Small-Scale Chp Potential in Latvia and Estonia

Abstract

In the research the small-scale CHP potential of Latvia and Estonia has
been defined. Factors, which influence the CHP development, were
analyzed in this paper, including political, geographic, climatological,
legislative and technological factors. For the small-scale CHP potential
assessment the three alternatives were chosen. The first alternative is
the case, when only the hot water is taken into account. In this case
the CHP can work with full load during the whole year because the heat
load will not change (k=0,13). For the second alternative the results of
the previous research were used. In this case an optimal relative heat
load has been found for a small-scale CHP. This optimum value is 0,3.
According to this optimum value the CHP can produce more electricity
working with full load than in the first case. However, the CHP does not
work whole year round. The third alternative shows the situation for the
small-scale CHP when a half of the maximum heat load will be covered by
the CHP. The formulas and the results for each case were provided.

Full text

ISSN 1691-5208
ENVIRONMENTAL AND CLIMATE
TECHNOLOGIES 2009-5208
VIDES UN KLIMATA
TEHNOLOĂIJAS
SMALL-SCALE CHP POTENTIAL IN LATVIA AND ESTONIA
MAZĀS JAUDAS KOĂENERĀCIJAS POTENCIĀLS LATVIJĀ UN IGAUNIJĀ
A. Volkova, Dr.Sc.Ing., senior researcher
Riga Technical University, Institute of Energy Systems and Environment
Address: Kronvalda boulvard 1, LV-1010, Riga, Latvia
Phone: 371+29167107, Fax: 371+67089908
e-mail: anna.volkova@rtu.lv
E.Latõšev, PhD student, researcher
Tallinn University of Technology
Department of Thermal Engineering
Address: Kopli 116, 11712 Tallinn, Estonia
Phone: 372+ 620 3900, Fax: 372+ 620 3901
e-mail: eduard.latosev@ttu.ee
A. Siirde, Dr.Sc.Ing., professor
Tallinn University of Technology
Department of Thermal Engineering
Address: Kopli 116, 11712 Tallinn, Estonia
Phone: 372+ 620 3900, Fax: 372+ 620 3901
e-mail: asiirde@sti.ttu.ee
10.2478/v10145-009-0017-4
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SMALL-SCALE CHP POTENTIAL IN LATVIA AND ESTONIA
MAZĀS JAUDAS KOĂENERĀCIJAS POTENCIĀLS LATVIJĀ UN IGAUNIJĀ
A.Volkova, E.Latõšev, A. Siirde
Keywords: cogeneration potential, small-scale cogeneration, small-scale CHP
Introduction
The potential for using cogeneration as a measure to
save energy is underused in the EU at the present
time, according to the EU Directive 2004/8/EC on the
promotion of cogeneration based on a useful heat
demand on the internal energy market. Promotion of
high-efficiency cogeneration (CHP) based on a useful
heat demand is a Community priority given the
potential benefits of CHP with regard to saving
primary energy, avoiding network losses and
reducing emissions, in particular of greenhouse
gases[1].
Latvia and Estonia are the member states of the
European Union and they both have a high potential
for CHP development. The Estonian vision,
according to the “Energy Sector Development Plan
2020” is that up to 20% of electricity should be
produced by CHP [2]. As for Latvia, regarding the
“Guidelines for Energy Sector Development 2007-
2016” the installed capacity of Latvian CHP potential
should reach 550 MWel [3]. These purposes include
both big centralised thermal electrical plants
development and small scale CHP development.
During the research the potential for CHP in Latvia
and Estonia is analyzed.
Factors, which have influence on the CHP
development in Latvia and Estonia
The factors, which influence the CHP development in
Latvia and Estonia, can be divided into political,
economical, geographic- climatological factors, and
technological factors.
Political factors: Strong political factor, which
influences the small-scale CHP development in
Latvia and Estonia, is Baltic dependence on Russian
fuel and electricity sectors. Baltic dependence on
Russian energy supplies can serve as a convenient
way of exerting economic pressure [4].
The Baltic countries can obtain natural gas only from
Russia and are thus totally dependent on the
“Gazprom” monopoly. There are oil pipeline
connections between Latvia on one side and Russia on the
other, but there are no connections with other countries.
