ME 432 Fundamentals of Modern Photovoltaics

Class 42:Life Cycle Analysis & Role of Policy

9 December 2019

Life Cycle AnalysisA life-cycle assessment (LCA, also known as life-cycle analysis, ecobalance, and cradle-to-grave analysis) is a technique to assess environmental impacts associated with all the stages of a product's life from-cradle-to-grave (i.e., from raw material extraction through materials processing, manufacture, distribution, use, repair and maintenance, and disposal or recycling).

From Wikipedia:

Notable Efforts in LCA of PV Technologies:

• Energy Center of the Netherlands• Vasilis M. Fthenakis, Brookhaven National Laboratory

Inputs:Module lifetime, wafer thickness, cell/module efficiency, manufacturing yield, energy mix

Outputs:Energy payback time, CO2emissions per unit energy generated, toxic releases due to production

Life Cycle Analysis

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Life Cycle Analysis

• Fossil fueled power plants produce electricity with about 440-1100 g CO2/kWh

• Typical values for nuclear power plants are around 65 g CO2/kWh, but exhibit a lot of variation

• Renewables range from 9-38 g CO2/kWh

A handful of other recent studies exist as well, such as:• Leeuwen & Smith, “Nuclear Power – the energy balance”, 2003. • “Climate Change 2007: Working Group III: Mitigation of Climate

Change”, Intergovernmental Panel on Climate Change, 2007.• Lenzen, “Life-Cycle Energy Balance and Greenhouse Gas Emission

of Nuclear Energy: A review”, Energy Conversion and Management 49, 2178 (2008.

• “Carbon footprint of electricity generation”, UK Office of Science & Technology, 2006.

Some consistent trends amongst the results:

Energy Payback TimeEnergy Payback Time - time in which the energy input during the PV system life-cycle is compensated by electricity generated by the PV system

From: Energy Center of the Netherlands, Life Cycle Analysis Group

Energy Payback Time

From: M. DeWild, Energy Center of the Netherlands, Life Cycle Analysis Group

Bottom Line on LCA for PV Technology

• Emits 90-95% less CO2per kWh than coal

• Has ~3 year energy payback time

• Varies minimally amongst different PV technologies

• Largest single source of toxic release to the environment in PV?

Production of batteries, for off-grid systemsSee T. Williams et al., Proc. 21st EU-PVSEC (Barcelona, Spain, 2005)

Costs and Markets

Elif Ertekin, University of Illinois -- ertekin@illinois.edu,

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Solar Power Europe (formerly European Photovoltaics Industry Association), 2019

Cumulative installed capacity at the end of 2018: 500 GW

Elif Ertekin, University of Illinois -- ertekin@illinois.edu,

US Solar Energy Industry Association, 2019

15

US EIA Annual Energy Outlook

Grid Parity

source: REC, 2009

A Cost Tipping Point

• Assume that historically the cost of PV limits market adoption.

• At $1/Wp, PV electricity is around $0.05/kWh• At this price, PV electricity is cost competitive in

almost all US states Courtesy: Tonio Buonassisi, MIT

Towards $1/Wp

Courtesy: Tonio Buonassisi, MIT

Tracking the Sun XII

• The following two slides are from the 2019 edition of Lawrence Berkeley National Laboratory’s annual publication “Tracking the Sun XII”

• This is an annually-compiled report detailing trends and statistics for PV installations in the United States

• The full report and presentation is available for download from

https://emp.lbl.gov/tracking-the-sun

Trends (US)

After: Tracking the Sun VIII: An Historical Summary of the Installed Cost of Photovoltaics in the United States from 1998 to 2041, Lawrence Berkeley National Laboratory, released Aug 2019.

• Figure shows the final cost to the installer, with no incentives• Average decline per year, from 1998 onwards, is 6% to 12% depending on the customer

segment ($0.50/W per year)• Stagnation from 2005 until 2009, followed by sharp decline • Recent cost drop comes from module price itself, and reductions in “soft costs”• Note the decline continues, in spite of great reductions in incentives!

Key Findings from the Last Year

• Installed Prices Continued to Fall through 2019. The report focuses its analysis of installed prices specifically on host-owned distributed PV systems. Among these systems national median installed prices fell year-over-year by 5-7%, depending on the specific distributed PV customer segment. Those declines are broadly in-line with trends over the past five years. National median installed prices in 2018 were $3.7/W for residential, $3.0/W for small non-residential, and $2.4/W for large non-residential systems..

• Pronounced Pricing Disparities Exist Across States. For example, among residential system installed in 2018, prices for host-owned systems ranged from $3.1/W to $4.5/W between the 20th and 80th percentile levels, and prices for small and large non-residential systems varied across similarly wide ranges. The report explores sources of that pricing variability, including differences in system size, module- and inverter-type, mounting-type, location, installer, host customer-type, and new construction vs. retrofits. This year’s report also contains a multi-variate regression analysis to isolate the effects of individual pricing drivers, including characteristics of the local PV market related to market size, competition, and installer experience, among other factors.Three of the largest state markets (California, Massachusetts, and New York) are relatively high-priced, pulling overall U.S. median prices upward.

