By Mike Stone
A recently-completed solar-plus-storage microgrid has contributed to “eyebrow raising” savings for a medical manufacturing facility in Costa Rica.
It shows how solar plus storage, which will be covered in depth at the 4th Annual PV O&M USA conference in November, can surpass diesel gensets, said Brian Schmidly, president and CEO of developer Rio Grande Renewables.
Rio Grande worked with Enel Group-owned storage systems developer Demand Energy on what the companies describe as “the largest microgrid in Central America” for Establishment Labs, a medical equipment manufacturer.
That system, said Schmidly, is “by far one of the best software control platforms available. When we tested it, DEN.OS stood out by a large margin.”
An alternative to diesel gensets
His company approached Establishment Labs directly in early 2016, when the manufacturer was in the middle of a design-and-build process for its medical manufacturing facility.
Establishment Labs was considering purchasing two large diesel generators for backup energy.
Having uninterrupted power was a big issue, as any outage resulting in lost air pressure in the clean room would mean going through a costly recertification process, as well as having to junk a large amount of stock.
A single interruption in supply could cost the company from at least USD$50,000 “up to six figures,” according to Schmidly.
And interruptions to the power supply are far from rare in Costa Rica. Rio Grande made the case that its microgrid would be the best way to avoid such costs, as well as providing ongoing savings on its electricity bill.
Savings over time
Solar developer Rio Grande’s solution was audacious in terms of price, weighing in at around four times the cost of buying a pair of gensets, said Schmidly.
Key to his company’s pitch was to demonstrate the savings the proposed system would make to the medical supplier’s electricity bills. These now add up to around 40% each month.
Unlike the gensets, which would just be used to supply emergency power, the microgrid contributes to savings day in, day out, effectively providing a continuous return on investment.
Within weeks of the plant’s completion, the microgrid demonstrated its value in keeping the power on. A lightning strike on a substation in Panama caused a big, disruptive power surge across the region.
Panama, Costa Rica and Nicaragua all suffered a three-to-four-hour blackout.
Keeping the power on in real life
Thanks to Demand Energy’s DEN.OS software, the microgrid swung into action immediately, with the solar array supplying 100% of the facility’s energy needs.
As sunlight started to taper off during the afternoon, the management system then ensured that the batteries kicked in until grid supply was restored.
Rio Grande Renewables now has a rolling five-year operations and maintenance contract with Establishment Labs, while Demand Energy’s network operation centre is constantly monitoring the health of the system.
Data on the quality of power coming into the site is also made available the client. Schmidly said adding storage to solar power was a major bonus for commercial and industrial concerns such as Establishment Labs.
“Solar alone is a great investment,” he said, “but it can only address the energy bill. It can’t do much for demand charges. If you can layer in storage to address that side of the utility bill, you provide savings which raise eyebrows.”
A further benefit of solar-plus-storage microgrid was their ability to improve energy system resilience and avoid losses. “That’s a game changer,” Schmidly said. “From our point of view as a developer, we like this.”
- For more on PV plus storage, head to New Energy Update’s 4th Annual PV O&M USA conference, in San Jose, California, on November 2 and 3. Download the brochure now.