The weekend read: C&I challenges and innovations

From pv magazine, September edition

The upward trajectory of the global solar industry is far from linear. Around the world, various markets are at various stages of maturation: from Italy’s and Germany’s high levels of grid penetration and balance between ground-mount and rooftop, to China’s vast solar fields and fledgling residential segment, sub-Saharan Africa’s microgrid-driven foundations, and the supportive pillars of storage shoring-up Australian PV growth, solar has many strands dangling across the globe.

Which hints not only at the different rates of adoption for PV from country-to-country, but also solar’s adaptability, no matter the landscape, climate, political will, or lack thereof. And there are fewer spaces within solar quite as adaptable and broad as the commercial and industrial (C&I) space.

C&I arrays are rarely seen as the ‘bread and butter’ of solar. When the layperson thinks of PV they likely imagine a stylish household with sleek solar panels adorning the rooftop. Equally, when a green energy advocate or government official talks of solar, they usually elicit images of vast ground-mounted arrays that have transformed undulating landscapes.

It is within the less glamorous ‘bits in between’ that C&I operates: the grey factory rooftops transformed by PV; the ugly flat facades of 1970s school buildings layered with solar panels; endless office buildings, bridges, greenhouses and garages – filled-in, tacked-on, topped-off.

But while C&I solutions may be seen as the functional-then-forgotten member of the solar family, for dedicated installers and developers, the C&I space can often be the most exciting of them all.

The sky’s the limit

As solar development, module and BOS costs continue to tumble, so too does the level of financial support offered by governments. This natural market evolution has led to the rise of larger-and-larger unsubsidized solar PV installations – predominantly in the C&I space where power purchase agreements (PPAs) with private companies are beginning to make more financial sense.

Indeed, in some of the more mature solar markets of Europe, an absence of government interference is actively welcomed by some solar installers, says Tom Lloyd, sales and marketing manager for British renewable energy developer RenEnergy. “A lack of government intervention in the UK’s solar sector is helping to underpin a more sustainable and market-driven industry, one in which the C&I sector will thrive. Returns on investment and project IRR in C&I is already very competitive; you just need a high level of self-consumption or a long-term PPA.”

A prime example of this market evolution is seen in one of RenEnergy’s most recent C&I installations: a 1 MW ground-mounted array for Cranfield University in the English county of Bedfordshire. The most interesting aspect of this solar plant – which was built with a zero net-export agreement and so is 100% self-consumption – is the not-insignificant fact that Cranfield University shares its grounds with Cranfield Airfield. This posed a set of unique challenges for the developer.

“Cranfield Airfield is an old World War Two (WWII) air base that forms part of the university,” Lloyd said. “This raised a few technical challenges. There are of course solar arrays installed near airfields the world over, but more often than not they are either redundant airfields or located in dead space near to the airfield. At Cranfield, the airspace is active, so there were considerations that needed to be made concerning the height of the array. This meant slightly altering the ground frame in order to come below a maximum height and avoid any interference with the radio tower.”

Another vital facet of the build was to ensure approaching aircraft were not impacted by any glare from the array, so an anti-glare assessment was conducted. “This meant we had to provide certain criteria to the Civil Aviation Authority (CAA) regarding the types of solar modules we were installing. The supplier, Hanwha Q Cells, which is a long-term partner of RenEnergy, were supportive in demonstrating that the modules installed – the Q.PLUS-G4.3 multicrystalline module – had passed all relevant CAA compliance measures.

But beyond ensuring that the array was the appropriate height and did not dazzle the pilots, RenEnergy had another challenge on its hands. “Given that the airfield is an old WWII air base, there was the potential for unexploded ordinance at the site,” reveals Lloyd. “We had to be aware that the grounds could contain live shells from the anti-aircraft guns that used to be stationed there, or even unexploded bombs that may have been scattered around.”

An Unexploded Ordinance Survey (UXO) was duly conducted by a third-party specialist, and this limited the area in which RenEnergy could install the array and fit the necessary cabling. “These limitations meant we opted for a four-panel landscape configuration, because we still wanted to fit as much generation capacity as possible into the available space,” Lloyd explains. “The UXO survey results dictated the space we were able to work in, and we could also not encroach too closely to the runway.” This meant ensuring high-power components were selected throughout, and it also meant that the point of connection was placed 2 km from the site. “There is a significant high-voltage cable running between the array and the 11 kV ring main onsite. From this point of view, the 1 MW installation is one of the largest behind-the-meter projects in the UK,” Lloyd stresses.

Having been completed in March this year, RenEnergy and Cranfield University observed a three-month probationary period, during which the site consistently hit 100% of its performance ratio. “The university is thrilled because the plant is performing better than they expected it to.” Not only does the array allow the university to offset its carbon and reduce its electricity bills, but it is also an educational and research tool. “Cranfield University is a leading engineering and physics energy research institute, so academics being able to have onsite access to the plant and the data makes it a perfect fit.”