This factor can influence the small-scale CHP
development in two ways. Firstly, dependence on natural
gas supply results in local fuel consumption increasing.
Secondly, the political problems between the Baltic
countries and Russia stimulate Latvia and Estonia interest
to develop local electricity production.
Both Estonia and Latvia have big amount of bioenergy
resources, which results in increase of bioenergy based
CHP usage: wood-based CHP technologies, biogas
technologies, biofuel-based CHP. Peat can be used for
small scale CHP too, but this type of fuel has very high
CO
2
emissions and is not considered to be renewable
energy source. At present time the peat production in the
Baltic States is very low.
For Estonia the most important local energy source is an
oil shale. Share of energy converted by oil shale is more
than 90% [5]. There is no perspective for using oil shale
in a small-scale CHP because of various factors such as
high ash content and low efficiency of this type of fuel in
small-scale equipment. Electrical plants should have high
installed capacity [6].
The most widely used and perspective small-scale CHP
technology is an internal combustion engine, where
natural gas and oil can be used. Political instability can
decrease an interest to install natural gas and oil based
CHP both in Estonia and in Latvia.
The Baltic electricity grids are connected to each other
and to Russia. Estonia does not depend on import of
electricity from Russia which is minimal and much lower,
than Estonian electricity export to Latvia and Lithuania.
But as regards Latvia the political factor can influence the
local electricity production. Comparing prices for natural
gas and electricity, it is better to develop the local
electricity production based on natural gas and oil CHP,
rather than import electricity [4].
Summarizing the political factors influence on the small
scale CHP development:
• Baltic dependence on Russian oil and natural gas;
• Bioenergy and peat based CHP development;
• Decrease of interest to install CHP based on
natural gas/.
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Next factors, which influence the CHP potential in
Latvia and Estonia, are geographic-climatological
factors.
Estonia and Latvia are located in the northern part of
Europe, and an a
verage air temperature of the five
coldest days
ranges for Latvia from -18,3°C
(Liepāja) to -25,1°C(Alūksne) [7], but for Estonia
from - 18.5°C (Kärdla) to -25.5 °C(Tartu)[8]. The
heating season duration in Latvia is from 193 days
(Liepāja) to 214 (Alūksne)[7]. Heating period in
Estonia is from 216 days (Võrumaa) to 224 days
(Järvamaa) [9]. It means that there is a necessity in
high heating loads during a long period. It gives a
possibility for CHP produced heat consumption but at
the same time is considered to be one of the most
important problems for CHP.
Local natural resources in Latvia and Estonia are the
important geographical factors for CHP. The natural
resources' situation in both countries is different, but
common for the both countries is that there are no
local resources of natural gas or oil.
For Estonia the main fuel types are oil shale, peat and
wood. The oil shale can be used for two purposes: to
produce electricity in power plants or to produce the
so-called shale oil. The wood and the peat are used in
the boiler houses. The domestic fuels are dominant to
meet the need for energy. Although the domestic
resources of fossil fuel are large enough for covering
the domestic energy needs for the next decades, more
and more attention has been paid in recent years to
the utilization of alternative and renewable energy
resources.
One of the recent developments in the wood-based
CHP technology in Estonia was a new biofuel and
peat fired CHP plant located in Väo, which started to
produce electricity in the beginning of 2009.
Latvian main local resource for power production is
the hydroenergy. The largest part of electricity
generated in Latvia comes from the three leading
hydropower plants in Latvia: the Kegums HPP, the
Plavinas HPP and the Riga HPP. This type of energy
source can’t supply stable electricity production and
in a so-caller “dry” year it is estimated to be only
60% self-sufficient. The CHP technology can serve as
a balance capacity.
Another type of local fuel in Latvia is wood. There
are many wood-based boiler houses and 3 wood-
based CHP with 2 MW of common installed
electrical capacity. [13].
According to geographical-climatological factors we
can summarize the influence on the small scale CHP
development:
• the long and cold winters result in high and stable
load for central heating, where CHP produced
heat can be used;
• there are local electricity sources both in Estonia
(oil shale) and in Latvia (hydropower).The
Estonian oil shale is a fossil fuel which is not
eligible for CHP. But it is difficult for CHP
produced electricity to compete with cheap
electricity produced by oil shale power plants.
