# Most Up-To-Date Review Article on the Levelized Cost of Electricity from Solar Photovoltaic Technology

• K. Branker, M. J.M. Pathak, J. M. Pearce, A Review of Solar Photovoltaic Levelized Cost of Electricity, Renewable and Sustainable Energy Reviews, 15, pp.4470-4482 (2011). Open access DOI

Please leave any comments on the Discussion page (see tab above) including additional resources/papers/links etc. Papers can be added to relevant sections if done in chronological order with all citation information and short synopsis or abstract. Thank You.

# Background

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• LCOE Solar Grid parity

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## Levelised Cost of Electricity (LCOE)

From Wikipedia: Levelised Energy Cost "Levelized energy cost (LEC, also called Levelized Cost Of Energy or LCOE) is a cost of generating energy (usually electricity) for a particular system. It is an economic assessment of the cost of the energy-generating system including all the costs over its lifetime: initial investment, operations and maintenance, cost of fuel, cost of capital."

Also known as LUEC: Levelized Unit Energy Cost (LUEC) [2]

### What is LCOE?

The Levelised cost of electricity (LCOE) is also the levelised cost of energy(LCOE) or the levelised energy cost (LEC)

### How many methods?

Marcial T. Ocampo, (2009)How to Calculate the Levelized Cost of Energy – a simplified approach, April 28th, 2009 , Energy Technology Expert

