Completed design and cost-estimate documentation (PKD) does not mean that a solar power plant will appear on site any time soon. From documentation to construction, a project passes through a series of stages, and delays can arise at any of them: the project application waits for a competition, the application is returned for revision, and by the time funding comes through the cost estimate or the technical documents already need updating.
Design and cost-estimate documentation (PKD) is the approved textual and graphic material setting out the architectural, structural, technical, and technological decisions for a facility, the scope of works, and the estimated cost of construction. In plain terms, it is the document that defines what exactly will be built, how it is to be carried out, which works are required, and how much they will cost.
Some of these difficulties stem not from the documentation itself but from expectations about its role in the project. PKD is often treated as the decisive step towards construction, when in fact it resolves only part of the task. It is around this misunderstanding that several widespread myths arise. Let us look at four of them.
Myth 1. What matters is ordering the PKD; how it is prepared matters less
This is the most common oversimplification: once the documentation exists, the technical side is considered settled. In reality it is at the design stage that the decisions are made which later determine whether the plant performs as intended.
Developing the PKD involves calculating the required number and type of solar panels, setting their orientation and tilt angle, selecting the inverter’s power rating and type, determining the number of battery units and where they are placed, and sizing cable cross-sections, surge protection, lightning protection, and earthing.
All these decisions rest on the characteristics of the specific facility: actual electricity consumption and the load profile; the list of critical equipment and the required duration of its off-grid operation; the starting currents of pumps and ventilation; the capacity of the roof or land plot; the condition and throughput of the existing electrical grids; the connection point; and the logic governing how the plant works with the grid, the generator, and critical loads.
One important step that is often skipped to save time is the designer’s preliminary site visit. A single visit clarifies a range of technical questions at the outset and gives the contractor an understanding of the facility that no package of documents sent over could provide.
“The PKD is the set of instructions the work follows. If it is poor or unclear, the result can be something that simply does not work. Or the contractor will interpret a given decision their own way – whichever is easier or more profitable for them,” explains Dmytro Namchuk, technical lead of the project.
Errors made at this stage show up at the facility itself and tend to fall into several typical groups.
Actual generation is well below the calculated figure. The designers did not visit the facility and failed to account for real shading from trees or neighbouring buildings, got the panels’ tilt angle or orientation wrong, miscalculated the plant’s capacity, or selected the wrong inverter. The community ends up with a working solar plant that simply does not deliver its rated output.
- Problems with autonomy and load. The plant’s capacity does not match actual consumption, the battery capacity is too small for the stated running time of critical equipment, and the inverters or batteries cannot handle the start-up of pumps or ventilation because of high starting currents. A separate case: the plant does not switch properly into backup mode, so it fails precisely when it is needed most.
- Hazards and accidents. An incorrect calculation of cable cross-sections or the wrong choice of circuit protection causes grid overload, with consequences ranging from overheated cable runs and emergency shutdowns to equipment damage and, in the worst case, fire.
- Incompatibility with existing infrastructure. Without systematic analysis, the purchased equipment may not match the characteristics of the existing electrical grids, the generator, or the control system.
- Underestimated scope of works. The cost estimate leaves out distribution boards, protective gear, ventilation, repairs to premises, and other associated works. These surface during construction as extra costs and push back the delivery schedule.
Two further consequences reach beyond the technical sphere and bear on the community’s ability to carry a project from documentation to a finished plant. Technical requirements that are set out unclearly make it impossible to compare bidders’ offers objectively, so the client effectively selects a contractor blind. And once installation is complete, it is hard to establish who is responsible when the plant fails to deliver: the designer will point to how the works were carried out, and the contractor to the design decisions.
“A designer has to treat a solar power plant (SPP) as a single system. Even high-quality equipment will not deliver the required result if it is chosen incorrectly or is not matched to the characteristics of the facility,” stresses Volodymyr Dovbenko, an expert in renewable energy.
Done well, the work leaves the community with a complete technical solution setting out clear scopes of works, specifications, and delivery costs. Saving a few weeks and a few tens of thousands of hryvnias at the design stage regularly turns into far greater outlays during construction and operation.
