Months before the United States experienced its first solar eclipse in 26 years, utility companies were in a tizzy. The celestial event stretching 70-miles wide from Oregon to South Carolina would take one hour 33 minutes to traverse the US. During that time, photovoltaic resources were to be removed due to the obscuration of the sun causing a sudden increase in load that would otherwise have been supplied by behind-the-meter photovoltaic generators. This led to several concerns about ramping and balancing. Consumer awareness and public service announcements were made to reduce energy consumption and utility companies were asked to keep demand and energy prices under check.
On Monday, 21 August, millions of Americans were out on the streets with their eyes glued to the sky to witness the spectacular astronomical delight. At that time solar generation declined, but so did the demand for energy thereby easing the pressure on the grids.
“Utilities did not need to make as many calls on other power sources to replace solar as was predicted. Overall, despite many fears that the eclipse would destabilise the energy market in solar-dependent states, the American energy grid only suffered minor fluctuations,” explains James Watson, CEO of SolarPower Europe.
The sailing was smoother than expected, but the financial impact of the eclipse was unprecedented. According to an analysis of Bureau of Labor Statistics (BLS) data by global outplacement and executive coaching firm, Challenger, Gray & Christmas, the solar eclipse is estimated to have cost the American economy close to USD 700 million dollars in productivity. The cost to states and metro areas directly in the path of the eclipse, where traffic was expected to increase substantially could see almost USD 200 million in lost productivity, combined.
A case in point is Europe, which faced a total solar eclipse in 2015, putting its over 90 GW installed solar PV capacity under stress. It was estimated that the eclipse would potentially cause a reduction of the PV feed-in by more than 34 GW. The biggest challenge expected was the decrease of generation by 20 GW within one hour, and the increase of generation by almost 40 GW after the maximum impact of the eclipse.
Transmission System Operators (TSOs) in Europe prepared for over a year to create an efficient energy management system based on regional cooperation and coordination, ensured higher reserves via pump storage plants, increased primary, secondary and tertiary reserves for more control and increased, and trained staff in the lead up to the event. On the day of the eclipse, the efforts paid-off as Europe remained ‘switched-on’ through the three-hour eclipse while rarely using primary reserve power.
As solar power around the world grows exponentially, it’s not just the USA or Europe but the entire world that will have to be adequately prepared. According to a report by the International Renewable Energy Agency (IRENA), the levelled cost of electricity for utility-scale PV could fall by more than half between 2015 and 2025, and global solar PV capacity could reach 1,760 GW by 2030 or 7% of global power generation compared with just 1% currently.
But the big challenge for the renewable energy sector going forward is handling day-to-day variations in renewable energy sources and not from rare events like a solar eclipse. It is essential for utilities to have an optimal system and capacity via hybrid solutions like engines that combine PV. It is also important to have a stronger grid system by treating them as independent assets in the grid.
This is where Wärtsilä steps in. It has a unique solution to manage ongoing fluctuations in renewable energy sources. It makes solar PV plants of 10 MW and above and utility scale hybrid power plants which couple a solar PV park with an Ultra Flexible Smart Power generation power plant that enables its customers to balance generation and quickly respond to fluctuations.
Mikko Syrjänen, General Manager, Strategy, Renewables Wärtsilä Energy Solutions explains, “when you prepare for the day-to-day variations, you always need to have the backup or the balancing capacity for the days when it is cloudy and there is no PV production. So, if a solar eclipse happens in the worst case, it can just shut down the PV hours ahead and give the rest of the system time to respond. The control-systems of our PV plants already do that and can help slow down the impact of an eclipse.”
Investing in smarter and more efficient assets is the magic mantra to cope with events like the solar eclipse. As they say, hope for the best and prepare for the worst.