Journal of Green Energy Research and Innovation
Quarterly

Investigating Energy Consumption Reduction Strategies and ‎Their Effect on the Renewable Electricity Price: A Case Study ‎of a Climate-Compatible Villa in Saman, Iran

Document Type : Research article

Author

Narges Loghmani

Department of Architecture and Urban Planning, Technical and Vocational University (TVU), Tehran, Iran.‎

10.61882/jgeri.3.1.16
Abstract
The main objective of this study is to evaluate the impact of building energy efficiency ‎measures on the cost of solar electricity in a climate-compatible villa located in the suburbs ‎of Saman, Chaharmahal and Bakhtiari Province, Iran. Enhancing building energy efficiency ‎while lowering the cost of renewable electricity generation is particularly vital in Iran’s off-‎grid residential sector, where growing energy demand and dependence on fossil fuels ‎necessitate sustainable, climate-compatible solutions. A baseline case and five optimization ‎scenarios were modeled using DesignBuilder (v6.1.0.6) to estimate annual energy ‎consumption, followed by techno–economic–environmental assessment of an off-grid ‎solar–battery–diesel generator system using HOMER (v2.81). Results show that the net ‎present cost (NPC) of the baseline system is $947,243, with cost reductions of 17.6%, 5.4%, ‎‎22.7%, 63.1%, and 79.5% achieved through polystyrene insulation, green roof, UPVC ‎windows, VRF HVAC, and all measures combined, respectively. The optimal integrated ‎scenario also reduces annual emissions by ~130 tons and increases the return on investment ‎‎(ROI) by 146%. This work uniquely couples building-level energy efficiency modeling with ‎techno–economic–environmental optimization of a hybrid off-grid PV– Battery–Diesel ‎generator system, quantifying for the first time how demand-side measures propagate into ‎key renewable electricity cost metrics in off-grid residential contexts. These findings ‎highlight the substantial economic and environmental benefits of combining building ‎optimization strategies with renewable energy deployment in off-grid residential ‎applications‎‎‎‎‎.‎

Graphical Abstract

Investigating Energy Consumption Reduction Strategies and ‎Their Effect on the Renewable Electricity Price: A Case Study ‎of a Climate-Compatible Villa in Saman, Iran

Highlights

❖ Combining all energy efficiency measures reduced the Net Present Cost of the off-grid solar system by 79.5%, dropping it from $947,243 to approximately $194,000.
❖ Upgrading to a VRF HVAC system provided the largest single cost reduction at 63.1%, significantly outperforming insulation or window upgrades.
❖ The optimal integrated scenario increased the return on investment by 146% while reducing annual carbon emissions by roughly 130 tons.
❖ This study proves that prioritizing building energy efficiency before sizing renewable systems is crucial for cost-effective off-grid electrification. 

Keywords

Net present cost
Optimized scenario
Renewable electricity price
Reducing energy consumption
Climate-compatible villa

Declaration of Competing Interest

The author declare that she has no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper. The ethical issues, including plagiarism, informed consent, misconduct, data fabrication and/or falsification, double publication and/or submission, redundancy, have been completely observed by the author.

Credit Authorship Contribution Statement

Narges Loghmani : Conceptualization, Data curation, Formal analysis, Funding acquisition, Investigation, Methodology, Project administration, Resources, Software, Supervision, Validation, Visualization, Roles/Writing - original draft, Writing-review & editing. 

Bibliography

Narges Loghmani was born in 1991 in Shahrekord, Iran. received her Master's degree in Architecture from Yazd University, iran, In 2016. She has been a faculty member of the Department of Architectural Engineering at the National University of Skills since 2022. Her areas of expertise in research include architecture, sustainable architecture, architecture and energy.

Citation

N. Loghmani, "Investigating Energy Consumption Reduction Strategies and their Effect on the Renewable Electricity Price: A Case Study of a Climate-Compatible Villa in Saman, Iran," Journal of Green Energy Research and Innovation, vol. 3, no. 1, pp. 16-30, 2026.

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Journal of Green Energy Research and Innovation
Volume 3, Issue 1
Spring 2026
Pages 16-30

  • Receive Date 18 May 2025
  • Revise Date 17 August 2025
  • Accept Date 03 September 2025
  • Publish Date 01 April 2026

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