The SolarMill solar-wind hybrid installation in Kingston, Jamaica has received much pressed since it was launched a year ago. It is the world’s largest hybrid solar-wind project and opened to much fanfare. However, at least one solar expert is questioning how much persons within the heart of Kingston will be able to benefit from the SolarMill hybrid systems being offered by the Jamaica Public Service (JPS).
Former president of the Jamaica Solar Energy Association, Roger Chang, believes given the limited wind in some of the residential areas, coupled with the use of less efficient vertical axis wind turbines, some persons might find themselves buying a system expecting to harness energy from two sources when, in fact, they are only fully exposed to one.
“If you look at the wind map, Kingston doesn’t have any breeze. So all it is really is some panels with a racking system with some built-in vertical axis wind turbines and the wind is brawta. And vertical axis wind turbines are not efficient at all, as oppose to horizontal ones,” Chang reasoned.
Garth McKenzie, director of energy solutions at JPS, acknowledges that the main source of energy will be the sun, but believes what little extra energy the breeze provides makes their systems well worth it.
“The dominant thing is the solar, but whenever you have breeze it is about harvesting all that is available,” McKenzie said. “I am giving something for equal to or better price, and if a little breeze blows you get some more power. How can you be worse off?”
The JPS hybrid systems, which are a combination of solar panels and vertical axis wind turbines, come in three versions for residential customers. These are the Power On+ which is priced at $339,000 and has an 1,100w installed capacity and is projected to generate 1,000kWh/year. There is also the PowerStar ($499,000) with an estimated generating capacity of 1,400kWh/year and an installed capacity of 1,750W. The third is the PowerStar+ ($699,000) with an installed capacity of 2,500W and is expected to generate 2,800kWh/year.
‘Doesn’t make sense’
Chang contends that the prices quoted do not necessarily include the balance of the system’s cost, plus soft costs such as permit, license, insurance, inspection fees, etc, and therefore persons have to be mindful of hidden costs.
“What JPS is selling doesn’t make any sense,” Chang said. “Run the numbers and you will see, the cost, the payback.”
McKenzie has defended the product which was launched in October 2013 with just in excess of 100kw having already been installed islandwide.
“Of your light bill 70 per cent of it is fuel, so when you use a renewable energy source like this you literally save off the top 70 per cent of your cost of energy and that is just because 70 per cent of what you pay is not about the energy you generate; it is really the fuel that it takes to generate that energy,” McKenzie reasoned. “So anytime you use any kind of renewable energy source your cost automatically goes down, so that is why it is an attractive thing.”
The generators, which harness both wind and solar power, were introduced into the island a little under a year ago.
JPS President and CEO Kelly Tomblin admitted that not all customers, to date, have been totally satisfied with the system, but put this down to start-up glitches.
“For some customers it was worth it, for others not so much. Certainly, like any new thing, we had some birthing pains when we just started,” Tomblin shared. “I am excited about the hybrid solar system because it takes advantage of the wind and it takes advantage of the solar. My job is to provide customers with alternatives and I am happy that we have another option for them.”
The light and power company does offer different variations of the system that can be configured to meet customers’ specific needs.
“Although we talk about the common residential ones we have industrial, commercial, large house, anything,” McKenzie shared. “We have the flexibility of mixing more mills and less panels, depending on where you are. We can customise the system for anywhere you are; we can do solar panel systems only, so it is the solar panel, the hybrid system and anything in between.”
McKenzie contends that the way to get the maximum economic benefit from the system is to use as much of the energy generated as possible.
“That is the difference between what we are trying to do and what the rest of the industry is trying to do. They are trying to sell the customers as big a system as possible, theoretically to get them off the grid,” McKenzie said. “But in selling them these very large systems, the only way they can pay for themselves is if a lot of excess is generated; and you have to find a way to sell the excess back to JPS, so as to help to recover your expense. With ours, if you use up as much as you produce, you don’t have to sell back to the grid and that is why our cost to customers is very competitive, because our strategy and our approach is different.”
Chang countered that because most residential customers go to work during the day, “they would either have to store the energy generated, so that they can use it when they get home in the nights, or sell it back to the grid”.
Credit: Ryon Jones, Jamaica Gleaner