A HVDC (High Voltage Direct Current) transmission system connects these wind sites with the centres of demand while also integrating existing hydropower storage facilities, thus providing backup capacities that are enhanced by regional biomass power and given additional support by solar thermal electricity production.

Other system configurations have been determined for scenarios with reduced investment costs for various technologies (e. g. Photovoltaics). Further scenarios demonstrate the influence of possible new technologies or of particular restrictions imposed, for example,
on transnational electricity exchanges. The purpose of these additional scenarios is to obtain a broader view of various possibilities for a future electricity supply employing renewable energies and thus to provide a basis for political decision. The scenarios show that the shift towards a totally renewable electricity system is much less a technical or economic problem, but instead almost entirely a matter to be resolved by the necessary evolution of political attitudes and subsequent political decisions.

The most important insights derived from this study have been:

1. ) An entirely renewable and thus sustainable electricity supply is possible using current


2. ) The costs of electricity need not to lie far above today’s costs even if very conservative

assumptions are made; however, the costs are dependent on the future system configuration, and could be reduced by ongoing technical progress, or be negatively influenced by wrong energy policies.

3. ) There is more than enough evidence to justify a confident call for a comprehensive

transition to a sustainable electricity supply, bearing in mind that a broad variety of solutions is possible.

4. ) A Transeuropean renewable electricity system would simultaneously enable the

realization of a combined strategy for developmental assistance and climate protection as a win-win arrangement for all participating states.

Financing and Marketing

The financing of the facility demanded a total investment of approx. 4.7 mill. €. Two — thirds of the total investment was covered by a loan and about one third was raised by shareholder’s capital. Working within the framework of the citizen investment model, the Sparkasse Fuerth took charge of the external financing and the acquisi­tion of investors.

The project was placed on the capital market as closed funds. The WPD Regenera­tive Energien GmbH conceptualized the sales brochure and took over the commer­cial project controlling. The invested-in company was, in cooperation with a joint practice of lawyers, fiscally optimized but in view of the income tax law it did not rep­resent a loss allocation company but rather a return fund.

With a closed fund in the legal form of a limited liability company and cooperative lim­ited partnership, the limited partner’s interest share was sold to the capital investor. The selling and transferring of the partner’s interest shares was done by the WPD Vertrieb GmbH.

The project was marketed as the citizen investment model. The minimum investment sum was 5.000€. The distribution was made by the Sparkasse Fuerth. The neces­sary shareholder’s capital amounted to around 1.5 to 1.6 mill. €. Around a third of this amount was covered by the financial engagement of the city of Fuerth with a contribution of 500,000 €. The rest of the necessary capital amounting to approx. 1.2 mill. € was secured from approx. 120 citizens within 2 months after the start of con­struction of the facility.

Construction start: with official ground breaking ceremony on the 26.09.03 Construction period: 3 months Start of operation: in Dec. 2003

Policy instruments in the field of energy efficiency

Fig. 2: Policy instruments, with examples from the energy field

A range of policy instruments already exists: these have already shown their usefulness for example in encouraging energy efficiency, one of the most important means of decreasing greenhouse gas emissions. Such instruments can be characterized as penalties or incentives, and be implemented by fiscal or bureaucratic means (fig. 2). An example of a bureaucratic penalty, for example, would be regulation, perhaps through building performance standards. Conversely, a fiscal incentive might be a grant or tax break to support energy efficiency improvements.

There are pros and cons to each type of instrument. Bureaucratic instruments give predictable outcomes, and are seen as creating a “level playing field” for all participants. On the other hand, they can tend to be rigid, and thus lock in the assumptions made when the scheme was designed. Fiscal instruments are flexible and easily reversed, but are politically sensitive and less certain in their outcomes.

In recent years, there has been increasing interest in market-based mechanisms such as trading systems that aim to combine advantageous features of the different instrument described above. In the environmental field, the traditional approach has been one of bureaucratic “Command and Control”. A typical trading system substitutes this with a fiscal “Cap and Trade” (C&T) approach in which a cap of total desirable emissions is set, and organizations covered by the scheme are then permitted to trade allocations between themselves.