New mandatory law

Why is now the right time to invest in solar energy?

The Turkish authorities have issued new legislation that comes into force starting in 2026. The full text and practical interpretation from the CAGLAYAN SOLAR ENERJİ legal and engineering team

New mandatory law for buildings

10% renewable energy starting from 2026

Any new building with an area of 2.000 m² or more must integrate a renewable energy system into its design from the start, covering at least 10% of its annual energy needs. The most efficient and economical solution is a rooftop solar energy system (GES).

Official legal text (summary)

«يُلزَم جميع المباني الجديدة ذات المساحة الإجمالية 2,000 م² أو أكثر، التي يتم استصدار رخصة بناء لها اعتباراً من 01/01/2026، بدمج أنظمة طاقة متجددة في التصميم والتنفيذ، تغطي ما لا يقل عن 10% من الاستهلاك الطاقي السنوي المقدّر للمبنى. تشمل الأنظمة المقبولة: الطاقة الشمسية الكهروضوئية (GES)، أنظمة التسخين الشمسي، أنظمة الرياح الصغيرة، أنظمة الطاقة الحرارية الأرضية. يُعتبَر نظام الطاقة الشمسية الكهروضوئية السقفي هو الحل المعياري الموصى به من قبل الجهات التنظيمية لتفوقه الاقتصادي وسهولة تنفيذه.»

2,000 m²
The minimum area covered by the law
10%
The minimum to cover energy consumption
01/01/2026
The date the law comes into effect
3 detailed use cases

How does the law apply to your case?

The 2026 law does not impose a single solution — but the solution differs radically according to the building type, its electricity consumption, and peak consumption times. Here is a detailed analysis of three common cases we face daily with our clients

Home use

التحليل: الاستهلاك منخفض نهاراً (الأسرة في العمل/المدرسة) ومرتفع ليلاً. الفائض النهاري يُصدّر للشبكة عبر عداد صافي الإنتاج (Net Metering).

الحل: نظام On-Grid بدون بطاريات مع عداد صافي — الأرخص والأبسط.

Suggested capacity:5-8 kW
cost approximate:$5,000-8,000
Payback period:5-7 years
Annual savings:60-80%

Villa use

التحليل: أحمال إضافية مرتفعة طوال اليوم: مسبح، مضخات حرارة (Heat Pumps)، شاحن سيارة كهربائية، نظام تكييف مركزي. الاستهلاك الليلي مرتفع بشكل خاص صيفاً.

الحل: نظام Hybrid 10-20 kW مع بطاريات Lithium-ion بسعة 10-20 kWh لضمان استمرار التيار وتشغيل الأحمال الأساسية ليلاً.

Suggested capacity:10-20 kW
cost approximate:$15,000-28,000
Payback period:4-6 years
Annual savings:70-90%

Companies and factories

التحليل: استهلاك نهاري مرتفع طبيعياً (ساعات العمل 8-10 ساعات). توافق مثالي بين الإنتاج والاستهلاك — معظم الكهرباء تُستهلَك لحظياً.

الحل: نظام ثلاثي الأطوار 50-500 kW، مع خيار إضافة بطاريات فقط لقطاعات حرجة (خوادم، تبريد).

Suggested capacity:50-500 kW
cost approximate:$50,000-500,000
Payback period:3-5 years
Annual savings:75-90%
Comprehensive comparison

Comparison table for the three cases

Quick decision: which case suits you? This table summarizes the essential differences between the three systems across 8 decisive criteria

Criterion Residential (Home) Villa Company (Business)
System type On-Grid Hybrid (with batteries) Three-phase
Capacity 5-8 kW 10-20 kW 50-500 kW
Battery capacity None 10-20 kWh Optional (critical only)
Approximate cost $5K-8K $15K-28K $50K-500K
Payback period 5-7 years 4-6 years 3-5 years
Annual savings 60-80% 70-90% 75-90%
Installation time 1-2 days 2-4 days 2-8 weeks
Compliant with 2026 law? نعم (للمنازل +2000م²) نعم (مثالي للفيلات الكبيرة) إلزامي (المستهلك الأكبر)
Economic aspects

Current cost, depreciation, and settlement

Three crucial economic concepts for understanding the feasibility of your project under the 2026 law: current cost, accounting depreciation, and grid settlement. Understand them well before signing any contract.

