EME 807
Technologies for Sustainability Systems

5.6. Solar PV Recycling

5.6. Solar PV Recycling

 - The Next Big Thing on the Trash List – Solar?

Solar power is probably the fastest-growing market in the world. According to Solar Energy Industries Association (SEIA), in the past decade, solar power industry experienced an average annual growth rate of ~59%. An estimated 500,000 solar panels were installed globally every day in 2015. If we think of roof-tops, a typical American home would require 28 to 34 solar panels to cover its power consumption. The U.S. Department of Energy forecasted that by 2050, the U.S. will have cumulatively installed 700 GW of solar, or hundreds of billions of PV modules [Mulvaney, 2015].

But here is the question: What will happen to the billions of those solar panels now spreading across the globe at the end of their useful lives?

Professional working on PV panels
Rapid growth of photovoltaic installations over the past decade requires radical action for establishing a robust and economically viable PV disposal and recycling system. 
Credit: Oregon Department of Transportation via Flickr

On the average, solar photovoltaic (PV) modules have a useful lifespan of 25-30 years, so with the current growth rates, the first peak of PV waste can be expected around 2030. And there is still some time to plan ahead. Now as we know how externalities have magnified due to the lack of foresight with fossil fuels, there is an opportunity to do things right with solar.

As the photovoltaic panels contain a variety of valuable metals and materials, which are mined and refined at increasing rates, it is imperative to create recycling methodologies, infrastructure, and policies to maintain the flow of those materials within the industry. This important action would address two problems – waste regulation and resource depletion.

Reading Assignment

These two short articles outline some options for PV recycling available in the US and in Europe. For example, “PV Cycle, a European solar panel recycling association, developed a mechanical and thermal treatment process that achieves 96% recovery rate for silicon-based photovoltaic panels.” This sounds quite impressive! “The remaining 4 percent is utilized in an energy recovery process, using a waste-to-energy technology.”

Web Article: Lozanova, S., Are Solar Panels Recyclable, Earth 911, 2018. URL: https://earth911.com/eco-tech/recycle-solar-panels/

Web Article: Marsh, J., Recycling Solar Panels in 2018, EnergySage, 2018. URL: https://news.energysage.com/recycling-solar-panels/

There are a number of recyclable components included in PV module – some of those are rare, and some of those are toxic and thus require a proactive plan for recycling. Crystalline Si PV modules, in addition to silicon, contain materials such copper, aluminum, silver, and glass. CdTe PV modules contain cadmium, steel, and copper. Metal components are usually much more expensive than non-metal materials and extracting them during recycling process and reusing in manufacturing brings sensible economic benefits. Materials such as silicon wafers are critical to recycle as a substantial amount of energy is spent to purify them for use in PV modules. Thin-film modules contain such elements as tellurium, indium, gallium, and molybdenum, which are in limited supply in the Earth’s crust. Indium is the element that will face resource use competition between solar and flat-screen displays. [Williams, B., 2016]

If you want a deeper insight in the process of recovering of specific elements and design of the material flow, this article provides a comparative analysis of recycling of two types of PV panels - Deutsche Solar and First Solar - including LCA considerations and cost analysis.

Supplemental Reading:

Journal publication: Kim, S., Jeong, B., Closed-Loop Supply Chain Planning Model for a Photovoltaic System Manufacturer with Internal and External Recycling, Sustainability 2016, 8(7), 596.

URL: https://www.mdpi.com/2071-1050/8/7/596

The presented analysis and modeling shows that using the external recycling facilities as material source, the PV manufacturers can save on some costs. Joining a recycling association decreases the total cost of c-Si panels by 55.28% and CdTe panels by 2.28%.

What are the current US domestic programs designed to address the growing PV waste flow? Until recently, the regulations on PV waste did not exist in the USA, except California. However, things have to change soon. In lieu of summary of this section, the video below talks about some of the emerging options and initiatives, many of which utilize the successful experience of the European recycling programs.

Probing Question

Do you know what programs and policies for electronic and PV recycling exist in your town, city, or area? Do residents and business choose to use them? Why yes or why not?

 

References:

Mulvaney, D., Act Now To Handle The Coming Wave Of Toxic PV Waste, Solar Industry Mag 2015. Accessible from URL: .solarindustrymag.com

Williams, B., Photovoltaic (PV) Recycling, Final Project, EME 807 Technologies for Sustainability Systems, Renewable Energy and Sustainability Systems (RESS) Program, Penn State University, 2016.