SUSTAINABLE POWER SUPPLY FOR CARIBBEAN ISLAND ST. EUSTATIUS WITH THE SMA FUEL SAVE SOLUTION
SMA Solar Technology AG (SMA) and its subsidiary SMA Sunbelt Energy GmbH have commissioned a PV Hybrid System on the Caribbean island of St. Eustatius, Caribbean Netherlands, to completely electrify the island with the smart combination of utility scale PV, battery storage and diesel generators. Up until March 2016 the island´s power supply was fully based on diesel gensets. By integrating 1,9 MWp of PV power and 1 MW of batteries with the SMA Fuel Save Controller 2.0, the local utility company is now able to reduce its fossil fuel consumption significantly by up to 30 percent and save more than 800.000 liters of diesel fuel and 2,200 tons of CO2 per year. In 2010, St. Eustatius became a special municipality of the Netherlands. The Dutch Ministry of Economic Affairs decided to make the island and the Statia Utility Company (STUCO) less dependent on imported fossil fuel oils by financing a solar power plant. “We were looking for fossil fuel reduction and at the same time for a solution with both very low maintenance and also stand-alone operation,” Fred Cuvalay, CEO of STUCO, summarized the technical challenges. “SMA provided a hybrid system solution exactly tailored to our needs, which is extremely user-friendly.”
SMA sets a good example for a more sustainable power supply in the Caribbean
“The project fully integrates three different energy sources on a large scale that work together in a harmonized manner: solar power, battery storage and diesel gensets,” said Volker Wachenfeld, Executive Vice President SMA business unit Off-Grid and Storage. The project is designed to generate enough clean solar power to cover more than 23% of St. Eustatius’ annual electricity demand of 13.5 GWh. The Sunny Central Storage 1000 integrated into the SMA Medium Voltage Power Station 1000 enables a measured solar fraction of up to 88% during sunshine hours and supports the grid with stability functions such as frequency regulation, ramp-rate control for smoothing PV power fluctuations and optimization of diesel genset operation. “Rapid movement of clouds in this region, in particular, leads to extreme fluctuations in solar power generation which constrains the integration of large-scale photovoltaics into diesel-based grids,” Wachenfeld commented on one of the challenges. “That's why using large-scale storage systems is meaningful for this application as they minimize the impact of fluctuating energy sources on diesel generators.” “Via SMA Sunbelt Energy GmbH, SMA can now offer fully integrated hybrid and large-scale grid-connected battery energy storage systems as a turnkey supplier,” said Fabian Jochem, General Manager at SMA subsidiary SMA Sunbelt Energy GmbH. The project also includes a system service contract and a customized PV hybrid monitoring system design for integrated data logging of power management system, PV inverters, battery inverter, diesel generators and the complete storage system, engineered and commissioned by SMA Sunbelt Energy GmbH. Local system integrator, Eco Energy N.V. from Curaçao, was responsible for installation of the PV plant. Its experience on Caribbean logistics and high quality workmanship played an important role in realizing this project successfully within the ambitious schedule of 9 months. The installation in St. Eustatius is the first project of its kind in the entire Caribbean region and will likely serve as an example of what’s possible to neighboring islands.
The SMA Group with sales of about €1 billion in 2015 is the global market leader for solar inverters, a key component of all PV plants, and offers innovative key technologies for future power supply structures. It is headquartered in Niestetal, near Kassel, Germany, and is represented in 20 countries. The Group employs more than 3,000 people worldwide. SMA has an extensive range of products, which offers the right inverters for all module types and plant sizes; for small residential systems as well as large-scale plants, grid-connected photovoltaic systems as well as off-grid and hybrid systems. Moreover, SMA offers system technology for various battery technologies and system sizes and collaborates with renowned battery manufacturers and companies from the automotive industry. The SMA technology is protected by about 700 patents and utility models worldwide. The range of services is supplemented by comprehensive services and operational management of large-scale PV power plants. Since 2008, the Group’s parent company, SMA Solar Technology AG, has been listed on the Prime Standard of the Frankfurt Stock Exchange (S92) and is currently the only company in the solar industry that is listed in the TecDAX index.