Currently, the solar plant meets 5% of the university campus’s energy needs, with CHP meeting 60%. There is a net zero export agreement at the site, controlled with smart software that enables automatic ramping down of the CHP to a minimum of 50% to allow the solar array to shine. “There is scope to expand the PV array of course,” Lloyd adds. “That is the beauty of C&I solar: it is a little bit like Lego. We can add more and more as the university wishes, which would gradually reduce the requirement for CHP. Working with Hanwha Q Cells is also a benefit for all concerned, because the company was actively involved in technical and project support, assisting with commercial discussions for the end client and, of course, supplying the actual solar modules – the most vital component of the lot.”

A greener greenhouse

In Atri, in the Teramo Province of the Abruzzo region of Italy, many notable farms produce some of the country’s finest fruit, vegetable and meat products. One particular farm, famous for its prosciutto Crudo Parma ham, first adopted solar PV in 2009, back when the government offered very generous FIT rates.

For seven years a 500 kWp solar array pumped out PV electricity atop the farm’s 8,000 m² greenhouse roof, until a particularly snowy winter in 2016 brought the greenhouse – and its solar array – crashing down.

“On such a large, single rooftop, the weight of the snow on top of the array proved too much, compounded by immediate heavy rain” said Marco Panzavuota, sales and marketing manager at Italian renewable energy developer Green Energy Services. “Because the snow had collected in the middle of the rooftop, it did not melt, and eventually this caused the structure to collapse.”

Faced with a decision to make on how best to rebuild, the farm operator enlisted Green Energy Services to discuss with the insurance company how to avoid a similar fate. They decided to build five smaller, separate greenhouses on the site, each comprising its own solar array, but all connected to a single central inverter.

This approach gave the farm more flexibility for rearing and growing different produce and crops, but it meant a few engineering and regulatory challenges for the renewable energy developer. “We assessed that having five separate rooftops would be safer than installing one large array on to another 8,000 square meter greenhouse,” Panzavuota explained. “But because the terms of the new installation were different from the old array, we had to go back to Italy’s energy regulator, the GSE, in order to secure permission to receive the same FIT. The GSE had to approve the new shape design and sizing of the array, but it was actually a straightforward process.”

In technical terms, the new system is actually slightly smaller – at 492 kWp – than its predecessor, but produces more in terms of power output. “The old array used 225 W solar panels from a Chinese supplier, but we rebuilt the five separate arrays using Hanwha Q Cells’ 300 W Q.PEAK-G4.1 monocrystalline modules, which gave us more flexibility,” said Panzavuota.

Solar powers solar

Remaining in Italy, microinverter specialist Elettronica FM has recently begun ­construction of a large C&I solar installation that will cover its main microinverter production facility in Guidizzolo, Mantova, northern Italy.

The rooftop portion of the array will be 451.44 kWp once completed, with the front and sides of the factory also set to be bedecked in solar panels – adding an extra 95.04 kWp capacity. Every solar panel installed will be fitted with Elettronica’s own microinverters, making the completed array one of the largest microinverter-powered C&I installations in Europe.

“The main portion of the array, on the rooftop, is being built using half-cell technology from Hanwha Q Cells, the Q.PEAK DUO-G5, while the sides and front of the building are being fitted with the Q.PEAK BLK 310 W modules, for their aesthetic appeal,” said Mauro Ferrari, general manager at Elettronica FM. By combining high power modules with microinverter technology, Ferrari is convinced that this installation can demonstrate how microinverters can play a leading role in shaping the subsidy-free solar markets of the future.

The need for speed

For many C&I customers, adopting solar PV is contingent upon how the costs stack up. Although solar module prices have tumbled in recent years – and are set to fall even further following recent policy shakeups in China and the removal in Europe of the Minimum Import Price – other financial factors are at play. Hence, the more quickly a solar array can be installed and connected is vital.

In Germany, established solar developer Kintlein & Ose GmbH recently installed a 749 kWp solar array atop a series of agricultural buildings to the west of Berlin in just ten days. The subsidy-free project is another building block for Germany’s expanding C&I solar space – a sector that Kintlein & Ose MD Steffen Kintlein believes has vast capacity to not only grow, but actively take the lead on the nation’s energy transition.

“Germany has vast potential for C&I installations,” Kintlein said. “Companies in this space represent a huge part of the nation’s electricity consumption, and a growing number of firms have already made firm commitments to solar energy and international initiatives, such as sourcing 100% renewable energy.” A lofty goal indeed for companies, entire cities, nations, even the entire planet – and one that can only be made likely with global and innovative C&I solar support.

By Ian Clover, Manager Corporate Communications, Hanwha Q Cells.