As electricity prices continue to rise, many people are planning to install solar energy systems in their homes.
How much capacity do I need to cover my electricity consumption?
What are the procedures for rooftop solar systems under 10 kVA?
What do I gain if I install a solar system on my roof?
What is the cost?
What about shared roofs (apartments or buildings)?
If you are considering installing a rooftop solar system, start by checking your electricity bill.
Let’s calculate using a real example from a bill:
Installed Power → 26.510 kW
Contracted Power → 15.910 kVA
Consumer Type → Low Voltage (Residential)
Monthly Average Consumption → 417.819 kWh
In Turkey, the average solar energy potential is about 1,250 kWh/year per kWp of installed capacity.
If your monthly consumption is 417 kWh,
then your annual consumption is:
12 × 417 = 5,004 kWh/year
Required system size = (Annual Consumption) / (Annual Production per kWp)
= 5,004 ÷ 1,250 = 4 kWp
You can choose 60-cell or 72-cell panels.
(60-cell panels are about 1 m × 1.7 m, and 72-cell panels are about 1 m × 2 m.)
We recommend 60-cell panels.
If one panel = 400 Wp,
then you need 4,000 ÷ 400 = 10 panels,
which will require about 20 m² of roof space.
You can use a 4–5 kVA string inverter or microinverters for more flexibility.
If your roof faces multiple directions or has shading, microinverters will be more efficient and cost-effective.
For residential projects, we recommend installing at least 5 kVA systems.
Below that level, grid-connected projects may not be economically viable.
For residential consumers in Turkey, electricity prices are regulated by EPDK (Energy Market Regulatory Authority).
As of late 2021, the average household electricity cost (including taxes) was 0.915555 TL/kWh.
Apply to the grid operator.
The operator reviews your request and gives approval (usually within 2 months).
Prepare an electrical project approved by a certified electrical engineer, plus structural documents.
Submit the project for final approval.
Once approved, installation can begin.
The grid operator performs a temporary acceptance test.
After passing the inspection, final acceptance is issued.
The system begins producing and selling electricity to the grid.
Since this process requires technical expertise, it’s best to work with an experienced EPC company.
With a 10-panel system, you can produce 5,000–5,500 kWh per year.
When production is below your monthly consumption, you buy the remaining energy from the grid.
When production is above, the extra energy can be sold to the grid.
The sale price for excess electricity is about 0.7394 TL/kWh
(based on EPDK residential tariffs).
Example:
If you produce 750 kWh and consume 400 kWh in June,
then 350 kWh is sold at 0.7394 TL/kWh.
Even without detailed calculations, with an average cost of 1,000 USD/kWp,
your electricity production cost becomes around 0.044 USD/kWh.
That means — your biggest gain is cheap energy!
Average cost: 1,000 USD per kWp
Additional expenses (project design, permits, etc.): about 500 USD
For apartment buildings, a joint decision and signatures from all owners are required.
The system can be connected to a shared meter for common uses like pool, garden, or lighting,
helping reduce common energy expenses.
For professional assistance, please don’t hesitate to contact us.
We would be honored to share our knowledge and experience with you.