However some certain EU ecology norms
demand the reduction of oil shale share in state
energy sources consumption. This may bring an
interest growth towards the wood-based and
natural gas based CHP systems installation. In
Latvia the CHP can serve as a balance capacity
for the hydropower plants. Amount of an
accessible energy wood in Latvia and Estonia can
motivate the wood-based CHP development.
Legislative factors: Common for the both states is the
Directive 2004/8/EC on the promotion of CHP based on a
useful heat demand in the internal energy market
potential.
In the framework of this Directive is proposed a
mechanism which ensures that the producers and others
with an interest in the CHP can request a guarantee of
origin for the electricity produced from CHP; additionally
is defined a methodology to determine the energy savings
from the CHP.
The Directive determines that the Member States are
obliged to carry out the analysis of their national potential
for the CHP. Both Latvia and Estonia have improved the
legislative acts in accordance of the support schemes for
the CHP.
As regards legislative acts in Estonia, a supporting
scheme for the use of renewable energy sources for
electricity generation was established in 1998. The
Electricity Market Act (EMA) describes the obligation for
grid operators to purchase electricity from the renewable
sources. Up to May 2007 the rate of the feed-in tariff has
been 51.77 EUR/MWh. In May 2007, amendments of the
EMA came into force that established the subsidies for the
high efficiency CHP of heat and electricity.
The new regulation supports the CHP with feed-in tariffs
in the following cases:
• the CHP uses the renewable energy sources or
fossil fuels such as peat or waste or oil or the
shale gas;
• the CHP plant (up to 10 MW) has been started on
the basis of a former heat only boiler (HOB) plant
(See Table 1). Before that there was neither
political nor financial support for the CHP in
Estonia [10].
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Table 1.
Support to electricity produced from the renewable energy sources and/or CHP in Estonia (EUR/MWh)
Energy source Tariff alternatives (EUR/MWh)
Compulsory feed-in-tariff Subsidized tariff
Renewable energy sources (facilities < 100 MWel)
Other renewable energy sources 73,5 53,69
Renewable energy sources in efficient CHP 73,5* 53,69*
Efficient CHP
Peat, waste, oil shale gas 51,77* 31,96*
CHP plant replacing heat-only boiler plant 51,77 31,96*
* A different tariff rate may be approved by the Energy Market Inspectorate.
On April the 3
rd
, 2009 the regulation draft regarding
the grant payments to expand the renewable energy
production and construction of CHP plants in Estonia
was enacted. The regulation draft assumes the grant
payments for the biofuel-based CHP plants under 2
MWel (except the Estonian islands) for up to 50%
from expenses eligible for assistance. Enactment of
this regulation is an extremely important for the
small-scale biofuel-based CHP plants expansion.
Latvia supports the CHP by means of the feed-in
tariffs. The tariffs depend on the installed electrical
capacity of the CHP units. The new Cabinet
regulation Nr.221 regarding Electricity production,
price defining and producing electricity in CHP was
adopted in 2009. The overview of the feed-in tariffs
according to this regulation is presented in the Table 2
[11].
Latvian policy does not support industrial or auto-use of
heat, produced in cogeneration.
As regards legislative basis, certain support is provided
for the CHP development. There are still problems and
the CHP projects are not very popular.
Table 2.
Support to electricity from CHP in Latvia
Installed capacity Source type
Renewable sources or peat Fossil fuel
More than 0,08 MW less than 1
MW
0,51÷0,6·Tg*
(~ EUR 145÷190 /MWh)
0,39÷0,45·Tg*
(~ EUR 110÷145 /MWh
more than 1 MWe and less than 4
MWe
0,47÷0,5·Tg* (~ EUR
124÷133 /MWh)
0,35÷0,38·Tg* (~ EUR 90÷100
/MWh)
more than 4 MWe Regulator approves the price Regulator approves the price
* Tg - price of natural gas
Technological factors: Historically both Estonia and
Latvia are the countries with district heating systems.
