エネルギー転換：ガーナの公共機関からの技術的・経済的視点

Unofficial AI-generated summary based on the public title and abstract. Not an official translation.

🔬研究者:新興国における公共施設のエネルギー転換モデルと、太陽光・水素・アンモニアの経済性比較手法を提供する。

🏢実務担当者:公共施設や企業が太陽光発電と系統売電を組み合わせた投資判断を行う際の、NPV・IRR・LCOE等の評価フレームとして活用できる。

🏛政策担当者:系統売電を促進する法整備や、水素・アンモニア普及のためのCAPEX・電力コスト低減策の必要性を示唆する。

The study uses a case study (Parliament House, Ghana) to identify a sustainable energy pathway for public institutions in emerging economies, from technical and economic viewpoints, towards the net-zero agenda. Technically, the study uses GIS (Google Earth Pro, v7.3.7) mapping and Python (Jupyter notebook from Anaconda, v4.20) simulation to assess rooftop/carport solar PV–grid integration and explore green hydrogen and ammonia productions. It combines a GIS rooftop solar resources assessment with a forward/backward sweep hosting-capacity analysis and a cascaded economic comparison of grid, hydrogen (H2), and ammonia (NH3) to inform decisions about RE investment scenarios in Ghana. The economic assessment uses net present value (NPV), internal rate of return (IRR), profitability index (PI), discounted payback period (DPP), and levelized cost of energy (LCOE, LCOH, and LCOA). A 6.3 MW (10,569 MWh) solar electricity system is proposed to meet the 2.56 MW (7554 MWh) demand with 3014 MWh excess. Hydrogen and ammonia production stood at 60.3 tons and 343,579 kg from excess electricity, respectively. The facility’s CO2 contribution in 25 years period with the grid supply is 160,539 tons, while with PV deployment, it can save 211,611 tons. A total of GHS 58,558,962 (GHS 36,306,556 for local demand and GHS 22,252,405 for grid sales), GHS 12,328,785, and GHS 43,805,636 are required to set up the solar PV, hydrogen, and ammonia plants, respectively. Results from 100% local consumption and grid sales scenarios indicate an NPV of GHS 106.91, an IRR of 75%, a payback period of 3 years, a profitability index of 3.1, and an LCOE of GHS 0.68. An NPV of GHS 84.57 million, IRR of 56%, PI of 3.8, DPP of 4 years, and LCOE of GHS 1.06/kWh were recorded for the grid sales. Hydrogen sales had a negative NPV of GHS 16.78 million, a PI of 0.7, and an LCOH of GHS 87.2 per kg. Similarly, a negative NPV of GHS 70.72 million, a PI of 0.27, and an LCOA of GHS 29,419.55 per ton were recorded for the ammonia sales. The Parliament House can save 106.91 million GHS over 25 years if it chooses to go solar after meeting its local requirements. Results from the Python simulation show a 5.6% reduction in bus voltage for the system without PV, while the configuration with PV injections saw a voltage increase of up to 11.4%. The system loss increased 113.3 kW in case 1 to 1659.2 kW in case 2. Solar-to-grid is the recommended pathway, while H2/NH3 are not competitive under present costs. The sensitivity analysis shows that changes in key input variables (CAPEX, electricity input cost, and selling price) affect the prospective H2/NH3 sales under current market conditions in Ghana. Therefore, policymakers should make conscious efforts to lower these parameters (CAPEX and electricity input cost) to boost green hydrogen and ammonia penetration in the transition agenda. A new law is required to encourage consumers to sell to the grid rather than rely on the current net metering scheme, which limits prosumers’ generation to 500 kW and forbids grid sales.

• semanticscholar https://doi.org/10.3390/en19184271first seen 2026-09-12 05:23:18 · last seen 2026-09-22 04:56:59