Flagship Project in the Caribbean:
PV Hybrid System on the Island of St. Eustatius
The setting: An island with 4,000 inhabitants and three diesel generators to supply power. The mission: Reduce fossil fuel usage and establish a grid stabilizing energy supply based on renewable energies. The challenge: Supply a smart combination of a 2 MWp PV farm and diesel generators; introduce the largest lithium battery storage system in the Caribbean; use the latest SMA products; and develop a new monitoring platform—within the space of just nine months. The PV farm on the island of St. Eustatius, which includes one of the largest lithium battery storage systems, went into operation in March 2016. Thanks to the SMA Fuel Save Controller, the island is now saving 800,000 liters of diesel a year. I worked on-site as a project manager during the 10-day commissioning process and was part of a fantastic international team. You can read my blog here, which details my experiences of an exceptional project on a special island:
Setting a green example in the Caribbean
To climb the second-highest mountain in the Netherlands at a height of 600 meters, we had to undertake a journey that took approximately 24 hours—from Kassel via Amsterdam to St. Maarten, and from there to St. Eustatius by propeller-driven plane. Sitting majestically above this island of 4,000 inhabitants in the Netherlands Antilles, the extinct Quill volcano is a real landmark as well as being the emblem on the flag. In its checkered history, which has been shaped by trade, slavery and piracy, the island has changed hands a recorded number of 22 times and now has the status of a special municipality in the Netherlands. On the island, also known as Statia, things have been a lot calmer over the past few decades. It is an island on which animals—particularly donkeys, cows, sheep and chickens—roam free. And now the island wants to make a name for itself with its ambitious PV hybrid project and set a green example for the whole region with this flagship project.
Everyone knows about the PV farm
We were already identified as newcomers by the locals while sitting on the 20-seat propeller-driven plane, and were asked about the purpose of our trip. Four flights a day connect Statia with the lifeline of St. Maarten. Of course, the primary objective of our trip was neither the archeological treasures nor the sea turtles of the marine national park, but the PV farm. Absolutely everyone on the island has heard about it. “The solar park? Yes of course, great!”exclaimed the taxi driver, which was a typical response.
Saving 800,000 liters of diesel fuel
Two years ago, the utility company Stuco was spun off from a former group of companies, which included St. Maarten and Saba, to form an independent company. Conserving diesel fuel is expected to improve its operating business figures. The target is to use 800,000 liters less diesel fuel a year. For this purpose, the Dutch Ministry of Economic Affairs is financing construction of a PV hybrid system. In the past, eight PV system managers manually operated the three Caterpillar diesel generators with a nominal power output of between 900 kW and 1,200 kW around the clock. The employees were trained to recognize the smallest changes in frequency or inconsistencies in the operating noise of the generators, so that they could intervene at lightning speed.The genset system is now set to be complemented by a PV farm and a battery storage system. To optimally combine these different energy sources, at SMA Sunbelt Energy GmbH we focused on the system design. Despite the more complex system layout, it is designed with automatic operation and low maintenance in mind.
Hurricane-resistant PV modules and protected Sunny Tripower inverters
During our planning and production phase in Kassel, our local partner Eco Energy worked from September 2015 to February 2016 on construction of the 1.89 MWp PV farm. The Sunbelt team in Kassel followed the construction progress live via camera links. To withstand the frequent barrage of hurricanes in the Caribbean without sustaining any damage, extremely pressure-resistant PV modules by Suntech were used on a frame produced by Schletter. The 73 SMA Sunny Tripower 25000TL-30 PV inverters were installed in containers to protect them against corrosion from the sea air.
Customized hybrid system for extreme energy management
SMA Sunbelt Energy GmbH was responsible for the overall technical design and on-time delivery of the large-scale storage system, the battery inverter including MVPS as well as the monitoring and control system. The components used included the new Fuel Save Controller and the Sunny Central Storage 1000. Designing the system was made a lot harder by a lack of data on solar irradiation and cloud movements. The battery power of 1 MW and charge rate of 2.5-4C mean that the system is designed for the worst-case scenarios. We have seen battery inverter power outputs of up to 800 kW when the system is in operation, which means that the impact of cloud movement is much greater than we originally thought. But high-performance and flexible energy management can safely offset these extreme step loads. PV penetration is 89%. This means that 89% of the power consumption of around 1.7 MW is covered by solar power. By way of comparison, without a storage system PV penetration of 60% was classed as a very good value.
The first week of commissioning went without a hitch. One of the most exciting moments was the first time the battery was discharged into the utility grid via the Sunny Central Storage. This was followed by system functionality tests to check the interaction between the diesel generators and the Fuel Save Controller. Over the course of these tests, we simulated step loads and ramps by connecting and disconnecting the generators. The commissioning process took just 10 days in all. The system functioned perfectly right from the first moment it was switched on. We were excited, especially because this gave us extra time for a Sunday excursion to Quill National Park. In the volcanic crater of the park, we discovered the local wildlife and wild banana trees.This experience served to remind us once again for whom and for what we commissioned this sustainable power supply in the first place—not only for our client Stuco, not only for the 4,000 inhabitants living on the volcanic island, but also to preserve this remarkable flora and fauna.