By NEIL HARTNELL
Tribune Business Editor
A SENIOR Grand Bahama Power Company executive yesterday voiced optimism that its $10m battery storage facility will prevent its major industrial customers “wreaking havoc in the grid”.
Neilsen Beneby, the utility’s renewable energy manager, told a Bahamas Society of Engineers (BSE) luncheon that the 10 Mega Watt (MW) facility - the largest of all such assets owned by its Canadian parent in the Caribbean - should finally ease its long-standing grid stability and frequency issues when it comes online this summer.
These are typically caused by the sudden, significant load increases generated by Freeport’s major industrial players - typically Bahama Rock and the Freeport Container Port.
Mr Beneby said the battery storage facility was designed to “kill two birds with one stone” as the improved grid stability will also help pave the way for its planned introduction of utility-scale solar energy.
Pointing out that solar energy’s arrival would create some grid volatility by itself, Mr Beneby said: “We already have issues in Grand Bahama with two of the major industrial customers that create power disturbances in the grid, and we need to fix that.
“We have a frequency issue in Grand Bahama. There are two major industrial customers, Freeport Container Port and Martin Marietta (Bahama Rock). Both of them require large amounts of power in a very short period of time... When those two fellas come on line, they wreak havoc in the grid.”
While Freeport Container Port’s 10 cranes each consumed around 1 MW each when they came online, Mr Beneby explained that the greatest volatility was produced when Bahama Rock used its “dragline” and excavator for dredging in the harbour.
Mr Beneby, who is moving to head up Emera Caribbean Renewables, the regional solar installer and designer owned by GB Power’s Canadian parent, revealed that together these two industrials could produce “load swings” greater than 8 MW “within a fraction of a second” with 5.5 MW needed “instantaneously”.
As a result, GB Power has traditionally been forced to keep 15 MW of generation capacity as “a spinning reserve” to meet such spikes in load demand when these assets come online, and 8 MW when they are offline.
Mr Beneby disclosed that these “swings make up 30 percent of the island’s load in some cases”, and reiterated: “We have a big stability issue with these two. Once they start the dragline it requires 12 MW just to serve him. About 30 percent of what is needed on the island is required to serve him.
“We try to set the [system] frequency at 60 hertz (HZ) but can’t. They call us when they come on line but there’s nothing we can do. We can’t maintain the 60 HZ. We have to sit back and watch the show.”
The particular demands of Freeport’s major industrial players would have resulted in higher fuel charges being passed through to GB Power’s residential customers had it not been for the utility’s five-year fuel hedging strategy which will keep this fixed at 10 cents per kilowatt hour (KWh) until 2022, Mr Beneby added.
With GB Power seeking to reduce its diesel fuel consumption, improve efficiency, reduce engine maintenance and lower its “spinning reserve”, he explained that it decided to “kill two birds with one stone” through the battery storage facility that will stabilise the frequency and voltage fluctuations in the grid and pave the way for solar energy’s introduction.
Mr Beneby said the utility is aiming to perform “a site acceptance test” on its 10 MW battery storage facility, which sits on 30,000 square feet of land, this June. “We’re fairly confident that it will be able to operate as designed,” he told Tribune Business.
“We’re hoping the system is online by summer, June and July, and at that time we’ll see how the system performs in real life versus how it’s designed from a conceptual basis. This technology has worked; it’s proven.”
Mr Beneby added that achieving grid stability was “top priority for us” ahead of GB Power’s utility-scale solar introduction, adding: “Solar by its very nature creates some instability in the grid.”
Emphasising that GB Power was not singling out Freeport Container Port and Bahama Rock “in a negative way”, he said: “Those are the cause of the most dynamic loads. We’ve been communicating with them, and they are aware of some of the difficulties they can create in the system.
“They support this, and would like to see the project be successful so that the customer experience in Grand Bahama becomes more enjoyable.”
Mr Beneby told Tribune Business that GB Power also has a $15m, five-year budget to bolster its transmission and distribution network’s resilience. “We’re trying to ensure that when the next storm comes through we’ll be ready for it and the infrastructure is beefed up,” he said.
Mr Beneby, though, refuted claims from some GB Power customers that they are being billed for energy not consumed as a result of the grid instability, which is making their meter spin faster.
“We have not seen that as factual,” he said. “Prove it. It’s something out there in the public, but we’ve not seen it. We only bill you for what we consume. It’s not because of the high system frequencies. It’s only what you consume that we bill you for.”