Rethinking energy: increased solar power storage to reduce oil import

LAHORE: It is high time for Pakistan to move towards environment friendly renewable energy solutions to resolve power issues on a sustainable basis. Solar PV power is now less expensive than any fossil-fuel option and that too without state assistance.

The costs for renewable energy technologies decreased to a record low in the last few years. The global weighted-average cost of electricity from concentrating solar power (CSP) declined by 26 percent.

Cost reductions, particularly for solar and wind power technologies, are set to continue into the next decade. Solar PV costs between three and four US cents per kilowatt hour are already possible in areas with good resources and enabling regulatory and institutional frameworks.

For example, record-low auction prices for solar PV in Chile, Mexico, Peru, Saudi Arabia, and the United Arab Emirates have seen a levelized cost of electricity as low as three US cents per kilowatt hour ($0.03/kWh).

In Pakistan, the last approved tariff was for five cents per kWh. These tariffs are for medium and large power projects.

The advantage of solar energy is that its fuel (the sun light) is freely available in the country.

The government should remove all barriers on installing solar projects and announce a tariff of around four US cents at which the producer could supply power in industrial zones.

Globally even in countries like United States, Canada or Germany where sun light intensity is low, solar energy is replacing grid power. Most of them store the power during day to be able to consume it in the evening.

More than 60 percent of the electricity in Pakistan is consumed by households. If we succeed in converting even 30 percent of residences to solar, we would save billions of dollars of foreign exchange we spend on import of oil and gas.

Many households are converting to solar, but they face problem in storage. They have to use lead-acid batteries that cost less up front, but they have a shorter lifespan and require regular maintenance to keep the system running properly.

Pakistan unfortunately has not yet started producing lithium batteries that are more expensive up front, but are maintenance-free and have a longer lifespan to match their higher price tag.

Pakistan has a well-established battery industry with some players operating since 1960’s. The domestic manufacturers are catering to the need of the entire automobile industry.

Manufacturers need to upgrade their technologies to produce more efficient storage vehicles. Regulation is also missing, and there are no checks on the standard of batteries being supplied in the market.

Households are forced to buy imported lithium batteries to ensure better and reliable solar power supplies at their residences. Lithium batteries are gradually replacing the relatively inefficient lead batteries the world over.

Our government should facilitate domestic manufacturers in producing lithium batteries through concessions in import of inputs and eliminating irregularities practiced by some in this sector.

The best lithium battery chemistry for solar applications is Lithium Iron Phosphate, shorted to LiFePO4 or LFP batteries. This new technology lasts longer and can be put through deeper cycles.

They also require no maintenance or venting, unlike lead-acid batteries. Upfront cost of the solar system whether used with lead-acid battery or lithium ion is the same.

The life span of lead batteries is less than three years; the life span of lithium battery is 10 years. Total battery cost over a 10-year period, including system cost is 20 percent cheaper for lead batteries.

But the system would require eight lead batteries with a weight of 976 pound compared with two lithium batteries weighing 384 pounds only.

Lead batteries require regular maintenance while lithium batteries need no maintenance. Lithium batteries are more efficient. This means that more of your solar power is stored and used.

It may be pointed out that lead acid batteries are only 80-85 percent efficient depending on the model and condition. For every 1,000 watts of solar coming into the batteries, there are only 800-850 watts available after the charging and discharging process.

Lithium batteries are over 95 percent efficient. That means over 950 watts of power would be available from 1000 watt solar input into the battery.

This way despite being expensive upfront the lithium batteries supply cheaper energy compared with a lead battery.