By synergizing renewable energy deployment with clean flexibility solutions, the EU can leverage abundant domestically produced wind and solar resources to reduce dependence on imported fossil fuels and achieve cost savings.

Table of Contents

• Executive Summary

• Flexibility Expansion Delivers Multiple Benefits

• Renewables and Clean Flexibility: A Perfect Synergy

• Urgent Need for Accelerated Clean Flexibility Deployment

• Growing Hours of Wind and Solar Dominance

• Solar-Battery Pairing Dynamics

• Battery Opportunities Emerge Amid Solar Boom

• Batteries Reduce Evening Fossil Fuel Reliance

• Policy Recommendations

• Supporting Materials

• Methodology

• Acknowledgements

Report Overview

This report analyzes the systemic benefits of integrating renewables with clean flexibility solutions, focusing on solar-battery synergy in the EU. Leveraging Ember’s hourly generation mix and electricity price datasets, the study demonstrates the strategic value of midday solar surplus and outlines how clean flexibility can reduce fossil fuel dependence while offering cost avoidance. Policy recommendations emphasize immediate battery storage deployment to meet decarbonization goals.

Key Findings

€9 Billion
By 2030, the EU could avoid €9 billion in gas costs through utilization of excess wind and solar power.

80%+
Nine EU countries recorded solar generation exceeding 80% of hourly demand between August 2023 and July 2024.

36 GWh
Additional 2 GW of battery storage in Germany could have displaced 36 GWh of fossil fuel generation in June 2024 alone, saving up to €2.5 million in fuel costs.

Executive Summary

Flexibility Expansion Delivers Multiple Benefits

Accelerating clean flexibility deployment enables 24/7 low-cost renewable power utilization across the EU. As renewable penetration grows rapidly, power systems require enhanced responsiveness. Current gaps in flexibility planning demand urgent policy interventions to unlock synergies between renewables and storage technologies.

Solar-battery pairing exemplifies this synergy. Years of solar expansion and volatile gas prices have amplified electricity price fluctuations, creating revenue opportunities for battery storage. By enabling midday solar capture and evening peak shaving, battery deployment can reduce fossil fuel reliance while supporting solar profitability.

Data Insights

01 €9 Billion Gas Cost Avoidance Potential

By 2030, EU wind and solar generation is projected to exceed demand by 183 TWh (equivalent to Poland’s annual consumption). Flexibility solutions like batteries and interconnectors could shift this surplus to displace fossil gas generation, avoiding €9 billion in annual gas procurement costs.

02 Solar Peaks Surpass 80% in Nine Countries

Between August 2023 and July 2024, the Netherlands and Greece achieved solar generation exceeding 100% of hourly demand, while seven other EU countries saw solar peaks above 80%.

03 Germany’s Battery Storage Demonstration

Adding 2 GW of battery capacity (+20% to existing infrastructure) in June 2024 would have displaced 36 GWh of fossil generation during evening peaks. This translates to €1.3 million in hard coal cost savings or €2.5 million in gas cost avoidance.

Expert Perspective

"Maximizing low-cost renewable utilization is imperative. As solar capacity soars, batteries will ensure surplus power availability across all hours. While EU renewables growth has been rapid, clean flexibility deployment lags. Accelerating this transition is critical for consumers and businesses to reap the benefits of reduced fossil dependence."
Dr. Beatrice Petrovich, Senior Energy & Climate Analyst, Ember

Technical Analysis

Renewables and Clean Flexibility: A Perfect Synergy

Grid interconnections, demand-side flexibility, pumped hydro, and battery storage are essential for balancing variable wind and solar generation. These solutions enable temporal and spatial power redistribution, optimizing grid stability.

Urgent Need for Accelerated Clean Flexibility Deployment

Under REPowerEU targets, the EU aims to:

• Triple solar capacity

• Double wind capacity by 2030

• Achieve 66% renewable share in annual generation

Ember modeling projects:

• 49% hourly average wind/solar contribution by 2030 (vs. 27% in 2023)

• 4% of hours with renewables exceeding total demand (up from 0.1% in 2023)

• 35% of hours with renewables covering >50% of demand (vs. 3% in 2023)

Expanding Renewable Dominance

In H1 2024:

• Wind and solar generated 30% of EU electricity

• Fossil fuels fell to 27%

Key trends (August 2023–July 2024):

• 15 EU countries experienced >80% wind/solar hourly penetration

• Germany: 36% of hours powered by renewables (up from 26%)

• Netherlands: 44% renewable penetration (up from 31%)

• EU-wide wind/solar hourly contribution ranged 6%-64%

System Inflexibility Constraints

Summer 2024 observations:

• Midday renewables (20-60% penetration) reduced fossil reliance

• Evening peaks remained dependent on gas/coal

Germany's fossil share:

• 1 PM: Dropped from 36% (2021) to 20% (2024)

• 8 PM: Declined only marginally (47% → 44%)

Key limitations:

• Inflexible baseload plants

• Conservative grid practices (e.g., Poland’s 55-60% renewable curtailment threshold)

Battery Storage Breakthroughs

Solar Boom Unlocks Battery Opportunities

• Dramatic cost reductions driven by EV industry advancements

• Grid-scale and behind-the-meter deployment now viable

• German studies confirm solar-battery hybrids outcompete coal/gas on LCOE

Current EU battery specs:

• Average duration: 1.5 hours

• Emerging systems: 2-4 hour duration

Price Volatility Strengthens Storage Economics

2024 intraday price spreads:

Battery benefits:

• Capitalize on arbitrage opportunities

• Flatten peak prices

• Support solar capture rates

Germany’s Storage Leadership

• Holds 46% of EU battery capacity (9.5 GW by June 2024)

• Projection: 11.4 GW by end-2024

• Simulation: 2 GW added storage could eliminate hard coal generation for 12 evening hours in June 2024

Policy Recommendations

Remove Barriers to Renewable-Storage Integration

1. Streamline grid connection rules for co-located solar-battery systems

2. Include storage in renewable acceleration zone planning

3. Publish granular grid hosting capacity data

Advance National Flexibility Strategies via NECPs

• Finalize NECPs with explicit storage/demand-side flexibility targets

• Implement EU storage guidelines (e.g., eliminate double grid fee charging)

• Introduce flexibility support schemes under Electricity Market Design reforms

Optimize Market Access for Flexibility Resources

• Allow battery participation in capacity markets and ancillary services

• Design carbon-adjusted capacity mechanisms

Enhance EU System Planning Transparency

• Improve modeling of fossil flexibility phase-out pathways

• Mandate public disclosure of flexibility deployment data

Develop EU-Wide Clean Flexibility Strategy

• Integrate storage, smart electrification, and demand-side solutions into Clean Industrial Deal

• Promote west-facing solar panels to align generation with evening demand

Methodology

• Hourly generation data: Synthesized from ENTSO-E, national grid operators, and Eurostat

• 2030 surplus estimation: Based on 2009 climate year profiles scaled to NECP targets

• German storage simulation: Assumed 1.9 GW/1.6-hour batteries displacing evening fossil generation