Solar Photovoltaic Deployment Research Articles

Solar feed-in tariffs in a post-grid parity world: The role of risk, investor diversity and business models

Over the past decade, feed-in tariffs have spurred significant deployment of solar photovoltaics in Germany and other countries. With recent cost trends, several countries are approaching retail grid parity. Some policymakers conclude that now is the time to remove feed-in tariffs, as grid parity creates a self-sustaining market, where economically rational investors will invest even in the absence of government incentives. Recent experience in key European solar markets, however, shows that with the advent of grid parity and the reduction of feed-in tariffs, investment in new solar capacity has decreased rather than increased, making it questionable whether low-carbon energy policy targets will be reached. We conduct a cross-case study analysis of three PV markets – Germany, Italy and Switzerland – to investigate the role of feed-in tariffs for the near- and post-grid parity stages of diffusion, accounting for investor diversity and distinguishing between implications for revenue-based and savings-based business models. We find that recent market trends are strongly driven by increased levels of risk, especially policy risk and exposure to revenue risk. We therefore suggest that relatively frugal but stable policy environments may be conducive to further growth of investment in photovoltaics and minimize cost to society.

Hybridizing low-carbon technology deployment policy and fossil fuel subsidy reform: a climate finance perspective

The environmental argument behind fossil fuel subsidy reform is strong, particularly among international finance institutions wishing to support ‘transformational’ low-carbon development. However, supporting reform in practice has often met methodological and political barriers. Instead, a large share of international climate finance has flowed to national policies and measures that incentivize the deployment of low-carbon technologies such as renewable energy technologies. In this paper, we propose that ‘hybrid’ policies that package fossil fuel subsidy reform with low-carbon technology deployment policy offer an opportunity for donors to support mitigation activities that achieve both concrete environmental impacts as well as long-term structural change. Specifically, we model the abatement cost, fossil fuel subsidy savings, and generation cost resulting from combining wind and solar photovoltaic deployment policy with fossil fuel subsidy phase-out in four country case studies. Our results not only show the extent to which fossil fuel subsidies can undermine the financial viability of low-carbon energy technologies, but also how cost uncertainties can be buffered by combining fossil fuel subsidy reform with renewable energy deployment. Furthermore, we assess the proposed hybrid policy against typical climate finance criteria and thus contribute to debates surrounding donor strategies to support low-carbon development.

Forecasting residential solar photovoltaic deployment in California

Residential distributed photovoltaic (PV) deployment in the United States has experienced robust growth, and policy changes impacting the value of solar are likely to occur at the federal and state levels. To establish a credible baseline and evaluate impacts of potential new policies, this analysis employs multiple methods to forecast residential PV deployment in California, including a time-series forecasting model, a threshold heterogeneity diffusion model, a Bass diffusion model, and National Renewable Energy Laboratory's dSolar model. As a baseline, the residential PV market in California is modeled to peak in the early 2020s, with a peak annual installation of 1.5–2GW across models. We then use the baseline results from the dSolar model and the threshold model to gauge the impact of the recent federal investment tax credit (ITC) extension, the newly approved California net energy metering (NEM) policy, and a hypothetical value-of-solar (VOS) compensation scheme. We find that the recent ITC extension may increase annual PV installations by 12%–18% (roughly 500MW) for the California residential sector in 2019–2020. The new NEM policy only has a negligible effect in California due to the relatively small new charges (<100MW in 2019–2020). Furthermore, impacts of the VOS compensation scheme ($0.12 per kilowatt-hour) are larger, reducing annual PV adoption by 32% (or 900–1300MW) in 2019–2020.

Citywide Impacts of Cool Roof and Rooftop Solar Photovoltaic Deployment on Near-Surface Air Temperature and Cooling Energy Demand

Assessment of mitigation strategies that combat global warming, urban heat islands (UHIs), and urban energy demand can be crucial for urban planners and energy providers, especially for hot, semi-arid urban environments where summertime cooling demands are excessive. Within this context, summertime regional impacts of cool roof and rooftop solar photovoltaic deployment on near-surface air temperature and cooling energy demand are examined for the two major USA cities of Arizona: Phoenix and Tucson. A detailed physics-based parametrization of solar photovoltaic panels is developed and implemented in a multilayer building energy model that is fully coupled to the Weather Research and Forecasting mesoscale numerical model. We conduct a suite of sensitivity experiments (with different coverage rates of cool roof and rooftop solar photovoltaic deployment) for a 10-day clear-sky extreme heat period over the Phoenix and Tucson metropolitan areas at high spatial resolution (1-km horizontal grid spacing). Results show that deployment of cool roofs and rooftop solar photovoltaic panels reduce near-surface air temperature across the diurnal cycle and decrease daily citywide cooling energy demand. During the day, cool roofs are more effective at cooling than rooftop solar photovoltaic systems, but during the night, solar panels are more efficient at reducing the UHI effect. For the maximum coverage rate deployment, cool roofs reduced daily citywide cooling energy demand by 13–14 %, while rooftop solar photovoltaic panels by 8–11 % (without considering the additional savings derived from their electricity production). The results presented here demonstrate that deployment of both roofing technologies have multiple benefits for the urban environment, while solar photovoltaic panels add additional value because they reduce the dependence on fossil fuel consumption for electricity generation.

