Category Archives: SonSolar

Solar thermal systems: potential and policy proposals

The actual solar thermal exploitation in Sicily represents an instance of under utilization a resource widely available and, at the same time, with competitive costs.

The assessment of solar thermal potential carried out in Energy Master Plan has been referred to the sector and end uses listed in the following table.

Sector

End Uses

Residential

DHW production and back up of space heating

Tertiary

DHW production in the hotel under-sector

Tertiary

DHW production nearby collective users: swimming pools, camping, barracks, prisons, sporting plants, etc.

Tertiary

Summer and Winter air-conditioning for offices and commerce

Tertiary

Agroindustrial processes and desalination

Table 4. Sectors and end uses considered in the assessment of solar thermal potential

As an example, a brief description of the methodology for assessment of the potential of energy saving in the residential sector is now reported.

A reference building stock has been defined taking into consideration all the family house buildings and all the apartments located at the top floor of the buildings. Assuming the climate conditions and the building park characteristics, the possible energy production and saving have been assessed comparing different conventional sources.

All the one store buildings and all the apartments located at the top floor of the multi-storey buildings have been considered as suitable for solar thermal plants. Only apartments already equipped with an autonomous heating system have been considered "technical” suitable for a solar integration installation.

The solar fraction has been evaluated with the f-chart method. The economic analysis has been performed considering several fuel for the back-up system.

In addition, the typical user has been assumed to be a family of 4 people.

All these data have been utilised in order to set up a new type of "economic suitable graph”, in which are compared for different investment costs and different conventional sources (variable price of kWh), the annual costs saving and back-up costs using the optimised solar thermal system.

The use of this diagram is explained using the corresponding points indicated on it:

1. plant specific cost [€/m2];

2. cost of conventional fuel curve [€/kg];

3. optimal surface to be installed in this climatic areas for 4 persons [m2];

4. solar fraction;

5. annual costs saving curve [€];

6. annual back-up costs with conventional source [€];

7. pay back time curve;

8. pay back time [year].

Table 5 reports the potential of solar energy utilization in the residential sector together with the set of actions foreseen in the short and in the medium term in Action Plan.

Figure 4. Tool to assess the economic benefits of solar thermal systems

In the residential sector, a program funding 235.000 m2 in the short term and 400.000 m2 in the medium term of solar collectors have been proposed for DHW systems. The primary energy saving and the avoided CO2 are expected to be about 33 ktep and 77,4 ktCO2 (short t.) and 51 ktep and 114,2 ktCO2 (medium t.). The assumed share of capital cost financed is 30% in the short term (about 35 M€ ) and of 15% (about 21 M€) in the medium term when, in addition, a reduction of unitary costs has been hypothesized.

For the tertiary sector a program financing 25.000 m2 (short t.) and 50.000 m2 (medium t.) of solar collectors has been proposed for low temperature systems. The energy saving and the avoided CO2 are about 1,8 ktep and 3,7 ktCO2 (short t.) and 4,5 ktep and 9,0 ktCO2 (medium t.). The share of funding was assumed to be from the 30% (about 3,5 M€ ) to the 20% (about 4 M€). The sectors that have to be privileged are the ones in which the demand shows a summer peak load or alternatively the users characterized by steady and substantial consumptions during the course of years. The most interested users to be considered are: swimming pools, camping, barracks, prisons, sporting plants, hospitals and clinical medicines, bathing establishments.

A program for an extensive demonstration of solar cooling systems in tertiary and public buildings of about 15 M€ has been proposed. The expected energy and CO2 saving up are in the medium term about 5,2 ktep and 10,5 ktCO2 considering a share of financing of 50%. In the short term the funding intensity will be higher (70%) in order to evaluate the technical and economic performances of some configurations user/plant and to promote the diffusion of a local know-how.

Solar Thermal

Investment

Public

Authority [k€]

Surface installed [m2]

Fossil fuel saving [GWh/year]

Electric energy saving [GWh/year]

% of final consumptions in the civil sector

%of gross internal

primary energy consumption

Emissions

avoided

Technical and Economic potential DHW residential

174150

1161000

385,0

475,0

5,1%

1,160%

438,

Technical and Economic potential DHW+SH residential

227610

1323000

530,3

534,7

6,3%

1,360%

522,

Short term

Residential Action (contr. 30%)

35000

235000

96,6

119,2

1,3%

0,290%

96,7

Action: Hotels and big users (contr. 30%) e P. A.