In the case where the effect of income tax and depreciation needs to be considered, the RP MTO formula developed by Engr. Marcial T. Ocampo is shown:
Net COE = Total Cost / ((1 – g) * (1 – t)), in US $/kWh or US cents/kWh where Total Cost = ( ICC * CRF + (FixO&M + VarO&M + DOE + Fuel) * (1 – t) – t * DEPN ) / AEPnet ICC = (Capacity, kW) * (Overnight Cost,$/kW)
Overnight Cost = Installed Cost + Interest During Construction
CRF = capital recovery factor, 1/yr = int / (1 – (1 + int)^-Life)
AEPnet = Net Annual Energy Production, kWh/yr (net of plant own use)= (kW capacity) * (capacity factor) * (hours/year)
FixO&M = (Fixed O&M, $/kW/yr) * (Capacity, kW) VarO&M = (Variable O&M,$/kWh) * AEPnet
DOE = (PhP 0.10 / kWh) / (Exchange Rate, PhP / US $) * AEPnet Fuel = (net Heat Rate) * AEPnet * (Price of fuel)= (3600 / Efficiency, kJ/kWh net) * AEPnet * (Price,$/kJ net)
DEPN = Depreciation, $/ yr = ICC / Life g = Franchise Tax + Business Tax = 2.5% + 0.005% = 2.005% t = Income Tax = 35% int = Interest Rate, % Life = Economic Life or Project Life, yrs Please note that when the RP MTO formula of Marcial is simplified by disregarding depreciation, franchise tax & business tax and income tax, the RP MTO formula becomes similar to the US NREL formula: Net COE = ICC * CRF / APEnet + (FixO&M + VarO&M + DOE + Fuel) / AEPnet where the last term (FixO&M + VarO&M + DOE + Fuel) / AEPnet are unit costs per kWh. Levelised Cost of Energy It can be defined in a single formula as: ${LEC} = \frac{\sum_{t=1}^{n} \frac{ I_t + M_t + F_t}{\left({1+r}\right)^t} }{\sum_{t=1}^{n} \frac{E_t}{\left({1+r}\right)^{t}} }$ where • LEC = Average lifetime levelized electricity generation cost • It = Investment expenditures in the year t • Mt = Operations and maintenance expenditures in the year t • Ft = Fuel expenditures in the year t • Et = Electricity generation in the year t • r = Discount rate • n = Life of the system This manual is a guide for analyzing the economics of energy efficiency and renewable energy (EE) technologies and projects. ### Important Issues #### Cost of Capital & Incentives ##### Financing Dearth Holds Solar Back in U.S.(2010) MATT DAILY and SARAH McBRIDE, Financing Dearth Holds Solar Back in U.S.(2010),New York Times,October 17, 2010 [3] • Commercial Solar PV plants struggle to find financing to benefit from economies of scale and rival Germany ##### Chipping away at levelized costs: SunPods, Sunsonix seek lower solar LCOE in field and fabs Tom Cheyney - 01 July 2010 [4] • The solar photovoltaic metric du jour is levelized cost of energy, commonly referred to by its initials, LCOE. • First Solar’s Kii Miller put it this way: “To focus on anything else [other than LCOE] would be a mistake.” • "One day, these two upstart companies—SunPods and Sunsonix—may see their contributions to lowering solar power’s levelized cost of energy coexist in an elegant synergy, as decontaminated, degradation-resistant cells nestle in modules racked up in preassembled plug-and-play PV systems." ##### Effect of financial and fiscal incentives on the effective capital cost of solar energy technologies to the user.[not solar PV case study] Chandrasekar, B., and Tara. C. Kandpal. 2005. Effect of financial and fiscal incentives on the effective capital cost of solar energy technologies to the user. Solar Energy 78, no. 2 (February): 147-156. doi:10.1016/j.solener.2004.05.003.[1] AbstractDevelopment and dissemination of solar energy technologies in India has been aided by a variety of policy and support measures. One of the promotional measures is the provision of financial and fiscal incentives such as capital subsidy, low interest loan and accelerated depreciation related income tax benefits to the users on the purchase of solar energy technologies. In this study an attempt has been made to determine the effective capital cost of solar energy technologies to the user with the provision of financial and/or fiscal incentives. Results of exemplifying calculations for a domestic and an industrial solar water heating system, a solar home lighting system and a solar drying system have been presented and discussed. • financial and fiscal incentives: -Captial Subsidy -Low Interest Loan (Interest Subsidy) -Accelerated Depreciation related income tax benefits -Income tax benefits on capital gain related investments -Income tax benefits on interest paid on the loan availed for the purchase of a solar energy system -combinations of the above • Mathematical expressions for determining the effective present value of the capital cost to the end user in each of the above cases are presented in Appendix A. • the provision of income tax benefit on the amount of investment made by the user on the purchase and installation of renewable energy system is likely to be more attractive than the provision of low interest loan. ##### Effect of economic parameters on power generation expansion planning Sevilgen, Süleyman Hakan, Hasan Hüseyin Erdem, Burhanettin Cetin, Ali Volkan Akkaya, and Ahmet Dagdas. 2005. Effect of economic parameters on power generation expansion planning. Energy Conversion and Management 46, no. 11-12 (July): 1780-1789.[2] AbstractThe increasing consumption of electricity within time forces countries to build additional power plants. Because of technical and economic differences of the additional power plants, economic methodologies are used to determine the best technology for the additional capacity. The annual levelized cost method is used for this purpose, and the technology giving the minimum value for the additional load range is chosen. However, the economic parameters such as interest rate, construction escalation, fuel escalation, maintenance escalation and discount factor can affect the annual levelized cost considerably and change the economic range of the plants. Determining the values of the economical parameters in the future is very difficult, especially in developing countries. For this reason, the analysis of the changing rates of the mentioned values is of great importance for the planners of the additional capacity. In this study, the changing rates of the economic parameters that influence the annual levelized cost of the alternative power plant types are discussed. The alternative power plants considered for the electricity generation sector of Turkey and the economic parameters dominating each plant type are determined. It is clearly seen that the annual levelized cost for additional power plants varies with the economic parameters. The results show that the economic parameters variation has to be taken into consideration in electricity generation planning. • equations given • no solar • the construction escalation and interest rate have increased the annual levelized costs of the plants considerably having the higher capital costs and the longer construction time. #### Subsidies Subsidies by the government to various sectors decrease the price paid by consumers. The grid is currently largely subsidized (especially fossil fuels), so that it is difficult to simply compare electricity generated from solar PV and other renewables to the grid, without acknowledging that they are not subsidized equally. ##### Investors: Renewables Growth is Slower but Steady Stephen Lacey, 2010. Investors: Renewables Growth is Slower but Steady, RenewableEnergyWorld.com,July 5, 2010[3] • "Solar PV will be the fastest growing industry, as it is less capital intensive, is faster to build out and does not face many of the same regulatory challenges as wind, geothermal and concentrating solar power." • "..Solar PV will be the fastest growing industry, as it is less capital intensive, is faster to build out and does not face many of the same regulatory challenges as wind, geothermal and concentrating solar power.."IEA (2010):Energy Subsidies: Getting the Prices Right, 7,June, 2010 # Literature Review of LCOE and Solar Lazard’s Levelized Cost of Energy Analysis Version 8 (2014) : http://web.archive.org/web/20150704042906/http://www.lazard.com/PDF/Levelized%20Cost%20of%20Energy%20-%20Version%208.0.pdf Levelized Cost of Energy Analysis - Version 5.0 http://web.archive.org/web/20180309230242/http://blog.cleanenergy.org/files/2009/04/lazard2009_levelizedcostofenergy.pdf Certain Alternative Energy generation technologies are becoming increasingly cost-competitive with conventional generation technologies under some scenarios, before factoring in environmental and other externalities (e.g., RECs, transmission and back-up generation/system reliability costs) as well as construction and fuel costs dynamics affecting conventional generation technologies Levelized Cost of Solar Photovoltaics in North Carolina http://www.greentechmedia.com/articles/read/grid-parity-for-solar-in-north-carolina-study/ http://web.archive.org/web/20130820204048/http://energync.org/assets/files/LCOE%20of%20Solar%20PV%20in%20North%20Carolina-FINAL.pdf A key component of the research evaluated the levelized cost of energy (LCOE) of North Carolina solar PV systems. The LCOE of solar PV systems reflects the price at which energy must be sold to break even over the assumed economic life of the system. The LCOE equation takes into account system costs, as well as factors including financing, insurance, operations and maintenance, aepreciation schedules and any applicable incentives. The analysis used the System Advisor Model (SAM) developed by the National Renewable Energy Laboratory2 to calculate the LCOE under a series of ownership and systems capacity scenarios from 2006 to 2020. In addition, retail electricity prices were calculated for 2006 to 2020. Finally, the evaluation compared the LCOE of solar PV systems and the retail electricity prices in nine scenarios to identify if and when the declining LCOE of solar PV intersects with increasing retail electricity prices. ### Value of Solar Power Far Exceeds the Electricity J. Farrell, Value of Solar Power Far Exceeds the Electricity , 24 June, 2011, Renewable energy world,[5] From the ability to reduce peak demand on the transmission and distribution system, hedge against fuel price increases, or enhance grid and environmental security, solar power has a monetary value as much as ten times higher than its energy value. Distributed solar power provides electricity on-site or near to demand, reducing transmission losses, as well as wear-and-tear on utility equipment by mitigating peak demand. It also eliminates the need to hedge against fuel price swings. These benefits add 3 to 14 cents per kWh to the utility bottom line. See the report used for the blog: R. Perez, K. Zweibel, T. E. Hoff,2011, Solar Power Generation in the US: Too Expensive or a bargain?, pp 1-16 ABSTRACT: This article identifies the combined value that solar electric power plants deliver to utilities’ rate payers and society’s tax payers. Benefits that are relevant to utilities and their rate payers include traditional,measures of energy and capacity. Benefits that are tangible to taxpayers include environmental, fuel price mitigation, outage risk protection, and long‐term economic growth components. Results for the state of New York suggest that solar electric installations deliver between 15 to 40 cents per kWh to ratepayers and taxpayers. These results provide economic justification for the existence of payment structures (often referred to as incentives) that transfer value from those who benefit from solar electric generation to those who invest in solar electric generation. ### Where Renewables Stack Up: Comparative Chart on Levelized Cost of Energy and the “Value” of Clean Energy By Stephen Lacey on Jun 24, 2011 at 2:56 pm According to a report released this week by three leading solar researchers, the value of solar PV is between 3 and 14 cents a kilowatt-hour for a utility. The contributing factors include: stabilizing the grid during peak times, requiring less infrastructure for transmitting electricity and, of course, the reduction in GHG emissions and particulates. The Institute for Local Self Reliance illustrates the findings: ### Achievements and Challenges of Solar Electricity from Photovoltaics (2011) S. Hegedus and A. Luque, 2011, Achievements and Challenges of Solar Electricity from Photovoltaics, in Handbook of Photovoltaic Science and Engineering, Second Edition,Edited by Antonio Luque and Steven Hegedus, © 2011 John Wiley & Sons, Ltd, pp 1-38[6] ### Assumptions and the levelized cost of energy for photovoltaics Seth B. Darling, Fengqi You, Thomas Veselkad and Alfonso Velosae, Assumptions and the levelized cost of energy for photovoltaics,[7] DOI: 10.1039/c0ee00698j Photovoltaic electricity is a rapidly growing renewable energy source and will ultimately assume a major role in global energy production. The cost of solar-generated electricity is typically compared to electricity produced by traditional sources with a levelized cost of energy (LCOE) calculation. Generally, LCOE is treated as a definite number and the assumptions lying beneath that result are rarely reported or even understood. Here we shed light on some of the key assumptions and offer a new approach to calculating LCOE for photovoltaics based on input parameter distributions feeding a Monte Carlo simulation. In this framework, the influence of assumptions and confidence intervals becomes clear. ### Should solar photovoltaics be deployed sooner because of long operating life at low, predictable cost? (2010) Ken Zweibel, Should solar photovoltaics be deployed sooner because of long operating life at low, predictable cost?, Energy Policy, Volume 38, Issue 11, Energy Efficiency Policies and Strategies with regular papers., November 2010, Pages 7519-7530, ISSN 0301-4215, DOI: 10.1016/j.enpol.2010.07.040. • large increases in deployment of solar PV over past decade, although still too slow to affect energy and environmental challenges (small % of global mix) • "Classic economic evaluations would put PV electricity in the range of 15–50c/kWh,depending on local sunlight and system size." - still percieved as too costly ### Fuel-Parity: New Very Large and Sustainable Market Segments for PV Systems Christian Breyer, Alexander Gerlach, Daniel Schäfer, Jürgen Schmid,Fuel-Parity: New Very Large and Sustainable Market Segments for PV Systems, IEEE EnergyCon 2010, Manama/ Bahrain, 18-22 December, pp 1-6 Abstract—Global power plant capacity largely depends on burning fossil fuels. Increasing global demand and degrading and diminishing fossil fuel resources are fundamental drivers for constant fossil price escalations. Price trend for solar PV electricity is vice versa. Fuel-parity concept, i.e. PV systems lower in cost per energy than fuel-only cost of fossil fired generators and power plants, well describes the fast growing economic benefit of PV systems. Fuel-parity is already reached in first markets and first applications and will establish very large markets in the 2010s. Solar PV electricity will become a very competitive energy option for most regions in the world. • LCOE eqns and cost comparisons between PV and fossil fuels globally ### Assumptions and the levelized cost of energy for photovoltaics [2011] S. B. Darling, F. You, T. Veselka, and A. Velosa, “Assumptions and the levelized cost of energy for photovoltaics,” Energy Environ. Sci., 2011.