Power system balancing for deep decarbonization of the electricity sector

We explore the operations, balancing requirements, and costs of the Western Electricity Coordinating Council power system under a stringent greenhouse gas emission reduction target. We include sensitivities for technology costs and availability, fuel prices and emissions, and demand profile. Meeting an emissions target of 85% below 1990 levels is feasible across a range of assumptions, but the cost of achieving the goal and the technology mix are uncertain. Deployment of solar photovoltaics is the main driver of storage deployment: the diurnal periodicity of solar energy availability results in opportunities for daily arbitrage that storage technologies with several hours of duration are well suited to provide. Wind output exhibits seasonal variations and requires storage with a large energy subcomponent to avoid curtailment. The combination of low-cost solar technology and advanced battery technology can provide substantial savings through 2050, greatly mitigating the cost of climate change mitigation. Policy goals for storage deployment should be based on the function storage will play on the grid and therefore incorporate both the power rating and duration of the storage system. These goals should be set as part of overall portfolio development, as system flexibility needs will vary with the grid mix.

Multilevel governance and deployment of solar PV panels in U.S. cities

Solar photovoltaic (PV) installations have been growing rapidly in the United States over the last few years, incentivized by policies from federal, state and local governments. The complex relationships between solar policies at multiple levels of government and solar deployment are questions of importance to policy makers and scholars. Extant literature on solar policies pays less attention to the role of local governments and policies than to their federal and state counterparts. Local governments and policies play indispensable roles in the deployment of solar PVs. This paper studies the multilevel governance of solar development in the U.S. by evaluating the relative effectiveness of state and local policy tools in stimulating solar PV installations, with an emphasis on local solar policies. With a regression analysis on a national sample of 186 U.S. cities, we find that cities with local financial incentives deploy 69% more solar PV capacities than cities without such policies. We also find that cities subject to RPS requirements have 295% more solar PV capacity, compared with cities not regulated by state RPS.

The role of the complementary sector and its relationship with network formation and government policies in emerging sectors: The case of solar photovoltaics between 2001 and 2009

Understanding the role of government policies in promoting the introduction of renewable technologies can help to catalyze the transition toward a more sustainable energy system. The literature on technological transitions using a multi-level perspective suggests that the co-evolution of the niche market (the new technology) and the complementary regime may have an important role to play in shaping this transition. This paper provides a quantitative analysis of the interactions between different types of solar photovoltaic (PV) networks at the niche level, the complementary semiconductor sector at the complementary regime level, and the solar PV policies in 14 different countries. Using three equations for solar PV knowledge generation, manufacturing, and deployment, we investigate linkages between feed-in-tariff (FiT) and renewable portfolio standard (RPS) policies, network development, and the existence of a complementary sector. The empirical findings show that the complementary sector is an important determinant in solar PV deployment and manufacturing and network effects are dependent on the strength of the complementary sector in solar PV deployment and manufacturing. Feed-in-tariff and renewable portfolio standards are associated with solar PV diffusion and not with manufacturing. Finally, domestic government policies promoting renewable energy markets, which often lead to domestic electricity rate increases, have contributed to increased manufacturing capabilities internationally, including also in countries without a strong complementary sector, such as China, through the channel of manufacturing collaborations from countries with a strong complementary sector.

The impact of state policy on deployment and cost of solar photovoltaic technology in the U.S.: A sector-specific empirical analysis

Using a panel database for 27 programs in 16 U.S. states over 1998–2009, we assess the impact of 12 state-level policies on the cost and deployment of solar photovoltaic (PV) technologies for two sectors defined by system sizes: residential (<10 kW) and commercial (10−100 kW). We first examine the impact of policies on the deployment of solar PV. We show that cash incentives increase the deployment of commercial systems. We also show that interconnection standards potentially promote the deployment of residential systems, whereas property tax incentives potentially foster the deployment of commercial systems. We next examine the impact of policies on the cost of solar PV, and show that the key policies have different effects on costs. The cost of residential systems declines faster if there are cash or property tax incentives in place, whereas the presence of interconnection standards potentially accelerates the decline in commercial system costs. Further, states with a renewable portfolio standard see residential system costs potentially declining slower than states without such a policy. As solar PV is at the brink of becoming cost competitive, our findings assist regulators in fine-tuning their set of support tools.