Myth 2. Quality PKD guarantees funding
PKD answers the question of what exactly is to be built and how. A donor asks different questions: why the project is being done, whether the technical solution matches the facility’s real needs, whether the client is ready to deliver, and who will operate the plant once the project is complete.
“Design and cost-estimate documentation is only the technical decisions and the cost of carrying them out. On its own, it will not explain to a donor or investor why this particular community facility should receive funding,” says Ihor Shcherbak, project engineer.
Preparation should begin by defining the goal – before the documentation is ordered. The plant might provide backup power during outages, keep critical equipment running without interruption, cut electricity costs, or combine savings with autonomy. Everything in the technical solution that follows depends on this choice, so the goal will have to be defined one way or another; the only question is whether the community does so deliberately or leaves it to the designer.
Data comes next. This is the minimum set, without which the designer cannot substantiate any decisions:
- electricity consumption for at least the past 12 months (and ideally for 3 years);
- load profiles, where available;
- a list of primary and critical equipment, with power ratings and operating modes;
- power-supply diagrams and details of transformers, distribution boards, cable lines, and generators;
- documents for the building or land plot;
- inspection results and photographs of the facility;
- information on any planned changes in load.
Legal readiness forms a separate block: ownership or usage rights for the building, roof, or land plot; the client’s authority to act; and the absence of court disputes, property seizures, or other restrictions that could hold up delivery.
Before the full PKD is developed, it is worth preparing a preliminary technical solution or a feasibility study (TEO) setting out several delivery options, their economic viability, payback, generation forecast, off-grid operation calculation, and a justification for the preferred option. It is the feasibility study that explains the logic of the choice: why this facility, why this capacity, why this option proved better than the alternatives. The PKD embodies that logic in specific decisions, so it does not restate it separately.
Boxout: If you are planning a solar power plant project, it makes sense to start with the feasibility study. Ecoclub has prepared a free online course, “How to Develop a Feasibility Study for a Solar Plant”, which explains step by step how to gather the source data, weigh delivery options, and justify the choice of the best solution before the PKD is developed. The course is available here: https://ecoclubrivne.org/peredteo/
Alongside the design documentation and a positive expert report, the package for a donor application to install a solar power plant may also include: a description of the problem and the rationale for choosing the facility;
- a feasibility study;
- a general cost estimate of the scope of works (Bill of Quantities, BoQ);
- an implementation timetable;
- a procurement plan;
- information on co-financing;
- an analysis of the main risks;
- an operation and maintenance plan;
- details of the persons responsible;
- information on the project’s beneficiaries.
The list is not exhaustive and varies from one programme to another, but it shows the scale of the work that lies beyond design.
Myth 3. Documentation suits any competition equally well
This follows on from the previous myth, and it costs communities the most time. Because the technical solution flows from the goal, documentation prepared for one goal fits poorly into a competition announced for another.
Consider the three types of programme communities encounter most often.
A competition on the energy resilience of critical infrastructure. Here the emphasis falls on calculating how long the facility can run off-grid during outages, a list of critical equipment with its starting characteristics, the capacity and compatibility of battery systems, and the arrangement for switching into backup mode. The plant must guarantee power to a defined set of consumers for a defined period.
A competition on cutting emissions and climate neutrality. Here the decisive factors become the annual generation of clean electricity, the volume of fossil fuel displaced, the calculation of CO₂ emission reductions, and the techno-economic payback indicators. Off-grid running time takes a back seat.
Programmes aimed at saving budget funds. Here the decisive factors are the generation forecast, the calculated savings on electricity bills, and the payback period.
A plant designed to cut bills runs in parallel with the grid, makes the most of daytime generation, and needs only minimal battery capacity. A plant designed for energy resilience calls for substantially larger storage, a different connection scheme, and allowance for starting currents – and it costs noticeably more for the same panel capacity. An application built on “savings” documentation but submitted to an energy-resilience competition will look complete on paper yet fail to match the programme’s logic.
The requirements for the package itself also differ: the set of documents, the budget format, the procurement rules (donor procedures do not always align with national ones), the co-financing requirements, the rules for confirming ownership, and the period during which the facility may not be repurposed or transferred.
