Strategies for Redundant Renewable Power Generation (2024)

As nations aim to transition towards renewable energy sources, developing resilient power systems has become a priority. Energy security, the uninterrupted availability of energy sources at an affordable price, is vital for supporting economic growth and functioning modern societies. However, renewable sources like solar and wind are inherently variable and uncertain. Building redundancy into renewable generation is therefore crucial to guarantee reliable supply during disruptions.
This article analyses methods for incorporating redundancy across renewable assets to minimize supply shortfalls and ensure energy security.

The Need for Resilient Renewable Infrastructure

The transition towards variable renewable energy (VRE) like solar photovoltaics and wind power is well underway. VRE already accounts for over 10% of global electricity generation. However, inherent variability from fluctuating weather conditions makes integrating large shares of VRE challenging. Output from solar panels drops on cloudy days, while calm reduce wind turbine generation. In some cases, near-zero VRE production occurs for days. Managing such variability requires robust complementary assets.

Additionally, climate change is increasing the frequency of extreme weather events. Fires, storms, and floods can damage generation assets, transmission infrastructure, and distribution networks. The 2021 winter storm in Texas highlighted such vulnerabilities, as frozen wind turbines contributed to widespread blackouts. Building redundancy and flexibility into systems is therefore vital to supply security. Diversified assets and generation locations allow renewable power supply to better withstand disruptions from variability and extreme events.

Many countries are building new gas and coal power plants as backup capacity to support their growing renewable energy generation. This is particularly the case in China, which is leading the world in the construction of new coal power plants. According to reports, China permitted over 100 GW of new coal power capacity in 2022 – the equivalent of about two large coal plants per week. This surge in new coal plant approvals appears to be a response to recent droughts and heatwaves that have strained China's electricity grid and reduced hydropower generation. High natural gas prices due to the war in Ukraine have also led some Chinese provinces to turn to coal as a backup.

Other countries are also building new gas power plants as backup capacity for renewables. For example, Germany has plans to auction 10 GW of new gas plant capacity by 2026, with the intention of eventually converting these plants to run on green hydrogen. However, these plans have been delayed by a year due to negotiations with the EU over support conditions.

Overall, the construction of new fossil fuel power plants as backup capacity raises concerns about the ability of some countries to meet their climate commitments. While backup capacity is needed to support the growth of renewables, over-reliance on coal and gas risks locking in high-emitting infrastructure for decades to come.

Geographic Diversity of Renewable Assets

Constructing renewable assets across a wide geographic area helps mitigate correlated production losses. Wind and solar resources are localized weather phenomena. Conditions causing low generation in one area rarely extend across an entire region. Distributed assets provide greater aggregate output stability despite local volatility.

For example, a 2021 study analysed wind power across 26 sites spanning over 1000km in the central United States. It found that as distance between sites increased, wind output became less correlated and overall generation variability declined. Constructing wind farms hundreds of kilometres apart can minimize coinciding lulls. Geographic diversity provides redundancy against localized disruptions to renewable output.

Network interconnections further allow sharing of generation resources. Expanding transmission connects otherwise isolated assets into a wider weather system. The European Network of Transmission System Operators reports that increased interconnection has lowered variability of wind power across countries. A Europe-wide network makes renewables more dependable through aggregation benefits. Despite uncertain generation at individual sites, overall supply consistency increases.

Complementary Renewable Technologies

While the same resource type facing shared weather patterns can exhibit correlated output changes, different renewable technologies respond divergently to conditions. Wind and solar generation profiles are largely uncorrelated, with only 10-15% overlapping variability. Cloud cover only affects solar output, just as daytime wind lulls have limited impact on nightly wind production.

Blending wind and solar assets coupled with geographic distribution creates more reliable aggregate supply. Modelling by the National Renewable Energy Lab confirms that combining solar, wind and storage across four US regions could have met hourly power demand 99.8% of the time from 2007-2018. Complementing solar and wind power with other renewables like hydropower and geothermal further expands technology diversity for redundancy.

Renewable Generation Overcapacity

Excess renewable generation capacity buffers against resource uncertainty. Installing solar and wind capacity well beyond peak demand enables assets to continue meeting loads despite output variations. Overcapacity factors like 150% ensure sufficient generation remains available after accounting for volatile conditions. Building abundant renewable plants provides a redundancy margin against fluctuations.

However, overcapacity alone creates excess energy that must be managed. Curtailing renewable generation presents challenges in recuperating investments. But combining overcapacity with storage or transmission mitigates these drawbacks. Storing excess renewable MWhs or exporting through interconnections allows productive use of surplus energy. Overcapacity with such mechanisms provides cost-efficient redundancy.

Storage and Backup Generation

Energy storage technologies like batteries paired with renewables create resilient hybrid systems. Storage charges during renewable output surpluses. The stored energy then discharges during generation shortfalls to smooth overall variability. Lithium-ion batteries with 90-95% roundtrip efficiency are particularly promising. Utility-scale batteries with capacities up to 1000 MWh now enable affordable large-scale renewable integration.

Intelligent Management of Distributed Assets

Advanced communication and automation infrastructure enables better coordination of diverse assets. A distributed network of smaller renewable sources relies on smart management for aggregation benefits. High-resolution forecasting maximizes asset productivity by predicting generation levels days ahead. Weather-adaptive control algorithms extract optimal generation from resources under varying conditions.

Sophisticated grid management platforms balance minute-to-minute supply and demand across entire systems. Machine learning and artificial intelligence optimize operations. These highly advanced technologies are unlocking the full potential of renewable diversity and redundancy.

Key Takeaways

• Inherent variability of solar and wind power necessitates building redundancy into renewable assets and infrastructure to ensure resilient energy supply.
• Many countries are building new gas and coal plants as backup capacity, but over-reliance on fossil fuels risks hindering the renewable transition.
• Geographic distribution of assets provides aggregation benefits and mitigates localized disruptions and weather effects to minimize output volatility.
• Complementing solar with wind power and other renewables creates technology diversity and reduces correlated production losses.
• Installing renewable overcapacity and expanding storage offers buffers against fluctuations in generation.
• Advanced forecasting, automation and intelligent management of distributed assets underpin reliable and flexible renewable power systems.

Pursuing renewable power redundancy through diversity, overcapacity and smart control provides pathways for guaranteeing energy security amidst accelerating variability. As extreme weather impacts intensify, creating robust and resilient renewable infrastructure must remain an utmost priority. Redundant systems will be critical to maintaining reliable supplies through the global energy transition.

CLOU supports this effort by providing reliable energy storage solutions that help maintain consistent power availability. Our systems are designed to store renewable energy effectively, offering a steady backup during fluctuations. For more information on how CLOU's energy storage solutions can support your renewable energy needs, please don't hesitate to contact us. We're here to help you build a more reliable and sustainable energy future.