Repurposing mine sites for hydropower

To build a PSH facility, you need large reservoirs of water. Decommissioned mine sites are ideal because construction time and cost are cut, with the reservoirs already existing as craters from mining activities. Also, the existing site infrastructure can be repurposed, including the roads and certain facilities, and already existing pumps and water sources which are usually available on mining sites.

A pumped hydro power storage project has been built at a former gold mine in Kidston, Far North Queensland.

“The Kidston Pumped Storage Hydro Project is the first pumped hydro project in Australia for over 40 years, the first to be developed by the private sector, and the third largest electricity storage device in the country.” ­- Genex

There are a few challenges when converting a mine site to a hydro storage facility. One of the core challenges is the presence of contaminants in mine sites, which when filled with water seep into groundwater. According to research, a solution is to line reservoirs with ‘geomembrane lining materials’, synthetic materials designed to control the seepage of liquid.

Hydropower engineers design hydropower systems by analysing water resources, project objectives and local environments. These designs include turbine configurations, dam layouts, water flow calculations, energy yield estimates and budget projections.

They work closely with project managers to set achievable goals and deadlines. They assess potential risks on an ongoing basis with their systems and designs and implement preventative measures to mitigate risk. They monitor the progress of hydropower projects, making sure everything is according to design, and intervene if the construction needs to be more efficient or eco-friendly.

Hydropower engineers use hydrological modelling and simulation software to create and analyse hydropower and hydroelectric system models, water flow predictions, and energy production forecasts. This software helps to plan hydropower systems, optimise performance and allocate resources. 

1. Biomass energy from agricultural waste

“Bioenergy is a form of renewable energy generated from the conversion of biomass into heat, electricity, biogas and liquid fuels. Biomass is organic matter derived from forestry, agriculture or waste streams available on a renewable basis. It can also include combustible components of municipal solid waste.” – Australian Renewable Energy Agency

A range of technology is available to convert biomass to bioenergy. The specific technology used depends on the raw material of the biomass, as well as the size of the project and the form of energy that will be produced. These technologies include combustion, pyrolysis, gasification, transesterification, anaerobic digestion and fermentation. Biomass is beneficial because it reduces emissions, efficiently disposes of waste, supports rural economies and improves the overall air quality.

2. Floating solar power plants

Reservoirs and other bodies of water, including abandoned mining pits, are being repurposed for floating solar power plants. These installations not only generate renewable energy but also reduce water evaporation and algae growth, improving water quality. Floating solar or floating photovoltaics (FPV), are solar panels on structures that float on bodies of water, such as drinking water reservoirs, quarry lakes, irrigation canals or remediation and tailing ponds.

Floating solar has advantages over land solar. Water surfaces can be more affordable and have fewer regulations than land facilities, and floating solar can be more efficient because water cools the panels, which can also be treated with special coating to prevent rust and corrosion.

3. Geothermal power from abandoned oil wells

In areas with a high volume of oil and gas activity, abandoned oil wells can be repurposed for geothermal energy production. These wells have the inherent benefit of providing access to the Earth's heat, which can be harnessed to generate electricity or provide heating for buildings.