3560

25000

16,4

1,5

0,1%

0,007%

3,7

Action:

demonstrative plants/Solar Cooling (contr. 70%)

1500

1800

2,4

0,2

Medium term

Action Residential (contr. 15%)

21000

400000

252

108

2,1%

0,363%

114,

Action : Hotels and big users (contr. 20%) and P. A.

4000

50000

42,8

3,1

0,3%

0,032%

9,0

Action : Solar Cooling (contr. 50%)

15000

41667

46,7

4,3

0,3%

0,037%

10,’

Table 5. Potential of solar energy utilization in short and medium term

Another key issue is the involvement of the Energy Service Companies stimulating the market of "energy saving”. A significant contribution by the private market of "white certificates” is expected to be free of public funding. At the same time, there will be activated measures voted to stimulate the existing economic potential through enterprise support, information, training and cultural activities in order to promote a diffusion of this technology with lower costs.

The voluntary agreement among the system suppliers and a Regional control Body is one of crucial tool to successfully achieve the actions. The supplier has to grant the energy performances of the system installed according to standard contracts. In addition suppliers, installers and technicians must be affiliated in a Regional Register.

Conclusion

The new Energy Action Plan for the Sicily Region will apply measures for the support of PV and solar thermal on the basis of a more "user oriented” approach and a merit strategy for SMEs and public actors.

For PV systems, where the economic efficiency of the last funding policies, resulted very low, particular attention will be dedicated to the "quality” of the project and the system. This will be obtained through new assessment procedures for project funding and a shift from capital cost to produced energy funding. Private enterprises will be supported on the basis of voluntary agreements for the certification of the products quality.

Residential DHW system will be stimulated through direct incentives to the small user such as bonus distributed by sellers and/or installers. A positive factor to be supported is the involvement of energy utilities and Energy Saving Companies in the "energy saving” market created by the new national rules.

The results of these policies might be very relevant in the Regional energy contest: about 4,5% of saving of primary energy in the civil sector (of which 0,5% due to PV system), correspondent to the 1% of the gross internal demand, and about 290 ktCO2 of avoided emission per year, correspondent to 4-5% of the objective of Kyoto Protocol for Sicily.

Finance and Insurance Markets

Experience in the different branches became very important because the insurance market changed dramatically and hardened. Today the market is characterized by restrictions in capacities (with the decline in stocks there was a decrease of the reserves of the insurers). The increasing demand caused an increase in price — meaning premiums. Higher premiums are also reached with hardened conditions — meaning coverage of less risks for the same price.

Past:

Risk

Own risk

-►

Insurance

Today:

Risk

Insurance

-►

Own risk

Figure 2: The Insurance Markets worldwide increase the Importance of Risk Management

Figure 2 shows the change in the insurance markets. In the past it was considered which part of the risk was to bear self (this could be the deductible) and the remaining was transferred onto insurances. Today there is only few possibility to choose. The Insurer lays down what he is willing to insure and the remaining rest cannot be transferred.

This means: Risk management becomes more and more important. If the risk in the beginning is reduced as far as possible, there is only a minor part remaining.

In outside financing projects a loan is only granted if the repayment is assured. For this reason often the financing institute lays down which risks have to be insured and the institute itself is the recipient of the indemnification.

A comprehensive and conclusive Risk Management program gives confidence to the operator in the future and gives evidence to the financial institutes that the owner has examined the risks of the project. Furthermore it is possible that the financing conditions are improved because according to Basle II less risk mean better financing conditions. Finally the project cost will decrease because there will be less unexpected expenses. Taking these points into consideration it can be stated that the financing of photovoltaic projects is facilitated if Risk Management is included.

Current Activities and Future Prospects

There are several organizations and companies currently active in development of solar energy applications in Georgia:

A non-governmental group, International Energy Center ENECO, has been involved in renewable energy activities in Georgia since 1994. The most interesting of their projects are:

• Installation of NRG Systems (USA) wind data logger on Mount Sabueti in August 1996. The obtained data is to be used for assessing the feasibility of constructing a pilot wind station (3 wind turbines, rated at 110 kW each). Thus, ENECO possesses high accuracy data for one of the promising sites for future wind park development.

• Pilot Solar Station for a Children’s Orphanage. In 1996-97, with financial support from UNDP and Foundation Energies Pour le Monde, ENECO developed and installed a solar system consisting of Giordano (France) solar collectors and Isofoton (Spain) PV panels to supply hot water and electricity to one of the orphanage houses in Tbilisi.

