Short answer. Panel power in kilowatts is not equal to savings. The calculation links at least a year of consumption, an hourly profile, available area, shading, climate data, system losses, connection rules, and equipment cost. The battery is added only for a measurable task.
Formulate what the station should change
One client wants to reduce daily consumption from the grid, another wants to keep servers and security systems running during a shutdown, and a third wants to supply energy to a remote site. These goals require different architectures. A grid-tied station without storage saves energy when there is sun and load. A hybrid system can reserve some consumers. Full autonomy requires the strictest energy balance and a reserve for unfavorable periods.
Before selecting equipment, set a measurable outcome: share of own daily consumption, reserve hours for a specific list of loads, or permissible generator use. The phrase “I want to pay less” is too general to honestly choose the capacity.
Collect not just one invoice, but an annual profile
The initial set consists of invoices or meter data for at least twelve months. They show seasonality but do not explain when energy is consumed. Two companies with the same monthly consumption will get different economics if one operates during the day and the other at night.
For a commercial facility, half-hour or hourly data is useful. If it is not available, measurements are taken with a network analyzer or a profile is built based on equipment operation schedule. Take into account weekends, seasonal heating or cooling, pump start currents, and production expansion plans.
- Energy consumption and cost over 12–24 months
- Maximum Power & Daily Chart
- List of critical loads
- Planned new machines, air conditioners, chargers, or tenants
Do not confuse panel power with annual output
Kilowatt-peak describes the nominal power of the array under standard conditions. Actual output varies by hour and season due to the position of the sun, module temperature, cloudiness, snow, shading, orientation, angle, contamination, and losses in cables and the inverter.
Calculation services like PVWatts use weather data and a system model to estimate the range of output. This is a forecast, not a promise. The actual year may differ from the long-term average, so in the financial model it is better to show the base, cautious, and adverse scenarios.
Inspect the roof or site before fixing capacity
Area on the plan is not equal to usable area. Margins from edges, walkways, smoke removal, ventilation, hatches, parapets, and shading reduce the number of modules. On the ground, consider the terrain, future construction, and the possibility of equipment maintenance.
Load-bearing capacity and fastening nodes are checked by a specialized expert. Wind and snow loads, the condition of waterproofing, and its remaining service life affect the decision. Installing a new station on a roof that will soon be repaired creates double costs for dismantling and reinstallation.
- Shadows in different hours and seasons
- Orientation and Permissible Installation Angle
- Load-bearing capacity and condition of the coating
- Safe passages, fences, and access for washing
Inverter and Electrical Part Set the Quality of the System
The modules are visible on the roof, but it is the electrical architecture that determines how energy is collected, converted, and disconnected in the event of an accident. Compare input voltage ranges, the number of independent trackers, performance under partial shading, DC and AC protection, monitoring, and compatibility with the facility's grid.
A single-line diagram is needed with cables, switching, grounding, surge protection, and connection points. Assess the existing input: reconstruction of the cabinet or coordination of operation mode may be required. Separately determine what happens if the external network disappears — a standard grid-tied inverter, as a rule, does not automatically become a backup source.
The battery is purchased for a specific scenario
The storage device does not create energy. It transfers it over time and adds losses, cost, and placement requirements. For backup, first make a list of critical loads, measure their power, and specify the required runtime. The server room, checkpoint lighting, and pump have different startup currents and priorities.
Useful capacity is less than that indicated on the nameplate and varies with temperature, permissible depth of discharge, power, and aging. The project requires a battery management system, protection, ventilation or temperature regime, fire safety concept, and safe access. Sometimes a small storage unit plus a generator is more rational than a very large battery.
Calculate economics based on self-consumption
The highest predictability is achieved by the energy that the facility generates and immediately uses itself. Excess daytime generation is only beneficial if there is a clear mode for feeding into the grid, load transfer, or storage. Connection conditions and calculations with the energy supplying organization must be confirmed before financial promises.
The budget includes design, equipment, delivery, installation, switchboard reconstruction, approvals, monitoring, maintenance, insurance, and possible replacement of individual components. The payback period depends on the tariff and future consumption, so it cannot be guaranteed with a single figure without listing the assumptions.
How to compare two sentences
Request the same calculation format: initial weather data, array power, orientation, losses, monthly output, share of self-consumption, and grid limitations. If one company shows only an ideal annual figure while another takes shadows and limitations into account, their results cannot be compared directly.
A good proposal explains which data is still unknown and what will be checked during the inspection. It contains the scheme, composition of equipment, scope of work, warranty conditions, remote monitoring, and acceptance plan. After launch, it is useful to compare actual output with the calculated one, considering weather and system availability.
- Monthly Generation and Model Assumptions
- Proportion of energy used in the facility
- Equipment List with Exact Models
- All Construction and Electrical Works
- Guarantees, monitoring, and service request procedures
PRIMARY SOURCES AND METHODS
The material was written by KRONIS GROUP in their own words. The links below are needed so that the customer can verify the original requirements and professional recommendations.
The material is for informational purposes. Final requirements for a specific facility, project, and permitting documents are determined after inspection and review of applicable Kazakh standards.