[8] DOI: 10.1039/C0EE00698J http://www.renewableenergyfocususa.com/_virtual/article-downloads/LCOE-SolarPaper_a15788.pdf and http://www.mcs.anl.gov/uploads/cels/papers/P1810.pdf Photovoltaic electricity is a rapidly growing renewable energy source and will ultimately assume a major role in global energy production. The cost of solar-generated electricity is typically compared to electricity produced by traditional sources with a levelized cost of energy (LCOE) calculation. Generally, LCOE is treated as a definite number and the assumptions lying beneath that result are rarely reported or even understood. Here we shed light on some of the key assumptions and offer a new approach to calculating LCOE for photovoltaics based on input parameter distributions feeding a Monte Carlo simulation. In this framework, the influence of assumptions and confidence intervals becomes clear ## Estimates ### Technology Roadmap – Solar Photovoltaic Energy 2010 International Energy Agency (IEA), 2010. Technology Roadmap – Solar Photovoltaic Energy, October, 2010 [9] • The primary PV economic goal is to reduce turnkey system prices and electricity generation costs by more than two-thirds by 2030. • PV is already competitive today in selected off-grid applications, and will achieve competitiveness in three phases. • Annual CO2 savings with PV deployment ### True cost of solar energy and other renewables: California case study (2010) Tan Hunt, True cost of solar energy and other renewables: California case study ,December 13, 2010, ElectoIQ/Renewable Energy Word. [10] • misreporting still an issue with considering renewable energy costs fairly - they are comparable with conventional sources in several places ### Achieving Low-Cost Solar PV: Industry Workshop Recommendations for Near-Term Balance of System Cost Reductions (2010) Lionel Bony, Stephen Doig, Chris Hart, Eric Maurer,Sam Newman.2010, Achieving Low-Cost Solar PV: Industry Workshop Recommendations for Near-Term Balance of System Cost Reductions, Rocky Mountain Institute, September 2010,pp1-24 [11] • balance of system costs account for roughly 50% of total solar PV system cost • recommendations for design have potential to reduce BOS costs ~50% more than current best practice ### Solar Electricity Global Benchmark Price Indices, Dec 2010 Survey Results [Updated monthly] SolarBuzz.com. 2010.Solar Electricity Global Benchmark Price Indices, Dec 2010 Survey Results[12] [4] • increasing order of average prices: industrial (500kW), commercial (50kW), residential (2kW) • Some Key Assumptions (Short Term): 5% interest rate assumption. If "Free money" rather than the 5% interest assumption used, could bring the price of a Solar System which calculates at 24 cents per kilowatt hour down to 15 cents per kilowatt hour -Personal and Corporate taxation can affect the "after tax" cents per kilowatt hour. Tax regimes that provide attractive allowances for capital equipment against high marginal tax rates can significantly enhance the economics of solar relative to Utility tariffs. This effect is dependent upon individual circumstances and therefore has been excluded from the Solarbuzz Index • Some Key Assumptions (Long Term): -All Solarbuzz Price Indices exclude the impact of rebate programs that are available today in some European Countries, Japan, some States of the USA and through bi-lateral aid programs. It is possible to find your local government or utility offering rebates of anything from$3 - $5 Watt peak. • Done considering 20 years? • Decreasing trend in price ### Reconsidering solar grid parity. Yang, Chi-Jen. 2010. Reconsidering solar grid parity. Energy Policy 38, no. 7 (July): 3270-3273. [5] AbstractGrid parity–reducing the cost of solar energy to be competitive with conventional grid-supplied electricity–has long been hailed as the tipping point for solar dominance in the energy mix. Such expectations are likely to be overly optimistic. A realistic examination of grid parity suggests that the cost-effectiveness of distributed photovoltaic (PV) systems may be further away than many are hoping for. Furthermore, cost-effectiveness may not guarantee commercial competitiveness. Solar hot water technology is currently far more cost-effective than photovoltaic technology and has already reached grid parity in many places. Nevertheless, the market penetration of solar water heaters remains limited for reasons including unfamiliarity with the technologies and high upfront costs. These same barriers will likely hinder the adoption of distributed solar photovoltaic systems as well. The rapid growth in PV deployment in recent years is largely policy-driven and such rapid growth would not be sustainable unless governments continue to expand financial incentives and policy mandates, as well as address regulatory and market barriers. • Table 1.Cost structure of a typical (3.8 kW) residential PV system (source: Solarbuzz, NREL Solar Advisor Model 2009). • Table 2.Financial spreadsheet for a typical residential PV system. ### Toward a Sunny Future? Global Integration in the Solar PV Industry ### Levelized Costs of Electricity Generation (LCOE), Reference List Check the references in this list:[15] I. LCOE of Every Power Technology Committee on America's Energy Future. (2009). America's Energy Future: Technology and Transformation. Washington, DC: The National Academies Press. [Full-text at http://bit.ly/8ZsYVM] Energy Information Administration. (2010). Cost and Performance Characteristics of New Central Station Electricity Generating Technologies. In Annual Energy Outlook 2010: Early Release Overview. Washington, DC: Energy Information Administration. [Full-text at http://bit.ly/d3bWF9; Spreadsheet at http://bit.ly/9MCyDZ] European Commission. (2008). Commission staff working document accompanying the communication from the Commission to the European Parliament, the Council, the European Economic and Social Committee and the Committee of the Regions - Second Strategic Energy Review : an EU energy security and solidarity action plan - Energy Sources, Production Costs and Performance of Technologies for Power Generation, Heating and Transport. SEC(2008) 2872. Brussels, Belgium: European Commission. [Full-text at http://j.mp/9BST2r] Hutchinson, J., Inwood, S., James, R., Ramachandran, G., Hamel, J., & Libby, C. (2009). Program on Technology Innovation: Integrated Generation Technology Options (1019539). Palo Alto, CA: Electric Power Research Institute. [Full-text at http://bit.ly/cxGmpU] International Energy Agency. (2010). Projected Costs of Generating Electricity - 2010 Edition. Paris, France: International Energy Agency. [Full-text at http://bit.ly/9clY1X] Kaplan, S. (2008). Power Plants: Characteristics and Costs. CRS Report for Congress, RL34746. Washington, DC: Congressional Research Service. [Full-text at http://bit.ly/d7M0Ja] Klein, J. (2010). Comparative Costs of California Central Station Electricity Generation: Final Staff Report (CEC-200-2009-017-SF). Sacramento, CA: California Energy Commission. [Full-text at http://bit.ly/bINOG5] Lazard Ltd. (2009). Levelized Cost of Energy Analysis - Version 3.0. New York, NY: Lazard Ltd. [Full-text at http://bit.ly/agFmJA] II. LCOE of Renewable Power Black & Veatch Corporation. (2010). Renewable Energy Transmission Initiative Phase 2B: Draft Report. Sacramento, CA: RETI Stakeholder Steering Committee. [Full-text at http://bit.ly/bnSAmY] III. LCOE of Fossil Energy Power Klara, J.M. (2007). Fossil Energy Power Plant Desk Reference: Bituminous Coal and Natural Gas to Electricity Summary Sheets (DOE/NETL-2007/1282). Pittsburgh, PA: National Energy Technology Laboratory. [Full-text at http://bit.ly/a5aD1d] Lako, P. (2009). Coal-Fired Power. Technology Brief, E01. Paris, France: International Energy Agency. [Full-text at http://web.archive.org/web/20150516140722/http://www.etsap.org:80/E-techDS/] Research and Development Solutions, LLC (RDS). (2007). Cost and Performance Baseline for Fossil Energy Plants, Volume 1: Bituminous Coal and Natural Gas to Electricity (DOE/NETL-2007/1281). Pittsburgh, PA: National Energy Technology Laboratory. [Full-text at http://bit.ly/9RTcEV] Seebregts, A. J. (2009). Gas-Fired Power. Technology Brief, E02. Paris, France: International Energy Agency. [Full-text at http://web.archive.org/web/20150516140722/http://www.etsap.org:80/E-techDS/] IV. LCOE of Nuclear Power Congressional Budget Office. (2008). Nuclear Power’s Role in Generating Electricity. Washington, DC: Congressional Budget Office. [Full-text at http://bit.ly/dz8eov] Deutch, J. M., Forsberg, C. W., Kadak, A. C., Kazimi, M. S., Moniz, E. J., Parsons, J. E., Yangbo, D., & Pierpoint, L. (2009). Update of the MIT 2003 Future of Nuclear Power Study. Cambridge, MA: Massachusetts Institute of Technology. [Full-text at http://bit.ly/aoItOj] Hempstead, J., Sabatelle, A. J., Haggarty, M., Rose, K., Schumacher, L., Smyth, W., & Hess, W. L. (2008). New Nuclear Generating Capacity: Potential Credit Implications for U.S. Investor Owned Utilities. New York, NY: Moody's Investers Service. [Full-text at http://bit.ly/akSoVd] Simbolotti, G. (2009). Nuclear Power. Technology Brief, E03. Paris, France: International Energy Agency. [Full-text at http://web.archive.org/web/20150516140722/http://www.etsap.org:80/E-techDS/] Posted by Hun Park at 3:33 PM ### Realistic generation cost of solar photovoltaic electricity Parm Pal Singh, Sukhmeet Singh, Realistic generation cost of solar photovoltaic electricity, Renewable Energy, Volume 35, Issue 3, March 2010, Pages 563-569, DOI: 10.1016/j.renene.2009.07.020.[7] Abstract: Solar photovoltaic (SPV) power plants have long working life with zero fuel cost and negligible maintenance cost but requires huge initial investment. The generation cost of the solar electricity is mainly the cost of financing the initial investment. Therefore, the generation cost of solar electricity in different years depends on the method of returning the loan. Currently levelized cost based on equated payment loan is being used. The static levelized generation cost of solar electricity is compared with the current value of variable generation cost of grid electricity. This improper cost comparison is inhibiting the growth of SPV electricity by creating wrong perception that solar electricity is very expensive. In this paper a new method of loan repayment has been developed resulting in generation cost of SPV electricity that increases with time like that of grid electricity. A generalized capital recovery factor has been developed for graduated payment loan in which capital and interest payment in each installment are calculated by treating each loan installment as an independent loan for the relevant years. Generalized results have been calculated which can be used to determine the cost of SPV electricity for a given system at different places. Results show that for SPV system with specific initial investment of 5.00$/kWh/year, loan period of 30 years and loan interest rate of 4% the levelized generation cost of SPV electricity with equated payment loan turns out to be 28.92 [cent sign]/kWh, while the corresponding generation cost with graduated payment loan with escalation in annual installment of 8% varies from 9.51 [cent sign]/kWh in base year to 88.63 [cent sign]/kWh in 30th year. So, in this case, the realistic current generation cost of SPV electricity is 9.51 [cent sign]/kWh and not 28.92 [cent sign]/kWh. Further, with graduated payment loan, extension in loan period results in sharp decline in cost of SPV electricity in base year. Hence, a policy change is required regarding the loan repayment method. It is proposed that to arrive at realistic cost of SPV electricity long-term graduated payment loans may be given for installing SPV power plants such that the escalation in annual loan installments be equal to the estimated inflation in the price of grid electricity with loan period close to working life of SPV system.