“Mze, Ltd” is still manufacturing, at less than 10% of its soviet era production capacity, simple solar collectors for water heating. As Soviet Union broke up and central governmental orders are no longer forthcoming, demand for these solar collectors is low
due to insufficient advertisement/education, low income of the population and competition from other companies importing similar, but higher quality/efficiency collectors from abroad.

Renewable Energy Department at “Energogeneratsia” (state power generation company of Georgia) has been liaising renewable energy activities in the country. The department was directly involved in solar, geothermal, biogas and wind energy generation feasibility studies. One of the projects implemented, together with Tomen and Nichimen Corporations (Japan), ENECO and “Karenergo” (state wind energy company of Georgia), was a wind energy potential assessment measurements for several promising sites (including Mount Sabueti) in Georgia.

Former military aviation factory “Tbilaviamsheni”, still manufacturing and servicing well- known Su-25 and MiG-21 fighters, due to lack of military orders, has started to manufacture various types of civil equipment, including hydro power plant turbines. Possessing military technology and assembly lines, the plant is capable of producing high efficiency solar installations so needed for the Georgian market.

Under the United States Agency for International Development (USAID) funding PA Government Services — Georgia through its local sub-contractors has recently implemented two small solar energy installations as parts of Energy Efficiency projects:

• 20 m2 solar collectors in Bolnisi (southern Georgia) — providing hot water to an elderly nursing house “Chagara”.

• 60 m2 solar collectors in Batumi (Ajara, south-western Georgia) — providing hot water to a small private hotel “L-Bakuri”.

Few entrepreneurs and small construction firms are also importing solar water heaters (mostly Turkish and Italian-made) and on occasional basis more expensive PV panels (island systems) for individual housing projects.

Although long a matter of discussions and various drafts by the State Chancellery and Ministry of Fuel and Energy, only in early 2002 a “Program of Application of Natural (Renewable) Energy Resources of Georgia” was submitted by the Ministry to the President for approval. The program is still in the air and not implemented.

Georgia is a mountainous country with numerous resorts and settlements scattered in remote locations, often cut off from the main electricity grid and in acute need of energy supply. These instances could be well suited for solar energy applications, similar to Aspindza Solar Settlement project, but driven by economic levers of small business and tourism industry.

2. CONCLUSIONS

The weakness of the power sector is one of the major obstacles to economic growth in Georgia. Long power outages are a daily occurrence in much of the country, and parts of Georgia do not receive any electricity for several days at all. Especially during the last few years, due to financial crisis in the energy sector, it is very difficult to pay for natural gas or oil imports to meet the country’s energy needs and the country is forced to rely heavily on hydropower resources and to look for alternatives to thermal power generation.

Although renewable sources other than hydro currently have no significant share in the electrical energy sector of Georgia, their importance is well acknowledged and there is a certain (but not sufficient) activity in this direction. Hopefully, in the near future we will see
much wider application of solar, wind, biogas and geothermal energy systems satisfying the population’s basic energy needs.

As to solar energy, in contrast to western countries where governments provide incentive programs and legal frameworks for development of solar (and other renewable) energy applications, the driving force in Georgia most likely will be population and small businesses (unsupported from the government) looking for viable, dependable and economically justified small island power installations providing alternative energy independent of unreliable and already very expensive national grid.

CURRENT MECHANISMS IN THIN FILM CdS-CdTe SOLAR. CELLS FABRICATED BY CMBD

T. M. Razykov*, K. M. Kouchkarov

Physical-Technical Institute, Scientific Association “Physics-Sun", G. Mavlyanov Str.2B, Tashkent 700084, Uzbekistan

Phone: + 998-71-135-4103, Fax: +998-71-135-4291, E-mail: razykov@uzsci. net

Abstract

Analysis of the temperature dependence of the current-voltage characteristics of polycrystalline thin film glass-ITO-n-CdS-p-CdTe-graphite solar cells is reported in this paper. CdTe films were fabricated by a low cost, novel, chemical molecular beam deposition (CMBD) method in an atmospheric pressure Ar flow, from separate Cd and Te sources.