This system is working both in big cities and in small
towns. Usually heat is supplied by small-scale or
middle scale boiler houses. This means, that there is
enough heat load for the installation of new CHP
equipment.
There are not so many small scale CHP plants in Latvia
and Estonia and it means that there is a high potential
for the new installations.
The overall summary of factors listed above and their
influence is shown in Table 3.
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Table 3.
Summary of factors, which influence the CHP development
Factors Influence on the CHP development
Positive Negative
Political Dependence on
Russian natural gas and
oil sectors
Baltic dependence on
Russian electricity
(Latvia)
Development of
biomass CHP
Local electricity
production
development, incl.
CHP
Decrease of interest to
install the internal
combustion engine
based CHP
Geographical-
climatological
Low temperature and
long winters
Local energy wood
resources
Local hydropower
resources (Latvia)
Local oil shale
resources (Estonia)
High heat load for CHP
Bio-CHP development
In wet years is no
necessity for the CHP
electricity
Not possible to use in
CHP
Legislative Feed-in tariffs
CHP support Bureaucratized
procedures
Restrictions and criteria
for CHP operating
Technological District heating
High grid capacity
High heat load Connection to the grid
restriction, old grid
Small scale CHP potential calculation
According to the Cogeneration Directive the Small-
scale CHP are the CHP units whose electrical
generation output is less than 1MWe. [1]
We will analyze the potential of the small scale CHP.
The small scale CHP is optimal for application in small
cities. The CHP potential in certain places can be
defined using information about the existing boiler
houses and heat load.
Various alternatives for the CHP potential will be
analyzed.
First alternative is the case when only the hot water is
being taken into consideration. In this case the CHP can
work with full load whole year round, because the heat
load will not change. In this case the 13% from
maximum heat load will be covered by CHP. For
assessment k=0,13.
As a second alternative the optimum defined during
previous research will be used. In this case the optimal
relative heat load has been found for a small-scale CHP.
This optimum is 0,3 [12]. According to this optimum
the CHP can produce more electricity working with full
load than in the first case. But the CHP is not working
during whole year.
The third scenario will show the situation for a small-
scale CHP, when a half of the maximum heat load is
covered by the CHP.
To define the maximum heat load a formula(1) has been
used:
α
k
P
P
el
th
=
max
(1)
where
k is ratio between CHP heat capacity and maximum
heat load,
α
is power to heat ratio.
According to this formula the boiler house ranges for
each alternative were defined for the CHP potential
calculation (see Table 4.)
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Table 4.
Boiler houses which can be used for the small-scale CHP in Latvia and Estonia [13, 14]
Alternative Boiler houses
range
Latvia Estonia
Total capacity MW th.
Total capacity MW th
k
1
=0.15 1-20 MW
1547
3873
k
2
=0.3 1-5 MW
791
1475
k
3
=0.5 1-5 MW
791
1475
Data are not taken from the energy balance sheet
because the corresponding transformation sector in the
autoproducer heat plants includes only the heat
produced for sale, however all of the heat load can be
used for electricity production. That’s why the specific
boiler houses statistics for 2007 is taken for
calculations. The amount of total heat capacity is higher
in Estonia than in Latvia, no matter that Latvia is bigger
than Estonia by the size of territory and by the amount
of inhabitants. After an assessment of statistical data it
has been concluded that the main reasons of such
results are: the active heat use in the industry in Estonia,
colder climate in Estonia and difference in approach for
data collection and calculation.
The basics of data collection methodology are the same
for the both states: data are collected from all the
enterprises whose main or secondary activity is steam
and hot water supply. But calculation basics in Latvia
and Estonia can vary.
For calculation the two types of technology are used: an
internal combustion gas engine for gaseous and liquid
fuel types (natural gas, biogas, fuel oil, shale oil) and
steam backpressure turbine for solid fuel (wood, peat
and coal).
The number of boilers is difficult to define, because for
Estonia there is a statistical data about the number of
boilers [14], but for Latvia is given information about
the number of heat plants [13].
