Solar Steps Up

MARIE FREEBODY, CONTRIBUTING EDITOR, marie.freebody@photonics.com

Despite a challenging environment, there is hope for the solar market with progress being made across many areas of technology. While the advances may not be revolutionary, the small steps toward improving the key features of cost, efficiency and lifetime should not be overlooked.V According to market analysts at Yole Développement in Lyon, France, when it comes to commercial production, among the top advances in solar cell technology are diamond-wire sawing of crystalline silicon wafers, CdTe panel efficiency improvements by First Solar Inc. in Tempe, Ariz., and multi-wire interconnection of busbar-free crystalline silicon solar cells such as SmartWire Connection technology by Meyer Burger Technology Ltd.

Europe’s largest floating solar project on the Queen Elizabeth II reservoir in Surrey, England. Courtesy of Lightsource.

Even though several revolutionary technologies have been announced in the past years, Milan Rosina, senior analyst of Energy Conversion and Emerging Materials at Yole Développement, sounds a note of caution — cost, efficiency and lifetime are all three mandatory parameters for commercial success and some of the recent “innovative technologies” are good in only one or two of those three parameters.

“Investors and insurance companies often prefer ‘bankable’ solar technologies, such as well-proven crystalline silicon,” Rosina said. “New technologies have to face well-proven technologies, manufactured by big players with established distribution and selling channels, and technologies manufactured at low cost and in high volumes.”

Storage

One of the most promising solar advancements is in the ability to store some of the energy generated by photovoltaics (PV), which not only allows system owners to optimize their self-consumption, but it also helps to stabilize the grid. While not a new concept, storage has become more widespread in the past year due to technology advances that allow for cost-efficient systems. Storage is important to PV because solar energy production does not typically match consumption.

A PV storage installation. Courtesy of SolarEdge.

Lior Handelsman, a founder and vice president of Marketing and Product Strategy at SolarEdge Technologies Inc. in Fremont, Calif., likens solar energy storage to the water system.

“Imagine a water system without any reservoirs, no tanks or collection pools. This would mean that the water utility [supplier] would have to provide the exact amount of water at every given second. The utility would need to make sure to not provide too much pressure or the pipes would blow, or too little, because then no one would have water,” he said. “Then on top of this system, people were adding rain collection to their homes and feeding it into the water system — this would make it even more difficult to manage. That is what PV is to the electrical grid.”

Adding storage to PV takes away some of the unpredictable and inconsistent nature of managing the influx of energy into the grid, similar to installing water tanks in homes.

Combined PV and storage solutions allow the shifting of excess energy produced to the time of use. By placing energy production and storage at the same location as the load, a decentralized model of mini power stations is created.

“This model can offer utilities many more possibilities than the traditional network in which power generation is built on large, single-source energy production that requires costly transmission,” Handelsman said. “This could unlock solar energy’s grid parity potential and provide a more dynamic grid with minimal outages.”

Some important challenges must first be overcome before storage solutions become better integrated into the grid, including updating grid policies and capabilities.

“The grid needs to be able to support voltage regulation, frequency control and power supply/reservoirs in order to advance and stabilize the grid,” he said. “By enabling distributed PV ‘power stations’ coupled with storage, utilities can reduce the load from the grid at peak times. This would lessen the need for utility investments in generation, transmission and distribution.”

Inverters

Initially, the role of the inverter was AC-DC conversion and they were measured only by their efficiency. But new inverter topologies have been introduced to the market that come with added functionalities including monitoring, communications, smart energy management, storage, grid interaction and safety.

This trend is expected to continue with predictions of inverters taking on roles managing smart homes, such as load control for energy shifting. On a macro level, smart inverters could allow a more decentralized power structure with mini power stations versus a large single source for energy.

“Another development is that as the industry evolves we will be forced to make smaller inverters with an improved power/kg ratio. Inverters will get smaller and become more cost-effective,” Handelsman said. “SolarEdge recently announced its HD-Wave inverter technology, which represents one of the most significant leaps in solar technology in the past 20 years.”

The initial market release will be localized in Europe in 2016, with plans to expand the market as the introduction continues.

While inverters may only account for around 10 percent of the system cost, they influence around 30 percent, manage 100 percent of system production, and control lifetime operations and maintenance expenses. This has resulted in an increasing shift toward string inverters and module-level power electronics (MLPE) technology in commercial systems. MLPE offers increased power production by not only eliminating energy loss for module-level mismatch, but also by allowing optimal roof utilization and installation of more modules through constraint-free design.

A commercial solar array. Courtesy of SolarEdge.