• Cost of solar generation as a function of initial investment and solar output: http://en.wikipedia.org/wiki/Photovoltaics
• Note that most studies do 20-25 years...but systems could be functional 30-40years. Thus, after the loan repayment period of 20 years, the energy will be free and not accounted for in the cost analysis, resulting in a much higher PV cost
• Fig. 1: specific initial investment vs. specific electric output for different system costs
• Lower generalized capital recovery factor for longer loan period, lower interest, higher escalation of grid
• expressed need for scientists to give a better value for the working life of PV since it significantly affects the LCOE, and financing
• Loan terms important (LCOE sensitive to this) since the cost of PV electricity is mainly the cost of financing the huge initial investment

### 2008 Solar technologies market report

S.Price,R.Margolis,2008 Solar technologies market report,Energy Efficiency & Renewable Energy,US Department of Energy,2010.[8]

*Levelized cost of energy (LCOE) is the ratio of an electricity-generation system's amortized lifetime costs (installed cost plus lifetime O&M costs) to the system's lifetime electricity generation. The calculation of LCOE is highly sensitive to installed system cost, O&M costs, location, orientation, financing, and policy. Thus it is not surprising that estimates of LCOE vary widely across sources.

• worldwide, the range of LCOE is approximately $0.20–$0.80 per kWh for rooftop PV and $0.12–$0.18 per kWh for parabolic trough CSP, not including government incentives (REN21 2008), due largely to the effect on LCOE of location and the corresponding solar radiation (insolation).
• Figure 3.1 shows LCOE for residential PV systems in selected U.S. cities ranging from about $0.20/kWh to more than$0.32/kWh (when calculated with the federal ITC) based on the quality of the solar resource. Without the ITC, the range for these same cities is about $0.28/kWh to$0.46/kWh.
• PV cell type and efficiency,
• Table 3.2. Module Price, Manufacturing Cost, and Efficiency Estimates by Technology, 2008
• replacing/rebuilding inverters every 10 years was projected to almost double annual O&M costs by adding an equivalent of 0.1% of the installed system cost, bringing total annual O&M cost to 0.22% of installed system cost (Moore and Post 2007).
• manufacturers have begun offering customers optional warranties with up to 10 years of coverage for an additional fee for inverters
• T.Peterson,T.Key,S.Rosinsky,N.Jones,in:Solar Photovoltaics:Status,Cost,and Trends,EPRI,Paolo Alto,CA,2009(10150804)[16].

### Comparative Costs of California Central Station Electricity Generation

Klein, J. (2010). Comparative Costs of California Central Station Electricity Generation: Final Staff Report (CEC-200-2009-017-SF). Sacramento, CA: California Energy Commission. [Full-text at http://bit.ly/bINOG5][9]

• Very Detailed Report on LCOE of several energy techs
• Table 1: Summary of Average Levelized Costs—In-Service in 2009, depends on Merchant, IOU or POU . For Solar PV (single axis)from 26 to 32 Cents/kWh (All of these costs vary depending on whether the project is a merchant facility, an investor owned utility (IOU), or a publicly owned utility (POU))- Assumed 20 year life
• Large decrease in LCOE from 2007 to 2009 for Solar PV
• Used Energy Commission’s Cost of Generation Model, Definition of Levelized Cost
• Table 6: Average Levelized Cost Components for In-Service in 2009—Merchant Plants
• Sensitivity to tax benefits covered (Fig. 19-21)

### Renewable Energy Transmission Initiative Phase 2B: Draft Report.

Black & Veatch Corporation. (2010). Renewable Energy Transmission Initiative Phase 2B: Draft Report. Sacramento, CA: RETI Stakeholder Steering Committee. [Full-text at http://bit.ly/bnSAmY] [17][10]

