Põllumajandusministeeriumi ja Maaelu ... - bioenergybaltic

The studies on the use of boilers, their technical state and investment needs carried out after
2000 show that in average the boilers installed in Estonian boiler plants are either underloaded
or in reserve. Over 60% of the total capacity of boilers run on liquid fuel, natural gas or coal is
not actively used. From the total capacity of wood and peat fired boilers 30% is estimated not
to be in active use.
Since the mandatory purchase price for renewable electricity has risen to 115 Estonian sents
per kWh according to the Electricity Market Act, feasibility of the designed biomass based
CHP plants has improved significantly. In the feasibility analysis the average prices for
Estonia in July 2007 for bulk woodchips 127 EEK per cubic meter (169 EEK/MWh), heat
selling price to network 450 EEK/MWh th , electricity selling price 1150 EEK/MWh el and
annual utization time 6000 h/a were taken for the basis. The analysis allowed drawing the
following conclusions:
• building of a CHP plant with 17 MW el and 40 MW th (and higher) capacity using the
steam cycle is economically feasible and relatively risk free investment in case of the
possible rise of fuel price;
• building of a CHP plant with 3.5 MW el and 16 MW th capacity using the steam cycle is
economically feasible, but still a risk related business. A 30% rise in fuel prices or
decrease in the plant load would make the feasibility of the project problematic;
• small CHP plants using the steam cycle may be feasible only in special cases, for
example in case of subsidized investments, available uniform heat load throughout a
year or guaranteed options for purchasing inexpensive fuel. One of the reasons for the
modest feasibility of small CHP plants using the steam cycle is also the low heat and
power ratio (10 – 20%, in special cases up to 25%).
Today several large CHP plants are under construction or are being designed at Väo, Tartu and
Ahtme. When the construction of all these plants is completed and in addition to wood fuels
also peat is used, in Estonia the need for wood fuels in energy production would still grow
64% altogether compared to the demand in 2006. There is no such an amount of fuel available
in the market now and it could be supplied only when the logging residues were more widely
utilized while the 30% price rise should be taken into account. The rise in fuel prices and
difficulties with supply may end with the bankruptcy or at least economic difficulties of
several small wood fuel fired boiler plants.
The main barrier for building CHP plants is the low level of heat load in summer. The loads
appropriate for building the plant are available only in large DH systems (Tallinn, Tartu,
Kohtla-Järve, Narva, and some other cities). However, building of a biofuel based CHP plant
in the Kohtla-Järve region (Ahtme) is still unlikely, because then the reasonable use of gas
generated by the shale oil production would become complicated. At the same time Eesti
Energia is designing the 10% use of biofuels in the 11 th unit of Balti Power Plant. In several
locations, if CHP plants were built, they would remain without sufficient load.
Building of new biofuel fired boiler plants may be economically feasible when the number of
in-service nominal load hours is sufficiently high – at least 5000 h/a. Considering the fairly
low load and technical level of existing boilers, it would be reasonable to renovate a part of
these boilers and provide higher load for these boilers. The present coal fired boilers should
be replaced with modern combustion equipment burning other fuels. Considering the low unit
capacity and location of coal boilers, one of the alternatives could be replacing them with
pellet boilers. For all biofuel related projects it is indispensable to prepare a profound business
plan which should include an analysis of loads and load curves, also potentials for the fuel
supply as well as an analysis of economic risks.
99