Influence of Policy

Case Studies:Germany, United States, and China

Policies in Germany

• 1990: 1,000 Roofs Measurement and Analysis Program– Largely financed and supported by the government, performance monitoring leading to technical

and regulatory improvements

• 1990: Adopts the world’s first feed-in tariff (FiT) requiring electric utilities to purchase electricity from PV systems at a price equal to at least 90% of retail electricity rates

• 1999: 100000 Roof Solar Energy Program provides 10-year, zero-interest loans with the final installment waived

• 2000: Renewable Energy Source Act increased the FiT by a factor of 6– During the first four months, more than 70 MW of PV projects were initiated (previous total installed

capacity of 69 MW)– Gov’t dropped waiver on last installment and increased loan interest rate to 2%

• 2004: Renewable Energy Source Act amended– Increased initial FiT rate, but incorporated a decline in the tariff paid to PV system owners of 5-6.5%

per year

• 2009: Annual FiT schedule again adjusted, so that PV tariffs drop at 8-10% per year, and 11% per year starting in 2011. Additional adjustments possible

Summary: A combination of low-interest financing and multi-year FiT pricing, Germany grew it’s market faster than any country and solidified its position at the top in installed PV capacity.

Policies in Germany

http://www.bmu.de/files/english/pdf/application/pdf/ee_in_deutschland_graf_tab_en.pdf

Policies in Germany

Installations

It’s all part of a larger plan …

Policies in Germany

Policies of United StatesSummary: A lack of federal leadership/initiatives (historically) has led to a very fractionalized energy policy with substantial variations between states.

Detailed state policies available at: http://www.dsireusa.orgDatabase of State Incentives for Renewables and Efficiency

• 1978: Investment Tax Credit (ITC) established under the Energy Tax Act– Provides a tax credit of 15% for solar energy installations

• 1986: Tax Reform Act reduced the ITC to 10%• 2005: Energy Policy Act increased ITC to 30%, in effect until 2015• 2008: Energy Improvement and Extension Act

– Removes cap of $2000 on the ITC for residential installations– Extends 30% ITC through 2016

• 2009: American Recovery and Reinvestment Act– Allows commercial entities to obtain cash grants from the US Treasury for PV installations in 2009 and 2010

• 2015: ITC of 30% extended by Congress• Support measures introduced at the state level include:

– Renewable Portfolio Standards …. Electricity providers must obtain a portion of their electricity supply from PV or other distributed renewable technologies, and thereby obtain a certain number of renewable energy credits (RECs). RECs can be sold and purchased as necessary; prices set by market mechanisms.

– Net Metering … You can sell excess electricity back to the utilities at retail rates, now being challenging in some states

– Rebate Programs

States with Personal Tax Credits 2016

States with Rebate Programs 2016

States that have adopted renewable portfolio standards 2016

Trends (US)Renewable energy credit – average prices by state

Policies in China

• 2005: Renewable Energy Law targets 10% renewable energy by 2020– Requires grid operators to purchase resources from registered renewable energy producers; buying price is

set by government commissions (adjustments allowed as necessary)– Cost of purchasing this will be distributed across all customers on the grid– Offers finanical incentives (funding, discounted taxes) for renewable projects

• 2005: Renewable Energy Medium and Long-term Development Plan– Targetted 300 MW in 2010, 1800 MW by 2020

• 2009: China announces a series of plans and subsidies intended to support the development of the Chinese solar power industry

– Open bidding for solar power plant licenses– Solar Rooftop Plan (to develop a domestic solar industry; as foreign markets were suffering) offers a fixed

upfront subsidy of 15-20 yuan per watt (overwhelming response, applications totalling 500MW in 2 months)– Golden Sun Demonstration Projects offer government subsidies of 50-70% of total installation costs for

600MW of installations in 2-3 years (includes BIPV, rooftop, utility-scale plants, and off-grid projects)

• 2011: National PV Feed-in Tariff introduced at ~ $0.15/kWh; domestic stimulus plan is targeting an installed capacity of 30GW by 2020

Summary: Rapid economic development has result in a significant increase in energy consumption. In the last 5-10 years, the government has announced a series of plans aimed at using solar power to bring electricity to remote areas and to support the development of domestic solar power industries.

Chinese Market Growth

• Result: Large growth rate, with installations in 2011 expected to exceed those of the United States and Japan (numbers not out yet)

Annual PV Manufacturing Worldwide

http://www.electroiq.com/articles/pvw/2010/10/inside-taiwan_s_pv.html

Paths Forward

Towards $1/Wp installed costs

Courtesy: Tonio Buonassisi, MIT

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Driving Force for Cost Reduction?

Source: 1366 Technologies, http://globalwarming.house.gov/pubs?id=0007

How To Get Involved• Expose yourself to new ideas and learn how the system

works– Intern at the DOE

• Advanced Research Projects Agency – Energy (ARPA-E)• Solar Energy Technologies Program (DOE-EERE)

– Undergraduates: REU– Intern at a company

• Advice– Know the fundamentals– Choose meaningful, use-inspired scientific projects– Develop an interest, and excel at something you are

passionate about