The Sun Is Here To Stay: Despite Downsides, Solar Is The Way To Go

Utility scale solar power and urban scale rooftop solar panels hold promise and will not necessarily prove to be as expensive as it is being made out.

Jaideep Prabhu’s informative article in Swarajya on why solar energy may not be all that it is touted to be offers new insights. Without a doubt, the challenges are manifold in the power sector. But the dismissive attitude towards solar energy needs to be corrected.

Solar energy is not going to be the base load in any grid, to be sure. However, does it have to be coal either? Interactions with the state-level generation, transmission and distribution utilities will tell you that solar energy is not their enemy because they see it as complementing the base load, not replacing it.

In any future scenario, especially with the government’s commitments to the global community in combating climate change, we are going to need solar plants. In the agitation over baseload, we tend to forget that many of our thermal power stations are already running beyond their decommissioning periods, and are in need for replacement. While we add capacity, we would need to swiftly replace moribund capacity where plant load factors are pretty poor due to outdated technology and ageing equipment.

It takes about a year-and-a-half for a photovoltaic (PV) plant, or solar thermal plant, to come up, whereas coal plants have gestation periods of three years or more, as seen in the provisional tariff orders issued by the Central Electricity Regulatory Commission (CERC). Plant load factors at these solar power stations are better than what can be replaced. Also, the capital cost of coal-fired thermal power stations has risen from the 2012 benchmark of about Rs 4.5 crore per mw, as evidenced in the CERC orders, while the capital cost for solar photovoltaic plants on a utility scale has touched Rs 5 crore per mw.

Moreover, predictability, fundamental to stabilising grid, is easier with solar power due to its diurnal nature unlike wind, which can pick up any time, wreaking havoc on grid stability. Problems related to solar forecasting at a utility scale are indeed worthy of serious redress. However, wind forecasting is far more problematic, and yet it has been incorporated into the grid on a massive scale. Solar forecasting could be far easier to predict, according to state-level power officials, as sunny days are easier to predict if the duration of the day is known.

The concern can be over supply of power in the night. In that respect, West Bengal’s efforts to link solar power to pumped hydro storage are worthy of consideration, and could hold the key to offsetting the issue of night baseloads. Material availability of lithium is certainly an area of concern for solar power. New research in this area going on at the Swiss Federal Institute of Technology in Zurich, or ETH Zurich, however, shows much promise as it relies on sulphur, iron and magnesium, which are in plentiful supply. Sodium ion batteries are another promising area given the plentiful availability of sodium’s key ore – salt.

Lower solar generation relative to installed capacity is an issue, but capacity utilisation has increased manifold over the past few years. Having touched an average 20 percent, we are now looking at the future in perovskite solar cells with a theoretical limit of 31 percent, as explained by Varun Sivaram’s review among other research. It is important to put this in contrast to wind energy capacity utilisation, which is around 20 percent in states like Rajasthan and Gujarat.

Another issue that has been raised is of land. Land availability is the least of solar energy’s problems, and this has nothing to do with ‘waste land’ – a silly terminology for a whole host of reasons. State governments across India are sitting on their own land banks and not making any productive use of them. In that respect, Punjab has shown the way by putting up land owned by its irrigation department for lease to interested parties, in turn earning revenue for the state. Farmers owning land in Rajasthan do not need to convert land use for solar power projects, while several states are now exempting conversion charges, a crucial cost component in overall land costs. Solar power parks are coming up across the country, particularly under the Jawaharlal Nehru National Solar Mission, which allows them to offset costs, as seen in lower bids for solar tariffs.

The reluctance of utilities to pay generators on time has many aspects to it. Key to them has been the financial stress among distribution companies owned by the state, and it is a result not of the cost of power purchased by utilities but cross-subsidisation of domestic tariffs and agricultural tariffs. Few states are willing to touch this subsidy.This, in addition to commercial losses (another way of saying power theft and unpaid dues) has crippled our utilities and their ability to buy renewable energy.

The NDA government’s Ujjwal Discom Assurance Yojana (UDAY) has a role to play here. Rooftop solar power, in theory, is now feasible since several states have tariffs, particularly at the industrial and commercial level, in urban areas that are much higher than the per unit generation cost, resulting in a quick return on investment. Of course, there are technical issues that need resolution; partially offsetting industrial loads through rooftop solar can help deal with increasing power demand in the short run as well.

A reading of the above points will clearly demonstrate that whether we like it or not, solar power is here to stay. Utility scale solar power and urban scale rooftop solar panels hold promise and will not necessarily prove to be as expensive as it is being made out. Of course, there are several problems that need to be addressed; but there is no need to think they are insurmountable.