Value of the series resistance determined from the direct current-voltage characteristics is RS= 1.2 x 105 Ohm. It is rather high for thin film solar cells. Changing of the forward current with temperature is caused by the temperature dependence of the diffusion potential V>. The slope of the forward current — voltage characteristics does not depend on temperature. It is shown that the predominant mechanism of the forward current is the multistep tunneling and recombination. The reverse current mechanism is the thermal excitement of carriers in the space charge region at kT/e < V < 1.0 V and the tunneling of carriers at 1 < V< 10 V.

1. Introduction

Polycrystalline CdTe films based solar cells remain one of candidates for large scale terrestrial application. The optimal band gap of 1.46 eV and sufficiently high absorption coefficient of 104 — 105 cm-1 make it attractive for a number of research groups. At present the worldwide record efficiency for CdS-CdTe thin film solar cells is 16.5 % [1]. This is highest value for thin film solar cells after Cu(In, Ga)Se2 (18-19 %) based solar cells.

More than 10 % efficient CdS-CdTe thin film solar cells were fabricated by different technologies: chemical vapor deposition, electrochemical deposition, physical vapor deposition etc. Novel chemical molecular beam deposition (CMBD) of polycrystalline II-VI binary and multinary films in atmospheric pressure gas flow [2] has many advantages of chemical vapor deposition and molecular beam epitaxy techniques. We have fabricated glass — ITO — CdS-CdTe-graphite solar cells by CMBD for the first time. The current mechanisms in this structure are discussed in this paper.

2. Experimental

n-CdS film was deposited on ITO-glass by vacuum evaporation. p-CdTe film was fabricated by CMBD in the atmospheric pressure Ar flow from separate Cd and Te sources. Details of CMBD process were described by Razykov [2]. The thickness of CdS and CdTe films were 0.1 pm and 3.0 pm respectively. The temperature dependence of the current-voltage characteristics was carried out in the wide range of 193-300 K.

Contact to the PCB

The bus bar of the last solar cell is contacted to the PCB. Therefore the following two possibilities were examined: on the one hand the bus bar was contacted by soldering with a standard copper tab on the PCB, on the other hand an electrically conductive tape was used (see Fig. 4). After gluing the solar cells on the PCB the electrical parameters of the module were measured by contacting the bus bar of the last cell.

The adhesive film was applied manually and under light pressure to the solar cell and the PCB. After this step all electrical parameters of the module were measured again. The average loss in the fill factor (FF) caused by the connection with the PCB are illustrated in Fig. 5. The fill factor is a very good indicator for the series resistant in the module (the smaller the fill factor, the higher the series resistant).

Fig. 4: Schematic detail of the plated-through hole. The last front bus is contacted by copper tabs or conductive tape to the front of the PCB and led then by a standard plated-through hole on the back.

The results of the measurements which are illustrated in Fig. 5 show that by using the tape the average loss in the FF is about 1.5% higher than using soldered copper tabs. These 1.5% can be fully attributed to the higher contact resistance of the tape.

The measurements show that the conductive tape is not suitable for the use in high efficient solar modules. For the further modules soldered copper tabs were used.

solder conductive tape

Fig. 5: Fill factor loss (FF) caused by contacting a bus bar with the PCB by soldered tabs and conductive tape.

Encapsulation

Small test modules were manufactured to examine the suitability of different materials in the solar modules. In these test modules different cover and encapsulation materials were combined and measured on their electrical characteristics at standard test conditions. A special indication for the quality of the transmission of the packaging is the short circuit current of the module. A comparison of the short circuit current before and after the packaging supplies directly the portion of the transmitted radiation. The losses, which arise as a result of the encapsulation, are shown for the different material combinations in Fig. 6.

PC + EVA PET + EVA PMMA + EVA PVF + EVA PVF + PVB

-10

Fig. 6: Losses of the Isc caused by the lamination of the solar cells in dependence of the covering and encapsulation material.

The variation of the loss due to the change of the cover material can be recognised clearly. PC has the best cover material properties. Beside the higher firmness the examined PVB has the larger transmission in comparison to EVA. The material properties and a lamination process for PVB are shown in [SCHMIDHUBER01b].

Usage of Self-formation in PV

In self-formation [4] only the first photo-mask, to create initial object, and sequence of chaotic or oriented media are brought from outside.

Fig. 4: Self-formation version transformation takes place.

If the interaction between a chaotic medium and structural object causes an evolution of configurations involving changes in the number of figures, we have self-formation.