There is no universal documentation that fits every programme. But the risk can be cut substantially if the community looks ahead at the two or three programmes it realistically plans to apply to and checks the project goal against them. The goal is fixed in the design brief – this is the document in which the community sets out what it wants to achieve, and it is what determines how well the finished PKD will fit. Supporting justifications, chiefly the feasibility study, are then tailored to the criteria of the specific donor.
Myth 4. PKD can be prepared “in advance, to have on hand”
The reasoning is understandable: documentation costs money, the budget for it exists this year, and the competition is next year. The problem is that documentation ages unevenly.
Let us start with a point that, for some reason, is rarely made: PKD has no statutory validity period after which it becomes void. What loses currency is the source data, the cost estimate, the equipment, and individual technical decisions.
“The PKD has no expiry date, but the cost estimate does, because prices change. Usually the PKD is revised only in its cost-estimate part. If the design itself has to be revised, it means something has changed at the facility that has made the electrical or structural decisions obsolete, or that new equipment has appeared that better meets the project’s needs,” explains Dmytro Namchuk, technical lead of the project.
The estimated cost changes fastest. The price of panels, inverters, batteries, cabling, and installation work depends on the exchange rate, logistics, inflation, and the availability of equipment on the market. A year-old cost estimate must be checked and updated before procurement in any case.
The equipment range moves on. The panels, inverters, or batteries specified in the project may be unavailable from suppliers, discontinued, or superseded by newer models. A substitution means re-checking the entire technical solution: a different module model has different dimensions, power, voltage, and current, and this affects the number of modules, the string layout (panels connected in series), the cables, protective devices, mounting structures, and panel placement. Replacing batteries or an inverter can affect compatibility with the battery management system (BMS), the permissible load, and the operation of backup mode.
The regulatory framework does not stand still either. Regulations, building codes, electrical-safety rules, connection requirements, or the procedure for determining construction costs may be updated. The designer has to verify whether decisions taken earlier comply with the requirements in force at the time of delivery. This is the factor that most often makes a repeat expert review necessary.
The facility itself changes over the waiting period. The connection conditions, the load factor, or the equipment on site may have changed – for instance, more energy-efficient systems may have been installed in the building, so that the earlier consumption calculations no longer reflect reality.
The designer’s responsibility for the technical decisions is tied to the source data provided when the documentation was developed. If the loads, equipment, client requirements, or regulations have since changed, the decisions taken must be re-checked.
For donor projects, the following working procedure makes sense:
- up to six months have passed – check that market prices and the availability of equipment from suppliers are still current;
- six months to a year have passed – check the facility’s source data, load profiles, equipment specifications, and the cost estimate; where the technical changes are substantial, the PKD is sent for revision and a repeat expert review.
These periods are not set in law. They are worth treating as a practical way to check a project’s readiness before procurement is announced and construction begins.
What This Means for the Community
A sequence of steps that reduces the risk of documentation remaining just documentation:
1. Define the plant’s goal: backup power, uninterrupted operation of critical equipment, savings, or a combination of these.
2. Check that goal against the requirements of the programmes the community realistically plans to apply to.
3. Gather the source data – electricity consumption over 12–36 months, load profiles, a list of critical equipment, power-supply diagrams, and documents for the facility.
4. Prepare a feasibility study setting out several delivery options.
5. Draw up the design brief and order the PKD from a qualified contractor, with a mandatory site visit.
6. Pass the expert review and, in parallel, assemble the full donor package: legal documents, the budget, the procurement plan, confirmation of co-financing, and the operation plan.
7. Before procurement is announced, check that the cost estimate, the equipment, and the applicable standards are still current.
It is also worth weighing the risk of ordering documentation without knowing where the funding will come from. Every year of waiting means local-budget money spent on updating cost estimates, revising decisions, and repeat expert reviews – money that has to be spent before the first panel even reaches the site.
Quality PKD reduces the risk of choosing the wrong equipment, of extra costs during construction, and of operational problems. But a plant materialises only when, alongside the documentation, there is a well-founded goal, a legally ready facility, a realistic budget, and a clear answer to the question of who will service it in five years’ time.
This project is implemented by NGO Ecoclub with financial support from the German Federal Foreign Office and under the coordination of Help – Hilfe zur Selbsthilfe and the Help Localization Programme.