• The Renewable Energy Transmission Initiative (RETI) is a statewide planning process to identify the transmission projects needed to accommodate California’s renewable energy goals.www.energy.ca.gov/reti
• Figure 1-1. Typical Cost of Generation Ranges (Levelised cost of generation)- several technologies: Thin Film $138-206$/MWh (13.8c/kWh)
• Rather than comparing projects on the levelized cost of generation alone, the rank cost includes the cost of generation and the cost of transmission and also considers the energy and capacity values of the generation profile of the project.
• Rank Costs = Generation Cost + Transmission Cost + Integration Cost - Energy Value - Capacity Value (determining energy and capacity value unclear)
• Cost of Generation Calculator used
• Effect of incentives on LCOE shown. Canadian and Mexican incentives considered.
• Solar 8760 profiles were modeled using PVsyst and TMY2 solar data.
• Figure 6-10. Tradeoff Between Generation and Transmission at Various Levels of Overbuild.
• Sensitivity Analysis done with and without incentives and other variables changed

### Chipping away at levelized costs: SunPods, Sunsonix seek lower solar LCOE in field and fabs

• The solar photovoltaic metric du jour is levelized cost of energy, commonly referred to by its initials, LCOE.
• Some issues on effects of actions on the equations commented on

### Photovoltaics Power Up

Swanson, Richard M. 2009. Photovoltaics Power Up. Science 324, no. 5929 (May 15): 891-892. [11]

• Graph of grid parity for different technologies [Source: Lazard Capital Markets, 1/9/09]
• "An upshot of these cost reductions is that the levelized cost of energy (LCOE) for PV plants (see the figure) is now in the range of conventional generation options when taking into account the impact of the U.S. federal 30% investment tax credit, and will be fully competitive without that incentive in 5 years. Perhaps surprisingly, PV electricity today costs less than that from a new natural gas peaking plant, and is rapidly encroaching on combined cycle base-load generation costs."
• For PV, not only take into account its cost effectiveness but also its lack of fuel price risk, lack of potential carbon emission costs, minimal siting limitations, and lack of water use.
• Thin films are rather new technologies that may, if successful, help drive costs lower over time.

### The technical, geographical, and economic feasibility for solar energy to supply the energy needs of the US

Vasilis Fthenakis, James E. Mason, Ken Zweibel,The technical, geographical, and economic feasibility for solar energy to supply the energy needs of the US, Energy Policy, Volume 37, Issue 2, February 2009, Pages 387-399,[12] .
Abstract: So far, solar energy has been viewed as only a minor contributor in the energy mixture of the US due to cost and intermittency constraints. However, recent drastic cost reductions in the production of photovoltaics (PV) pave the way for enabling this technology to become cost competitive with fossil fuel energy generation. We show that with the right incentives, cost competitiveness with grid prices in the US (e.g., 6-10 US[cent sign]/kWh) can be attained by 2020. The intermittency problem is solved by integrating PV with compressed air energy storage (CAES) and by extending the thermal storage capability in concentrated solar power (CSP). We used hourly load data for the entire US and 45-year solar irradiation data from the southwest region of the US, to simulate the CAES storage requirements, under worst weather conditions. Based on expected improvements of established, commercially available PV, CSP, and CAES technologies, we show that solar energy has the technical, geographical, and economic potential to supply 69% of the total electricity needs and 35% of the total (electricity and fuel) energy needs of the US by 2050. When we extend our scenario to 2100, solar energy supplies over 90%, and together with other renewables, 100% of the total US energy demand with a corresponding 92% reduction in energy-related carbon dioxide emissions compared to the 2005 levels.

### Lazard LCOE

Lazard,Levelised Cost of Energy Analysis- Version 3.0, June 2009, pp1 -16[15]
"Conventional generation technologies are subject to uncertainty regarding the potential for future carbon emission costs, which would not affect Alternative Energy generation technologies except positively through credit positions or otherwise"

• Sensitivity Analysis to various costs: Fuel cost, illustrative carbon emission costs, U.S. federal tax subsidies, anticipated capital costs over time
• Key Assumptions : pp 14-16
• Solar PV- Crystalline $116,$160-$196$/MWh; Solar PV-Thin-film $87,$131-$182$/MWh [compare against peak price for 10 largest cities in U.S.]
• Solar- no sensitivity to fuel costs/carbon emission costs . Capital cost main cost.
• "20 Percent Wind Energy Penetration in U.S. appended from page 25 - 126

### A Financial Worksheet for Computing the Cost of Solar Electricity

A Financial Worksheet for Computing the Cost (¢/kWh) of Solar Electricity Generated at Grid Connected Photovoltaic (PV) Generating Plants J. Sol. Energy Eng. -- August 2002 -- Volume 124, Issue 3, 319 (3 pages) doi:10.1115/1.1488162[22]

• Simple LCOE methodology and assumptions outlined

### Solar photovoltaic systems: the economics of a renewable energy resource

Jean-Baptiste Lesourd,Solar photovoltaic systems: the economics of a renewable energy resource, Environmental Modelling & Software, Volume 16, Issue 2, March 2001, Pages 147-156[23]

Abstract: This paper analyses some emerging aspects of the economics of grid-connected photovoltaic systems. While the 1997 cost of photovoltaic systems is estimated as 5.5 US$/Wp, a 1997 cost estimate for photovoltaic grid-connected electricity is (deflated terms) 0.25 or (nominal terms) 0.29 US$/kWh, for US sunbelt conditions, prevailing US capital market conditions, and an economic lifetime of 20 years. This compares to about 0.10 US$/kWh for conventional electricity production. Other estimates for are, respectively, in deflated and nominal terms and in US$/kWh, 0.30 and 0.35 (average US conditions), 0.29 and 0.33 (average Western European conditions), 0.23 and 0.27 (sunbelt European conditions), and 0.33 and 0.34 (average Japanese conditions). Assuming a longer system lifetime (30 years) lowers these costs by 15-20%. Dividing costs by 2, a reasonable future possibility, would bring them close to competitiveness. Further cost decreases, although possible, are still uncertain. The structure and future evolution of the world photovoltaic industry are also discussed.

## Grid Parity

Important note on grid parity: Grid parity is not a fixed number. The price of electricity in the grid varies between users, time of day and geographical location. Some solar systems will certainly be at grid parity already at peak energy prices. Further, the price of electricity will continue to increase if based on fossil fuels and other scarce fuels. [18]

### New eBook Shows How Solar Manufacturers Can Shorten the Path to Grid Parity

Enhanced Online News, [19],Chapter 3 in Camstar’s eBook Series “Winning Profits in the Age of Continuous Innovation” Addresses Solar Industry Challenges,March 31, 2010 08:33 AM Eastern Time

Grid parity is the point at which electricity generated from Solar power is equal to grid power. The eBook applies Camstar’s Advancing Product Quality (APQ) model to the Solar industry, and shows how the model enables the achievement of grid parity today. Beyond grid parity, the eBook discusses how the infrastructure creates additional long term value in the areas of global orchestration, greener manufacturing and lifecycle intelligence. “The analysis shows a shift down in the cost per kWh curve by 13-17%, putting some companies in the grid parity region today, and shortening the time to achieve grid parity for the entire Solar industry.”