Fig. 5. Technological graph of solar cell manufacturing with 5 patterning processes

The interaction matrix describes the way in which medium will interact with initial object. If in the object there are peculiar points and the evolution goes through them there is the possibility to form the new patterns self-aligned with the initial object without structured media using. The possible evolution result in self-formation depends on interaction matrix, interaction set, form of initial object and evolution graph. Multivaluedness of initial object evolution if interaction matrix stable, is based on evolution possibility to move object boundary inside or outside (upwards or downwards). After the defined time of evolution the equidistant surfaces S1 or S-1 will be

formed from initial object surface S0. Which of surfaces will be formed depends on interaction direction.

On basis of surfaces S1 or S-1 under the other interaction the new equidistant surfaces can be created. In other words we can have an evolution graph defining an order of evolution steps:

S-3^ S-2* S-1< S0^ S1 > S2^S3

Undoubtedly we can construct infinite combinations of evolution graphs. The simplest of them is the reverse graph defining reverse evolution.

S0 ^ S1
S-1 ^

In most self-formation cases evolution is irreversible and is a main cause of self-formation arising. In all cases the evolution graph is defined by man or automatics through the media sequence and sometimes through evolution duration. Different evolution graphs are the
reason of solar cells difference which can be self-formed from similar initial object. These processes were simulated by software [5] created especially for self-formation investigation. Both media sequences are based on initial object evolution upwards-downwards.

In both versions initial object is doping glass island, which after serves as mask in silicon wafer etching. In both versions spatial surface evolution upwards — downwards is played. Spatial object with peculiar points is going through evolution until the mapping of these points at the top of object disappears. The evolution direction changes by medium changing and the new structures arise.

The result of technological graphs in Fig.5 and Fig.6 a are the same — PERL type SSC. But the first is formed by external formation with five patterning processes and the second is self-formed. The initial object in this version is formed by photolitography and the other patterns are self-formed from doping glasses, or by electroless metal plating. The other graph reflects self-formation of one-sided solar cell. The important feature is spin-on doping glasses used in these versions, what permit doping source coating, localisation and diffusion.

Perspectives of Russian Bio-Fuels Export to the European Union

D. S. Strebkov, V. G. Chirkov, All-Russian Institute for Electrification in Agriculture, Russian Academy of Agricultural Science.

The extended use of bio-fuels is an important part of the sustainable development strategy declared by the EU for the several forthcoming decades. For transport applications alone, the target of 2% share of bio-fuels and other renewables is set for 2005 which shall rise by 0.75% per year up to 5.75% in the year 2010 [1]. Russia has the highest in Europe potential of reproducible plant biomass and is capable of making a substantial contribution to the EU biofuel market. The aim of this paper is to give a brief analysis of the current economic, social and technological conditions for Russia’s integration into the EU bio-fuel strategy.

Biomass resources in Russia

Plant biomass wastes applicable to energy purposes in Russia are estimated to be 100 Mt/year of plant cultivation residues and 700 Mt/year of timber-felling and wood­working wastes [2]. It is equivalent to about 1400 TWh of energy per year, while the amount of biomass to be commercially available in the EU by 2010 is only approx. 1100 TWh (90 Mt o. e.) per year [3]. Biomass resources in the European part of Russia alone amount to over 400 TWh/year, according to the evaluation made by the Swedish organisation NUTEK [4]. Long-fallow and unused arable lands constitute additional biomass resources potential. In 1995, 15 million hectares of arable land in Russia stayed unused, which is more than twice as much that, according to EU experts, would be allocated for energy crops in Europe (5.6 million hectares or 10 %) by 2020 [5]. If this land were used for SRC, it could annually yield, for instance, about 105 Mt of oven dry willow wood [6], which is equivalent to over 500 TWh. Agricultural production in Russia has considerably decreased since 1990s when the economic policy of the new federal government retrenched abruptly the subsidies to agricultural enterprices. This has led to the bankruptcy of most of the large-scale farms that were the backbone of the rural economic structure for over half a century. Since then, unused arable land has considerably increased providing favourable conditions for implementation of modern SRC energy crop production technologies.

Smoothing Effects for Wide-Area Employment of Wind Energy

150 -100 -50 0 50 100 150

Fig. 4 Seasonal comparison of average electricity generation from wind, quotient of average monthly values of July and January production 1979-1992; met. data: ECMWF.

The most favourable areas for electricity production from wind power in EU countries are dominated by winter winds. For this reason, as is illustrated in Fig. 4, the major contribution of wind generation occurs during this period.

