Preliminary design &
yield simulation
for PV and BESS projects as well as substations
We prepare preliminary designs for PV, BESS, and co-location projects with variant comparison and simulation-based yield forecasts, as well as preliminary designs for substations – providing a reliable foundation for early project decisions.
Determine technical potential and obtain corresponding yield indication
From site-specific system design to realistic yield forecast for PV, BESS, or co-location
In the early project phase, a well-founded preliminary design provides the basis for realistically assessing the technical possibilities and associated yield potential of a site. Following a site and route analysis or receipt of relevant documentation, we develop designs for substations as well as design variants for PV, BESS, or co-location projects according to customer requirements and objectives, demonstrating what installable capacity and land use are possible under the project-specific constraints.
For PV projects, we derive a yield forecast from the results of corresponding simulations. The simulation is based on the system design and additionally considers irradiation and shading assumptions as well as key design parameters such as the DC/AC ratio.
For BESS projects, we derive the forecast at preliminary design level from the designed system configuration – particularly from power, capacity, and design duration – and contextualize it within project-specific constraints such as available grid connection capacity or feed-in limits. This creates a transparent decision-making basis for further project planning and next steps.
In addition to PV, BESS, and co-location designs with yield simulation, we also support with preliminary designs for substations (SS) – as a drawing and coordination basis (without yield simulation).
If you already have a fully designed or constructed PV system in your portfolio and are considering expanding the existing design with a battery storage system, you will also need a preliminary design. We are happy to support you here or determine the optimal, technically feasible, and economically most advantageous configuration of your BESS through our co-location potential analysis.
When you should consider a preliminary design (with yield simulation)
When you need to assess site potential for PV and/or BESS early regarding technical feasibility and yield prospects
When you need to coordinate or secure a substation site
An preliminary design creates a reliable basis for coordination with owners, authorities, or grid operators – e.g., in the context of site selection and development.
When you want to compare multiple design variants
If a preliminary design is fundamentally plausible, the design is refined through targeted iterations (e.g., row spacing, tilt angle, DC/AC, infrastructure) to further improve land use and yield potential. This creates transparency about which configuration makes most sense at the site.
When you want to determine the effects of topography and shading on future yield as accurately as possible
When grid connection capacity and feed-in limits determine the design
Available grid connection capacity should be considered early – it significantly influences the configuration and optimal design approach.
When you need to resolve conflicts between land utilization, performance, and practicability
Depending on row spacing and layout, you can either increase installable capacity (and usually total energy yield) or improve specific yield by reducing shading. A scenario comparison makes it clear which configuration best fits your constraints – including site access and long-term operability (maintenance, repairs, and vegetation management).
When you are preparing documentation for the building permit
When you need the basis for a yield assessment for project financing
A bankable yield assessment for PV or co-location projects requires reliable input parameters – particularly a consistent system layout (site plan) and transparent design assumptions. We provide this foundation so that yields can be realistically simulated and properly derived for banks/investors.
Our Approach
Depending on the project setup (PV, BESS/co-location, or substation), we set appropriate priorities in the preliminary design. For PV and BESS projects, we compare variants using suitable evaluation logic – from PV yield metrics to storage-related assessment parameters.
Kick-off: Clarify objectives, constraints, and data availability
We align on objectives and the most important design specifications – e.g., regarding grid connection/feed-in, site boundaries, and permit-relevant requirements – and verify which documentation we need to create a design and, if applicable, a corresponding simulation.
Develop design variants (layout & cabling)
We create an initial layout and develop variants based on it, for PV e.g., regarding row spacing, tilt angles, or DC/AC configuration – always with a view to feasibility and future operations.
Yield simulation & plausibility check
Variant comparison & recommendation
Results handover for the next project stage
Service spectrum for PV, BESS, Co-Location and substations
Different project setup – different requirements: Preliminary designs and yield forecasts for PV, BESS, co-location and substation projects.