For calculations the ratio between the boilers based on
gaseous and liquid fuel and the boiler houses
based on solid fuel will be taken for range 1-5 MW
N
g,l(1-5MW)
/ N
s(1-5MW)
=1, for range 5-20 MW N
g,l(5-20MW)
/
N
s(5-20MW)
=2. N
g,l
is number of boilers which are
working on the basis of gaseous and liquid fuel and N
s
is number of boilers, which are working on the basis of
solid fuel. There is no exact statistical data, but for the
calculation of potential this ratio for the both states can
be used. According to the Cogeneration Directive the
calculation of electricity from CHP must be based on
the actual power to heat ratio. If the actual power to
heat ratio of a CHP unit is not known the following
default values may be used, notably for statistical
purposes, for steam backpressure turbine
α
=0,45, for
internal combustion engine
α
=0,75[1].
Formula used for calculation of the CHP potential for
each range is following:
)51()51(,
,,
MWsMWlg
sthKOGlglgthKOG
el
NN
NPNP
P
−−
+
+
=
α
α
(2)
where
P
thKOG -
heat, which is covered by CHP (P
thKOG=
P
th
k
n
,
where n- alternative Nr);
N
g,l
is the number of boilers which work on the basis of
gaseous and liquid fuel;
N
s
is the number of boilers, which work on the basis of
solid fuel.
The formulas and results for an alternative calculation
are shown in Table 5(3,4,5).
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Table 5.
Calculation of the small-scale CHP potential
Alternative Formula Latvia Estonia
k
1
=0.13
)205()51(
)205(
)51(
)205()205(,
)205(1,,)205(1
)51()51(,
)51(1,,)51(1
083655,0*078,0
)45,0*33,0*13,075,0*66,0*13,0(
)45,0*5,0*13,075,0*5,0*13,0((
MWthMWth
MWth
MWth
MWsMWlg
ssMWthlglgMWth
MWsMWlg
ssMWthlglgMWth
e
PP
P
P
NN
NPkNPk
NN
NPkNPk
P
−−
−
−
−−
−−
−−
−−
+=
+
++=
=
+
+
+
+
+
+
=
αα
α
α
(3)
125
MWel
200
MWel
k
2
=0.3
)51()51(
)51()51(,
)51(2,,)51(2
*18,0)45,0*5,0*3,075,0*5,0*3,0((
MWthMWth
MWsMWlg
ssMWthlglgMWth
e
PP
NN
NPkNPk
P
−−
−−
−−
=+=
+
+
+
=
α
α
(
4)
142
MWel
265,5
MWel
k
3
=0.5
)51()51(
)51()51(,
)51(3,,)51(3
*3,0)45,0*5,0*5,075,0*5,0*5,0((
MWthMWth
MWsMWlg
ssMWthlglgMWth
e
PP
NN
NPkNPk
P
−−
−−
−−
=+=
+
+
+
=
α
α
(5)
237
MWel
442,5
MWel
These alternatives for potential calculation show that
the small-scale CHP potential is rather high in all
cases, but in reality there are technological and
economical restrictions and the features related with
them:
• The economical calculation of every certain CHP
plant is based on consumers’ heat load duration
curve. The consumer with constant heat
consumption (mainly industrial consumers) is
more preferable than the consumer with variable
heat consumption. Both in Estonia and in Latvia
the biggest part of consumers consists of
households.
• Many boilers in Latvia and Estonia are the
modern and effective boilers working on fossil
and biofuels, which recently replaced the old
boilers. Replacement of those boilers by CHP
plants is not always the right decision, because
the expenses for those boilers mainly are not
covered.
• One of the problems is related to the industrial
consumers. The experience shows that in such
kind of industrial enterprises the heat supply is
organized in a very cheap way. Taking into
account the relatively high investment costs, an
interest to the CHP plants construction is limited.
Conclusions
There are many factors influencing improvement of the
CHP usagein each state: political (energy dependence),
geographic-climatological (cold winters, long heating
period duration), legislative (support, bureaucratic
procedures), technological (district heating system). As
regards Latvia and Estonia many of the factors are just the
same for the both states. There are some specific factors,
however, varying for each country, such as the local
energy resources: high share of hydroenergy in electricity
production in Latvia and oil shale in electricity production
in Estonia. There are factors, which can be influenced by
state policy to stimulate the CHP development: legislative
and assistance to solution of the technological problems.