The achievable production — Graph E) — Fig. 5 varies from month to month significantly more than the electricity demand — Graph G). The trade wind regions of northern Africa (southern Morocco and Mauritania, Graph c) and d))exhibit similarly strong seasonal variations, but their peak production is during the summer months. By purposefully selecting a combination of certain areas for production, the typical monthly electricity generation may largely be matched to demand. This fact is illustrated in Graph F), in which one-third of the rated capacities are assumed to lie within the EU, with the rest equally divided among the other regions. In this manner, the area of generation and thus the total potential is greatly expanded, simultaneously accompanied by very beneficial smoothing effects.

P_Mean/P_Rated

0.37 ■ a) Northern Russia and Western Siberia

0.28 b) Kazakhstan

0.38 c) Southern Morocco

0.36 d) Mauritania

0.30 [33] E) Good Wind Sites within EU and Norway 0.33 —F) Combination: 1/3 E) and each 1/6 a), b), 0.47^- G) Electric Demand within EU and Norway

Fig. 6 Seasonal comparison of average photovoltaic electricity generation, quotient of average monthly values of July and January production 1979-1992; met. data: ECMWF and NCEP

1.0

0.9

0.8

s

0.7

0.6

> “

05

ф s

04

0.3

c

о

0.2

0.1

0.0

Time [Month]

1.5

1.2

и

c

«

I

Q

о

0.9

m

0.6

0.3

§

0.0

Fig. 5 Relative monthly average: electricity production from wind turbines (WT) in selected good wind areas and electricity consumption of EU and Norway. a.) to d.) represent Extraeuropean production E.) represents European production and F.) is the combined production of wind power at all regions whereas G.) represents the average consumption in the EU & Norway weighted with the today’s rated power of all power plants installed. The variations in the electricity production from wind power diminish by transcending from the simultaneous feed-in from domestic European locations to generation that includes production from outside of Europe. In the case of a high percentage of electricity being produced from wind power, the instances of excessive generation will be significantly reduced as well as the periods of relatively low feed-in from wind power.

c) und d)

• 4.3 Temporal Behaviour of the Electricity Produced by Parabolic Trough Power Plants

Fig. 7 Seasonal comparison of average heat production by mirror arrays in concentrating parabolic power plants, quotient of average monthly values of December and July production 1983-1992; met. data: ECMWF and NCEP.

Due to the parallel configuration of the mirror elements, the trough array may partially block the rays of the sun when it is low on the horizon. For this reason, and because of the low angle of incidence during the winter, the output varies throughout the months of the year in addition to random changes of incident radiation caused by local weather phenomena. This effect is diminished gradually while approaching equatorial latitudes, but it is still distinctly noticeable even at locations in southern Mauritania, where the achievable production in December reaches more than 80% of July production, as indicated in Fig. 7. Solar thermal generation alone is therefore not adequate to track the seasonal variations in European electricity consumption. In combination with European wind power, however, this requirement may be quite easily met.

Focus I — Assessment of the Solar Energy Resources

The solar energy resources in the building stock is assessed in several steps of which the key features are presented in the table below.

Solar-architectural key features for the assessment of the buildings and their potential for solar energy purposes (photovoltaic and thermal)

Major

characteristics

Descriptive and analytical elements

Solar

characteristics

• Irradiation (general in the area concerned)

• Yield (specific for the surfaces concerned)

• Shading caused by elements other than construction features of the building concerned, e. g. trees, neighbouring buildings, wider horizon)

Architectural

characteristics

• Shape (eight basic types of roof forms)

• Construction features of the relevant building skin parts (e. g. chimneys, windows, terrasses, HVAC, etc.)

Other

characteristics

• Listed buildings

• Cultural / historical zones

With respect to the solar irradiation, it can be stated that sunshine is quite generous a) for the Canton of Geneva as a whole (if compared to other densely populated areas in Switzerland) with 1350 kWh per square meter of optimally oriented surface and b) for a wide range of differently oriented surfaces, too. Examples can illustrate the latter point (compare with the figure below):

1. a surface oriented south yields at least 90% of the maximum annual solar irradiation if it is tilted between 2° and 62°

2. a surface tilted by 25° yields at least 90% of the maximum annual solar irradiation if it is oriented between — 67° et 67°, thus grosso modo between ESE and WSW.

3.