Strategic considerations for deployment of solar photovoltaics in the Middle East and North Africa

The strategic rationale for adoption of solar energy, particularly solar photovoltaics (PV), in the Middle East and North Africa (MENA) is considered here through analysis of a recent report produced by the Emirates Solar Industry Association (ESIA), an industry association based in the United Arab Emirates (UAE). Electricity supply and demand modeling shows that solar PV is commercially viable in many MENA countries due to rapidly falling costs of solar PV, excellent fit of solar resource availability to regional electricity demand patterns, and rising regional gas prices. Opportunities and challenges to regional solar PV deployment, including electricity exports, electricity subsidies, development of domestic unconventional gas, and demand side energy management are considered with regard to potential impact on the strategic role that solar PV will play in shaping the MENA energy landscape.

The Impact of State Policy on Deployment and Cost of Solar PV: A Sector-Specific Empirical Analysis

Using a panel database for 27 programs in 16 U.S. states over 1998-2009, we assess the impact of 12 state-level policies on the cost and deployment of solar photovoltaic (PV) technologies for two sectors defined by system sizes: residential (

The potential for air-temperature impact from large-scale deployment of solar photovoltaic arrays in urban areas

Among the many benefits of solar photovoltaic (PV) systems, the direct effects are those of providing local power and the indirect ones include avoided generation from fossil-fuel power plants. The latter translate into reduced emissions of greenhouse gas (thus reduced radiative forcing) and other pollutants, such as ozone precursors (thus improved air quality). Because large-scale PV deployments can alter the radiative balance at the surface-atmosphere interface, they can exert certain impacts on the temperature and flow fields.In this analysis, meteorological modeling was performed for the Los Angeles region as a case study to evaluate the potential atmospheric effects of solar PV deployment. The simulations show no adverse impacts on air temperature and urban heat islands from large-scale PV deployment. For the range of solar conversion efficiencies currently available or expected to become attainable in the near future, the deployment of solar PV can cool the urban environment. The cooling can reach up to 0.2C in the Los Angeles region. Under hypothetical future-year scenarios of cool cities (urban areas with extensive implementations of highly-reflective roofs and pavements) and high-density deployments of urban solar PV arrays, some adverse impacts (0.1C or less in warming) might occur. However, such extreme high-density deployments of cool surfaces are not expected and thus the warming effects are unlikely to result.

The Application of LiDAR to Assessment of Rooftop Solar Photovoltaic Deployment Potential in a Municipal District Unit

A methodology is provided for the application of Light Detection and Ranging (LiDAR) to automated solar photovoltaic (PV) deployment analysis on the regional scale. Challenges in urban information extraction and management for solar PV deployment assessment are determined and quantitative solutions are offered. This paper provides the following contributions: (i) a methodology that is consistent with recommendations from existing literature advocating the integration of cross-disciplinary competences in remote sensing (RS), GIS, computer vision and urban environmental studies; (ii) a robust methodology that can work with low-resolution, incomprehensive data and reconstruct vegetation and building separately, but concurrently; (iii) recommendations for future generation of software. A case study is presented as an example of the methodology. Experience from the case study such as the trade-off between time consumption and data quality are discussed to highlight a need for connectivity between demographic information, electrical engineering schemes and GIS and a typical factor of solar useful roofs extracted per method. Finally, conclusions are developed to provide a final methodology to extract the most useful information from the lowest resolution and least comprehensive data to provide solar electric assessments over large areas, which can be adapted anywhere in the world.

Should solar photovoltaics be deployed sooner because of long operating life at low, predictable cost?

Governments subsidize the deployment of solar photovoltaics (PV) because PV is deployed for societal purposes. About seven thousand megawatts were deployed in 2009 and over 10,000 are expected in 2010. Yet this is too slow to strongly affect energy and environmental challenges. Faster societal deployment is slowed because PV is perceived to be too costly. Classic economic evaluations would put PV electricity in the range of 15–50 c/kWh, depending on local sunlight and system size. But PV has an unusual, overlooked value: systems can last for a very long time with almost no operating costs, much like, e.g., the Hoover Dam. This long life is rarely taken into account. The private sector cannot use it because far-future cash flow does not add to asset value. But we should not be evaluating PV by business metrics. Governments already make up the difference in return on investment needed to deploy PV. PV deployment is government infrastructure development or direct purchases. Thus the question is: Does the usually unevaluated aspect of long life at predictably low operating costs further motivate governments to deploy more PV, sooner?

