Solar and wind emission-effect on fossil fuel plants ‘negligible’

Share on facebook
Share on twitter
Share on linkedin
Share on reddit
Share on email

High penetrations of wind and solar on the grid in the western United States has a negligible impact on the emissions associated with cycling thermal power plants, new research from the National Renewable Energy Research Laboratory published yesterday reveals.

To accommodate higher amounts of wind and solar power on the electric grid, utilities must ramp down and ramp up or stop and start conventional generators more frequently to provide reliable power for their customers – a practice called cycling.

Last year, research paper from another US government laboratory, the Argonne National Laboratory indicated that the carbon reduction benefits might not be as high as expected because of this cycling which makes gas and coal fired power stations less efficient.

But the new NREL study finds that the carbon emissions induced by more frequent cycling are negligible (<0.2%) compared with the carbon reductions achieved through the wind and solar power generation evaluated in the study.

Debra Lew, NREL project manager for the study, spent two years investigating the impact of cycling and the impact of wear and tear on the additional demand on thermal plants that have to ramp up and down in response to renewable generation.

“The fact that wind and solar do decrease overall emissions across the system across the west and that these impacts of cycling on emissions are relatively small, that I think we expected to see,” she told PV Tech.

Phase 2 of the Western Wind and Solar Integration Study follows on from the phase 1 study in 2010 into the viability, benefits and challenges of integrating high penetrations of wind and solar power into the western grid. The first report found that integration of 35% wind and solar energy into the electric power system will not require extensive infrastructure if changes are made to operational practices.

Wind and solar can increase annual operating costs for fossil-fuelled generators by $35 million to $157 million, while reducing fuel costs by $7 billion, the study found.

The study also revealed some unexpected differences in the impacts on coal and gas generation and in high wind or high solar penetration scenarios.

Wear and tear costs of cycling in high wind scenarios were more favourable than for high solar penetrations.

“High wind scenarios tend to turn off coal plants over time on a weekly cycle when there is a lot of wind,” said Lew. “Whereas solar tends to keep the thermal plants on but turned down to minimum generation levels on an almost daily basis. In order to meet the evening peak, the high solar case tends to turn on the thermal plants in the evening to meet that peak. If there's a lot of wind in the evening, that helps to deal with the evening peak.”

But Lew added that the predictability of sunrise, sunset and the direction the sun moves throughout the day should reduce the variability issues associated with solar.

“This was the first time we'd really been able to dive deep into high penetrations of solar,” she said. “We find with solar that the sunrise and sunset events dominate our variability issues. The good thing is that you know when the sun is going to rise or set. We find that when you take out that known solar variability, cloud variability is smoothed out by the fact that we're aggregating solar over many plants.

“Solar dominates our variability issues and wind dominates our uncertainty issues but both we find are manageable we just have to make sure we do these things to manage them. The most important thing is flexibility in the system.”

28 July 2021
LONGi has launched its Hi-MO N module, the company's first bifacial module with N-type TOPCon cells, designed to deliver ultra- high value and lower LCOE to utility-scale PV power plants. This PV TechTalk Product Series webinar will provide an overview of the module’s technology and how the introduction of n-type technologies will provide efficiency and performance gains for solar project developers.
19 August 2021
The utility-scale PV market is poised for exponential growth and yet the industry still has many fundamental opportunities to improve on standards and best practice. Tracker shade loss has been one of those topics that deserve more attention, but has been typically handled by derate factors rather than trying to accurately forecast the loss over the life of the system. Join Nextracker’s subject matter experts, Aron Dobos and Neelesh Umachandran, and Rounak Kharait, director of solar energy assessments at DNV, for a webinar about why shade modeling matters and recommendations on what the solar industry should do about it.
25 August 2021
Energy Next is a new industry exhibition focusing on the latest renewable energy and energy efficiency technology, which will be held for the first time in 2021 in Sydney, Australia alongside the Clean Energy Council’s Australian Clean Energy Summit, the peak gathering of leaders driving Australia's energy transformation. Organised by the same people behind Australia’s largest clean energy event, All-Energy Australia, Energy Next will give visitors two days of access to key suppliers in the industry, free-to-attend professional development and industry workshops, and networking opportunities to better understand clean energy issues and solutions and learn about the latest developments in this transformational, dynamic sector.
25 August 2021
The Intersolar Summit Brasil Nordeste takes place in Fortaleza, Brazil. It addresses leading local and international experts on solar power and renewable energy in the region. The Summit’s mission is to provide in-depth education, enable high-quality networking opportunities, expand the use of PV technologies at regional and national level and strengthen the local PV industry. The Intersolar Summit Brasil Nordeste is organized by Intersolar South America - Latin America’s largest exhibition and conference for the solar industry: Solar Promotion International GmbH, Pforzheim, Freiburg Management and Marketing International GmbH (FMMI) and Aranda Eventos & Congressos Ltda, São Paulo as co-organizer.
25 August 2021
Join us to hear directly from the CTOs and heads-of-research from the top-20 cell/wafer producers to the PV industry today. The event will focus on predicting the key metrics underpinning the next big shift to n-type with answers to the key questions: When will the transition to n-type happen? Which companies will be first to 10 GW capacity and production? Who will be the key equipment suppliers for the new production lines? Which n-type process flow/architecture will emerge as the front-runner? What will polysilicon purity and wafer thickness levels look like for optimized n-type manufacturing? What will the upstream poly/wafer supply-chain look like in 5 years from now?
26 August 2021
In this webinar, JA Solar will present its product portfolio based on the latest technologies to improve your PV projects, ensuring maximum reliability and performance. During the webinar we will receive insight from JA Solar about its solar technology roadmap and how the manufacturer is providing customers with innovative solutions to suit their needs, while we will also analyse how to determine the best product solution for each solar project.

Read Next

July 27, 2021
Greek industrial group Mytilineos recorded a net profit of €77 million (US$91 million) in H1 2021, however the firm’s renewables division witnessed a drop in revenue year-on-year.
July 27, 2021
Canadian Solar has closed a BRL500 million (US$100 million) financing facility to develop a Brazilian solar portfolio claimed to be the country’s largest, while also giving it the option to hold built solar assets for longer.
July 27, 2021
Community Choice Aggregators (CCA) Central Coast Community Energy (CCCE) and Silicon Valley Clean Energy (SVCE) have signed contracts for 778MW of renewable energy generation and 118.75MW of energy storage in California.
July 27, 2021
More than 140 business leaders have urged the US Congress to pass President Joe Biden’s bipartisan infrastructure bill, telling lawmakers that the bill is “desperately needed” to renew the nation’s infrastructure
July 27, 2021
A round-up of the latest news from the US solar market, featuring Vision Solar’s commitment to hire “hundreds” of sales staff as part of a two-state expansion, Recurrent Energy’s sale of two major assets in Texas and news of 8minute Solar Energy strengthening its legal team.
July 27, 2021
Tesla reported retrofit solar installations of 85MW in Q2 2021, cementing its recovery from a worst-ever performance in the corresponding period last year.

Subscribe to Newsletter

Upcoming Events

Upcoming Webinars
August 19, 2021
At 9am (PT) | 6pm (CEST)
Solar Media Events
August 25, 2021
Solar Media Events
October 6, 2021