### Global Solar Energy Outlook

Pike Research. 2010. Global Solar Energy Outlook - Solar Demand Dynamics, Cost Structures, Policy Factors, and Competitive Differentiators for Suppliers: Market Analysis and Forecasts. [24]

• Report outline and summary given. (Cost )
• anticipates that by 2013, in many markets, solar costs will reach the long-elusive goal of grid parity, the cost of electricity from traditional power sources. Between 2010 and 2013, Pike Research forecasts that solar demand will increase at a compound annual growth rate (CAGR) of 24%.
• Related: Solar Energy Costs to Achieve Grid Parity by 2013, According to Pike Research, http://web.archive.org/web/20100806140755/http://www.electroiq.com:80/index/display/pv-wire-news-display/1214189234.html
• Contact: Pike Research, Matt LeBeau, +1-303-953-9765 begin_of_the_skype_highlighting +1-303-953-9765 end_of_the_skype_highlighting begin_of_the_skype_highlighting +1-303-953-9765 end_of_the_skype_highlighting, press@pikeresearch.com

### Grid-Parity Analysis for EU and US Regions and Market Segments 2009

C. Breyer, A. Gerlach, J. Müller, H. Behacker, A. Milner Grid-Parity Analysis for EU and US Regions and Market Segments - Dynamics of Grid-Parity and Dependence on Solar Irradiance, Local Electricity Prices and PV Progress Ratio,24th European Photovoltaic Solar Energy Conference, 21-25 September 2009, Hamburg, Germany, 4492 - 4500 [20]
Grid-parity is a very important milestone for further photovoltaic (PV) diffusion. A grid-parity model is presented, which is based on levelized cost of electricity (LCOE) coupled with the experience curve approach. Relevant assumptions for the model are given and its key driving forces are discussed in detail. Results of the analysis are shown for all member states of the European Union and the United States of America, respectively. High PV industry growth rates enable a fast reduction of LCOE. Depletion of fossil fuel resources and climate change mitigation forces societies to internalize these effects and pave the way for sustainable energy technologies. In the EU and the US, first grid-parity events will occur in late 2009 or early 2010 in Italy and Hawaii, respectively. The 2010s are characterized by ongoing grid-parity events throughout the most regions in the EU and the US, reaching an addressable market of about 90% and 65% of total electricity market, respectively. In parallel to grid-parity events, next milestones for PV industry will be diesel-parity and natural gas-parity. Reaching grid-parity will require new political frameworks for maximizing social benefits. PV technology is on the pathway to become a highly competitive energy technology.

### Break-Even Cost for Residential Photovoltaics in the United States: Key Drivers and Sensitivities

P.Denholm, R. M. Margolis, S. Ong, and B. Roberts 2009, Break-Even Cost for Residential Photovoltaics in the United States: Key Drivers and Sensitivities , December¸2009, Natioal Renewable Energy Laboratory (NREL) Technical Report http://www.nrel.gov/docs/fy10osti/46909.pdf

• calculation in appendix
• various sensitivities discussed
• Achieving PV breakeven is a function of many variables, including the solar resource, local electricity prices, and various incentives. As a result, for a country like the United States, where these factors vary regionally, there can be considerable variation in break-even cost.

### Oerlikon discusses path to $0.70/W thin-film PV panels Vogler, D.. (2009, August).Oerlikon discusses path to$0.70/W thin-film PV panels. Solid StateTechnology, 52(8), 9. Retrieved July 13, 2010, from ABI/INFORM Trade & Industry. (Document ID: 1852027921).[25]

• O'Brien also addressed the points frequently being discussed at technical conferences - i.e., grid parity - and the seeming concurrence among industry insiders of a constant 80%/20% split (or maybe 70%/30%) of market share that favors c-Si over thin-film PV. "There's so much interest in thin-film technologies in general because they have dramatically simpler manufacturing steps and use much less material when making a module compared with c-Si," explained O'[Brien].
• Some companies produce panels at a cost of $0.70/W by the end of 2010 ### Prometheus Institute Study: Solar Power to Reach Grid Parity in U.S. in 2015 Michael Graham Richard, 2009. [http://web.archive.org/web/20110821134134/http://www.treehugger.com:80/files/2009/07/solar-power-to-reach-grid-parity-2015-usa.php Prometheus Institute Study: Solar Power to Reach Grid Parity in U.S. in 2015, treehugger.com, Science & Technology (solar), 07.14.09 [26][27] ### A Countdown towards Solar Power at Grid Parity:Policy Analysis Based on the Evolution of Price-Performance Nitin R. Jogleka, Eric S. Graber-Lopez, 2008.A Countdown towards Solar Power at Grid Parity:Policy Analysis Based on the Evolution of Price-Performance,in format for Proceedings of the 2008 ISDSI International Conference,18 pages [28] • simulation model that has been set up to examines the behavioral mode associated with the growth of the announced solar capacity generation and allied LMP issues in California • Figure 7: Sensitivity Study – Effect of Learning Rates on Grid Parity • Figure 8: Sensitivity Study – Effect of Transmission Cost on the Grid Parity • Brown,S. and I. Rowlands 2009, Nodal pricing in Ontario, Canada: Implications for solar PV electricity. Renewable Energy 34 (1): 170-178 • Cleanedge 2008, Utility Solar Asessment (USA) Study Reaching Ten Percent Solar by 2025, JUNE , www.cleanedge.com. • Ford, A. 2005. Simulating the Impact of a Carbon Market on the Electricity System in the Western USA, Inter. Conf. of the System Dynamics Society, Neijmegen. ### The True Cost of Solar Power Song, Joonki, Ryan Boas, Chris Bolman, Mark Farber, Hilary Flynn, Martin Meyers, and Michael Rogol. 2008. True Cost of Solar Power: Race to$1/W. Photon Consulting LLC. .[29]

• Detailed benchmarks of cost structures for solar companies through 2012 (Report cost $1950 USD) • Average cost if <$2/W for models and <$5/W for systems (race is to$1/W)...LCOE is <$0.25/kWh without incentives in sunnier places • At$1/W module and $1/W BOS, LCOE is <$0.10/kWh by 2012 is sunnier places

### Progress Report on Ontario’s Solar Initiatives [Canada]

JoAnne Butler, VP of Electricity Resources, OPA. 2008.[https://ozone.scholarsportal.info/bitstream/1873/13484/1/288589.pdf Progress Report on Ontario’s Solar Initiatives], Ontario Power Authority,December 9, 2008 [30]

• CanSIA’s roadmap for development of solar in Ontario -- twoprogram approach, target for grid parity 2016-2020

### Coming Soon: Solar Power Grid Parity [Canada] =

Warren Brazier,2008.Coming Soon: Solar Power Grid Parity,British Columbia Renewable Energy Blog - MegaWatt, December 14, 2008, [31]

• "The Canadian Solar Industries Association Solar Conference 2008 held last week in Toronto, was told by Navigant Consulting that utility-scale solar photovoltaic projects could reach "grid parity" without subsidies between 2020 and 2023 if fossil fuel prices increase as expected and if, under an emissions trading regime, carbon dioxide is priced at $70 per tonne." ### Thin Film PV: The Pathway to Grid Parity B. Buller and D. Eaglesham, "Thin Film PV: The Pathway to Grid Parity," in Optics and Photonics for Advanced Energy Technology, OSA Technical Digest (CD) (Optical Society of America, 2009), paper ThD1.http://www.opticsinfobase.org/abstract.cfm?URI=Energy-2009-ThD1[21] [32] • LCOE solar graph, lower LCOE with PPA (Power Purchase Agreement) with ITC (Investment Tax Credit) & optimized capital versus simplified LCOE ($0.08 $/kWh if system cost is$2.5/W)
• thin films cheaper so can approach parity faster
• FSLR is driving towards grid parity at $2.50/W (System)and$0.08/kWh before 2012

### Solar power edges towards boom time.

Wynn, Gerard. 2007. Solar power edges towards boom time. Reuters, October 19. http://www.reuters.com/article/idUSL1878986220071019.[33]

• General Electric's Chief Engineer predicts grid parity without subsidies in sunny parts of the United States by around 2015. Other companies predict an earlier date
• costs are dropping by around 5 percent a year and "grid parity," without subsidies, is already a reality in parts of California.

