Diagnostic Toolkit for Reducing Regulatory Barriers to Solar, Wind and Pumped Hydro Storage in the European Union

2. Instructions for use of the Diagnostic Tool

2.1. Purpose and Approach

This Report provides a practical legal analysis of barriers to renewable energy deployment, accompanied by a self-assessment tool for policymakers at national, regional, and local levels. The tool uses a qualitative screening system, rooted in competition and regulatory best practices (notably the OECD Product Market Regulation indicators), to help users identify and score regulatory barriers across their frameworks.

Note: By working through the diagnostic questions - even without assigning scores - policymakers can systematically identify barriers within their current regulatory framework. This structured approach helps reveal gaps, ambiguities, and duplications in existing rules, supporting a more evidence-based and transparent pathway for regulatory reform.

The Report is organised into five parts:

I. Part I: Scene setting and Main Findings.

II. Part II: Cross-cutting issues on spatial planning and permitting - foundational elements that affect all renewable projects and must be addressed in the context of every individual technologies / market segments.

III. Parts III–V: Individual assessments for ten renewable energy technologies and market segments, including:

PV solar (utility scale, innovative solutions such as agrivoltaics and floating PV, and demand response/flexibility, including energy communities and aggregators)

Wind energy (onshore and offshore)

Pumped hydro storage

IV. Part VI: Cross-cutting issues on electricity grids, focusing on capacity expansion and optimisation as well as access challenges that apply across all technology segments.

V. Part VII: Case Studies, offering a practical application of the diagnostic tool at sub-national level (e.g., Apulia and Algarve).

Figure 2.1. Structure of the Tool

Source: OECD Analysis

2.1.1. How to use the Questionnaire

At the end of each chapter, a questionnaire enables policymakers to self-assess barriers within their jurisdiction. Questions are grouped by:

VI. Barrier type (e.g., legal definitions, roles and responsibilities, permitting);

VII. Level of government (national, regional, or local).

The questionnaires draw on identified barriers and recognised good practices. For a complete analysis, users should also fill out the spatial planning and permitting questionnaires, which complement the technology-specific assessments.

2.1.2. Scoring and Assessment

Each question addresses a specific barrier or good practice. Policymakers respond using a simple 0–1 scale:

VIII. 0 = Good practice

IX. 0.5 = Partial alignment with good practice

X. 1 = Burdensome condition

This systematic approach helps identify regulatory gaps, benchmark against good practice, and prioritise reforms at the appropriate level.

The questions then function as a screening checklist, allowing policymakers to score each regulatory barrier on a scale from 0 to 6 – where 0 represents the least restrictive and 6 the most restrictive condition. This approach enables users not only to systematically assess the presence and severity of barriers, but also to prioritise which areas require the most urgent regulatory reform.

Figure 2.2. Scoring instructions

Source: OECD Analysis

2.1.3. Who Should Complete Each Section

The questionnaire is divided between national and sub-national authority questions. Policymakers should consult their internal frameworks to determine which authority is competent or possessing information relevant for each question. This authority should assign the score and, if needed, coordinate responses where responsibilities overlap across services or authorities. This may also be used by policymakers even without responsibilities, if they wish to make policy proposals for adaptation of rules at another regulatory level that may impact the deployment in their own jurisdiction.

2.1.4. Comprehensive Assessment

To obtain a full overview, users should complete both the technology-specific and cross-cutting questionnaires on spatial planning and permitting as well as the grid access section in the Grids Chapter. The rest of the Grid Chapter is standalone. This ensures that regulatory, spatial planning, permitting and grid connection issues are all addressed and accurately scored.

2.1.5. Good Practice Annex

An Annex provides a database of regulatory good practices and case studies to inspire reforms and offer concrete examples for policymakers.