The evenings are hard

Mounting stress upon India’s grid engineers

Solar energy is growing. But in the evening, the sun goes down, and the big users of solar switch back to the grid. Economic growth and changes in the built environment are exacerbating cooling demand in the evening. Grid managers are manfully struggling with this problem of the surge in evening demand, but it is becoming harder to accommodate. The only way out is market prices.

The price of solar energy has dropped handsomely. For every firm, there is an opportunity to cut energy expenses in the day by obtaining solar electricity through some contracting mechanism. But the sun is a fickle friend, and every evening solar energy dwindles away while electricity demand surges. With economic growth and cheap Chinese manufacturing, air conditioning adoption grows by the day. The built environment is transitioning to heavier structures, which have more heat capacity, which irradiate the interiors in the evening, thus motivating more use of air conditioning into the evening.

Every evening, solar users turn back to the grid. This is hard for managers of the grid. The bulk of the Indian energy system is coal thermal, so what is filling in the breach each evening is coal thermal.

But in the day when the sun is shining, there aren't enough buyers for this electricity. It takes hours for coal plants to increase or lower their generation: They cannot respond to surges and declines that play out over short periods of time. The global financial system will no longer fund new carbon-intensive generation plants. Indian energy firms have therefore pivoted in favour of renewables, and the addition of capacity in electricity generation based on fossil fuel has stalled.