### Gaining on the grid.

Brown, Malcolm. 2007. Gaining on the grid. BP Global - Reports and publications, Issue 19. August, pp14-18.[34]

• Graph of solar grid parity for 2015 in the U.S.(in constant 2005 dollars)
• "The US Department of Energy estimates that if the 2015 goal is met it should involve between five and ten gigawatts of new electricity generating capacity (enough to power one to two million homes), and avoid ten million tonnes of CO2 emissions. It should also create 30,000 new jobs in the solar industry. "
• In the USA, parity with the electricity grid at peak charging rates has already been achieved in northern California and Hawaii (20cents/kWh)

### Going for grid parity.

Brown, Malcolm. 2005. Going for grid parity. BP Global - Reports and publications, Issue 12, April. pp 6-10. [35]

• the global solar business seeks achieving grid parity – reducing the cost of solar energy to be competitive with conventional grid-supplied electricity.
• "Grid parity will be achieved first in those areas of the world that have a combination of abundant sunshine and comparatively high grid electricity prices, places like California and Japan. Japan is already on the brink of grid parity, having one of the highest retail electricity prices in the world and good sunlight. It also has a government that has been prepared to encourage the use of solar power with incentives."
• cell efficiencies are achieving upwards of 15-18% depending upon the technology

Where Renewables Stack Up: Comparative Chart on Levelized Cost of Energy and the “Value” of Clean Energy

# Life Span of Solar PV

In general, manufacturer warranties cover the power output of Solar PV panels at roughly 20 to 25 years, and so the life is usually expected for 20 - 25 years [22]. This sections covers the literature for the reasonable life span of Solar PV panels. There are several types of panels that will be considered.

Searches:

• Life expectancy of solar PV/ Solar panels
• Lifespan of solar PV
• Zweibel solar lifespan

Types of Solar Materials

• Crystalline silicon
• Thin film – Amorphous Silicon
• Thin film – Indium Diselenide
• CIGS
• CdTe

Solar Technologies

• Flat Plate
• High Efficiency Multi Junction – IHCPV
• BIPV
• Concentrating
• Tracking vs Fixed

## *General

Nick Bosco. (S. Kurtz) 2010.Reliability Concerns Associated with PV Technologies. National Renewable Energy Laboratory, [36]

• This document is a non-comprehensive summary of known reliability concerns for PV technologies. It has 3 parts:

1. List of reliability concerns with corresponding references 2. Reference list 3. Prioritization of failures

• Several technologies listed

Anon. 2009.Solar panel costs 'set to fall' ,BBC, November 30, sec. Science & Environment.[37]

• "EU Energy Institute have found that 90 percent of solar panels last for 30 years or longer, a considerable leap from the 20 years generally recognized by banks and lenders."
• Dr Ossenbrink says 40-year panels will be on the market soon.

Dr. Heinz Ossenbrink presents 22nd EU PVSEC Technical Highlights - cannot find report?

Vasilis Fthenakis, Sustainability of photovoltaics: The case for thin-film solar cells, Renewable and Sustainable Energy Reviews, Volume 13, Issue 9, December 2009, Pages 2746-2750, [38]