In addition, MLPE offers enhanced maintenance and remote troubleshooting, which reduces lifetime operations and maintenance costs and enhances asset management capabilities by lowering the number of site visits, as well as time spent on site. Inherent to MLPE technology is its ability to reduce risk of fire and electrocution by enabling module-level shutdown of high DC voltages, protecting installers, maintenance personnel and firefighters.

Future progress

In photovoltaics there has been a significant increase in understanding of the manufacturing quality and longevity of solar modules — for example, with regard to potential induced degradation failure rates.

A look at proportion of the inverter market for photovoltaic applications. Courtesy of Inverter Technologies Trends & Market Expectations 2016 report, Yole Développement, May 2016.

“We are now into the second decade of volume PV deployment at Grid level, and performance modeling and accuracy of forecasting has shown huge improvement due to the amount of data available from the field,” said Chris Buckland, technical director of U.K.- based Lightsource Renewable Energy. “The commoditization of solar PV has driven cost of manufacturing down to component and material input pricing, as such the ‘old’ cheaper thin-film technology has been driven out of market share into specialized nonindustrialized business sectors.”

With technology performance gains predicted to continue into the next decade for conventional silicon-based technology, one or other disruptive technologies is expected to make it to market — most likely in the form of heterojunction or sandwich-cell industrialization.

A residential solar array. Courtesy of SolarEdge.

Continued adoption, at least in the short term, may hinge on government policy.

“While this does not mean that solar energy necessarily requires incentives, there are some supporting government policies that can promote solar energy by helping further accelerate and ease the process of going solar,” Handelsman said. “These government policies can include public education, removing bureaucratic road blocks and setting renewable energy targets.”

If governments can pave the way for PV adoption with friendly policies, it seems that the industry has the know-how to continue to develop innovative solutions to overcome challenges along the way.

UK Solar Adoption Slows in Wake of Subsidy Cuts, Brexit

It began with the scrapping of the first government incentive program on April 1, 2015. This was the first of many to go in the following months, resulting in large commercial and utility-scale projects all but ending, the loss of at least half the jobs in the U.K. solar industry, and grid parity becoming a distant dream.

The U.K. solar industry had been enjoying several years of generous incentive programs, namely a Renewable Obligation program and a feed-in tariff (FiT) program. But these halcyon days came to an end when the Renewables Obligation Certificate plan was scrapped and policy measures were taken against FiT, including tariff cuts and quarterly caps.

The first large-scale solar farm in Northern Ireland, at Crookedstone Road in Antrim, connects directly into the Belfast International Airport. Courtesy of Lightsource.

The shockwaves were still being felt when, on June 23, 2016, the people of the U.K. voted with a narrow majority to leave the European Union. This monumental decision to exit the EU sent the economy into an anxious downturn in anticipation of what this means for trading within the EU, as well as with global nations.

“The devaluation of the GBP [Great British Pound] and the increased currency insecurity have slashed profitability and raised the investment risk for photovoltaic projects, as components are usually paid in Euros or U.S. dollars, while the earnings would be in GBP,” said Susanne von Aichberger, senior analyst of Solar Power at IHS Technology in Berlin. “The increased currency insecurity caused by the Brexit decision has worsened the situation of the photovoltaic [PV] market in the U.K., which has already been hit hard by the recent dramatic downsizing of PV incentives.”

Market comparisons this year with the same period in 2015 already reflect the grim changes the industry is experiencing, however there is hope in some pockets of the industry, and some companies are taking matters into their own hands. In the mid-term, political changes in the U.K. could positively affect residential and small commercial markets, if they lead to an increase of retail electricity prices, making self-consumption more profitable. However, von Aichberger cautions that there is currently no indication of a significant change in power prices.

“Installers are seeking to become increasingly active in markets outside of the United Kingdom, and are diversifying their businesses,” von Aichberger said. “The PV market in the United Kingdom is likely to slightly recover from 2019 on, but IHS does not expect the annual U.K. market to come even close to the 1 GW level again in the foreseeable future.”

There are still some niche areas left for solar specialists to work within the U.K., but the volume of deployment enjoyed in recent years is not expected now, and some industry experts express great disappointment at what they see as the government’s shooting down of the region’s solar.

“Sadly, as things stand, solar is unlikely to reach its full potential here in the U.K. The recent subsidy cuts have all but killed the solar industry in the U.K., which is a real pity,” said Nick Boyle, CEO of Lightsource Renewable Energy, Europe’s largest developer and operator of solar PV projects, with offices in the U.K. and Ireland. “Our goal of reaching grid parity in the next few years was only achievable if adequate, stable and predictable levels of support had remained in place. The cuts have meant that this goal is unattainable and have brought about wide-scale job losses, bankruptcies and liquidations across the industry with many companies simply unable to weather the storm.”