Solar Irradiation in Relative Terms of Maximum Yearly Yield (Solar Criteria) for Different Surfaces (Tilt and Orientation) — Location: Geneva-Cointrin

180- 150- 120 * 90- 60- ЗО* 0* — ЗО* — Є0* -90* -120* -150* -180*

Orientation (Azimut)

о 95%-IOO%

□ 90%-85% o85%80% o80%-85%

□ 75%80%

■70%-75%

■65%-70%

■60%4′;5%

■55%«%

■50%-55%

■45%-50%

■«%-«%

a horizontal surface still yields 89% of the maximum annual solar irradiation.

Solar irradiation in relative terms of maximum yearly yield (solar criteria in % of 1350 kWh per square meter and year) for different surfaces (tilt and orientation) — location: Geneva- Cointrin

□ □ bailments

В □ batiments

H □ parcelles

I I <all other values^
PROPRI_PUB
0СДР; СЕН; CFF; C

0 □

0 0

communes

0 0 orthophoto В D mns_relief_ge В □ Plan de ville E 0 MNS

0 0 partiel_lm 0 0 partie2_lm 0 0 partie3_lm 0 0 partie4_lm 0 0 partie5_lm 0 0 partie6_lm

?Іх]

Identify (ram: | batiments_pub

Location: І497182.74 Л1Є175.75

SHAPE

Polygon

COMMUNE Onex NO_COMM 34 NO_BATIMEN 1315

BATDDP

DATEDT

DESTINATIO Salle despoil NOMENCLATU 4.5.2 NOME N_CLAS E quipement collectif PROVENANCE autie

SURFACE

OBJECTID 43093S3

EPOQUE

SHAPE_AREA 829.90775 SHAPE_LEN 11Є. 037047

The buildings and their surfaces are subsequently attributed to 19 categories while being visually assessed with GIS. First category comprises horizontal surfaces (e. g. flat roofs), the other 18 categories are defined through six orientation sectors (steps of 30°) and three tilt classes (moderate, medium and high tilt). An illustration of how the view and statistical data are screened is shown in the figure below.

Screenshot of aerial picture and statistical data provided by the GIS. Source: SITG

The different elements — both positively and negatively influencing the suitability of the building with respect to solar energy uses — are summarised on sequenced quality levels and aggregated in respective indexes providing quantitative reference values. The table below presents the global analysis results of the approx. 1700 public buildings assessed.

Levels of solar-architectural suitability and reduction factors

Surfaces

Suitability

index

Ground floor area

1’888’400 m2

1.00

Roof surfaces with suitable exposition (good solar yield)

1‘447‘921 m2

0.77

Reduction factor « construction — obstruction »

44.8%

Roof surfaces with suitable exposition and architecture

799‘517 m2

0.42

Reduction factor « shading »

18.6%

Solar-architecturally suitable surface

650‘546 m2

0.34

Levels of solar-architectural suitability and reduction factors as well as resulting surfaces and global suitability indexes (reference ratio « suitable area / ground floor area »)

A first assessment round is dedicated to the public buildings in Geneva, which belong either to the municipalities or to the canton and with a minimum ground floor area of 300 m2. A second assessment round is dedicated to a representative selection of buildings of the whole building stock in the territory.

Intermediary results based on the approx. 1700 objects assessed are available for the « geometry » potential, i. e. solar-architectural suitability of the building skin given. These results range from basic descriptions of the building stock in terms of building types, age structure, property structure, roofscape, etc. to elaborated analysis of the solar — architectural suitability of the public building stock for solar photovoltaic and thermal

570 public buildings have been identified with a tilted roof area being solar — architecturally suitable (minimum solar yield is 90%) for photovoltaic applica­tions. The most important system class in relative terms is the size category from 10 to 30 kWp with a share of 47%.

729 public buildings have been identified with a horizontal / flat roof area being solar-architecturally suitable (minimum solar yield is 90%) for photovoltaic appli­cations. The most important system class in relative terms is the size category from 10 to 30 kWp with a share of 40%.

203 public buildings have been identified with a tilted roof area being solar — architecturally suitable (orientation south ±30°) for solar thermal applications. The most important system class in relative terms is the size category from 100 to 300 m2 with a share of 42%. The solar active collector is calculated on a basis of 1 m2 of suitable roof area is equivalent to 1 m2 of suitable active collector area.