Photovoltaics (PV)
Preliminary design (layout at preliminary design level) including variant development based on site and terrain information, shading objects, and any known building height requirements and grid connection information
Yield forecast through simulation based on defined variants, including consideration of various irradiation data and shading analysis as well as classification of key assumptions/loss factors
Results preparation as a basis for next steps (e.g., tender, detailed design, financing)
Optional analysis of expected levelized cost of electricity (LCOE) to support decision-making. Through greentech’s own EPC and O&M divisions, we are able to view the project holistically and make correspondingly valid, up-to-date price assumptions.
Battery Energy Storage Systems (BESS)
Preliminary design (layout/site concept) for containers, battery inverters, and transformers – including basic access and maintenance logic
Preliminary configuration at design level: Coordination/derivation of target parameters such as power (MW) and capacity (MWh) (or C-rate/target operation) and derivation of a suitable system/container concept (within agreed scope)
Evaluation logic depending on use case: e.g., standalone or grid-supportive (within agreed scope)
Results preparation as a basis for further technical and economic specification.
Co-Location (PV and BESS)
Integrated design: Coordinated PV and BESS design as an overall system (site, infrastructure, operating logic), also possible for retrofitting an existing PV system.
Grid-side constraints considered: Configuration at preliminary design level under requirements such as feed-in limitation, controllability, and grid-supportive requirements.
Variant comparison with focus on technical feasibility and project objectives
Substation (SS)
Preliminary design according to greentech standard for a substation site or pole location – as a reliable basis for coordination (e.g., with owners, authorities, or grid operators)
Technical framework conditions & key planning constraints are considered in the design (e.g., plot, interfaces, site restrictions)
Results preparation & handover of documentation including presentation of results as a basis for next steps (site decision, further planning/applications)
Optional: Prior technical consultation on site selection as well as site inspection (up to three potential substation sites/pole locations)
Sound decision support for your project
Engineering with practical relevance from design, construction, and operations
Established software for reliable designs and simulations
For preliminary designs, we use established 3D layout design software (e.g., AutoCAD/PVcase). For simulation, we use PVsyst. This allows layout variants to be developed precisely and efficiently – even for complex sites.
Broad data basis instead of single-source approach
For yield simulations (PVsyst), we use multiple sources for irradiation and weather data, including DWD, SolarGIS, Meteonorm, or Copernicus. This increases the transparency and robustness of forecasts – particularly for site-specific characteristics.
Recognized, high-quality results
Our design variants and yield forecasts are transparent and reliable, providing an optimal foundation for informed decisions. We prepare bankable PV yield assessments and, as owner’s engineer, also review external assessments. Thus, our results enjoy high confidence among banks, investors, and technical consultants.
Quality assurance through standards & four-eyes principle
Our results are produced according to clear internal standards and defined review and approval processes. Through systematic plausibility checks and a consistent four-eyes principle, we ensure that assumptions, input parameters, and outputs are consistent, transparent, and reliable.
Best practices through active committee and association work
We actively participate in industry associations in Germany and Europe and contribute to guidelines and best practices. The latest standards and current market developments flow into our engineering approaches for PV, BESS and substation projects, as does our many years of practical experience.
Our quality standards -transparent, reliable, documented
We emphasize auditable results in the form of clear assumptions, consistent methodology, and proper documentation. This makes variants, risks, and influencing factors transparent – as a reliable foundation for the next steps.
- Plausibility checks & consistency reviews
- Transparent assumptions/derivation (auditable)
- Variant comparison with clear evaluation logic
- Assessor/owner’s engineer perspective (second opinion)
- Interface clarity for next steps (tender/detailed design)
- Documentation/handover quality
From preliminary to detailed design
The preliminary design creates a reliable preferred variant and a transparent yield forecast as a basis for decisions. Depending on the approval process, it is also relevant for filing the building permit application.
