How to Achieve a Truly Sustainable Renewable Energy Transition

How can we address the natural resource demands and environmental impacts of various renewable technologies?
 
 
 
Highlights
  • Concentrating solar power and certain geothermal technologies consume more water than other renewable energies, but still comparable or smaller amounts than coal, gas, or nuclear generation.
  • Scarcity of rare earths and some metals pose limits to manufacturing of solar photovoltaic panels as well as certain types of wind and hydropower turbines.
  • Rapidly declining renewable energy costs and the need to replace aging fossil fuel infrastructure present an opportunity to rapidly usher in a new era of truly sustainable energy.
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BY SHAKUNTALA MAKHIJANI | MAY 16, 2013 

(Originally posted to Johns Hopkins Environmental News)

Wind power. Flickr/Creative Commons by Timothy Tolle

Last month, the Worldwatch Institute launched the 2013 edition of our annual flagship publication, State of the World. This year’s book asks the question, Is Sustainability Still Possible?  by examining a wide range of social and environmental challenges ranging from managing freshwater scarcity to assessing the viability of various alternative energy technologies to building political and social movements around environmental causes. In the chapter I co-authored with Alexander Ochs – Worldwatch’s Director of Climate and Energy – we examined the natural resource requirements and environmental impacts of different renewable energy technologies.

Climate change and other environmental impacts of global reliance on fossil fuels have created a clear mandate for a transition to an electricity system based on renewable energy. However, the material requirements and environmental impacts of renewable energy vary widely by technology, location, and practices. In order to limit these impacts, they need to be thoroughly understood and managed.

While available land area can provide more than enough renewable resources  to meet global energy demand through solar, wind, small hydro, geothermal, and biomass energy, ecosystem impacts of individual projects can be significant, especially for large utility-scale power production. Aggregate impacts of small hydropower dam ecosystem disruptions, as well as agricultural land needs for growing biomass feedstock crops pose especially significant challenges. Consideration of land tenure rights and ecosystem sensitivity at individual locations should be paramount in siting power plants of any kind.

Concentrating solar power and certain geothermal technologies consume more water than other renewable energies, but still comparable or smaller amounts than coal, gas, or nuclear generation. Water requirements pose a particular difficulty for concentrating solar power, because the strongest solar resources are often located in deserts with scarce water resources. Air cooling systems are a potential technology alternative that can address this barrier. Growing crops for biomass energy production can require unsustainable amounts of water, depending on crop, location, and agricultural practices.

Scarcity of rare earths and some metals pose limits to manufacturing of solar photovoltaic panels as well as certain types of wind and hydropower turbines. However, proven alternative metals and generation technologies can address most of these limitations.

In addition to natural resource requirements, renewable energy technologies can have additional environmental impacts. Some solar PV technologies have a risk of cadmium emissions – though these are much lower than those associated with fossil fuel combustion and can be limited through panel recycling. Wind turbines can also interfere with bird migration routes and result in bird kills, depending on their location. Deforestation and biodiversity loss can result from almost all land use associated with renewable energy generation, but can be most significant for biomass, geothermal, and hydropower.

Integrated energy planning and sound environmental management should be practiced to limit natural resource consumption and ecosystem damages of renewable energy generation. First and foremost, energy demand must be reduced through energy conservation practices and energy efficiency technologies.

Decisions for siting energy projects must be fully integrated with sustainable and just land policies that ensure protection of ecologically sensitive areas, take into account alternative land uses and environmental services, and fully respect the rights of people living on or close to those lands. Renewable energy projects that would seriously compromise the surrounding environment or threaten local communities should be abandoned or re-sited. Renewable energy developments should also be in complete accord with priorities for sustainable water use to avoid large diversions of water from natural systems and to preserve scarce resources for human needs.

Strengthened environmental regulations are also needed for material resource extraction and use. The safe expansion of rare earth extraction requires new mining regulations in countries around the world. Recycling programs can also expand material availability and limit environmental impacts from mining. While recycling regimes are already in place for many metals, such as steel, more research is needed into the technical and financial feasibility of recycling certain rare earths.

The technical and sustainability challenges associated with transitioning to a fully renewable global energy system are significant, but they can be overcome with solutions that already exist today. Rapidly declining renewable energy costs and the need to replace aging fossil fuel infrastructure present an opportunity to rapidly usher in a new era of truly sustainable energy.

Table from "State of the World 2013: Is Sustainability Possible?" by Worldwatch Institute.