Benefits and Barriers for Photovoltaics

Like any technology, photovoltaic technology has its benefits and drawbacks. Its benefits range from its extremely low environmental impact, in fact the lowest of any electricity generating technology, and its accessibility to individual consumers. Many of the drawbacks of photovoltaics have been reduced as the technology continues to be developed, and it is expected they will be reduced much further in coming years.

Here we will look at the benefits and issues surrounding development and use of photovoltaics.

Environmental Impacts
Photovoltaic technology is one of the most environmentally friendly power producing technologies available today. As its systems require no fuel and produce no emissions, this technology has the potential to play a major role in climate change mitigation and pollution reduction.

Cost and Market Development
Though costs for solar electricity remain high in comparison to other electricity sources, they have gone down significantly over the past thirty years. Still, costs can appear prohibitive for many electricity users, particularly compared to utility power. Markets for photovoltaics have grown, but will depend on further cost reduction to increase demand for photovoltaic products.

Product and Installation Issues
Photovoltaics are one of the simplest renewable technologies to install and maintain, making them one of the most viable renewable energy options for individual consumers. At the same time, the approval processes for photovoltaic installations can present some complications and even barriers for some installations.

Power Quality Benefits and Issues
Photovoltaics can provide significant benefits for both building owners and utilities in diversifying sources of energy. As an intermittent power source, they have certain drawbacks, but these can be mitigated through connections to other power sources. In some cases, this intermittent power can be a good thing as photovoltaic production can match electricity needs as they change throughout the day and year.

Environmental Impacts

Solar power is one of the most environmentally friendly ways to produce electricity, producing no emissions and having minimal impact on the sites where it is installed. Because it is such a low-impact technology, it has become a major focus for people and groups concerned with the environmental impacts of conventional energy production.

Air Emissions

The greatest environmental benefit of using solar cells is that they require no fuel and therefore produce no emissions and do not generate waste.

[possibly add comparison chart - how much can air emissions be reduced by installing a solar panel; list the energy produced by a panel compared to same energy produced by natural gas or coal and then list the emissions from each that are saved by PV panel]

Site Impacts

Because photovoltaic systems can be mounted on roofs and other scattered sites, they have minimal or no impact on land use or the ecology of sites.

Cost and Market Development

The cost of solar power is currently the primary barrier to its use. Photovoltaics are one of the more expensive renewable energy technologies, particularly when compared to utility electricity. For some, the environmental benefits of this technology outweigh its costs. But for the photovoltaic market to fully develop and sustain itself, demand will need to increase and reduced costs will need to play a significant role in this demand.

Comparative costs can vary depending on how much utility electricity costs in particular areas. Because extension of utility lines can be prohibitive, photovoltaics are actually the most economical option in remote areas because they are easy to transport and cost less to install than a new power line. However, in areas like Massachusetts where the grid reaches most places and electricity costs are low, photovoltaics can seem much more expensive.

Production Costs

The main factors behind the high cost of photovoltaics are twofold. First, photovoltaic panels are relatively expensive to produce. Second, the market for photovoltaics has been relatively small until recent years, so photovoltaic production has not achieved the economy of scale necessary for truly low costs.

Both of these factors are gradually changing. Demand has increased over the past thirty years, and much research and development work has been done to increase the efficiency and lower the costs of photovoltaic systems. In fact, costs have fallen dramatically since the 1970s when photovoltaic panels first appeared on the consumer market. In 1975, the average cost for photovoltaic modules was $30 per watt, or $30 per the unit of electricity a panel could produce. By the 1990s, this cost had dropped to approximately $5 per watt.

Technological developments that improve efficiency and lower manufacturing costs are expected to continue reducing overall costs. As these costs fall, it is expected that demand will continue to increase due to the other benefits of photovoltaic systems. There is no set date when photovoltaics are predicted to become competitive with utility power, but some sources predict it will happen sometime within the next 10-20 years. If advanced technologies emerge from research and development that cause a significant drop in prices, this timeframe could be shortened even further.