When the project moves into implementation after building approval, the next step required is detailed design: It specifies the chosen concept technically to the extent that tender, procurement, construction, and commissioning can be properly prepared. This avoids planning discontinuities between “design concept” and actual implementation and creates clear interfaces for EPCs and project participants.
We are happy to support you with detailed design for your project as well.
Questions & Answers
Frequently asked questions about preliminary design and yield forecasting for PV, BESS, co-location and substation projects
For which projects is a preliminary design (& yield simulation) useful?
For projects in development and early development, when design variants are to be compared and risks understood early. Also before tender or financing, when reliable assumptions and transparent results are required. Also for existing projects when an existing design or forecast is to be validated or optimized.
For which project types does greentech offer preliminary designs and yield forecasts?
We support PV projects, BESS projects, and co-location setups (PV+BESS). Depending on the setup, development priorities and evaluation logic differ – e.g., PV yield metrics, storage-related target parameters, or grid-side requirements in the overall system.
In addition, we prepare preliminary designs for substations (e.g., for substation/pole locations and interfaces) – without yield simulation.
What is the difference between preliminary design and detailed design?
The preliminary design delivers a reliable preferred variant and clear decision-making foundations (variant comparison, assumptions, risks) – without drawing every detail “construction-ready.” Detailed design goes significantly deeper, e.g., with complete detail plans, specifications, and implementation details for construction and commissioning. Preliminary design is thus typically the step that sets the direction before detailed effort is invested.
What documentation is required to start a preliminary design and yield simulation?
This depends on project phase and setup – typically helpful are site/planning documents, restrictions from permits/land use, and information about the desired grid connection or feed-in situation. If designs, topography, or shading information already exist, we can work faster and more precisely. In the kick-off, we jointly clarify which basic documentation is actually needed in your case.
How does greentech ensure that results are transparent and reliable?
We work with clearly defined assumptions, validate inputs and results, and document the derivation so that decisions remain auditable. Additionally, our assessor perspective flows in: In addition to preliminary design and yield forecasting, we also prepare bankable yield assessments and review external assessments as owner’s engineer – this sharpens methodology and quality standards.
Does greentech also review existing preliminary designs or yield simulations?
What are typical results/deliverables from preliminary design & yield simulation?
How long does preliminary design including yield simulation take?
How does preliminary design (& yield simulation) support banks and financing?
Does greentech also accompany the next steps after preliminary design?
Yes – depending on requirements, we support the transition to tender, detailed design, or assessment services. What matters to us is a clear interface: What was decided in the preliminary design should be consistently continued in the next stage without unnecessary loops.
Still have questions?
Can’t find the answer you’re looking for? Please get in touch with our team of experts
Engineering & Technical Advisory
Here you can download an overview of our Engineering & Technical Advisory services:
Why work with greentech?
Years of experience
Employees active in 6 European countries
Projects in the development pipeline
Ground-mounted PV systems built
in technical consulting
in operational management
Your specialists for preliminary design & yield simulation at greentech
Viola Hoffmann
Commercial Head of Engineering
Johannes Liebich
Head of Engineering & Technical Advisory
Joern Carstensen
Chief Technical Officer (CTO)
In his role, Jörn Carstensen combines the management of all technical areas of the greentech group. As CTO, he is responsible for plant construction, engineering services and technical management. The aim is to create uniform standards and processes across all technical areas at greentech, thereby ensuring company-wide synergies, high quality and the greatest possible transparency.
Jörn Carstensen joined greentech in 2014 as Business Development Manager. In addition to developing various European markets, he built up the Engineering and Technical Advisory division. From 2006 to 2014, he worked for the Conergy Group in various international corporate and business development positions. Prior to that, he worked for a consulting unit of Accenture and supported utility companies in strategic and organisational issues. Jörn Carstensen holds a degree in Industrial Engineering with a specialisation in Energy and Environmental Management from the Universities of Flensburg and Southampton.
Contact
Only 45 seconds for your request