Current cost

Refers to the full actual cost of the project at the moment of execution, including: panels, inverters, mounting structures, cables, installation, permits, and grid connection. We calculate it accurately to avoid budget gaps.

مثال عملي:
نظام 10 kW لفيلا = ~€8,000 شامل كل البنود، بدون مفاجآت.

Accounting depreciation

Distributing the system cost over its productive life (usually 10 years for accounting). It reduces taxable profit and recovers part of the investment through tax savings. Crucial for companies to accelerate the real return.

مثال عملي:
مشروع €100,000 = إهلاك €10,000/سنة = توفير ضريبي ~€2,500/سنة (بنسبة 25%).

Grid settlement

Net-metering mechanism: the daytime surplus is exported to the grid and counted as credit used at night. Valid for one year. Do not sell surplus electricity cheaply — exchange it with the grid.

مثال عملي:
إنتاج نهاري 40 kWh + استهلاك ليلي 25 kWh = رصيد 15 kWh للشبكة ليوم آخر.

The economic conclusion of the 2026 law

The law is not a burden — but an investment opportunity in itself. The rooftop solar system achieves a 15-25% annual return with payback within 3-7 years (depending on the case), adds 3-5% to the building's value, and protects against future electricity tariff increases. The legal obligation turns into a profitable investment instead of a fine with no return.

Battery selection

Battery System Selection

Choosing the right battery system is the most complex decision in designing a GES. A battery that is too small = continued power outages. A battery that is too large = wasted money without benefit. Here is the framework we use

5 criteria for selecting the battery

1

Capacity sufficient for 1-2 days (DoP 80%)

Battery capacity = daily night-time consumption × 1.5. Do not pay for capacity you will not use.

2

Lithium-ion (LFP) type, not Lead-Acid

LFP: 6,000+ cycles, 10+ years. Lead-Acid: 1,500 cycles, 3-5 years. The price difference is recovered within 2 years.

3

Integrated BMS system (Battery Management System)

Protection against overcharging, deep discharge, and cell imbalance. Without BMS = potential fire.

4

Scalability

Buy a battery that allows adding modules later. Your needs will change — do not freeze your investment.

5

10-year warranty with 80% DoD

The acceptable minimum. Less than that = early replacement that cancels the savings achieved.

Our recommendation

Batteries we actually recommend

ملاحظة هامة: لا نوصي بأي بطارية بدون BMS متكامل أو ضمان أقل من 10 سنوات، حتى لو كان السعر مغرياً. السلامة والعمر الافتراضي أهم من التوفير اللحظي.

Suggested articles

Read more about the 2026 law

6 in-depth articles we are publishing successively on our blog — each one covers a specific aspect of the 2026-2027 law in greater detail than this general guide

Article 1

The complete legal text of the 2026 law and all amendments up to November 2025

An analytical reading of the official text with an explanation of each legal article in plain language and all exceptions and recent amendments.

Article 2

Current cost: how to calculate the real cost of your project step by step

A practical accounting guide for each cost item, with ready-to-download Excel spreadsheets that calculate the actual cost for you.

Article 3

Accounting depreciation: strategies to maximize tax returns

A comparison of different depreciation methods (straight-line, declining, accelerated) and their tax impact on Turkish companies under the 2026 law.

Article 4

Grid settlement: how to benefit from a net-metering meter

An explanation of the grid settlement mechanism, the financial settlement year, and optimal strategies to maximize the benefit of the surplus.

Article 5

Battery system: when do you need batteries and when are they a waste of money?

A simple mathematical equation that determines for you when battery investment is profitable and when it is a guaranteed loss.

Article 6

2026 law fines: how much will non-compliance cost you?

A detailed calculation of the expected fines, compared to the cost of the implemented GES system, shows that compliance is much cheaper than violation.

Ready to comply?

Turn your legal obligation into a profitable investment

Get a free consultation from the CAGLAYAN SOLAR ENERJİ team within 24 hours. We assess your building, calculate the real cost, analyze the accounting depreciation, and design an integrated GES system for you that turns the 2026 law obligation into an investment. No obligation, no hidden fees.