Abstract: To ensure photovoltaics become a major sustainable player in a competitive power-generation market, they must provide abundant, affordable electricity, with environmental impacts drastically lower than those from conventional power generation. The recent reduction in the cost of 2nd generation thin-film PV is remarkable, meeting the production milestone of $1 per watt in the fourth quarter of 2008. This achievement holds great promise for the future. However, the questions remaining are whether the expense of PV modules can be lowered further, and if there are resource- and environmental-impact constraints to growth. I examine the potential of thin-films in a prospective life-cycle analysis, focusing on direct costs, resource availability, and environmental impacts. These three aspects are closely related; developing thinner solar cells and recycling spent modules will become increasingly important in resolving cost, resource, and environmental constraints to large scales of sustainable growth. Allen Zielnik, Atlas Material Testing, 2009. PV Durability and Reliability Issues,Photovoltaics World Magazine, Nov/Dec 2009 - Volume 1 Issue 5,December 3, 2009[39] • While there are initial PV qualification tests, such as the IEC and UL requirements, among others, they are neither intended to, nor capable of, predicting long-term performance. As a result, there has been an evolution in the application of accelerated life testing (ALT) and accelerated environmental testing (AET) to the service life prediction (SLP) of PV modules and systems. • no test program can predict with 100% certainty that a module will properly perform in an environment for 25+ years (except for real-time 25 year testing, of course) Osterwald, C. R., and T. J. McMahon. 2009. History of accelerated and qualification testing of terrestrial photovoltaic modules: A literature review. Progress in Photovoltaics: Research and Applications 17, no. 1: 11-33.[40] • An important facet of this subject is the standard module test sequences that have been adopted by national and international standards organizations, especially those of the International Electrotechnical Commission (IEC). The intent and history of these qualification tests, provided in this review, shows that standard module qualification test results cannot be used to obtain or infer a product lifetime. Closely related subjects also discussed include: other limitations of qualification testing, definitions of module lifetime, module product certification, and accelerated life testing. T. McMahon, G. Jorgensen, R. Hulstrom,2000 “Module 30 Year Life: What Does it Mean and Is It Predictable/Achievable?,” National Renewable Energy Laboratory,Conference: National Center for Photovoltaics Program Review, Denver, CO (US), 04/17/2000--04/19/2000. 2000 Apr 11[41] • The authors define what they mean by a 30-year module life and the testing protocol that they believe is involved in achieving such a prediction. However, they do not believe that a universal test (or series of tests) will allow for such a prediction to be made. They can test for a lot of things, but they believe it is impossible to provide a 30-year certification for any PV module submitted for test. They explain their belief in this paper. • Reprinted in: T. McMahon, G. Jorgensen, R. Hulstrom, “Module 30 Year Life: What Does it Mean and Is It Predictable/Achievable?,” National Renewable Energy Laboratory, Reliability Physics Symposium, 2008 (IRPS 2008); IEEE Inter., April 27, 2008-May 1, 2008 pp.: 172–177. ## *Polycrystalline Silicon Martin Holladay, Testing a Thirty-Year-Old Photovoltaic Module-It’s time to hook up my oldest solar panel to a multimeter ,May, 21, 2010, Green Building Advisor.com,[23] • a panel from 1979 (over 30 years old)still performs respectfully with old technology. Imagine how long newer technologies will last ***Artur Skoczek, Tony Sample and Ewan D. Dunlop, The Results of Performance Measurements of Field-aged Crystalline Silicon Photovoltaic Modules, Progress in Photovoltaics: Research and Applications, Volume 17 Issue 4, 2009, Pages 227 - 240[42] Abstract This paper presents the results of electrical performance measurements of 204 crystalline silicon-wafer based photovoltaic modules following long-term continuous outdoor exposure. The modules comprise a set of 53 module types originating from 20 different producers, all of which were originally characterized at the European Solar Test Installation (ESTI), over the period 1982-1986. The modules represent diverse generations of PV technologies, different encapsulation and substrate materials. The modules electrical performance was determined according to the standards IEC 60891 and the IEC 60904 series, electrical insulation tests were performed according to the recent IEC 61215 edition 2. Many manufacturers currently give a double power warranty for their products, typically 90% of the initial maximum power after 10 years and 80% of the original maximum power after 25 years. Applying the same criteria (taking into account modules electrical performance only and assuming 2·5% measurement uncertainty of a testing lab) only 17·6% of modules failed (35 modules out of 204 tested). Remarkably even if we consider the initial warranty period i.e. 10% of Pmax after 10 years, more than 65·7% of modules exposed for 20 years exceed this criteria. The definition of life time is a difficult task as there does not yet appear to be a fixed catastrophic failure point in module ageing but more of a gradual degradation. Therefore, if a system continues to produce energy which satisfies the user need it has not yet reached its end of life. If we consider this level arbitrarily to be the 80% of initial power then all indications from the measurements and observations made in this paper are that the useful lifetime of solar modules is not limited to the commonly assumed 20 year. Copyright © 2008 John Wiley & Sons, Ltd. • Very detailed study J. Wohlgemuth, “Reliability of PV Systems, Reliability of Photovoltaic Cells, Modules, Components and Systems,” edited by Neelkanth G. Dhere, Proc. of SPIE ,Vol. 7048, 704802-1, (2008).[43] According to John Wohlgemuth (BP Solar), “Today, BP Solar offers a 25-year warranty on most of its crystalline silicon PV modules…while the modules have to last for 25 years of outdoor exposure, we cannot wait 25 years to see how they perform… no BP/Solarex module has been in the field longer than ten years. Even the oldest 20-year warranty modules have only been in the field 15 years.” • “Examples of accelerated stress tests of use for PV include: - Thermal cycling; -Humidity-freeze; -Damp heat; -Mechanical load both static and dynamic, and -Ultraviolet exposure” Ewan D. Dunlop and David Halt, 2005."The Performance of Crystalline Silicon Photovoltaic Solar Modules after 22 Years of Continuous Outdoor Exposure", PROGRESS IN PHOTOVOLTAICS: RESEARCH AND APPLICATIONS, DOI: 10.1002/pip.627 • the majority of modules exceeding the level of 92% of Pmax after 20 year, the actual lifetime of these products is significantly more than 20 years. • Figure 1. Relative power degradation of silicone-encapsulated PV modules after 22 years Dunlop, E.D.; Halton, D.; Ossenbrink, H.A.;20 years of life and more: where is the end of life of a PV module?, Photovoltaic Specialists Conference, 2005. Conference Record of the Thirty-first IEEE Proceedings 2005 , Page(s): 1593 - 1596.[44] • no visible evidence that degradation rate is increasing with time • no defined “end of life” if assume constant continuous degradation, such that life time is well beyond 20 years John H. Wohlgemuth, 2003.Long Term Photovoltaic Module Reliability,NCPV and Solar Program Review Meeting 2003, NREL/CD-520-33586 pp 179-183.[45] Abstract:The reliability of crystalline silicon PV modules has improved dramatically over the years. Module warranties of 25 years are now common. Extension of the warranties to 25 years was based on excellent field results for modules with 10 year warranties and on extensive accelerated testing. Since none of the 25 year warranty modules have been in the field that long, we do not know how or when they will eventually fail. It is important for the PV industry to know this, because it impacts the ultimate useful life of our PV systems, it provides critical input for future improvements in module reliability and it provides important data on the long term wear out or failure of today’s crystalline silicon PV modules. • Failure modes covered Antonella Realini, 2003. "MTBF - PVm, Mean Time Before Failure of Photovoltaic modules",Final report BBW 99.0579, June 2003,58 pages[46] • Extensive MTBF project under Solarec. Very detailed study. • Results after 20 year study (indoor) ▪ 59% of the modules exhibited a decrease lower than -10% to the stated nominal power ▪ 35% of modules exhibited a decrease between -10% and -20% ▪ only the 6% of modules showed a decrease greater than -20%. • The perspective to produce commercial modules with lifetimes of 30 years Italic textor more is so realizable, trying to avoid the degradation mechanisms which could compromise modules efficiency and lifetime (in particular encapsulant delamination and hot-spot formation). • Andy Black, one of the leading solar financial analysis experts and instructor, recently published his report on the lifespan of solar panels. His analysis showed that the first solar panels manufactured about 40 years ago are still creating power at about 80% of their original power. From that study combined with his other analysis, he concluded that most solar panels will lose about a half percent a year in efficiency. *Mono-crystalline Silicon ## *Other Resources Accelerated testing still a challenge : Energetics Incorporated, 2010. Preliminary Situation Analysis: Advances in Photovoltaic Technologies, Workshop on Grand Challenges for Advances in Photovoltaic Technologies and Measurements, Denver, Colorado, May 11-12, 2010. • Standards, market challenges, measurement issues, contacts fo various PV researchers U.S. Department of Energy, Accelerated Aging Testing and Reliability in Photovoltaics Workshop II, Summary Report, April 1 & 2, 2008. European Commission Joint Research Centre (EU JRC), 2005,Workshop Proceedings of the "1st International Workshop Thin Films in the Photovoltaic Industry" 10/11 November 2005,JRC Scientific and Technical Reports (EUR collection) • The various thin film technologies (TF) have the highest cost reduction potential of all PV technologies in middle and long term. Equally, competitive technologies are amorphous/microcrystalline Silicon, CdTe and the material family of Cu (In,Ga)(Se,S)2. thin films. • summary of presentations, lifetime prediction still a challenge European Commission Joint Research Centre (EU JRC), 2009,PV Status Report 2009 - Research, Solar Cell Production and Market Implementation of Photovoltaics,JRC Scientific and Technical Reports (EUR collection)[24] • The current solar cell technologies are well established and provide a reliable product, with sufficient efficiency and energy output for at least 25 years of lifetime. • The average lifetime of a residential home is 25 to 35 years and corresponds well with the lifetime of solar modules. • feed-in tariffs and other incentives covered • One of the research issues is ensuring module lifetime >35years # General LCOE Resources • PV exchange [25] - Prices • PV Insight [26] Weekly prices of Solar PV modules and cells ## United States of America (US) RETFinance is a levelized cost-of-energy model, which simulates a detailed 20-year nominal dollar cash flow for renewable energy projects power projects including project earnings, cash flows, and debt payment to calculate a project's levelized cost-of-electricity, after-tax nominal Internal Rate of Return, and annual Debt-Service-Coverage-Ratios. "SAM incorporates the best available models to allow analysis of the impact of changes to the physical system on the overall economics (including the levelized cost of energy)." [27] ## Canada -Chapter 4: Electricity, generation, costs, reliability • List of Agencies: -National Energy Board (NEB), http://www.neb-one.gc.ca/clf-nsi/rcmmn/hm-eng.html -Natural Resources Canada (NRCAN), http://www.nrcan-rncan.gc.ca/com/index-eng.php -Canadian Energy Research Institute,http://www.ceri.ca/ (CERI) - CanMEt: • Sophie Pelland, Daniel W. McKenney, Yves Poissant, Robert Morris, Kevin Lawrence, Kathy Campbell and Pia Papadopol, 2006,The Development of PV Resource Maps for Canada,31st Annual Conference of the Solar Energy Society of Canada (SESCI). Aug. 20-24th 2006, Montréal Canada, 8 pages www.retscreen.net/ Developed by Natural Resources Canada (NRCan), and available for free, this software can be used to evaluate the annual energy production, costs and financial viability of wind energy, small hydro, photovoltaics, solar air heating, biomass heating, solar water heating, passive solar heating and ground source heat pumps. # Subsidies for fossil fuel # Citation List 1. Chandrasekar, B., and Tara. C. Kandpal. 2005. Effect of financial and fiscal incentives on the effective capital cost of solar energy technologies to the user. Solar Energy 78, no. 2 (February): 147-156. doi:10.1016/j.solener.2004.05.003. 2. Sevilgen, Süleyman Hakan, Hasan Hüseyin Erdem, Burhanettin Cetin, Ali Volkan Akkaya, and Ahmet Dag[caron]das. 2005. Effect of economic parameters on power generation expansion planning. Energy Conversion and Management 46, no. 11-12 (July): 1780-1789. doi:10.1016/j.enconman.2004.09.006. 3. Stephen Lacey, 2010. 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