Quantifying rooftop solar photovoltaic potential for regional renewable energy policy

Abstract Solar photovoltaic (PV) technology has matured to become a technically viable large-scale source of sustainable energy. Understanding the rooftop PV potential is critical for utility planning, accommodating grid capacity, deploying financing schemes and formulating future adaptive energy policies. This paper demonstrates techniques to merge the capabilities of geographic information systems and object-specific image recognition to determine the available rooftop area for PV deployment in an example large-scale region in south eastern Ontario. A five-step procedure has been developed for estimating total rooftop PV potential which involves geographical division of the region; sampling using the Feature Analyst extraction software; extrapolation using roof area-population relationships; reduction for shading, other uses and orientation; and conversion to power and energy outputs. Limitations faced in terms of the capabilities of the software and determining the appropriate fraction of roof area available are discussed. Because this aspect of the analysis uses an integral approach, PV potential will not be georeferenced, but rather presented as an agglomerate value for use in regional policy making. A relationship across the region was found between total roof area and population of 70.0 m2/capita ± 6.2%. With appropriate roof tops covered with commercial solar cells, the potential PV peak power output from the region considered is 5.74 GW (157% of the region’s peak power demands) and the potential annual energy production is 6909 GWh (5% of Ontario’s total annual demand). This suggests that 30% of Ontario’s energy demand can be met with province-wide rooftop PV deployment. This new understanding of roof area distribution and potential PV outputs will guide energy policy formulation in Ontario and will inform future research in solar PV deployment and its geographical potential.

Towards a local learning (innovation) model of solar photovoltaic deployment

It is by now familiar that in the deployment of solar photovoltaic (PV) systems, the cost dynamics of major system component like solar cell/module is subjected to experience curve effects driven by production learning and research and development at the supplier side. What is less clear, however, is the economics of system integration or system deployment that takes place locally close to the user, involving other market players, in the downstream solar PV value chain. Experts have agreed that suppliers of solar PV system must customize their flexible characteristics to address local unique users’ and applications requirements and compete on price/performance basis. A lack of understanding of the drivers of the economics of system customization therefore is a deficiency in our understanding of the overall economics of this renewable energy technology option. We studied the non-module BOS cost for grid-connected small PV system using the experience curve framework. Preliminary analysis of PV statistics of the US from IEA seems to suggest that learning in one application type is taking place with respect to the cumulative installation among all types of grid-connected small PV projects. The effectiveness of this learning is also improving over time. A novel aspect is the interpretation of such experience curve effect or learning pattern. We draw upon the notion of product platform in the industrial management literature and consider different types of local small-scale grid-tied PV customization projects as adapting a standard platform to different idiosyncratic and local application requirements. Economics of system customization, which is user-oriented, involves then a refined notion of inter-projects learning, rather than volume-driven learning by doing. We formalized such inter-projects learning as a dynamic economy of scope, which can potentially be leveraged to manage the local and downstream aspect of PV deployment. This dynamic economy may serve as a focus of energy policy having implications on standardization of design and training for installation, facilitating knowledge reuse among different integration projects and enabling inter-projects learning.

Evaluating the limits of solar photovoltaics (PV) in traditional electric power systems

In this work, we examine some of the limits to large-scale deployment of solar photovoltaics (PV) in traditional electric power systems. Specifically, we evaluate the ability of PV to provide a large fraction (up to 50%) of a utility system's energy by comparing hourly output of a simulated large PV system to the amount of electricity actually usable. The simulations use hourly recorded solar insolation and load data for Texas in the year 2000 and consider the constraints of traditional electricity generation plants to reduce output and accommodate intermittent PV generation. We find that under high penetration levels and existing grid-operation procedures and rules, the system will have excess PV generation during certain periods of the year. Several metrics are developed to examine this excess PV generation and resulting costs as a function of PV penetration at different levels of system flexibility. The limited flexibility of base load generators produces increasingly large amounts of unusable PV generation when PV provides perhaps 10–20% of a system's energy. Measures to increase PV penetration beyond this range will be discussed and quantified in a follow-up analysis.

The market for solar photovoltaics

There has been an increasing interest in deploying renewable energy technologies as a means of supplying energy needs in a more sustainable manner. This paper describes the recent evolution of the market for solar photovoltaics (PVs) and discusses likely future developments. It provides an overview of the niche markets in which PVs are already competitive with other forms of electricity provision and assessment of the larger markets currently supported by governments, utilities and industry in the expectation that they will become competitive in the future. The paper briefly addresses remaining barriers to the deployment of solar PVs and outlines the principal policy mechanisms being used to foster the development of both the technology and the markets in different countries. The evidence indicates that the PV industry may be on the verge of rapid expansion as economies-of-scale improve production economics, government programmes encourage deployment and more large-scale applications of the technology become viable.