Potential for the small scale CHP was calculated, taking
into account the existing installed boiler houses. 3
alternatives were offered, where the ratio between the
CHP heat capacity and the maximum heat load was 0,13;
0,3 and 0,5. The ratio 0,13 allows to be used in a wider
consumer range for the small-scale CHP. The formulas
for potential calculation for each of the alternatives and
the results for Latvia and Estonia were given. For the first
alternative when ratio is 0,13 the potential for Estonia is
200 MWel, for Latvia is 125 MWel. In the case of second
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alternative when the ratio is 0,3, the potential for
Estonia is 265,5 MWel, for Latvia is 142 MWel. For
the third alternative when the ratio is 0,5, the small-
scale CHP potential in Estonia is 442,5 MWel, and
237 MWel in Latvia. For all of the alternatives the
small-scale cogeneration potential is higher in
Estonia. It can be explained by the following: there
are very few small-scale CHP in Estonia now; there
are high heat loads in the industry sector and colder
climate in Estonia. Concerning the methodology of
statistical data collecting, the basics are the same for
the Latvian and Estonian Statistical bureaus, as it has
been defined in the methodology description.
However, the calculation methodology can be
different what may have an influence on the result.
Final conclusions regarding the small-scale CHP
potential can be made only after an additional
research.
According to the calculations made in this paper
there are high perspectives for the small-scale CHP
development in Latvia and Estonia. The small-scale
CHP potential is partly used, more in Latvia than in
Estonia, but there are still big possibilities to enlarge
the share of electricity produced by the small-scale
CHP in both countries.
References
1. EU Directive 2004/8/EC on the promotion of
cogeneration based on a useful heat demand in
the internal energy market potential for use of
cogeneration as a measure
2. The State development plan for the energy sector
in Estonia until the year 2020, Estonia,
Riigikogu, June, 2009
3. Guidelines for Energy Sector Development
2007-2016, Latvia 2006
4. Energy Outlook, Macrooutlook The Baltic
region, 2006, Hansabank markets, 15 p.
5. Eesti Energeetika Arvudes, Majandus ja
Kommunikatsiooni Ministeerium, 2007, 44 p.
6. Arvo Ots, Oil Shale Fuel Combustion, Tallinn,
2006, 833 p.
7. Latvijas būvnormatīvs LBN 003-01
"Būvklimatoloăija", 2001.
8. EVS 829:2003 Hoone Soojuskoormuse
Määramine. Calculation of heat demand for
building, 2003
9.
T.-A.Kõiv
Eesti kraadpäevad ja nende
kasutusjuhend, I etapp, TTU, 2003
10. The Electricity Market Act, 1998, Estonia
11. MK noteikumi Nr.221 "Noteikumi par
elektroenerăijas ražošanu un cenu noteikšanu,
ražojot elektroenerăiju koăenerācijā"
12. Vološčuka A. Mazu koăenerācijas staciju
darbības analīze. Jaudas izvēles optimizācija,
Promocijas darba kopsavilkums.-R.:RTU, 2008.-
lpp.
