Renewable Energy in Industrial Applications – an ... - Unido

HEAT PUMPS
OECD countries have an important role to play in
the potential deployment of heat pumps for
industrial process heat. This reflects the fact that
most OECD countries already have reliable
electricity grids which deliver electricity at
competitive prices. The high efficiency of electric
industrial heat pumps makes this technology
competitive with solar thermal technologies
where electricity prices are low and solar
radiation is less than optimum, conditions which
describe many of the regions where OECD
industrial production is located.
Two other factors, the capital cost of the
equipment and its performance, are also
important in determining the competitiveness of
heat pumps. Performance is expressed in terms
of the number of units of energy the heat pump
can move from the lower temperature of the
source to the higher temperature needed, using
one unit of electricity. In most normal operating
conditions, the amount of electricity required is
considerably less than the amount of heat
provided, particularly in applications demanding
relatively low temperature process heat. The main
thermodynamically limiting factor in the use of
heat pumps for high temperature process heat,
however, is that their performance decreases the
greater the difference in temperature between the
input source and the output demanded. So heat
pumps are more efficient in delivering low
temperature process heat demands. And air heat
pumps are more efficient in warmer climates. This
factor has been taken into account in analysing
the cost of the process heat in individual
regions.
Supply cost curves have been calculated for 2007
and 2050 for the same temperature range
categories as in the supply cost curve for solar
thermal, using the cost per unit of useful energy
based on the cost of electricity, an indicative
capital cost of the heat pump and its
performance coefficient. The performance
coefficient of pumps decreases as the
temperature lift increases. It is much lower for
the 60o - 100oC range than for temperature lifts
less than 60oC. Electricity costs are taken from
the IEA Energy Prices and Taxes database, using
the data for the final price of electricity for the
industrial sector. For those regions not in the
database, the data of a representative country
have been used as a proxy, notwithstanding the
very significant differences in electricity prices
among different countries in the same region. For
those countries for which historical data are
missing, a 2007 figure has been calculated using
the OECD price in 1996 as base and rescaling as
a proportion of the OECD 2007 figure. The
resulting cost curve for the food and tobacco
sector, as an example, is shown in Figure 15.
The curve for 2050 has been created using
reduced capital costs, increased performances
and more homogeneous electricity prices, ranging
from USD 12 to USD 24/GJ (real terms 2007
prices).
Heat pumps can already provide a competitive
alternative to fossil fuels for low temperature
process heat in several regions. One of the
driving factors, for example in China, is the
availability of cheap electricity. But where this
electricity is generated by low-efficiency or coalfired
power plant, this can completely offset the
potential CO2 emission reductions associated
with the use of heat pumps.
The competition for low-temperature renewable
process heat production between heat pumps
and solar thermal will be heavily dependent on
regional and local conditions. This analysis
shows how the relative competitiveness of the
two technologies is likely to be both regionally
and sectorally polarised. Both technologies have
substantial improvement potentials between
2007 and 2050. But the cost of the electricity
that drives the cost of process heat from heat
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