RAPID development in solar energy technologies has made it an alternative to fossil-fuel power generation in many countries.
But
Pakistan does not have to depend on borrowed ideas for generating bulk
solar power at a high cost, when other economical options are available.
In
a bid to overcome electricity loadshedding, the Punjab government has
moved to tap possible energy resources for power generation on
fast-track basis. An agreement was signed by it in July last year with a
German firm to establish a 50-mw solar energy unit at Jalalpur Pirwala,
Multan, apparently without conducting any project feasibility study.
The first-ever solar farm costing $150 million, was to be installed
within six months. But there is no physical progress achieved as yet.
Likewise,
the government of Sindh has allowed an independent power producer (IPP)
to construct a 50-mw solar power generation unit at Dhabeji and
allotted 150-acres land to the investor at a nominal cost. The project,
for which an agreement was signed by the sponsor with the same foreign
company during the same period at a total cost of $125 million, was
scheduled to generate power commercially by December 2011. So far, no
construction activity has been undertaken at the site.
Both the
projects are based on solar photovoltaic (PV) system and are proposed to
be connected to the national grid. Seemingly, the projects are
non-starters for a number of reasons. First, solar thermal electricity
is the most expensive among other renewable energy resources.
In
case of hydropower, and even wind energy, availability, reliability and
affordability of power is comparatively much higher, since solar units
usually attain the rated output only for about two hours a day around
noon.
Also, capital cost is higher. Cost per mw for these solar
projects works out to be $3 million, whereas hydropower costs $1.5
million and coal-fired $1 millon per mw, according to international
markets.
Second, solar technology selected is not appropriate for
on-grid application as its adoptability to the existing grid remains
problematic, and in some cases, disruptive to the grid.
The power
generation occurs only when sunlight is strong, weather not cloudy and
supply to grid fluctuates broadly resulting in irregular, intermittent
feed.
Third, the plant module, technology selected and foreign
partner are apparently not suitable. The German company specialises in
commercial and residential PV systems, having individual installations
of maximum one megawatt only, and not having a utility-scale system.
There
are no references for large-scale utility projects either in Germany or
in export market. It has recently completed a 463-kW commercial project
in the UK (equivalent to meet energy requirements of 125 homes on
yearly basis).
Primarily, there are two solar systems for
generation of electricity using solar energy – directly, using PV
system, which is the most common, and indirectly, utilising concentrated
solar power (CSP) system. By the end of year 2010, global installed
capacity of solar PV power was about 40,000 mw. Germany alone ranked as
the world leader in the field has installations of 17,370-mw cumulative
capacity.
Normally, the maximum size of a solar electric system is
of 20-mw capacity. The Sarnia Solar Project in Ontario, Canada has just
become the largest PV solar power plant in the world with the recent
quadrupling of its size from 20-mw to 80-mw capacity. The CSP technology
is employed for large-scale power generation and has the ability to
store energy as sunlight generating strong heat that, in turn, is used
for power steam turbine.
The CSP technology, commercially
developed in the late 1980s, is now proven and has an installed capacity
of over 1,000 mw world over. There are four types of CSP plants: (i)
parabolic trough, (ii) compact linear Fresnel reflectors, (iii) dish
Stirling (parabolic) and (iv) solar power tower. International Energy
Agency (IEA) forecasts that technology could be developed as a source of
bulk power in peak and intermediate loads by 2020 and further, in base
load, by 2030. Thus, within two decades the CSP technology might be able
to compete with coal-fired power generation.
Currently, Mojave Desert of California has the world’s largest power plant, of 354-mw capacity, based on the CSP technology.
Now,
Abu Dhabi plans to develop a 100-mw solar power plant adopting the CSP
technology. Construction of the plant, which would cost $600 million, is
scheduled next month.
Pakistan has abundant solar resources,
while almost half of its population is devoid of electricity
connectivity. There are about 40,000 villages with more than three
million households that are without access to electricity and will
remain so for long if allowed to depend on grid connection.
Nevertheless, low-technology solar option offers long-term solution for
electrification in these far-flung areas.
Based on PV, stand-alone
solar systems are being used economically as a source of electric power
for remote areas not connected with the grid. By the year 2010, a total
of about 650 kW of PV have been installed for village electrification
in Sindh and Balochistan. In addition, another 4,500 houses in Dalbandin
(Balochistan) have recently been energised with solar power.
Moreover,
stand-alone solar systems in the range of 600 watts to 5 kW have been
installed in Sindh under the prime minister’s initiative.
Various
NGOs have also electrified 485 houses in the FATA, about 2,000 houses in
the AJK, and 12 solar panel systems of combined capacity of 3,600 watts
in ten villages of Ziarat district (Balochistan). Other applications of
solar energy in these areas are solar space heating, water heating,
lighting, cooking, process heating, water pumping and telecommunication,
etc.
The trend is being followed in urban areas. Besides street
lights, a number of public and commercial buildings, including mosques,
hospitals and parks, have been illuminated through solar energy. List
covers the Quaid-e-Azam’s mausoleum and two systems of 180-kW each on
grid solar system in Islamabad.
A number of solar thermal
appliances such as solar cookers, solar water heaters and solar lights
have been introduced in the country. Punjab also plans installation of
tube-wells to be operated with solar energy at a cost of Rs1.36 billion.
Large-scale
solar thermal power generation cannot play, and should not be allowed
to play, a significant role in meeting power demands mainly for the
reason that immense potential exists for hydropower and coal resources,
which are abundant and cheap, and comparatively have many advantages for
development under local conditions. This potential is required to be
harnessed optimally and speedily. Simultaneously, solar PV system also
needs to be developed further.
(Source: http://www.dawn.com/2011/09/12/comment-and-analysis-cheaper-options-for-solar-power.html)
