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Renewable energy: Power on the go

Shafiq Khan

Pakistan is presently facing a major problem with respect to power crisis. But this can be managed by exploiting our indigenous resources, i.e. natural resources like solar, wind, hydro and involving our energetic public. The solution would be long-lasting and sustainable because it will be based on our own resources unlike the power and gas supplies from other regional countries, such as from Central Asia or Iran.

The major component of Pakistan`s power demand is satisfied by fossil fuel, much of which is imported and therefore, by definition, is insecure. Therefore, in order to secure its energy, Pakistan must limit its use of fossil fuels to those it can produce within its boundaries, satisfy the balance of its consumption by either minimising its total demand, or maximising its generation from renewables, or both.

While global warming is the top reason to reduce or eliminate our dependence on fossil fuels, there are three other distinct reasons why we need to do that. Firstly, there is the fact that fossil fuels will run out, and therefore we will have to get our energy from elsewhere at some stage, although there are various estimates as to when this might be.

Secondly, Pakistan has significantly less fossil fuel within its boundaries than it consumes, and most of what it has got is coal. Therefore, Pakistan is compelled to import large quantities of fossil fuel. This situation is sustainable so long as other countries wish to sell us their fossil fuels. The fact that they can refuse to sell it to us means that Pakistan has an insecure supply of energy.

And thirdly, if Pakistan switches from fossil fuel imports to renewables, the balance of payments will be improved, and jobs will be created. This makes it a strong economic argument for going green.

Pakistan is ideally located in a tropical region and most of the area receives year-round strong solar irradiance (approximately 800 W/m2). If we cannot find ways to exploit it, it may be our unwillingness or incompetence. Present-day technology has made it possible for us to quite efficiently (at about 30 per cent) convert this sunshine into electricity, to power most of our appliances.

Given the fact that Pakistan`s economy—mainly based on agriculture—is being highly affected by the present energy crisis, immediate measures must be taken to address the issue. Directly coupled DC water pumps with solar panels have been very successful and economical for irrigation purpose. A small-scale solar water-pump, for instance, would discharge about 100,000 litres from a depth of about 100 feet on a typical day in Pakistan. This is a far better choice, when compared with diesel generators or even with grid power, which is not available in many areas anyway.

Pakistan can quickly overcome the present shortfall of about five GW of power if people go for microgeneration from renewable energy (RE) resources. This would engage common people in contributing towards a national cause of power shortage and a global cause of reducing carbon emission and therefore the change in weather patterns. Throughout the world, the microgeneration from RE resources has been encouraged in the masses, and various governments have introduced incentive legislation, including feed-in tariff (FiT) or net-metering. Broadly, the FiT has to take care of the energy payments to the power producers. In many advanced countries, this was not for the power shortage but was meant for replacing fossil-fuel power with green energy. However, for countries like Pakistan it can serve both purposes.

One important limiting factor in the case of all forms of renewable energy options (solar, wind, hydro and biofuels) is the requirement of large area for the deployment of their generators as compared with fossil-fuel powered generators. Fortunately, in Pakistan, while this may be a limiting factor in the cities, it creates no issues for most of non-urban Pakistan.

Another drawback in RE power is the fact that wind and solar resources are intermittent and non-dispatchable. So there should be a grid in place to integrate the generation as well as the power consumption, i.e., for demand and supply. The energy storage is also a setback and is still quite costly and inefficient for batteries to be used for the purpose.

However, hydropower can be used to store energy, which is very useful when significant wind or solar power is being exploited. Any energy strategy should, therefore, aim to maximise generation from this resource. In Pakistan, hydropower could be used in the night time while solar power during the day. The new plans would ideally be of run-of-river type, which do not need reservoirs and dams and all the associated ills.

The conservation measures both at the supply and demand could lead to a sustainable solution, regardless of the type of power generation. On the supply front, heat loss, transmission and distribution losses, including theft, should be reduced. The demand front includes the use of energy-efficient appliances as well as conserving energy at peak hours.

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