738 public buildings have been identified with a horizontal / flat roof area being solar-architecturally suitable for solar thermal applications. The most important system class in relative terms is the size category from 100 to 300 m2 with a share of 42%. The solar active collector is calculated on a basis of 3 m2 of suitable roof area is equivalent to 1 m2 of suitable active collector area.

applications. Hereunder, a set of results concerning the relative distribution of potentially installable system size classes is given for the public building stock assessed.

Currently, more implementation relevant issues (e. g. age and stability of building roofs, construction work envisaged, legal and financial issues, social and communal acceptance and willingness, etc.) are under analysis in close collaboration with the municipalities concerned. More results will be published in a report later this year.

Le Potentiel Solaire
dans le Canton de Geneve

Analyse et Evaluation du Potentiel Solaire
— Photovoltai’que et Thermique —
dans le Parc Immobilier Public
du Canton de Geneve

Front picture of the future report on the solar energy potential in the Canton of Geneva.

PROMOTION OF SUSTAINABLE FORMS OF RENEWABLE ENERGY KEY TO POVERTY ERADICTION STRATEGIES AMONG POOR PEOPLE IN RURAL AREAS OF KENYA — A CALL FOR SUPPORT

JOSEPH MUTITU NDEGWA1 & MARY MUTHONI GITHINJI RURAL FRIENDS KENYA, P. O BOX 11987, 00400,

TOM MBOYA STREET; NAIROBI-Kenya.

E-mail: mary@lion. meteo. go. ke

Abstract

There is now a global acknowledgement and greater understanding of the depth and extent of poverty especially in the least developed countries whose consequences affect all people everywhere one way or the other. Over 1.2 billion human beings suffer extreme deprivation and lack even the most basic of life sustenance — food, water and shelter among others (World Bank, 2000; IFAD, 2001; DFID, 2001).

In Kenya, one of the poorest and heavily indebted countries in the world, majority of the people live in rural areas where their only means of livelihood is subsistence agriculture. Alternative means of livelihoods for the majority of poor people in rural areas are rare. Opportunities for economic advancement are scarce and rural infrastructure upon which development activities hinge does not exist or is in an unusable state. There is a general lack of rural industries even for processing of agricultural produce. This situation makes the well-being and the welfare of the rural people extremely appalling.

Energy is very essential for sustainable development in rural areas. Electricity supply in Kenya is confined mostly in major urban centres only. Poor people rely on unsustainable forms of energy sources mainly burning of wood for domestic needs such as lighting resulting in serious environmental and health consequences among them, desertification and internal pollution. The latter is a pre-cursor of prevalent asthmatic conditions. There is therefore an urgent and greater need to provide sustainable and affordable forms of renewable energy to poor people in rural areas for household use and to help stimulate development activities in information technology and other light agro-industries. We propose a credit scheme through a revolving fund to enable poor people access solar technology to meet their energy needs. We appeal for support from the international community in this initiative.

1. Introduction

Over the recent years much focus has been placed on the issue of poverty and sustainable development by the international community through various fora with many discourses over these issues. Major strides have therefore been achieved as exemplified by the development of the Millenium Development Goals (MDGs) and identification of steps needed to achieve the goals at the World Summit for sustainable Development in 2002. The MDGs envisages halfing the number of people living in abject poverty by the year 2015. Over 1.2 billion people are in this category, majority of them being in poor developing countries.

In Kenya, over half of the population estimated at 32 million live in abject poverty. Majority of these people live in rural areas engaged in subsistence farming as the only means of
livelihood. These people lack the most basic of necessities needed to attain a decent living standard. They lack adequate food, proper shelter, safe drinking water and proper health service among others. There are no opportunities to generate most needed income. These people are cut off from the current global developments in communication technology with an alarming widening digital divide.

There is therefore great challenge in the task of transforming the lives of such people in line with the objectives of achieving MDGs. The fight on poverty and attainment of sustainable development should focus on development of assets in terms of financial, natural, physical environmental and social resources. In each of these aspects, there exists great potential for utilization of renewable energy strategies to develop the livelihood assets for the poor people particularly in the rural areas. These could be in the area of food processing, cooking, and preservation that enhances quality and amounts available to overcome hunger and food poverty. Solar energy could also be used to enhance health through water sanitization. In another aspect solar energy can also be used in soil solarisation to control soil infection for proper crop production.

Other areas with potential to develop applying renewable energy strategies include domestic lighting, water heating, information and communication technology, for example rural radios, e-mail and internet services, TV and video telephony. Others applications could be in the area of small agricultural-based processing facilities, cottage industries and community health facilities.