Installation and Use Costs

The other area where costs can be incurred is in installation of a photovoltaic system, as multiple components are needed to help photovoltaic panels transfer their electricity to an end use. In many cases, these components can double the cost of a photovoltaic system. However, much of this additional cost can be reduced as installation experience increases within the building trades and as new methods are developed for installing and connecting photovoltaics to their end use.

There are several financial benefits linked to installed photovoltaic systems. The primary benefit is the possibility of reduced electric bills and the potential for net metering, where excess electricity from a photovoltaic system can be sold back to the utility. While these benefits do not currently balance out the initial costs of a photovoltaic installation, they can help in reducing these costs.

Product and Installation Issues

For individual consumers, building owners and developers, photovoltaic systems are the most accessible and easily installed form of renewable energy. Today, there are a broad variety of panel manufacturers, balance of system component providers, and installers specializing in photovoltaic installations. These professionals assist customers in developing and installing a system that is sized and installed to meet their needs.

One barrier can arise in this process at the permitting level, particularly when a system is to be connected to a building that is also connected to a building. This process, called interconnection is currently complex, but many regulatory efforts are being developed to simplify and standardize the steps needed for approvals.

Product Availability

Solar electricity is the most accessible clean energy technology to individuals and building owners. Many companies offer solar electric products directly to consumers.

Scale and Modularity

The small scale and modular approach to photovoltaic installations make it easy to install different amounts of photovoltaics on individual buildings and sites.

Maintenance and Reliability of Equipment

Photovoltaic equipment is highly regulated by national standards and is generally a very reliable technology. Maintenance costs are extremely low and are often not factored into system costs because they are so minimal.

Getting Systems Approved

There are a number of issues in connecting photovoltaics to other power and storage sources, particularly when a grid-interconnected system must be approved for interconnection by the local utility. These issues are being addressed through regulation and policy developments. Many states, including Massachusetts , have either developed or are in the process of establishing standard processes for these approvals.

Power Quality Benefits and Issues

Power quality, or the consistency and reliability of our electricity sources, is an issue of great interest to both utilities who maintain the complex grid providing electricity to millions of buildings and to individual owners who expect electricity to work when and where it is needed.

While most electricity today is provided by centralized, fuel-powered plants, photovoltaics operate in a very different way. Because their production depends on solar energy, a power source that is not always available, they produce electricity intermittently. This can presents issues for owners and utilities alike in ensuring that photovoltaics produce enough electricity to meet needs and do not produce more electricity than an individual or utility system can handle.

Reliability of Power

Providing consistent power is one of the things that most photovoltaic systems cannot guarantee as they are an intermittent electricity source dependent upon the sun.

Although solar power is intermittent, there are many ways to increase its reliability by pairing it with another energy source or using battery storage to store the energy produced for a period of time when the PV is not producing energy.

Matching Energy Needs

Because photovoltaics produce most of their energy during the day and produce more in the summer, their power production can match energy needs in many buildings.

Particularly in the summer, air conditioners and other energy-intensive appliances are used more frequently, creating a surge in demand for electricity. This is called the summer peak, when the demand for energy reaches its highest point. In New England and other cooler climates, there is also a winter peak, when cold weather causes a sharp increase in demand for heat. The winter peak is slightly different though, as most of the heat used in New England comes from non-electric sources. Because of this, photovoltaic systems can be very practical for meeting the summer peak in the region.

Although this benefit works for many uses, there are some applications that need more power at night or even need it continuously, as in some industrial applications. In these cases, photovoltaics can still provide much of the building's electricity, but a second power source is still essential for times when the photovoltaic system is not producing electricity.

Security of Energy Sources

Photovoltaics, acting as a distributed energy resource on buildings and sites connected to the utility, can provide certain benefits to the utility system as a whole. On a larger scale, they help to displace fossil fuel use which can be subject to volatile price changes.

The opportunities for using photovoltaics as a means to energy security depends on large-scale planning of energy sources, and depends on a certain level of installation activity which we have not yet reached.