13. Centrālas statistiskās pārvaldes datu bāzes, Vide un
enerăija (9. Number of Heat Plants, capacity and
produced heat 2007., 11.Heat plants by fuel type,
2007_,
http://data.csb.gov.lv
14. Statistical Database, Statistics Estonia, (FE043
Boilers by type of boiler, fuel consumption and
generated heat 2007)
http://pub.stat.ee
A. Volkova, Dr.Sc.Ing., senior researcher
Riga Technical University, Institute of Energy Systems and
Environment
Address: Kronvalda boulvard 1, LV-1010, Riga, Latvia
Phone: 371+29167107, Fax: 371+67089908
e-mail: anna.volkova@rtu.lv
E.Latõšev, PhD student, researcher
Tallinn University of Technology
Department of Thermal Engineering
Address: Kopli 116, 11712 Tallinn, Estonia
Phone: 372+ 620 3900, Fax: 372+ 620 3901
e-mail: eduard.latosev@ttu.ee
A. Siirde, Dr.Sc.Ing., professor
Tallinn University of Technology
Department of Thermal Engineering
Address: Kopli 116, 11712 Tallinn, Estonia
Phone: 372+ 620 3900, Fax: 372+ 620 3901
e-mail: asiirde@sti.ttu.ee
Acknowledgement
This work has been partly supported by the European Social
Fund within the researcher mobility programme MOBILITAS
(2008-2015), 01140B/2009, Grant Nr.MJD10
Anna Volkova, Eduard Latišev, Andres Siirde, Mazas
jaudas koăenerācijas potenciāls Latvijā un Igaunijā
Izpētes laikā tika noteikts mazas jaudas koăenerācijas staciju
potenciāls Latvijā un Igaunijā. Rakstā analizēti faktori, kuri
ietekmē koăenerācijas attīstību, iekĜaujot politiskos,
ăeogrāfiskos, klimatoloăiskos, likumdošanas un tehnoloăiskos
faktorus. Mazās jaudas koăenerācijas potenciāla noteikšanai
tika izvēlētas trīs alternatīvas. Pirmā alternatīva Ħem vērā tikai
karstā ūdens izmantošanu. Šajā gadījumā koăenerācijas stacija
var strādāt ar pilno slodzi visa gada periodā tāpēc, ka siltuma
slodze netiks mainīta (k=0,13). Otrajai alternatīvai tika
izmantoti iepriekšējo pētījumu rezultāti. Šajā gadījumā autori
noteica, ka mazas jaudas koăenerācijas stacijai optimāla
relatīva slodze ir 0,3 (k=0,3). Attiecībā uz šo optimumu
koăenerācijā var saražot vairāk elektroenerăijas, strādājot ar
pilno slodzi, nekā pirmajā gadījumā, bet koăenerācija strādās
ne visu gadu. Trešā alternatīva parāda koăenerācijas
potenciālu, kad puse no maksimālās slodzes tiks nodrošināta ar
koăenerāciju. Ir izstrādātas formulas un piedāvāti rezultāti
katrai alternatīvai.
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Download Date | 9/18/15 5:35 PM

Anna Volkova, Eduard Latosev, Andres Siirde, Small-
scale CHP potential in Latvia and Estonia
In the research the small-scale CHP potential of Latvia
and Estonia has been defined. Factors, which influence the
CHP development, were analyzed in this paper, including
political, geographic, climatological, legislative and
technological factors. For the small-scale CHP potential
assessment the three alternatives were chosen. The first
alternative is the case, when only the hot water is taken
into account. In this case the CHP can work with full load
during the whole year because the heat load will not
change (k=0,13). For the second alternative the results of
the previous research were used. In this case an optimal
relative heat load has been found for a small-scale CHP.
This optimum value is 0,3. According to this optimum
value the CHP can produce more electricity working with
full load than in the first case. However, the CHP does not
work whole year round. The third alternative shows the
situation for the small-scale CHP when a half of the
maximum heat load will be covered by the CHP. The
formulas and the results for each case were provided.
Аннa Волкова, Эдуард Латышев, Андрес Сиирдеб,
Потенциал малых когенерационных станций в
Латвии и Эстонии
Во время исследования был определен потенциал
малых когенерационных станций в Латвии и Эстонии.
В статье были проанализированы факторы, которые
влияют на развитие когенерационных станций,
включая политические, географические,
климатические, законодательные и технологические
факторы. Для определения потенциала малых
когенерационных станций были выбраны три
альтернативы. Первая альтернатива это случай,
когда берется во внимание только нагрузка нагрева
горячей воды. В этом случае станция может
работать втечении всего года, потому что тепловая
нагрузка не будет меняться (k=0.13). Для второй
альтернативы были использованы результаты
предыдущих исследований. В этом случае было
определено, что для малых когенерационных станций
оптимальная относительная тепловая нагрузка 0,3
(k=0,3). Касательно данного оптимума, можно
произвести больше электроэнергии в когенерации, чем
в первом случае, но станция не будет работать весь
год. Третья альтернатива показывает
когенерационный потенциал, когда половина
максимальной мощности обеспечивается
когенерацией. Разработаны формулы и предложены
результаты для каждой альтернативы.
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Download Date | 9/18/15 5:35 PM