SUNSHINE FOR MINES: A SECOND LIFE FOR LEGACY MINING SITES

RMI's Sunshine for Mines program proposes a systematic approach to repurposing legacy mine sites, which are often liabilities due to contamination and maintenance costs, into productive energy assets. The methodology involves a multi-stage screening process covering environmental and regulatory constraints, technical feasibility (resource screening and reserve quantification), and financial viability via Net Present Value (NPV) calculations. The brief highlights that while mining companies often face high hurdle rates, the economic case is strengthened when compared to the 'business-as-usual' cost of maintaining closed sites. A practical application of this model with BHP in North America identified a subset of sites with a collective potential exceeding 0.5 GW, primarily for solar PV.

• Legacy mine sites often represent financial liabilities for companies due to the high costs of long-term care, maintenance, and regulatory compliance, with medium-sized closed sites potentially requiring 5–10 staff members and costing several million dollars annually to maintain.
• RMI has developed a screening methodology to prioritize legacy sites for renewable development, which includes an environmental, permitting, and regulatory scorecard to ensure development is favorable before technical assessments begin.
• Technical feasibility is determined through resource screening—including site characterization and levelized cost of electricity (LCOE) calculations—and reserve quantification, which uses 30 percent design estimates for solar and 10-year numerical simulations for wind.
• The economic viability of a project is assessed using Net Present Value (NPV), which considers capital and operating costs against revenue from electricity sales, while comparing the internal rate of return (IRR) against the company's hurdle rate.
• Interconnection costs are a critical factor in the economic case for development, with estimated costs ranging between $300,000 and $500,000 per mile for sites located far from the nearest grid substation.
• Beyond solar and wind, the methodology screens for alternative generation such as geothermal and biomass, as well as storage technologies including pumped hydro, Li-Ion batteries, and flywheels.
• An application of this methodology to BHP's North American portfolio identified a subset of legacy sites with a collective renewable energy potential of over 0.5 GW, with solar PV being the primary opportunity for most sites.

APA

Natali, P., Dabbagh, K., & Lund, J. (2017). SUNSHINE FOR MINES: A SECOND LIFE FOR LEGACY MINING SITES. RMI. https://rmi.org/app/uploads/2017/11/RMI_SecondLifeLegacyMiningSites.pdf

Chicago

Natali, Paolo, Kareem Dabbagh, and Jessie Lund. SUNSHINE FOR MINES: A SECOND LIFE FOR LEGACY MINING SITES. RMI, 2017. https://rmi.org/app/uploads/2017/11/RMI_SecondLifeLegacyMiningSites.pdf.

Wikipedia

{{cite report |last1=Natali |first1=Paolo |last2=Dabbagh |first2=Kareem |last3=Lund |first3=Jessie |title=SUNSHINE FOR MINES: A SECOND LIFE FOR LEGACY MINING SITES |publisher=RMI |date=November 2017 |url=https://rmi.org/app/uploads/2017/11/RMI_SecondLifeLegacyMiningSites.pdf |access-date=17 August 2026 |via=Climate Insights Directory}}

BibTeX

@techreport{natali2017sunshine, author = {Natali, Paolo and Dabbagh, Kareem and Lund, Jessie}, title = {{SUNSHINE FOR MINES: A SECOND LIFE FOR LEGACY MINING SITES}}, institution = {RMI}, year = {2017}, month = nov, url = {https://rmi.org/app/uploads/2017/11/RMI_SecondLifeLegacyMiningSites.pdf}, urldate = {2026-08-17}, note = {Indexed by Climate Insights Directory} }