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Economic and Environmental evaluation of
Large Solar Water Heating System installed in
Macedonian Sheepfold
Abstract— In this paper, we present a case study for a large
solar water heating system installed at a remote location. The
location, as well as the solar energy potential have been
identified in the RISE Project (FP6 call for Western Balkans)
dealing with renewables for isolated systems. We have
evaluated the main economical and environmental parameters
using the RETScreen software for a certain system selected
from its database. The results have shown that even for this
case when the avoided costs for heating energy (diesel oil) are
pretty high, the payback period is longer then 10 years mainly
due high investment costs and no grants. On the other hand,
such system is a win-win measure for GHG abatement and it
can greatly improve the quality of life at the location and
contribute to a much better cheese production process. This in
turn will produce higher incomes and better social situation in
the region. All of the results are a valuable input for the
further work under the other packages in the RISE Project.
Index Terms— hot-water solar system, cost estimation,
renewable energy sources, RETScreen
T
I. INTRODUCTION
he solar irradiation in Macedonia is amongst the
highest in Europe. The average solar radiation is about
3.8 kWh/m 2 /day which is 30% higher then the value in
many European countries. This promising solar energy
potential is considered in the set of renewable energy
sources (RES), which are investigated in the FP6 Project
“Renewables for Isolated Systems – Energy Supply and
Waste Water Treatment (RISE)”.
According to the radiation measurements performed by
the National Institute of Hydro-meteorology, the average
daily solar radiation varies between 3.4 kWh/m 2 in the
Northern part of Macedonia (Skopje) and 4.2 kWh/m 2 in the
South Western part (Bitola). Under the conditions of the
geographic belt where the meteorological stations are
located, the total annual solar radiation varies from a
minimum of 1,250 kWh/m 2 in Northern part of Macedonia
to a maximum of 1,530 kWh/m 2 in the South Western part
which leads to an average annual solar radiation of 1,385
kWh/m 2 .
Although the geographic position of Macedonia and its
climate provide favorable conditions for the successful
development of solar energy, the low electricity prices and
non-available investments are the main barriers to the largescale
dissemination of solar technology. However, ever
This work has been performed within the EC funded RISE project
(FP6-INCO-509161). The authors want to thank the EC for partially
funding this project.
N. Bitrak, M. Todorovski, N. Markovska
increasing oil prices, as well as the expected introduction of
a new electricity tariff system with prices close to the
European electricity prices will change the economic
situation of solar installations to a better position offering a
shorter payback period.
A. Methodology
II. STUDY CASE
Under the RISE Project, several software tools for
evaluation of renewable energy technologies (RET) have
been studied (HOMER, HYBRID2 and RETScreen) [1]. For
the evaluation of solar water heating system at one of the
locations considered in the RISE Project, the RETScreen
software package was found most suitable. RETScreen
provides many results concerning the economic and
environmental performances which are valuable input for
the further work (e.g. Work Package 4) under the RISE
Project.
The RETScreen International Renewable Energy Project
Analysis Software [2, 3] is a unique decision support tool
developed with the contribution of numerous experts from
government, industry, and academia. The software,
provided free-of-charge, can be used world-wide to evaluate
the energy production, life-cycle costs and greenhouse gas
emission reductions for various types of renewable energy
technologies. The software also includes product, cost and
weather databases; and a detailed online user manual.
RETScreen is dedicated to the preparation of pre-feasibility
studies. It uses international product data from great number
of suppliers, as well as international weather data from
many monitoring stations. In addition, RETScreen evaluates
the greenhouse gas emissions reduction for various
renewable energy technologies.
The RETScreen Solar Water Heating Project Model can
be used to evaluate solar water heating projects. There are
three basic applications that can be evaluated with the
RETScreen software: Domestic hot water; Industrial process
heat; and Swimming pools (indoor and outdoor).
Six worksheets (Energy Model, Solar Resource and
Heating Load Calculation (SR&HLC), Cost Analysis,
Greenhouse Gas Emission Reduction Analysis (GHG
Analysis), Financial Summary and Sensitivity and Risk
Analysis (Sensitivity)) are provided in the Solar Water
Heating Project Workbook file. The SR&HLC worksheet is
used to calculate the monthly energy load required to heat
water to the desired temperature. This worksheet also
calculates the annual solar radiation on the tilted collector
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